]> de.git.xonotic.org Git - xonotic/darkplaces.git/blobdiff - gl_backend.c
implemented r_glsl_water cvar (refraction and reflection rendering)
[xonotic/darkplaces.git] / gl_backend.c
index fb54eb8fa3437bd779e893a0e04928eb3f35860e..7daeff35e9586ac7b3a78735ed514eac55bb8b8a 100644 (file)
@@ -1,25 +1,23 @@
 
 #include "quakedef.h"
-#include "image.h"
-#include "jpeg.h"
 #include "cl_collision.h"
 
-cvar_t gl_mesh_drawrangeelements = {0, "gl_mesh_drawrangeelements", "1"};
-cvar_t gl_mesh_testarrayelement = {0, "gl_mesh_testarrayelement", "0"};
-cvar_t gl_mesh_testmanualfeeding = {0, "gl_mesh_testmanualfeeding", "0"};
-cvar_t gl_paranoid = {0, "gl_paranoid", "0"};
-cvar_t gl_printcheckerror = {0, "gl_printcheckerror", "0"};
-cvar_t r_stereo_separation = {0, "r_stereo_separation", "4"};
-cvar_t r_stereo_sidebyside = {0, "r_stereo_sidebyside", "0"};
-cvar_t r_stereo_redblue = {0, "r_stereo_redblue", "0"};
-cvar_t r_stereo_redcyan = {0, "r_stereo_redcyan", "0"};
-cvar_t r_stereo_redgreen = {0, "r_stereo_redgreen", "0"};
-
-cvar_t r_render = {0, "r_render", "1"};
-cvar_t r_waterwarp = {CVAR_SAVE, "r_waterwarp", "1"};
-cvar_t gl_polyblend = {CVAR_SAVE, "gl_polyblend", "1"};
-cvar_t gl_dither = {CVAR_SAVE, "gl_dither", "1"}; // whether or not to use dithering
-cvar_t gl_lockarrays = {0, "gl_lockarrays", "1"};
+cvar_t gl_mesh_drawrangeelements = {0, "gl_mesh_drawrangeelements", "1", "use glDrawRangeElements function if available instead of glDrawElements (for performance comparisons or bug testing)"};
+cvar_t gl_mesh_testarrayelement = {0, "gl_mesh_testarrayelement", "0", "use glBegin(GL_TRIANGLES);glArrayElement();glEnd(); primitives instead of glDrawElements (useful to test for driver bugs with glDrawElements)"};
+cvar_t gl_mesh_testmanualfeeding = {0, "gl_mesh_testmanualfeeding", "0", "use glBegin(GL_TRIANGLES);glTexCoord2f();glVertex3f();glEnd(); primitives instead of glDrawElements (useful to test for driver bugs with glDrawElements)"};
+cvar_t gl_paranoid = {0, "gl_paranoid", "0", "enables OpenGL error checking and other tests"};
+cvar_t gl_printcheckerror = {0, "gl_printcheckerror", "0", "prints all OpenGL error checks, useful to identify location of driver crashes"};
+
+cvar_t r_render = {0, "r_render", "1", "enables rendering calls (you want this on!)"};
+cvar_t r_waterwarp = {CVAR_SAVE, "r_waterwarp", "1", "warp view while underwater"};
+cvar_t gl_polyblend = {CVAR_SAVE, "gl_polyblend", "1", "tints view while underwater, hurt, etc"};
+cvar_t gl_dither = {CVAR_SAVE, "gl_dither", "1", "enables OpenGL dithering (16bit looks bad with this off)"};
+cvar_t gl_lockarrays = {0, "gl_lockarrays", "0", "enables use of glLockArraysEXT, may cause glitches with some broken drivers, and may be slower than normal"};
+cvar_t gl_lockarrays_minimumvertices = {0, "gl_lockarrays_minimumvertices", "1", "minimum number of vertices required for use of glLockArraysEXT, setting this too low may reduce performance"};
+cvar_t gl_vbo = {CVAR_SAVE, "gl_vbo", "1", "make use of GL_ARB_vertex_buffer_object extension to store static geometry in video memory for faster rendering"};
+
+cvar_t v_flipped = {0, "v_flipped", "0", "mirror the screen (poor man's left handed mode)"};
+qboolean v_flipped_state = false;
 
 int gl_maxdrawrangeelementsvertices;
 int gl_maxdrawrangeelementsindices;
@@ -73,18 +71,16 @@ void GL_PrintError(int errornumber, char *filename, int linenumber)
 }
 #endif
 
-#define BACKENDACTIVECHECK if (!backendactive) Sys_Error("GL backend function called when backend is not active\n");
+#define BACKENDACTIVECHECK if (!backendactive) Sys_Error("GL backend function called when backend is not active");
 
 void SCR_ScreenShot_f (void);
 
 static matrix4x4_t backend_viewmatrix;
 static matrix4x4_t backend_modelmatrix;
 static matrix4x4_t backend_modelviewmatrix;
-static matrix4x4_t backend_glmodelviewmatrix;
 static matrix4x4_t backend_projectmatrix;
 
 static unsigned int backendunits, backendimageunits, backendarrayunits, backendactive;
-static mempool_t *gl_backend_mempool;
 
 /*
 note: here's strip order for a terrain row:
@@ -140,23 +136,33 @@ for (y = 0;y < rows - 1;y++)
 }
 */
 
-int polygonelements[768];
+int polygonelements[(POLYGONELEMENTS_MAXPOINTS-2)*3];
+int quadelements[QUADELEMENTS_MAXQUADS*6];
 
-static void R_Mesh_CacheArray_Startup(void);
-static void R_Mesh_CacheArray_Shutdown(void);
 void GL_Backend_AllocArrays(void)
 {
-       if (!gl_backend_mempool)
-               gl_backend_mempool = Mem_AllocPool("GL_Backend", 0, NULL);
-       R_Mesh_CacheArray_Startup();
 }
 
 void GL_Backend_FreeArrays(void)
 {
-       R_Mesh_CacheArray_Shutdown();
-       Mem_FreePool(&gl_backend_mempool);
 }
 
+void GL_VBOStats_f(void)
+{
+       GL_Mesh_ListVBOs(true);
+}
+
+typedef struct gl_bufferobjectinfo_s
+{
+       int target;
+       int object;
+       size_t size;
+       char name[MAX_QPATH];
+}
+gl_bufferobjectinfo_t;
+
+memexpandablearray_t gl_bufferobjectinfoarray;
+
 static void gl_backend_start(void)
 {
        Con_Print("OpenGL Backend starting...\n");
@@ -172,17 +178,19 @@ static void gl_backend_start(void)
                Con_Printf("glDrawRangeElements detected (max vertices %i, max indices %i)\n", gl_maxdrawrangeelementsvertices, gl_maxdrawrangeelementsindices);
        }
 
-       backendunits = min(MAX_TEXTUREUNITS, gl_textureunits);
+       backendunits = bound(1, gl_textureunits, MAX_TEXTUREUNITS);
        backendimageunits = backendunits;
        backendarrayunits = backendunits;
        if (gl_support_fragment_shader)
        {
                CHECKGLERROR
-               qglGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS_ARB, &backendimageunits);
+               qglGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS_ARB, (int *)&backendimageunits);
                CHECKGLERROR
-               qglGetIntegerv(GL_MAX_TEXTURE_COORDS_ARB, &backendarrayunits);
+               qglGetIntegerv(GL_MAX_TEXTURE_COORDS_ARB, (int *)&backendarrayunits);
                CHECKGLERROR
                Con_Printf("GLSL shader support detected: texture units = %i texenv, %i image, %i array\n", backendunits, backendimageunits, backendarrayunits);
+               backendimageunits = bound(1, backendimageunits, MAX_TEXTUREUNITS);
+               backendarrayunits = bound(1, backendarrayunits, MAX_TEXTUREUNITS);
        }
        else if (backendunits > 1)
                Con_Printf("multitexture detected: texture units = %i\n", backendunits);
@@ -191,6 +199,8 @@ static void gl_backend_start(void)
 
        GL_Backend_AllocArrays();
 
+       Mem_ExpandableArray_NewArray(&gl_bufferobjectinfoarray, r_main_mempool, sizeof(gl_bufferobjectinfo_t), 128);
+
        Con_Printf("OpenGL backend started.\n");
 
        CHECKGLERROR
@@ -207,6 +217,8 @@ static void gl_backend_shutdown(void)
 
        Con_Print("OpenGL Backend shutting down\n");
 
+       Mem_ExpandableArray_FreeArray(&gl_bufferobjectinfoarray);
+
        GL_Backend_FreeArrays();
 }
 
@@ -214,11 +226,6 @@ static void gl_backend_newmap(void)
 {
 }
 
-cvar_t scr_zoomwindow = {CVAR_SAVE, "scr_zoomwindow", "0"};
-cvar_t scr_zoomwindow_viewsizex = {CVAR_SAVE, "scr_zoomwindow_viewsizex", "20"};
-cvar_t scr_zoomwindow_viewsizey = {CVAR_SAVE, "scr_zoomwindow_viewsizey", "20"};
-cvar_t scr_zoomwindow_fov = {CVAR_SAVE, "scr_zoomwindow_fov", "20"};
-
 void gl_backend_init(void)
 {
        int i;
@@ -229,17 +236,25 @@ void gl_backend_init(void)
                polygonelements[i * 3 + 1] = i + 1;
                polygonelements[i * 3 + 2] = i + 2;
        }
+       // elements for rendering a series of quads as triangles
+       for (i = 0;i < QUADELEMENTS_MAXQUADS;i++)
+       {
+               quadelements[i * 6 + 0] = i * 4;
+               quadelements[i * 6 + 1] = i * 4 + 1;
+               quadelements[i * 6 + 2] = i * 4 + 2;
+               quadelements[i * 6 + 3] = i * 4;
+               quadelements[i * 6 + 4] = i * 4 + 2;
+               quadelements[i * 6 + 5] = i * 4 + 3;
+       }
 
        Cvar_RegisterVariable(&r_render);
        Cvar_RegisterVariable(&r_waterwarp);
-       Cvar_RegisterVariable(&r_stereo_separation);
-       Cvar_RegisterVariable(&r_stereo_sidebyside);
-       Cvar_RegisterVariable(&r_stereo_redblue);
-       Cvar_RegisterVariable(&r_stereo_redcyan);
-       Cvar_RegisterVariable(&r_stereo_redgreen);
        Cvar_RegisterVariable(&gl_polyblend);
+       Cvar_RegisterVariable(&v_flipped);
        Cvar_RegisterVariable(&gl_dither);
        Cvar_RegisterVariable(&gl_lockarrays);
+       Cvar_RegisterVariable(&gl_lockarrays_minimumvertices);
+       Cvar_RegisterVariable(&gl_vbo);
        Cvar_RegisterVariable(&gl_paranoid);
        Cvar_RegisterVariable(&gl_printcheckerror);
 #ifdef NORENDER
@@ -250,27 +265,36 @@ void gl_backend_init(void)
        Cvar_RegisterVariable(&gl_mesh_testarrayelement);
        Cvar_RegisterVariable(&gl_mesh_testmanualfeeding);
 
-       Cvar_RegisterVariable(&scr_zoomwindow);
-       Cvar_RegisterVariable(&scr_zoomwindow_viewsizex);
-       Cvar_RegisterVariable(&scr_zoomwindow_viewsizey);
-       Cvar_RegisterVariable(&scr_zoomwindow_fov);
+       Cmd_AddCommand("gl_vbostats", GL_VBOStats_f, "prints a list of all buffer objects (vertex data and triangle elements) and total video memory used by them\n");
 
        R_RegisterModule("GL_Backend", gl_backend_start, gl_backend_shutdown, gl_backend_newmap);
 }
 
+void GL_SetMirrorState(qboolean state);
+
 void GL_SetupView_Orientation_Identity (void)
 {
-       Matrix4x4_CreateIdentity(&backend_viewmatrix);
+       backend_viewmatrix = identitymatrix;
+       GL_SetMirrorState(false);
        memset(&backend_modelmatrix, 0, sizeof(backend_modelmatrix));
 }
 
-void GL_SetupView_Orientation_FromEntity(matrix4x4_t *matrix)
+void GL_SetupView_Orientation_FromEntity(const matrix4x4_t *matrix)
 {
        matrix4x4_t tempmatrix, basematrix;
-       Matrix4x4_Invert_Simple(&tempmatrix, matrix);
+       Matrix4x4_Invert_Full(&tempmatrix, matrix);
        Matrix4x4_CreateRotate(&basematrix, -90, 1, 0, 0);
        Matrix4x4_ConcatRotate(&basematrix, 90, 0, 0, 1);
        Matrix4x4_Concat(&backend_viewmatrix, &basematrix, &tempmatrix);
+
+       GL_SetMirrorState(v_flipped.integer);
+       if(v_flipped_state)
+       {
+               Matrix4x4_Transpose(&basematrix, &backend_viewmatrix);
+               Matrix4x4_ConcatScale3(&basematrix, -1, 1, 1);
+               Matrix4x4_Transpose(&backend_viewmatrix, &basematrix);
+       }
+
        //Matrix4x4_ConcatRotate(&backend_viewmatrix, -angles[2], 1, 0, 0);
        //Matrix4x4_ConcatRotate(&backend_viewmatrix, -angles[0], 0, 1, 0);
        //Matrix4x4_ConcatRotate(&backend_viewmatrix, -angles[1], 0, 0, 1);
@@ -278,61 +302,39 @@ void GL_SetupView_Orientation_FromEntity(matrix4x4_t *matrix)
        memset(&backend_modelmatrix, 0, sizeof(backend_modelmatrix));
 }
 
-void GL_SetupView_Mode_Perspective (double fovx, double fovy, double zNear, double zFar)
+void GL_SetupView_Mode_Perspective (double frustumx, double frustumy, double zNear, double zFar)
 {
-       double xmax, ymax;
        double m[16];
 
-       if (!r_render.integer)
-               return;
-
        // set up viewpoint
+       CHECKGLERROR
        qglMatrixMode(GL_PROJECTION);CHECKGLERROR
        qglLoadIdentity();CHECKGLERROR
-       // pyramid slopes
-       xmax = zNear * tan(fovx * M_PI / 360.0);
-       ymax = zNear * tan(fovy * M_PI / 360.0);
        // set view pyramid
-       qglFrustum(-xmax, xmax, -ymax, ymax, zNear, zFar);CHECKGLERROR
-       qglGetDoublev(GL_PROJECTION_MATRIX, m);
-       backend_projectmatrix.m[0][0] = m[0];
-       backend_projectmatrix.m[1][0] = m[1];
-       backend_projectmatrix.m[2][0] = m[2];
-       backend_projectmatrix.m[3][0] = m[3];
-       backend_projectmatrix.m[0][1] = m[4];
-       backend_projectmatrix.m[1][1] = m[5];
-       backend_projectmatrix.m[2][1] = m[6];
-       backend_projectmatrix.m[3][1] = m[7];
-       backend_projectmatrix.m[0][2] = m[8];
-       backend_projectmatrix.m[1][2] = m[9];
-       backend_projectmatrix.m[2][2] = m[10];
-       backend_projectmatrix.m[3][2] = m[11];
-       backend_projectmatrix.m[0][3] = m[12];
-       backend_projectmatrix.m[1][3] = m[13];
-       backend_projectmatrix.m[2][3] = m[14];
-       backend_projectmatrix.m[3][3] = m[15];
+       qglFrustum(-frustumx * zNear, frustumx * zNear, -frustumy * zNear, frustumy * zNear, zNear, zFar);CHECKGLERROR
+       qglGetDoublev(GL_PROJECTION_MATRIX, m);CHECKGLERROR
+       Matrix4x4_FromArrayDoubleGL(&backend_projectmatrix, m);
        qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
        GL_SetupView_Orientation_Identity();
+       CHECKGLERROR
 }
 
-void GL_SetupView_Mode_PerspectiveInfiniteFarClip (double fovx, double fovy, double zNear)
+void GL_SetupView_Mode_PerspectiveInfiniteFarClip (double frustumx, double frustumy, double zNear)
 {
        double nudge, m[16];
 
-       if (!r_render.integer)
-               return;
-
        // set up viewpoint
+       CHECKGLERROR
        qglMatrixMode(GL_PROJECTION);CHECKGLERROR
        qglLoadIdentity();CHECKGLERROR
        // set view pyramid
        nudge = 1.0 - 1.0 / (1<<23);
-       m[ 0] = 1.0 / tan(fovx * M_PI / 360.0);
+       m[ 0] = 1.0 / frustumx;
        m[ 1] = 0;
        m[ 2] = 0;
        m[ 3] = 0;
        m[ 4] = 0;
-       m[ 5] = 1.0 / tan(fovy * M_PI / 360.0);
+       m[ 5] = 1.0 / frustumy;
        m[ 6] = 0;
        m[ 7] = 0;
        m[ 8] = 0;
@@ -343,66 +345,97 @@ void GL_SetupView_Mode_PerspectiveInfiniteFarClip (double fovx, double fovy, dou
        m[13] = 0;
        m[14] = -2 * zNear * nudge;
        m[15] = 0;
-       qglLoadMatrixd(m);
+       qglLoadMatrixd(m);CHECKGLERROR
        qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
        GL_SetupView_Orientation_Identity();
-       backend_projectmatrix.m[0][0] = m[0];
-       backend_projectmatrix.m[1][0] = m[1];
-       backend_projectmatrix.m[2][0] = m[2];
-       backend_projectmatrix.m[3][0] = m[3];
-       backend_projectmatrix.m[0][1] = m[4];
-       backend_projectmatrix.m[1][1] = m[5];
-       backend_projectmatrix.m[2][1] = m[6];
-       backend_projectmatrix.m[3][1] = m[7];
-       backend_projectmatrix.m[0][2] = m[8];
-       backend_projectmatrix.m[1][2] = m[9];
-       backend_projectmatrix.m[2][2] = m[10];
-       backend_projectmatrix.m[3][2] = m[11];
-       backend_projectmatrix.m[0][3] = m[12];
-       backend_projectmatrix.m[1][3] = m[13];
-       backend_projectmatrix.m[2][3] = m[14];
-       backend_projectmatrix.m[3][3] = m[15];
+       CHECKGLERROR
+       Matrix4x4_FromArrayDoubleGL(&backend_projectmatrix, m);
 }
 
 void GL_SetupView_Mode_Ortho (double x1, double y1, double x2, double y2, double zNear, double zFar)
 {
        double m[16];
 
-       if (!r_render.integer)
-               return;
-
        // set up viewpoint
+       CHECKGLERROR
        qglMatrixMode(GL_PROJECTION);CHECKGLERROR
        qglLoadIdentity();CHECKGLERROR
-       qglOrtho(x1, x2, y2, y1, zNear, zFar);
-       qglGetDoublev(GL_PROJECTION_MATRIX, m);
-       backend_projectmatrix.m[0][0] = m[0];
-       backend_projectmatrix.m[1][0] = m[1];
-       backend_projectmatrix.m[2][0] = m[2];
-       backend_projectmatrix.m[3][0] = m[3];
-       backend_projectmatrix.m[0][1] = m[4];
-       backend_projectmatrix.m[1][1] = m[5];
-       backend_projectmatrix.m[2][1] = m[6];
-       backend_projectmatrix.m[3][1] = m[7];
-       backend_projectmatrix.m[0][2] = m[8];
-       backend_projectmatrix.m[1][2] = m[9];
-       backend_projectmatrix.m[2][2] = m[10];
-       backend_projectmatrix.m[3][2] = m[11];
-       backend_projectmatrix.m[0][3] = m[12];
-       backend_projectmatrix.m[1][3] = m[13];
-       backend_projectmatrix.m[2][3] = m[14];
-       backend_projectmatrix.m[3][3] = m[15];
+       qglOrtho(x1, x2, y2, y1, zNear, zFar);CHECKGLERROR
+       qglGetDoublev(GL_PROJECTION_MATRIX, m);CHECKGLERROR
+       Matrix4x4_FromArrayDoubleGL(&backend_projectmatrix, m);
        qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
        GL_SetupView_Orientation_Identity();
+       CHECKGLERROR
+}
+
+void GL_SetupView_ApplyCustomNearClipPlane(double normalx, double normaly, double normalz, double dist)
+{
+       double matrix[16];
+       double q[4];
+       double d;
+       float clipPlane[4], v3[3], v4[3];
+       float normal[3];
+
+       // This is Olique Depth Projection from http://www.terathon.com/code/oblique.php
+       // modified to fit in this codebase.
+
+       VectorSet(normal, normalx, normaly, normalz);
+       Matrix4x4_Transform3x3(&backend_viewmatrix, normal, clipPlane);
+       VectorScale(normal, dist, v3);
+       Matrix4x4_Transform(&backend_viewmatrix, v3, v4);
+       // FIXME: LordHavoc: I think this can be done more efficiently somehow but I can't remember the technique
+       clipPlane[3] = -DotProduct(v4, clipPlane);
+
+#if 0
+{
+       // testing code for comparing results
+       float clipPlane2[4];
+       VectorCopy4(clipPlane, clipPlane2);
+       R_Mesh_Matrix(&identitymatrix);
+       VectorSet(q, normal[0], normal[1], normal[2], -dist);
+       qglClipPlane(GL_CLIP_PLANE0, q);
+       qglGetClipPlane(GL_CLIP_PLANE0, q);
+       VectorCopy4(q, clipPlane);
+}
+#endif
+
+       // Calculate the clip-space corner point opposite the clipping plane
+       // as (sgn(clipPlane.x), sgn(clipPlane.y), 1, 1) and
+       // transform it into camera space by multiplying it
+       // by the inverse of the projection matrix
+       Matrix4x4_ToArrayDoubleGL(&backend_projectmatrix, matrix);
+
+       q[0] = ((clipPlane[0] < 0.0f ? -1.0f : clipPlane[0] > 0.0f ? 1.0f : 0.0f) + matrix[8]) / matrix[0];
+       q[1] = ((clipPlane[1] < 0.0f ? -1.0f : clipPlane[1] > 0.0f ? 1.0f : 0.0f) + matrix[9]) / matrix[5];
+       q[2] = -1.0f;
+       q[3] = (1.0f + matrix[10]) / matrix[14];
+
+       // Calculate the scaled plane vector
+       d = 2.0f / DotProduct4(clipPlane, q);
+
+       // Replace the third row of the projection matrix
+       matrix[2] = clipPlane[0] * d;
+       matrix[6] = clipPlane[1] * d;
+       matrix[10] = clipPlane[2] * d + 1.0f;
+       matrix[14] = clipPlane[3] * d;
+
+       // Load it back into OpenGL
+       qglMatrixMode(GL_PROJECTION);CHECKGLERROR
+       qglLoadMatrixd(matrix);CHECKGLERROR
+       qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
+       CHECKGLERROR
+       Matrix4x4_FromArrayDoubleGL(&backend_projectmatrix, matrix);
 }
 
 typedef struct gltextureunit_s
 {
+       const void *pointer_texcoord;
+       size_t pointer_texcoord_offset;
+       int pointer_texcoord_buffer;
        int t1d, t2d, t3d, tcubemap;
        int arrayenabled;
        unsigned int arraycomponents;
-       const void *pointer_texcoord;
-       float rgbscale, alphascale;
+       int rgbscale, alphascale;
        int combinergb, combinealpha;
        // FIXME: add more combine stuff
        // texmatrixenabled exists only to avoid unnecessary texmatrix compares
@@ -411,14 +444,19 @@ typedef struct gltextureunit_s
 }
 gltextureunit_t;
 
-static struct
+static struct gl_state_s
 {
+       int cullface;
+       int cullfaceenable;
        int blendfunc1;
        int blendfunc2;
        int blend;
        GLboolean depthmask;
        int colormask; // stored as bottom 4 bits: r g b a (3 2 1 0 order)
        int depthtest;
+       float depthrange[2];
+       float polygonoffset[2];
+       int alphatest;
        int scissortest;
        unsigned int unit;
        unsigned int clientunit;
@@ -426,18 +464,47 @@ static struct
        float color4f[4];
        int lockrange_first;
        int lockrange_count;
+       int vertexbufferobject;
+       int elementbufferobject;
+       qboolean pointer_color_enabled;
        const void *pointer_vertex;
        const void *pointer_color;
+       size_t pointer_vertex_offset;
+       size_t pointer_color_offset;
+       int pointer_vertex_buffer;
+       int pointer_color_buffer;
 }
 gl_state;
 
+static void GL_BindVBO(int bufferobject)
+{
+       if (gl_state.vertexbufferobject != bufferobject)
+       {
+               gl_state.vertexbufferobject = bufferobject;
+               CHECKGLERROR
+               qglBindBufferARB(GL_ARRAY_BUFFER_ARB, bufferobject);
+               CHECKGLERROR
+       }
+}
+
+static void GL_BindEBO(int bufferobject)
+{
+       if (gl_state.elementbufferobject != bufferobject)
+       {
+               gl_state.elementbufferobject = bufferobject;
+               CHECKGLERROR
+               qglBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, bufferobject);
+               CHECKGLERROR
+       }
+}
+
 void GL_SetupTextureState(void)
 {
-       int i;
+       unsigned int i;
        gltextureunit_t *unit;
        CHECKGLERROR
-       gl_state.unit = -1;
-       gl_state.clientunit = -1;
+       gl_state.unit = MAX_TEXTUREUNITS;
+       gl_state.clientunit = MAX_TEXTUREUNITS;
        for (i = 0;i < MAX_TEXTUREUNITS;i++)
        {
                unit = gl_state.units + i;
@@ -448,12 +515,14 @@ void GL_SetupTextureState(void)
                unit->arrayenabled = false;
                unit->arraycomponents = 0;
                unit->pointer_texcoord = NULL;
+               unit->pointer_texcoord_buffer = 0;
+               unit->pointer_texcoord_offset = 0;
                unit->rgbscale = 1;
                unit->alphascale = 1;
                unit->combinergb = GL_MODULATE;
                unit->combinealpha = GL_MODULATE;
                unit->texmatrixenabled = false;
-               unit->matrix = r_identitymatrix;
+               unit->matrix = identitymatrix;
        }
 
        for (i = 0;i < backendimageunits;i++)
@@ -474,6 +543,7 @@ void GL_SetupTextureState(void)
        for (i = 0;i < backendarrayunits;i++)
        {
                GL_ClientActiveTexture(i);
+               GL_BindVBO(0);
                qglTexCoordPointer(2, GL_FLOAT, sizeof(float[2]), NULL);CHECKGLERROR
                qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
        }
@@ -491,9 +561,9 @@ void GL_SetupTextureState(void)
                {
                        qglDisable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
                }
-               qglMatrixMode(GL_TEXTURE);
-               qglLoadIdentity();
-               qglMatrixMode(GL_MODELVIEW);
+               qglMatrixMode(GL_TEXTURE);CHECKGLERROR
+               qglLoadIdentity();CHECKGLERROR
+               qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
                if (gl_combine.integer)
                {
                        qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB);CHECKGLERROR
@@ -518,6 +588,7 @@ void GL_SetupTextureState(void)
                {
                        qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);CHECKGLERROR
                }
+               CHECKGLERROR
        }
        CHECKGLERROR
 }
@@ -526,6 +597,7 @@ void GL_Backend_ResetState(void)
 {
        memset(&gl_state, 0, sizeof(gl_state));
        gl_state.depthtest = true;
+       gl_state.alphatest = false;
        gl_state.blendfunc1 = GL_ONE;
        gl_state.blendfunc2 = GL_ZERO;
        gl_state.blend = false;
@@ -534,18 +606,30 @@ void GL_Backend_ResetState(void)
        gl_state.color4f[0] = gl_state.color4f[1] = gl_state.color4f[2] = gl_state.color4f[3] = 1;
        gl_state.lockrange_first = 0;
        gl_state.lockrange_count = 0;
-       gl_state.pointer_vertex = NULL;
-       gl_state.pointer_color = NULL;
+       gl_state.cullface = v_flipped_state ? GL_BACK : GL_FRONT; // quake is backwards, this culls back faces
+       gl_state.cullfaceenable = true;
+       gl_state.polygonoffset[0] = 0;
+       gl_state.polygonoffset[1] = 0;
 
        CHECKGLERROR
 
        qglColorMask(1, 1, 1, 1);
-       qglEnable(GL_CULL_FACE);CHECKGLERROR
-       qglCullFace(GL_FRONT);CHECKGLERROR
-       qglEnable(GL_DEPTH_TEST);CHECKGLERROR
+       qglAlphaFunc(GL_GEQUAL, 0.5);CHECKGLERROR
+       qglDisable(GL_ALPHA_TEST);CHECKGLERROR
        qglBlendFunc(gl_state.blendfunc1, gl_state.blendfunc2);CHECKGLERROR
        qglDisable(GL_BLEND);CHECKGLERROR
+       qglCullFace(gl_state.cullface);CHECKGLERROR
+       qglEnable(GL_CULL_FACE);CHECKGLERROR
+       qglDepthFunc(GL_LEQUAL);CHECKGLERROR
+       qglEnable(GL_DEPTH_TEST);CHECKGLERROR
        qglDepthMask(gl_state.depthmask);CHECKGLERROR
+       qglPolygonOffset(gl_state.polygonoffset[0], gl_state.polygonoffset[1]);
+
+       if (gl_support_arb_vertex_buffer_object)
+       {
+               qglBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
+               qglBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
+       }
 
        qglVertexPointer(3, GL_FLOAT, sizeof(float[3]), NULL);CHECKGLERROR
        qglEnableClientState(GL_VERTEX_ARRAY);CHECKGLERROR
@@ -566,6 +650,7 @@ void GL_ActiveTexture(unsigned int num)
                gl_state.unit = num;
                if (qglActiveTexture)
                {
+                       CHECKGLERROR
                        qglActiveTexture(GL_TEXTURE0_ARB + gl_state.unit);
                        CHECKGLERROR
                }
@@ -579,6 +664,7 @@ void GL_ClientActiveTexture(unsigned int num)
                gl_state.clientunit = num;
                if (qglActiveTexture)
                {
+                       CHECKGLERROR
                        qglClientActiveTexture(GL_TEXTURE0_ARB + gl_state.clientunit);
                        CHECKGLERROR
                }
@@ -589,8 +675,7 @@ void GL_BlendFunc(int blendfunc1, int blendfunc2)
 {
        if (gl_state.blendfunc1 != blendfunc1 || gl_state.blendfunc2 != blendfunc2)
        {
-               if (r_showtrispass)
-                       return;
+               CHECKGLERROR
                qglBlendFunc(gl_state.blendfunc1 = blendfunc1, gl_state.blendfunc2 = blendfunc2);CHECKGLERROR
                if (gl_state.blendfunc2 == GL_ZERO)
                {
@@ -626,8 +711,7 @@ void GL_DepthMask(int state)
 {
        if (gl_state.depthmask != state)
        {
-               if (r_showtrispass)
-                       return;
+               CHECKGLERROR
                qglDepthMask(gl_state.depthmask = state);CHECKGLERROR
        }
 }
@@ -636,9 +720,8 @@ void GL_DepthTest(int state)
 {
        if (gl_state.depthtest != state)
        {
-               if (r_showtrispass)
-                       return;
                gl_state.depthtest = state;
+               CHECKGLERROR
                if (gl_state.depthtest)
                {
                        qglEnable(GL_DEPTH_TEST);CHECKGLERROR
@@ -650,24 +733,106 @@ void GL_DepthTest(int state)
        }
 }
 
+void GL_DepthRange(float nearfrac, float farfrac)
+{
+       if (gl_state.depthrange[0] != nearfrac || gl_state.depthrange[1] != farfrac)
+       {
+               gl_state.depthrange[0] = nearfrac;
+               gl_state.depthrange[1] = farfrac;
+               qglDepthRange(nearfrac, farfrac);
+       }
+}
+
+void GL_PolygonOffset(float planeoffset, float depthoffset)
+{
+       if (gl_state.polygonoffset[0] != planeoffset || gl_state.polygonoffset[1] != depthoffset)
+       {
+               gl_state.polygonoffset[0] = planeoffset;
+               gl_state.polygonoffset[1] = depthoffset;
+               qglPolygonOffset(planeoffset, depthoffset);
+       }
+}
+
+void GL_SetMirrorState(qboolean state)
+{
+       if(!state != !v_flipped_state)
+       {
+               // change cull face mode!
+               if(gl_state.cullface == GL_BACK)
+                       qglCullFace((gl_state.cullface = GL_FRONT));
+               else if(gl_state.cullface == GL_FRONT)
+                       qglCullFace((gl_state.cullface = GL_BACK));
+       }
+       v_flipped_state = state;
+}
+
+void GL_CullFace(int state)
+{
+       CHECKGLERROR
+
+       if(v_flipped_state)
+       {
+               if(state == GL_FRONT)
+                       state = GL_BACK;
+               else if(state == GL_BACK)
+                       state = GL_FRONT;
+       }
+
+       if (state != GL_NONE)
+       {
+               if (!gl_state.cullfaceenable)
+               {
+                       gl_state.cullfaceenable = true;
+                       qglEnable(GL_CULL_FACE);CHECKGLERROR
+               }
+               if (gl_state.cullface != state)
+               {
+                       gl_state.cullface = state;
+                       qglCullFace(gl_state.cullface);CHECKGLERROR
+               }
+       }
+       else
+       {
+               if (gl_state.cullfaceenable)
+               {
+                       gl_state.cullfaceenable = false;
+                       qglDisable(GL_CULL_FACE);CHECKGLERROR
+               }
+       }
+}
+
+void GL_AlphaTest(int state)
+{
+       if (gl_state.alphatest != state)
+       {
+               gl_state.alphatest = state;
+               CHECKGLERROR
+               if (gl_state.alphatest)
+               {
+                       qglEnable(GL_ALPHA_TEST);CHECKGLERROR
+               }
+               else
+               {
+                       qglDisable(GL_ALPHA_TEST);CHECKGLERROR
+               }
+       }
+}
+
 void GL_ColorMask(int r, int g, int b, int a)
 {
        int state = r*8 + g*4 + b*2 + a*1;
        if (gl_state.colormask != state)
        {
-               if (r_showtrispass)
-                       return;
                gl_state.colormask = state;
+               CHECKGLERROR
                qglColorMask((GLboolean)r, (GLboolean)g, (GLboolean)b, (GLboolean)a);CHECKGLERROR
        }
 }
 
 void GL_Color(float cr, float cg, float cb, float ca)
 {
-       if (gl_state.pointer_color || gl_state.color4f[0] != cr || gl_state.color4f[1] != cg || gl_state.color4f[2] != cb || gl_state.color4f[3] != ca)
+       if (gl_state.pointer_color_enabled || gl_state.color4f[0] != cr || gl_state.color4f[1] != cg || gl_state.color4f[2] != cb || gl_state.color4f[3] != ca)
        {
-               if (r_showtrispass)
-                       return;
                gl_state.color4f[0] = cr;
                gl_state.color4f[1] = cg;
                gl_state.color4f[2] = cb;
@@ -678,18 +843,13 @@ void GL_Color(float cr, float cg, float cb, float ca)
        }
 }
 
-void GL_ShowTrisColor(float cr, float cg, float cb, float ca)
-{
-       if (!r_showtrispass)
-               return;
-       r_showtrispass = false;
-       GL_Color(cr * r_showtris.value, cg * r_showtris.value, cb * r_showtris.value, ca);
-       r_showtrispass = true;
-}
-
-
 void GL_LockArrays(int first, int count)
 {
+       if (count < gl_lockarrays_minimumvertices.integer)
+       {
+               first = 0;
+               count = 0;
+       }
        if (gl_state.lockrange_count != count || gl_state.lockrange_first != first)
        {
                if (gl_state.lockrange_count)
@@ -713,7 +873,7 @@ void GL_LockArrays(int first, int count)
 void GL_Scissor (int x, int y, int width, int height)
 {
        CHECKGLERROR
-       qglScissor(x, vid.realheight - (y + height),width,height);
+       qglScissor(x, vid.height - (y + height),width,height);
        CHECKGLERROR
 }
 
@@ -732,8 +892,7 @@ void GL_ScissorTest(int state)
 
 void GL_Clear(int mask)
 {
-       if (r_showtrispass)
-               return;
+       CHECKGLERROR
        qglClear(mask);CHECKGLERROR
 }
 
@@ -744,9 +903,9 @@ void GL_TransformToScreen(const vec4_t in, vec4_t out)
        Matrix4x4_Transform4 (&backend_viewmatrix, in, temp);
        Matrix4x4_Transform4 (&backend_projectmatrix, temp, out);
        iw = 1.0f / out[3];
-       out[0] = r_view_x + (out[0] * iw + 1.0f) * r_view_width * 0.5f;
-       out[1] = r_view_y + (out[1] * iw + 1.0f) * r_view_height * 0.5f;
-       out[2] = r_view_z + (out[2] * iw + 1.0f) * r_view_depth * 0.5f;
+       out[0] = r_view.x + (out[0] * iw + 1.0f) * r_view.width * 0.5f;
+       out[1] = r_view.y + r_view.height - (out[1] * iw + 1.0f) * r_view.height * 0.5f;
+       out[2] = r_view.z + (out[2] * iw + 1.0f) * r_view.depth * 0.5f;
 }
 
 // called at beginning of frame
@@ -754,103 +913,81 @@ void R_Mesh_Start(void)
 {
        BACKENDACTIVECHECK
        CHECKGLERROR
+       if (gl_printcheckerror.integer && !gl_paranoid.integer)
+       {
+               Con_Printf("WARNING: gl_printcheckerror is on but gl_paranoid is off, turning it on...\n");
+               Cvar_SetValueQuick(&gl_paranoid, 1);
+       }
        GL_Backend_ResetState();
 }
 
-unsigned int GL_Backend_CompileProgram(int vertexstrings_count, const char **vertexstrings_list, int fragmentstrings_count, const char **fragmentstrings_list)
+qboolean GL_Backend_CompileShader(int programobject, GLenum shadertypeenum, const char *shadertype, int numstrings, const char **strings)
 {
-       GLint vertexshadercompiled, fragmentshadercompiled, programlinked;
-       GLuint vertexshaderobject, fragmentshaderobject, programobject = 0;
-       char compilelog[4096];
-       CHECKGLERROR
+       int shaderobject;
+       int shadercompiled;
+       char compilelog[MAX_INPUTLINE];
+       shaderobject = qglCreateShaderObjectARB(shadertypeenum);CHECKGLERROR
+       if (!shaderobject)
+               return false;
+       qglShaderSourceARB(shaderobject, numstrings, strings, NULL);CHECKGLERROR
+       qglCompileShaderARB(shaderobject);CHECKGLERROR
+       qglGetObjectParameterivARB(shaderobject, GL_OBJECT_COMPILE_STATUS_ARB, &shadercompiled);CHECKGLERROR
+       qglGetInfoLogARB(shaderobject, sizeof(compilelog), NULL, compilelog);CHECKGLERROR
+       if (compilelog[0])
+               Con_DPrintf("%s shader compile log:\n%s\n", shadertype, compilelog);
+       if (!shadercompiled)
+       {
+               qglDeleteObjectARB(shaderobject);CHECKGLERROR
+               return false;
+       }
+       qglAttachObjectARB(programobject, shaderobject);CHECKGLERROR
+       qglDeleteObjectARB(shaderobject);CHECKGLERROR
+       return true;
+}
 
-       programobject = qglCreateProgramObjectARB();
+unsigned int GL_Backend_CompileProgram(int vertexstrings_count, const char **vertexstrings_list, int geometrystrings_count, const char **geometrystrings_list, int fragmentstrings_count, const char **fragmentstrings_list)
+{
+       GLint programlinked;
+       GLuint programobject = 0;
+       char linklog[MAX_INPUTLINE];
        CHECKGLERROR
+
+       programobject = qglCreateProgramObjectARB();CHECKGLERROR
        if (!programobject)
                return 0;
 
-       if (vertexstrings_count)
-       {
-               CHECKGLERROR
-               vertexshaderobject = qglCreateShaderObjectARB(GL_VERTEX_SHADER_ARB);
-               if (!vertexshaderobject)
-               {
-                       qglDeleteObjectARB(programobject);
-                       CHECKGLERROR
-                       return 0;
-               }
-               qglShaderSourceARB(vertexshaderobject, vertexstrings_count, vertexstrings_list, NULL);
-               qglCompileShaderARB(vertexshaderobject);
-               CHECKGLERROR
-               qglGetObjectParameterivARB(vertexshaderobject, GL_OBJECT_COMPILE_STATUS_ARB, &vertexshadercompiled);
-               qglGetInfoLogARB(vertexshaderobject, sizeof(compilelog), NULL, compilelog);
-               if (compilelog[0])
-                       Con_Printf("vertex shader compile log:\n%s\n", compilelog);
-               if (!vertexshadercompiled)
-               {
-                       qglDeleteObjectARB(programobject);
-                       qglDeleteObjectARB(vertexshaderobject);
-                       CHECKGLERROR
-                       return 0;
-               }
-               qglAttachObjectARB(programobject, vertexshaderobject);
-               qglDeleteObjectARB(vertexshaderobject);
-               CHECKGLERROR
-       }
+       if (vertexstrings_count && !GL_Backend_CompileShader(programobject, GL_VERTEX_SHADER_ARB, "vertex", vertexstrings_count, vertexstrings_list))
+               goto cleanup;
 
-       if (fragmentstrings_count)
-       {
-               CHECKGLERROR
-               fragmentshaderobject = qglCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB);
-               if (!fragmentshaderobject)
-               {
-                       qglDeleteObjectARB(programobject);
-                       CHECKGLERROR
-                       return 0;
-               }
-               qglShaderSourceARB(fragmentshaderobject, fragmentstrings_count, fragmentstrings_list, NULL);
-               qglCompileShaderARB(fragmentshaderobject);
-               CHECKGLERROR
-               qglGetObjectParameterivARB(fragmentshaderobject, GL_OBJECT_COMPILE_STATUS_ARB, &fragmentshadercompiled);
-               qglGetInfoLogARB(fragmentshaderobject, sizeof(compilelog), NULL, compilelog);
-               if (compilelog[0])
-                       Con_Printf("fragment shader compile log:\n%s\n", compilelog);
-               if (!fragmentshadercompiled)
-               {
-                       qglDeleteObjectARB(programobject);
-                       qglDeleteObjectARB(fragmentshaderobject);
-                       CHECKGLERROR
-                       return 0;
-               }
-               qglAttachObjectARB(programobject, fragmentshaderobject);
-               qglDeleteObjectARB(fragmentshaderobject);
-               CHECKGLERROR
-       }
+#ifdef GL_GEOMETRY_SHADER_ARB
+       if (geometrystrings_count && !GL_Backend_CompileShader(programobject, GL_GEOMETRY_SHADER_ARB, "geometry", geometrystrings_count, geometrystrings_list))
+               goto cleanup;
+#endif
 
-       qglLinkProgramARB(programobject);
-       CHECKGLERROR
-       qglGetObjectParameterivARB(programobject, GL_OBJECT_LINK_STATUS_ARB, &programlinked);
-       qglGetInfoLogARB(programobject, sizeof(compilelog), NULL, compilelog);
-       if (compilelog[0])
+       if (fragmentstrings_count && !GL_Backend_CompileShader(programobject, GL_FRAGMENT_SHADER_ARB, "fragment", fragmentstrings_count, fragmentstrings_list))
+               goto cleanup;
+
+       qglLinkProgramARB(programobject);CHECKGLERROR
+       qglGetObjectParameterivARB(programobject, GL_OBJECT_LINK_STATUS_ARB, &programlinked);CHECKGLERROR
+       qglGetInfoLogARB(programobject, sizeof(linklog), NULL, linklog);CHECKGLERROR
+       if (linklog[0])
        {
-               Con_Printf("program link log:\n%s\n", compilelog);
+               Con_DPrintf("program link log:\n%s\n", linklog);
                // software vertex shader is ok but software fragment shader is WAY
                // too slow, fail program if so.
                // NOTE: this string might be ATI specific, but that's ok because the
                // ATI R300 chip (Radeon 9500-9800/X300) is the most likely to use a
                // software fragment shader due to low instruction and dependent
                // texture limits.
-               if (strstr(compilelog, "fragment shader will run in software"))
+               if (strstr(linklog, "fragment shader will run in software"))
                        programlinked = false;
        }
-       CHECKGLERROR
        if (!programlinked)
-       {
-               qglDeleteObjectARB(programobject);
-               return 0;
-       }
-       CHECKGLERROR
+               goto cleanup;
        return programobject;
+cleanup:
+       qglDeleteObjectARB(programobject);CHECKGLERROR
+       return 0;
 }
 
 void GL_Backend_FreeProgram(unsigned int prog)
@@ -876,36 +1013,42 @@ void GL_Backend_RenumberElements(int *out, int count, const int *in, int offset)
 
 // renders triangles using vertices from the active arrays
 int paranoidblah = 0;
-void R_Mesh_Draw(int numverts, int numtriangles, const int *elements)
+void R_Mesh_Draw(int firstvertex, int numvertices, int numtriangles, const int *elements, int bufferobject, size_t bufferoffset)
 {
-       int numelements = numtriangles * 3;
-       if (numverts == 0 || numtriangles == 0)
+       unsigned int numelements = numtriangles * 3;
+       if (numvertices < 3 || numtriangles < 1)
        {
-               Con_Printf("R_Mesh_Draw(%d, %d, %08p);\n", numverts, numtriangles, elements);
+               Con_Printf("R_Mesh_Draw(%d, %d, %d, %8p, %i, %p);\n", firstvertex, numvertices, numtriangles, elements, bufferobject, (void *)bufferoffset);
                return;
        }
+       if (!gl_vbo.integer)
+               bufferobject = 0;
        CHECKGLERROR
-       if (r_showtrispass)
-       {
-               R_Mesh_Draw_ShowTris(numverts, numtriangles, elements);
-               return;
-       }
-       c_meshs++;
-       c_meshelements += numelements;
+       r_refdef.stats.meshes++;
+       r_refdef.stats.meshes_elements += numelements;
        if (gl_paranoid.integer)
        {
-               int i, j, size;
+               unsigned int i, j, size;
                const int *p;
+               // note: there's no validation done here on buffer objects because it
+               // is somewhat difficult to get at the data, and gl_paranoid can be
+               // used without buffer objects if the need arises
+               // (the data could be gotten using glMapBuffer but it would be very
+               //  slow due to uncachable video memory reads)
                if (!qglIsEnabled(GL_VERTEX_ARRAY))
                        Con_Print("R_Mesh_Draw: vertex array not enabled\n");
-               for (j = 0, size = numverts * (int)sizeof(float[3]), p = gl_state.pointer_vertex;j < size;j += sizeof(int), p++)
-                       paranoidblah += *p;
-               if (gl_state.pointer_color)
+               CHECKGLERROR
+               if (gl_state.pointer_vertex)
+                       for (j = 0, size = numvertices * 3, p = (int *)((float *)gl_state.pointer_vertex + firstvertex * 3);j < size;j++, p++)
+                               paranoidblah += *p;
+               if (gl_state.pointer_color_enabled)
                {
                        if (!qglIsEnabled(GL_COLOR_ARRAY))
                                Con_Print("R_Mesh_Draw: color array set but not enabled\n");
-                       for (j = 0, size = numverts * (int)sizeof(float[4]), p = gl_state.pointer_color;j < size;j += sizeof(int), p++)
-                               paranoidblah += *p;
+                       CHECKGLERROR
+                       if (gl_state.pointer_color && gl_state.pointer_color_enabled)
+                               for (j = 0, size = numvertices * 4, p = (int *)((float *)gl_state.pointer_color + firstvertex * 4);j < size;j++, p++)
+                                       paranoidblah += *p;
                }
                for (i = 0;i < backendarrayunits;i++)
                {
@@ -914,15 +1057,17 @@ void R_Mesh_Draw(int numverts, int numtriangles, const int *elements)
                                GL_ClientActiveTexture(i);
                                if (!qglIsEnabled(GL_TEXTURE_COORD_ARRAY))
                                        Con_Print("R_Mesh_Draw: texcoord array set but not enabled\n");
-                               for (j = 0, size = numverts * ((gl_state.units[i].t3d || gl_state.units[i].tcubemap) ? (int)sizeof(float[3]) : (int)sizeof(float[2])), p = gl_state.units[i].pointer_texcoord;j < size;j += sizeof(int), p++)
-                                       paranoidblah += *p;
+                               CHECKGLERROR
+                               if (gl_state.units[i].pointer_texcoord && gl_state.units[i].arrayenabled)
+                                       for (j = 0, size = numvertices * gl_state.units[i].arraycomponents, p = (int *)((float *)gl_state.units[i].pointer_texcoord + firstvertex * gl_state.units[i].arraycomponents);j < size;j++, p++)
+                                               paranoidblah += *p;
                        }
                }
-               for (i = 0;i < numtriangles * 3;i++)
+               for (i = 0;i < (unsigned int) numtriangles * 3;i++)
                {
-                       if (elements[i] < 0 || elements[i] >= numverts)
+                       if (elements[i] < firstvertex || elements[i] >= firstvertex + numvertices)
                        {
-                               Con_Printf("R_Mesh_Draw: invalid vertex index %i (outside range 0 - %i) in elements list\n", elements[i], numverts);
+                               Con_Printf("R_Mesh_Draw: invalid vertex index %i (outside range %i - %i) in elements list\n", elements[i], firstvertex, firstvertex + numvertices);
                                return;
                        }
                }
@@ -933,14 +1078,14 @@ void R_Mesh_Draw(int numverts, int numtriangles, const int *elements)
                CHECKGLERROR
                if (gl_mesh_testmanualfeeding.integer)
                {
-                       int i, j;
+                       unsigned int i, j;
                        const GLfloat *p;
                        qglBegin(GL_TRIANGLES);
-                       for (i = 0;i < numtriangles * 3;i++)
+                       for (i = 0;i < (unsigned int) numtriangles * 3;i++)
                        {
                                for (j = 0;j < backendarrayunits;j++)
                                {
-                                       if (gl_state.units[j].pointer_texcoord)
+                                       if (gl_state.units[j].pointer_texcoord && gl_state.units[j].arrayenabled)
                                        {
                                                if (backendarrayunits > 1)
                                                {
@@ -990,7 +1135,7 @@ void R_Mesh_Draw(int numverts, int numtriangles, const int *elements)
                                                }
                                        }
                                }
-                               if (gl_state.pointer_color)
+                               if (gl_state.pointer_color && gl_state.pointer_color_enabled)
                                {
                                        p = ((const GLfloat *)(gl_state.pointer_color)) + elements[i] * 4;
                                        qglColor4f(p[0], p[1], p[2], p[3]);
@@ -1014,20 +1159,23 @@ void R_Mesh_Draw(int numverts, int numtriangles, const int *elements)
                }
                else if (gl_mesh_drawrangeelements.integer && qglDrawRangeElements != NULL)
                {
-                       qglDrawRangeElements(GL_TRIANGLES, 0, numverts, numelements, GL_UNSIGNED_INT, elements);CHECKGLERROR
+                       GL_BindEBO(bufferobject);
+                       qglDrawRangeElements(GL_TRIANGLES, firstvertex, firstvertex + numvertices, numelements, GL_UNSIGNED_INT, bufferobject ? (void *)bufferoffset : elements);
+                       CHECKGLERROR
                }
                else
                {
-                       qglDrawElements(GL_TRIANGLES, numelements, GL_UNSIGNED_INT, elements);CHECKGLERROR
+                       GL_BindEBO(bufferobject);
+                       qglDrawElements(GL_TRIANGLES, numelements, GL_UNSIGNED_INT, bufferobject ? (void *)bufferoffset : elements);
+                       CHECKGLERROR
                }
-               CHECKGLERROR
        }
 }
 
 // restores backend state, used when done with 3D rendering
 void R_Mesh_Finish(void)
 {
-       int i;
+       unsigned int i;
        BACKENDACTIVECHECK
        CHECKGLERROR
        GL_LockArrays(0, 0);
@@ -1047,14 +1195,14 @@ void R_Mesh_Finish(void)
                        qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, 0);CHECKGLERROR
                }
        }
-       for (i = backendarrayunits - 1;i >= 0;i--)
+       for (i = 0;i < backendarrayunits;i++)
        {
-               GL_ActiveTexture(i);
+               GL_ActiveTexture(backendarrayunits - 1 - i);
                qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
        }
-       for (i = backendunits - 1;i >= 0;i--)
+       for (i = 0;i < backendunits;i++)
        {
-               GL_ActiveTexture(i);
+               GL_ActiveTexture(backendunits - 1 - i);
                qglDisable(GL_TEXTURE_1D);CHECKGLERROR
                qglDisable(GL_TEXTURE_2D);CHECKGLERROR
                if (gl_texture3d)
@@ -1081,67 +1229,155 @@ void R_Mesh_Finish(void)
        qglBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);CHECKGLERROR
 }
 
+int R_Mesh_CreateStaticBufferObject(unsigned int target, void *data, size_t size, const char *name)
+{
+       gl_bufferobjectinfo_t *info;
+       GLuint bufferobject;
+
+       if (!gl_vbo.integer)
+               return 0;
+
+       qglGenBuffersARB(1, &bufferobject);
+       switch(target)
+       {
+       case GL_ELEMENT_ARRAY_BUFFER_ARB: GL_BindEBO(bufferobject);break;
+       case GL_ARRAY_BUFFER_ARB: GL_BindVBO(bufferobject);break;
+       default: Sys_Error("R_Mesh_CreateStaticBufferObject: unknown target type %i\n", target);return 0;
+       }
+       qglBufferDataARB(target, size, data, GL_STATIC_DRAW_ARB);
+
+       info = Mem_ExpandableArray_AllocRecord(&gl_bufferobjectinfoarray);
+       memset(info, 0, sizeof(*info));
+       info->target = target;
+       info->object = bufferobject;
+       info->size = size;
+       strlcpy(info->name, name, sizeof(info->name));
+
+       return (int)bufferobject;
+}
+
+void R_Mesh_DestroyBufferObject(int bufferobject)
+{
+       int i, endindex;
+       gl_bufferobjectinfo_t *info;
+
+       qglDeleteBuffersARB(1, (GLuint *)&bufferobject);
+
+       endindex = Mem_ExpandableArray_IndexRange(&gl_bufferobjectinfoarray);
+       for (i = 0;i < endindex;i++)
+       {
+               info = Mem_ExpandableArray_RecordAtIndex(&gl_bufferobjectinfoarray, i);
+               if (!info)
+                       continue;
+               if (info->object == bufferobject)
+               {
+                       Mem_ExpandableArray_FreeRecord(&gl_bufferobjectinfoarray, (void *)info);
+                       break;
+               }
+       }
+}
+
+void GL_Mesh_ListVBOs(qboolean printeach)
+{
+       int i, endindex;
+       size_t ebocount = 0, ebomemory = 0;
+       size_t vbocount = 0, vbomemory = 0;
+       gl_bufferobjectinfo_t *info;
+       endindex = Mem_ExpandableArray_IndexRange(&gl_bufferobjectinfoarray);
+       for (i = 0;i < endindex;i++)
+       {
+               info = Mem_ExpandableArray_RecordAtIndex(&gl_bufferobjectinfoarray, i);
+               if (!info)
+                       continue;
+               switch(info->target)
+               {
+               case GL_ELEMENT_ARRAY_BUFFER_ARB: ebocount++;ebomemory += info->size;if (printeach) Con_Printf("EBO #%i %s = %i bytes\n", info->object, info->name, (int)info->size);break;
+               case GL_ARRAY_BUFFER_ARB: vbocount++;vbomemory += info->size;if (printeach) Con_Printf("VBO #%i %s = %i bytes\n", info->object, info->name, (int)info->size);break;
+               default: Con_Printf("gl_vbostats: unknown target type %i\n", info->target);break;
+               }
+       }
+       Con_Printf("vertex buffers: %i element buffers totalling %i bytes (%.3f MB), %i vertex buffers totalling %i bytes (%.3f MB), combined %i bytes (%.3fMB)\n", (int)ebocount, (int)ebomemory, ebomemory / 1048576.0, (int)vbocount, (int)vbomemory, vbomemory / 1048576.0, (int)(ebomemory + vbomemory), (ebomemory + vbomemory) / 1048576.0);
+}
+
 void R_Mesh_Matrix(const matrix4x4_t *matrix)
 {
        if (memcmp(matrix, &backend_modelmatrix, sizeof(matrix4x4_t)))
        {
+               double glmatrix[16];
                backend_modelmatrix = *matrix;
                Matrix4x4_Concat(&backend_modelviewmatrix, &backend_viewmatrix, matrix);
-               Matrix4x4_Transpose(&backend_glmodelviewmatrix, &backend_modelviewmatrix);
-               qglLoadMatrixf(&backend_glmodelviewmatrix.m[0][0]);
+               Matrix4x4_ToArrayDoubleGL(&backend_modelviewmatrix, glmatrix);
+               CHECKGLERROR
+               qglLoadMatrixd(glmatrix);CHECKGLERROR
        }
 }
 
-void R_Mesh_VertexPointer(const float *vertex3f)
+void R_Mesh_VertexPointer(const float *vertex3f, int bufferobject, size_t bufferoffset)
 {
-       if (gl_state.pointer_vertex != vertex3f)
+       if (!gl_vbo.integer)
+               bufferobject = 0;
+       if (gl_state.pointer_vertex != vertex3f || gl_state.pointer_vertex_buffer != bufferobject || gl_state.pointer_vertex_offset != bufferoffset)
        {
                gl_state.pointer_vertex = vertex3f;
+               gl_state.pointer_vertex_buffer = bufferobject;
+               gl_state.pointer_vertex_offset = bufferoffset;
                CHECKGLERROR
-               qglVertexPointer(3, GL_FLOAT, sizeof(float[3]), gl_state.pointer_vertex);
-               CHECKGLERROR
+               GL_BindVBO(bufferobject);
+               qglVertexPointer(3, GL_FLOAT, sizeof(float[3]), bufferobject ? (void *)bufferoffset : vertex3f);CHECKGLERROR
        }
 }
 
-void R_Mesh_ColorPointer(const float *color4f)
+void R_Mesh_ColorPointer(const float *color4f, int bufferobject, size_t bufferoffset)
 {
-       if (gl_state.pointer_color != color4f)
+       // note: this can not rely on bufferobject to decide whether a color array
+       // is supplied, because surfmesh_t shares one vbo for all arrays, which
+       // means that a valid vbo may be supplied even if there is no color array.
+       if (color4f)
        {
-               CHECKGLERROR
-               if (!gl_state.pointer_color)
+               if (!gl_vbo.integer)
+                       bufferobject = 0;
+               // caller wants color array enabled
+               if (!gl_state.pointer_color_enabled)
                {
-                       qglEnableClientState(GL_COLOR_ARRAY);
+                       gl_state.pointer_color_enabled = true;
                        CHECKGLERROR
+                       qglEnableClientState(GL_COLOR_ARRAY);CHECKGLERROR
                }
-               else if (!color4f)
+               if (gl_state.pointer_color != color4f || gl_state.pointer_color_buffer != bufferobject || gl_state.pointer_color_offset != bufferoffset)
                {
-                       qglDisableClientState(GL_COLOR_ARRAY);
+                       gl_state.pointer_color = color4f;
+                       gl_state.pointer_color_buffer = bufferobject;
+                       gl_state.pointer_color_offset = bufferoffset;
                        CHECKGLERROR
-                       // when color array is on the glColor gets trashed, set it again
-                       qglColor4f(gl_state.color4f[0], gl_state.color4f[1], gl_state.color4f[2], gl_state.color4f[3]);
+                       GL_BindVBO(bufferobject);
+                       qglColorPointer(4, GL_FLOAT, sizeof(float[4]), bufferobject ? (void *)bufferoffset : color4f);CHECKGLERROR
+               }
+       }
+       else
+       {
+               // caller wants color array disabled
+               if (gl_state.pointer_color_enabled)
+               {
+                       gl_state.pointer_color_enabled = false;
                        CHECKGLERROR
+                       qglDisableClientState(GL_COLOR_ARRAY);CHECKGLERROR
+                       // when color array is on the glColor gets trashed, set it again
+                       qglColor4f(gl_state.color4f[0], gl_state.color4f[1], gl_state.color4f[2], gl_state.color4f[3]);CHECKGLERROR
                }
-               gl_state.pointer_color = color4f;
-               qglColorPointer(4, GL_FLOAT, sizeof(float[4]), gl_state.pointer_color);
-               CHECKGLERROR
        }
 }
 
-void R_Mesh_TexCoordPointer(unsigned int unitnum, unsigned int numcomponents, const float *texcoord)
+void R_Mesh_TexCoordPointer(unsigned int unitnum, unsigned int numcomponents, const float *texcoord, int bufferobject, size_t bufferoffset)
 {
        gltextureunit_t *unit = gl_state.units + unitnum;
        // update array settings
+       CHECKGLERROR
+       // note: there is no need to check bufferobject here because all cases
+       // that involve a valid bufferobject also supply a texcoord array
        if (texcoord)
        {
-               // texcoord array
-               if (unit->pointer_texcoord != texcoord || unit->arraycomponents != numcomponents)
-               {
-                       unit->pointer_texcoord = texcoord;
-                       unit->arraycomponents = numcomponents;
-                       GL_ClientActiveTexture(unitnum);
-                       qglTexCoordPointer(unit->arraycomponents, GL_FLOAT, sizeof(float) * unit->arraycomponents, unit->pointer_texcoord);
-                       CHECKGLERROR
-               }
+               if (!gl_vbo.integer)
+                       bufferobject = 0;
                // texture array unit is enabled, enable the array
                if (!unit->arrayenabled)
                {
@@ -1149,6 +1385,17 @@ void R_Mesh_TexCoordPointer(unsigned int unitnum, unsigned int numcomponents, co
                        GL_ClientActiveTexture(unitnum);
                        qglEnableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
                }
+               // texcoord array
+               if (unit->pointer_texcoord != texcoord || unit->pointer_texcoord_buffer != bufferobject || unit->pointer_texcoord_offset != bufferoffset || unit->arraycomponents != numcomponents)
+               {
+                       unit->pointer_texcoord = texcoord;
+                       unit->pointer_texcoord_buffer = bufferobject;
+                       unit->pointer_texcoord_offset = bufferoffset;
+                       unit->arraycomponents = numcomponents;
+                       GL_ClientActiveTexture(unitnum);
+                       GL_BindVBO(bufferobject);
+                       qglTexCoordPointer(unit->arraycomponents, GL_FLOAT, sizeof(float) * unit->arraycomponents, bufferobject ? (void *)bufferoffset : texcoord);CHECKGLERROR
+               }
        }
        else
        {
@@ -1162,10 +1409,10 @@ void R_Mesh_TexCoordPointer(unsigned int unitnum, unsigned int numcomponents, co
        }
 }
 
-void R_Mesh_TexBindAll(unsigned int unitnum, unsigned int tex1d, unsigned int tex2d, unsigned int tex3d, unsigned int texcubemap)
+void R_Mesh_TexBindAll(unsigned int unitnum, int tex1d, int tex2d, int tex3d, int texcubemap)
 {
        gltextureunit_t *unit = gl_state.units + unitnum;
-       if (unitnum >= backendunits)
+       if (unitnum >= backendimageunits)
                return;
        // update 1d texture binding
        if (unit->t1d != tex1d)
@@ -1176,17 +1423,20 @@ void R_Mesh_TexBindAll(unsigned int unitnum, unsigned int tex1d, unsigned int te
                        if (tex1d)
                        {
                                if (unit->t1d == 0)
-                                       qglEnable(GL_TEXTURE_1D);
+                               {
+                                       qglEnable(GL_TEXTURE_1D);CHECKGLERROR
+                               }
                        }
                        else
                        {
                                if (unit->t1d)
-                                       qglDisable(GL_TEXTURE_1D);
+                               {
+                                       qglDisable(GL_TEXTURE_1D);CHECKGLERROR
+                               }
                        }
                }
                unit->t1d = tex1d;
-               qglBindTexture(GL_TEXTURE_1D, unit->t1d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_1D, unit->t1d);CHECKGLERROR
        }
        // update 2d texture binding
        if (unit->t2d != tex2d)
@@ -1197,17 +1447,20 @@ void R_Mesh_TexBindAll(unsigned int unitnum, unsigned int tex1d, unsigned int te
                        if (tex2d)
                        {
                                if (unit->t2d == 0)
-                                       qglEnable(GL_TEXTURE_2D);
+                               {
+                                       qglEnable(GL_TEXTURE_2D);CHECKGLERROR
+                               }
                        }
                        else
                        {
                                if (unit->t2d)
-                                       qglDisable(GL_TEXTURE_2D);
+                               {
+                                       qglDisable(GL_TEXTURE_2D);CHECKGLERROR
+                               }
                        }
                }
                unit->t2d = tex2d;
-               qglBindTexture(GL_TEXTURE_2D, unit->t2d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_2D, unit->t2d);CHECKGLERROR
        }
        // update 3d texture binding
        if (unit->t3d != tex3d)
@@ -1218,17 +1471,20 @@ void R_Mesh_TexBindAll(unsigned int unitnum, unsigned int tex1d, unsigned int te
                        if (tex3d)
                        {
                                if (unit->t3d == 0)
-                                       qglEnable(GL_TEXTURE_3D);
+                               {
+                                       qglEnable(GL_TEXTURE_3D);CHECKGLERROR
+                               }
                        }
                        else
                        {
                                if (unit->t3d)
-                                       qglDisable(GL_TEXTURE_3D);
+                               {
+                                       qglDisable(GL_TEXTURE_3D);CHECKGLERROR
+                               }
                        }
                }
                unit->t3d = tex3d;
-               qglBindTexture(GL_TEXTURE_3D, unit->t3d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_3D, unit->t3d);CHECKGLERROR
        }
        // update cubemap texture binding
        if (unit->tcubemap != texcubemap)
@@ -1239,237 +1495,312 @@ void R_Mesh_TexBindAll(unsigned int unitnum, unsigned int tex1d, unsigned int te
                        if (texcubemap)
                        {
                                if (unit->tcubemap == 0)
-                                       qglEnable(GL_TEXTURE_CUBE_MAP_ARB);
-                       }
+                               {
+                                       qglEnable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
+                               }
+                       }
                        else
                        {
                                if (unit->tcubemap)
-                                       qglDisable(GL_TEXTURE_CUBE_MAP_ARB);
+                               {
+                                       qglDisable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
+                               }
                        }
                }
                unit->tcubemap = texcubemap;
-               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);CHECKGLERROR
        }
 }
 
-void R_Mesh_TexBind1D(unsigned int unitnum, unsigned int texnum)
+void R_Mesh_TexBind1D(unsigned int unitnum, int texnum)
 {
        gltextureunit_t *unit = gl_state.units + unitnum;
-       if (unitnum >= backendunits)
+       if (unitnum >= backendimageunits)
                return;
        // update 1d texture binding
        if (unit->t1d != texnum)
        {
                GL_ActiveTexture(unitnum);
-               if (texnum)
-               {
-                       if (unit->t1d == 0)
-                               qglEnable(GL_TEXTURE_1D);
-               }
-               else
+               if (unitnum < backendunits)
                {
-                       if (unit->t1d)
-                               qglDisable(GL_TEXTURE_1D);
+                       if (texnum)
+                       {
+                               if (unit->t1d == 0)
+                               {
+                                       qglEnable(GL_TEXTURE_1D);CHECKGLERROR
+                               }
+                       }
+                       else
+                       {
+                               if (unit->t1d)
+                               {
+                                       qglDisable(GL_TEXTURE_1D);CHECKGLERROR
+                               }
+                       }
                }
                unit->t1d = texnum;
-               qglBindTexture(GL_TEXTURE_1D, unit->t1d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_1D, unit->t1d);CHECKGLERROR
        }
        // update 2d texture binding
        if (unit->t2d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t2d)
-                       qglDisable(GL_TEXTURE_2D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t2d)
+                       {
+                               qglDisable(GL_TEXTURE_2D);CHECKGLERROR
+                       }
+               }
                unit->t2d = 0;
-               qglBindTexture(GL_TEXTURE_2D, unit->t2d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_2D, unit->t2d);CHECKGLERROR
        }
        // update 3d texture binding
        if (unit->t3d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t3d)
-                       qglDisable(GL_TEXTURE_3D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t3d)
+                       {
+                               qglDisable(GL_TEXTURE_3D);CHECKGLERROR
+                       }
+               }
                unit->t3d = 0;
-               qglBindTexture(GL_TEXTURE_3D, unit->t3d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_3D, unit->t3d);CHECKGLERROR
        }
        // update cubemap texture binding
        if (unit->tcubemap)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->tcubemap)
-                       qglDisable(GL_TEXTURE_CUBE_MAP_ARB);
+               if (unitnum < backendunits)
+               {
+                       if (unit->tcubemap)
+                       {
+                               qglDisable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
+                       }
+               }
                unit->tcubemap = 0;
-               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);CHECKGLERROR
        }
 }
 
-void R_Mesh_TexBind(unsigned int unitnum, unsigned int texnum)
+void R_Mesh_TexBind(unsigned int unitnum, int texnum)
 {
        gltextureunit_t *unit = gl_state.units + unitnum;
-       if (unitnum >= backendunits)
+       if (unitnum >= backendimageunits)
                return;
        // update 1d texture binding
        if (unit->t1d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t1d)
-                       qglDisable(GL_TEXTURE_1D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t1d)
+                       {
+                               qglDisable(GL_TEXTURE_1D);CHECKGLERROR
+                       }
+               }
                unit->t1d = 0;
-               qglBindTexture(GL_TEXTURE_1D, unit->t1d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_1D, unit->t1d);CHECKGLERROR
        }
        // update 2d texture binding
        if (unit->t2d != texnum)
        {
                GL_ActiveTexture(unitnum);
-               if (texnum)
-               {
-                       if (unit->t2d == 0)
-                               qglEnable(GL_TEXTURE_2D);
-               }
-               else
+               if (unitnum < backendunits)
                {
-                       if (unit->t2d)
-                               qglDisable(GL_TEXTURE_2D);
+                       if (texnum)
+                       {
+                               if (unit->t2d == 0)
+                               {
+                                       qglEnable(GL_TEXTURE_2D);CHECKGLERROR
+                               }
+                       }
+                       else
+                       {
+                               if (unit->t2d)
+                               {
+                                       qglDisable(GL_TEXTURE_2D);CHECKGLERROR
+                               }
+                       }
                }
                unit->t2d = texnum;
-               qglBindTexture(GL_TEXTURE_2D, unit->t2d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_2D, unit->t2d);CHECKGLERROR
        }
        // update 3d texture binding
        if (unit->t3d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t3d)
-                       qglDisable(GL_TEXTURE_3D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t3d)
+                       {
+                               qglDisable(GL_TEXTURE_3D);CHECKGLERROR
+                       }
+               }
                unit->t3d = 0;
-               qglBindTexture(GL_TEXTURE_3D, unit->t3d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_3D, unit->t3d);CHECKGLERROR
        }
        // update cubemap texture binding
        if (unit->tcubemap != 0)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->tcubemap)
-                       qglDisable(GL_TEXTURE_CUBE_MAP_ARB);
+               if (unitnum < backendunits)
+               {
+                       if (unit->tcubemap)
+                       {
+                               qglDisable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
+                       }
+               }
                unit->tcubemap = 0;
-               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);CHECKGLERROR
        }
 }
 
-void R_Mesh_TexBind3D(unsigned int unitnum, unsigned int texnum)
+void R_Mesh_TexBind3D(unsigned int unitnum, int texnum)
 {
        gltextureunit_t *unit = gl_state.units + unitnum;
-       if (unitnum >= backendunits)
+       if (unitnum >= backendimageunits)
                return;
        // update 1d texture binding
        if (unit->t1d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t1d)
-                       qglDisable(GL_TEXTURE_1D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t1d)
+                       {
+                               qglDisable(GL_TEXTURE_1D);CHECKGLERROR
+                       }
+               }
                unit->t1d = 0;
-               qglBindTexture(GL_TEXTURE_1D, unit->t1d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_1D, unit->t1d);CHECKGLERROR
        }
        // update 2d texture binding
        if (unit->t2d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t2d)
-                       qglDisable(GL_TEXTURE_2D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t2d)
+                       {
+                               qglDisable(GL_TEXTURE_2D);CHECKGLERROR
+                       }
+               }
                unit->t2d = 0;
-               qglBindTexture(GL_TEXTURE_2D, unit->t2d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_2D, unit->t2d);CHECKGLERROR
        }
        // update 3d texture binding
        if (unit->t3d != texnum)
        {
                GL_ActiveTexture(unitnum);
-               if (texnum)
-               {
-                       if (unit->t3d == 0)
-                               qglEnable(GL_TEXTURE_3D);
-               }
-               else
+               if (unitnum < backendunits)
                {
-                       if (unit->t3d)
-                               qglDisable(GL_TEXTURE_3D);
+                       if (texnum)
+                       {
+                               if (unit->t3d == 0)
+                               {
+                                       qglEnable(GL_TEXTURE_3D);CHECKGLERROR
+                               }
+                       }
+                       else
+                       {
+                               if (unit->t3d)
+                               {
+                                       qglDisable(GL_TEXTURE_3D);CHECKGLERROR
+                               }
+                       }
                }
                unit->t3d = texnum;
-               qglBindTexture(GL_TEXTURE_3D, unit->t3d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_3D, unit->t3d);CHECKGLERROR
        }
        // update cubemap texture binding
        if (unit->tcubemap != 0)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->tcubemap)
-                       qglDisable(GL_TEXTURE_CUBE_MAP_ARB);
+               if (unitnum < backendunits)
+               {
+                       if (unit->tcubemap)
+                       {
+                               qglDisable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
+                       }
+               }
                unit->tcubemap = 0;
-               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);CHECKGLERROR
        }
 }
 
-void R_Mesh_TexBindCubeMap(unsigned int unitnum, unsigned int texnum)
+void R_Mesh_TexBindCubeMap(unsigned int unitnum, int texnum)
 {
        gltextureunit_t *unit = gl_state.units + unitnum;
-       if (unitnum >= backendunits)
+       if (unitnum >= backendimageunits)
                return;
        // update 1d texture binding
        if (unit->t1d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t1d)
-                       qglDisable(GL_TEXTURE_1D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t1d)
+                       {
+                               qglDisable(GL_TEXTURE_1D);CHECKGLERROR
+                       }
+               }
                unit->t1d = 0;
-               qglBindTexture(GL_TEXTURE_1D, unit->t1d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_1D, unit->t1d);CHECKGLERROR
        }
        // update 2d texture binding
        if (unit->t2d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t2d)
-                       qglDisable(GL_TEXTURE_2D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t2d)
+                       {
+                               qglDisable(GL_TEXTURE_2D);CHECKGLERROR
+                       }
+               }
                unit->t2d = 0;
-               qglBindTexture(GL_TEXTURE_2D, unit->t2d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_2D, unit->t2d);CHECKGLERROR
        }
        // update 3d texture binding
        if (unit->t3d)
        {
                GL_ActiveTexture(unitnum);
-               if (unit->t3d)
-                       qglDisable(GL_TEXTURE_3D);
+               if (unitnum < backendunits)
+               {
+                       if (unit->t3d)
+                       {
+                               qglDisable(GL_TEXTURE_3D);CHECKGLERROR
+                       }
+               }
                unit->t3d = 0;
-               qglBindTexture(GL_TEXTURE_3D, unit->t3d);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_3D, unit->t3d);CHECKGLERROR
        }
        // update cubemap texture binding
        if (unit->tcubemap != texnum)
        {
                GL_ActiveTexture(unitnum);
-               if (texnum)
-               {
-                       if (unit->tcubemap == 0)
-                               qglEnable(GL_TEXTURE_CUBE_MAP_ARB);
-               }
-               else
+               if (unitnum < backendunits)
                {
-                       if (unit->tcubemap)
-                               qglDisable(GL_TEXTURE_CUBE_MAP_ARB);
+                       if (texnum)
+                       {
+                               if (unit->tcubemap == 0)
+                               {
+                                       qglEnable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
+                               }
+                       }
+                       else
+                       {
+                               if (unit->tcubemap)
+                               {
+                                       qglDisable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
+                               }
+                       }
                }
                unit->tcubemap = texnum;
-               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);
-               CHECKGLERROR
+               qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);CHECKGLERROR
        }
 }
 
@@ -1481,14 +1812,15 @@ void R_Mesh_TexMatrix(unsigned int unitnum, const matrix4x4_t *matrix)
                // texmatrix specified, check if it is different
                if (!unit->texmatrixenabled || memcmp(&unit->matrix, matrix, sizeof(matrix4x4_t)))
                {
-                       matrix4x4_t tempmatrix;
+                       double glmatrix[16];
                        unit->texmatrixenabled = true;
                        unit->matrix = *matrix;
-                       Matrix4x4_Transpose(&tempmatrix, &unit->matrix);
-                       qglMatrixMode(GL_TEXTURE);
+                       CHECKGLERROR
+                       Matrix4x4_ToArrayDoubleGL(&unit->matrix, glmatrix);
+                       qglMatrixMode(GL_TEXTURE);CHECKGLERROR
                        GL_ActiveTexture(unitnum);
-                       qglLoadMatrixf(&tempmatrix.m[0][0]);
-                       qglMatrixMode(GL_MODELVIEW);
+                       qglLoadMatrixd(glmatrix);CHECKGLERROR
+                       qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
                }
        }
        else
@@ -1497,10 +1829,11 @@ void R_Mesh_TexMatrix(unsigned int unitnum, const matrix4x4_t *matrix)
                if (unit->texmatrixenabled)
                {
                        unit->texmatrixenabled = false;
-                       qglMatrixMode(GL_TEXTURE);
+                       CHECKGLERROR
+                       qglMatrixMode(GL_TEXTURE);CHECKGLERROR
                        GL_ActiveTexture(unitnum);
-                       qglLoadIdentity();
-                       qglMatrixMode(GL_MODELVIEW);
+                       qglLoadIdentity();CHECKGLERROR
+                       qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
                }
        }
 }
@@ -1508,6 +1841,7 @@ void R_Mesh_TexMatrix(unsigned int unitnum, const matrix4x4_t *matrix)
 void R_Mesh_TexCombine(unsigned int unitnum, int combinergb, int combinealpha, int rgbscale, int alphascale)
 {
        gltextureunit_t *unit = gl_state.units + unitnum;
+       CHECKGLERROR
        if (gl_combine.integer)
        {
                // GL_ARB_texture_env_combine
@@ -1556,23 +1890,18 @@ void R_Mesh_TexCombine(unsigned int unitnum, int combinergb, int combinealpha, i
        }
 }
 
-void R_Mesh_State(const rmeshstate_t *m)
+void R_Mesh_TextureState(const rmeshstate_t *m)
 {
-       int i;
+       unsigned int i;
 
        BACKENDACTIVECHECK
 
-       R_Mesh_VertexPointer(m->pointer_vertex);
-
-       if (r_showtrispass)
-               return;
-
-       R_Mesh_ColorPointer(m->pointer_color);
-
+       CHECKGLERROR
        if (gl_backend_rebindtextures)
        {
                gl_backend_rebindtextures = false;
                GL_SetupTextureState();
+               CHECKGLERROR
        }
 
        for (i = 0;i < backendimageunits;i++)
@@ -1580,603 +1909,153 @@ void R_Mesh_State(const rmeshstate_t *m)
        for (i = 0;i < backendarrayunits;i++)
        {
                if (m->pointer_texcoord3f[i])
-                       R_Mesh_TexCoordPointer(i, 3, m->pointer_texcoord3f[i]);
+                       R_Mesh_TexCoordPointer(i, 3, m->pointer_texcoord3f[i], m->pointer_texcoord_bufferobject[i], m->pointer_texcoord_bufferoffset[i]);
                else
-                       R_Mesh_TexCoordPointer(i, 2, m->pointer_texcoord[i]);
+                       R_Mesh_TexCoordPointer(i, 2, m->pointer_texcoord[i], m->pointer_texcoord_bufferobject[i], m->pointer_texcoord_bufferoffset[i]);
        }
        for (i = 0;i < backendunits;i++)
        {
                R_Mesh_TexMatrix(i, &m->texmatrix[i]);
                R_Mesh_TexCombine(i, m->texcombinergb[i], m->texcombinealpha[i], m->texrgbscale[i], m->texalphascale[i]);
        }
-}
-
-void R_Mesh_Draw_ShowTris(int numverts, int numtriangles, const int *elements)
-{
-       qglBegin(GL_LINES);
-       for (;numtriangles;numtriangles--, elements += 3)
-       {
-               qglArrayElement(elements[0]);qglArrayElement(elements[1]);
-               qglArrayElement(elements[1]);qglArrayElement(elements[2]);
-               qglArrayElement(elements[2]);qglArrayElement(elements[0]);
-       }
-       qglEnd();
        CHECKGLERROR
 }
 
-/*
-==============================================================================
-
-                                               SCREEN SHOTS
-
-==============================================================================
-*/
-
-qboolean SCR_ScreenShot(char *filename, qbyte *buffer1, qbyte *buffer2, qbyte *buffer3, int x, int y, int width, int height, qboolean flipx, qboolean flipy, qboolean flipdiagonal, qboolean jpeg)
+void R_Mesh_ResetTextureState(void)
 {
-       int     indices[3] = {0,1,2};
-       qboolean ret;
+       unsigned int unitnum;
 
-       if (!r_render.integer)
-               return false;
+       BACKENDACTIVECHECK
 
-       qglReadPixels (x, y, width, height, GL_RGB, GL_UNSIGNED_BYTE, buffer1);
        CHECKGLERROR
-
-       if (scr_screenshot_gamma.value != 1)
+       if (gl_backend_rebindtextures)
        {
-               int i;
-               double igamma = 1.0 / scr_screenshot_gamma.value;
-               unsigned char ramp[256];
-               for (i = 0;i < 256;i++)
-                       ramp[i] = (unsigned char) (pow(i * (1.0 / 255.0), igamma) * 255.0);
-               for (i = 0;i < width*height*3;i++)
-                       buffer1[i] = ramp[buffer1[i]];
+               gl_backend_rebindtextures = false;
+               GL_SetupTextureState();
+               CHECKGLERROR
        }
 
-       Image_CopyMux (buffer2, buffer1, width, height, flipx, flipy, flipdiagonal, 3, 3, indices);
-
-       if (jpeg)
-               ret = JPEG_SaveImage_preflipped (filename, width, height, buffer2);
-       else
-               ret = Image_WriteTGARGB_preflipped (filename, width, height, buffer2, buffer3);
-
-       return ret;
-}
-
-//=============================================================================
-
-void R_ClearScreen(void)
-{
-       if (r_render.integer)
+       for (unitnum = 0;unitnum < backendimageunits;unitnum++)
        {
-               // clear to black
-               qglClearColor(0,0,0,0);CHECKGLERROR
-               qglClearDepth(1);CHECKGLERROR
-               if (gl_stencil)
+               gltextureunit_t *unit = gl_state.units + unitnum;
+               // update 1d texture binding
+               if (unit->t1d)
                {
-                       // LordHavoc: we use a stencil centered around 128 instead of 0,
-                       // to avoid clamping interfering with strange shadow volume
-                       // drawing orders
-                       qglClearStencil(128);CHECKGLERROR
+                       GL_ActiveTexture(unitnum);
+                       if (unitnum < backendunits)
+                       {
+                               qglDisable(GL_TEXTURE_1D);CHECKGLERROR
+                       }
+                       unit->t1d = 0;
+                       qglBindTexture(GL_TEXTURE_1D, unit->t1d);CHECKGLERROR
                }
-               // clear the screen
-               GL_Clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | (gl_stencil ? GL_STENCIL_BUFFER_BIT : 0));
-               // set dithering mode
-               if (gl_dither.integer)
+               // update 2d texture binding
+               if (unit->t2d)
                {
-                       qglEnable(GL_DITHER);CHECKGLERROR
+                       GL_ActiveTexture(unitnum);
+                       if (unitnum < backendunits)
+                       {
+                               qglDisable(GL_TEXTURE_2D);CHECKGLERROR
+                       }
+                       unit->t2d = 0;
+                       qglBindTexture(GL_TEXTURE_2D, unit->t2d);CHECKGLERROR
                }
-               else
+               // update 3d texture binding
+               if (unit->t3d)
                {
-                       qglDisable(GL_DITHER);CHECKGLERROR
+                       GL_ActiveTexture(unitnum);
+                       if (unitnum < backendunits)
+                       {
+                               qglDisable(GL_TEXTURE_3D);CHECKGLERROR
+                       }
+                       unit->t3d = 0;
+                       qglBindTexture(GL_TEXTURE_3D, unit->t3d);CHECKGLERROR
+               }
+               // update cubemap texture binding
+               if (unit->tcubemap)
+               {
+                       GL_ActiveTexture(unitnum);
+                       if (unitnum < backendunits)
+                       {
+                               qglDisable(GL_TEXTURE_CUBE_MAP_ARB);CHECKGLERROR
+                       }
+                       unit->tcubemap = 0;
+                       qglBindTexture(GL_TEXTURE_CUBE_MAP_ARB, unit->tcubemap);CHECKGLERROR
                }
        }
-}
-
-/*
-====================
-CalcFov
-====================
-*/
-float CalcFov (float fov_x, float width, float height)
-{
-       // calculate vision size and alter by aspect, then convert back to angle
-       return atan (((height/width)/vid_pixelaspect.value)*tan(fov_x/360.0*M_PI))*360.0/M_PI;
-}
-
-int r_stereo_side;
-
-void SCR_DrawScreen (void)
-{
-       for (r_showtrispass = 0;r_showtrispass <= (r_showtris.value > 0);r_showtrispass++)
+       for (unitnum = 0;unitnum < backendarrayunits;unitnum++)
        {
-               R_Mesh_Start();
-
-               R_TimeReport("setup");
-
-               if (r_showtrispass)
+               gltextureunit_t *unit = gl_state.units + unitnum;
+               // texture array unit is disabled, disable the array
+               if (unit->arrayenabled)
+               {
+                       unit->arrayenabled = false;
+                       GL_ClientActiveTexture(unitnum);
+                       qglDisableClientState(GL_TEXTURE_COORD_ARRAY);CHECKGLERROR
+               }
+       }
+       for (unitnum = 0;unitnum < backendunits;unitnum++)
+       {
+               gltextureunit_t *unit = gl_state.units + unitnum;
+               // no texmatrix specified, revert to identity
+               if (unit->texmatrixenabled)
                {
-                       rmeshstate_t m;
-                       r_showtrispass = 0;
-                       GL_BlendFunc(GL_ONE, GL_ONE);
-                       GL_DepthTest(GL_FALSE);
-                       GL_DepthMask(GL_FALSE);
-                       memset(&m, 0, sizeof(m));
-                       R_Mesh_State(&m);
-                       GL_ShowTrisColor(0.2,0.2,0.2,1);
-                       r_showtrispass = 1;
+                       unit->texmatrixenabled = false;
+                       CHECKGLERROR
+                       qglMatrixMode(GL_TEXTURE);CHECKGLERROR
+                       GL_ActiveTexture(unitnum);
+                       qglLoadIdentity();CHECKGLERROR
+                       qglMatrixMode(GL_MODELVIEW);CHECKGLERROR
                }
-
-               if (cls.signon == SIGNONS)
+               if (gl_combine.integer)
                {
-                       float size;
-
-                       size = scr_viewsize.value * (1.0 / 100.0);
-                       size = min(size, 1);
-
-                       if (r_stereo_sidebyside.integer)
+                       // GL_ARB_texture_env_combine
+                       if (unit->combinergb != GL_MODULATE)
                        {
-                               r_refdef.width = vid.realwidth * size / 2.5;
-                               r_refdef.height = vid.realheight * size / 2.5 * (1 - bound(0, r_letterbox.value, 100) / 100);
-                               r_refdef.x = (vid.realwidth - r_refdef.width * 2.5) * 0.5;
-                               r_refdef.y = (vid.realheight - r_refdef.height)/2;
-                               if (r_stereo_side)
-                                       r_refdef.x += r_refdef.width * 1.5;
+                               unit->combinergb = GL_MODULATE;
+                               GL_ActiveTexture(unitnum);
+                               qglTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, unit->combinergb);CHECKGLERROR
                        }
-                       else
+                       if (unit->combinealpha != GL_MODULATE)
                        {
-                               r_refdef.width = vid.realwidth * size;
-                               r_refdef.height = vid.realheight * size * (1 - bound(0, r_letterbox.value, 100) / 100);
-                               r_refdef.x = (vid.realwidth - r_refdef.width)/2;
-                               r_refdef.y = (vid.realheight - r_refdef.height)/2;
+                               unit->combinealpha = GL_MODULATE;
+                               GL_ActiveTexture(unitnum);
+                               qglTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB, unit->combinealpha);CHECKGLERROR
                        }
-
-                       // LordHavoc: viewzoom (zoom in for sniper rifles, etc)
-                       r_refdef.fov_x = scr_fov.value * r_refdef.fovscale_x;
-                       r_refdef.fov_y = CalcFov (scr_fov.value, r_refdef.width, r_refdef.height) * r_refdef.fovscale_y;
-
-                       R_RenderView();
-
-                       if (scr_zoomwindow.integer)
+                       if (unit->rgbscale != 1)
                        {
-                               float sizex = bound(10, scr_zoomwindow_viewsizex.value, 100) / 100.0;
-                               float sizey = bound(10, scr_zoomwindow_viewsizey.value, 100) / 100.0;
-                               r_refdef.width = vid.realwidth * sizex;
-                               r_refdef.height = vid.realheight * sizey;
-                               r_refdef.x = (vid.realwidth - r_refdef.width)/2;
-                               r_refdef.y = 0;
-                               r_refdef.fov_x = scr_zoomwindow_fov.value * r_refdef.fovscale_x;
-                               r_refdef.fov_y = CalcFov(scr_zoomwindow_fov.value, r_refdef.width, r_refdef.height) * r_refdef.fovscale_y;
-
-                               R_RenderView();
+                               GL_ActiveTexture(unitnum);
+                               qglTexEnvi(GL_TEXTURE_ENV, GL_RGB_SCALE_ARB, (unit->rgbscale = 1));CHECKGLERROR
+                       }
+                       if (unit->alphascale != 1)
+                       {
+                               GL_ActiveTexture(unitnum);
+                               qglTexEnvi(GL_TEXTURE_ENV, GL_ALPHA_SCALE, (unit->alphascale = 1));CHECKGLERROR
                        }
                }
-
-               if (!r_stereo_sidebyside.integer)
+               else
                {
-                       r_refdef.width = vid.realwidth;
-                       r_refdef.height = vid.realheight;
-                       r_refdef.x = 0;
-                       r_refdef.y = 0;
+                       // normal GL texenv
+                       if (unit->combinergb != GL_MODULATE)
+                       {
+                               unit->combinergb = GL_MODULATE;
+                               GL_ActiveTexture(unitnum);
+                               qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, unit->combinergb);CHECKGLERROR
+                       }
                }
-
-               // draw 2D stuff
-               R_DrawQueue();
-
-               R_Mesh_Finish();
-
-               R_TimeReport("meshfinish");
        }
-       r_showtrispass = 0;
-}
-
-void SCR_UpdateLoadingScreen (void)
-{
-       float x, y;
-       cachepic_t *pic;
-       rmeshstate_t m;
-       // don't do anything if not initialized yet
-       if (vid_hidden)
-               return;
-       r_showtrispass = 0;
-       VID_GetWindowSize(&vid.realx, &vid.realy, &vid.realwidth, &vid.realheight);
-       VID_UpdateGamma(false);
-       qglViewport(0, 0, vid.realwidth, vid.realheight);
-       //qglDisable(GL_SCISSOR_TEST);
-       //qglDepthMask(1);
-       qglColorMask(1,1,1,1);
-       //qglClearColor(0,0,0,0);
-       //qglClear(GL_COLOR_BUFFER_BIT);
-       //qglCullFace(GL_FRONT);
-       //qglDisable(GL_CULL_FACE);
-       //R_ClearScreen();
-       R_Textures_Frame();
-       GL_SetupView_Mode_Ortho(0, 0, vid_conwidth.integer, vid_conheight.integer, -10, 100);
-       R_Mesh_Start();
-       R_Mesh_Matrix(&r_identitymatrix);
-       // draw the loading plaque
-       pic = Draw_CachePic("gfx/loading.lmp");
-       x = (vid_conwidth.integer - pic->width)/2;
-       y = (vid_conheight.integer - pic->height)/2;
-       GL_Color(1,1,1,1);
-       GL_BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-       GL_DepthTest(false);
-       memset(&m, 0, sizeof(m));
-       m.pointer_vertex = varray_vertex3f;
-       m.pointer_texcoord[0] = varray_texcoord2f[0];
-       m.tex[0] = R_GetTexture(pic->tex);
-       R_Mesh_State(&m);
-       varray_vertex3f[0] = varray_vertex3f[9] = x;
-       varray_vertex3f[1] = varray_vertex3f[4] = y;
-       varray_vertex3f[3] = varray_vertex3f[6] = x + pic->width;
-       varray_vertex3f[7] = varray_vertex3f[10] = y + pic->height;
-       varray_texcoord2f[0][0] = 0;varray_texcoord2f[0][1] = 0;
-       varray_texcoord2f[0][2] = 1;varray_texcoord2f[0][3] = 0;
-       varray_texcoord2f[0][4] = 1;varray_texcoord2f[0][5] = 1;
-       varray_texcoord2f[0][6] = 0;varray_texcoord2f[0][7] = 1;
-       GL_LockArrays(0, 4);
-       R_Mesh_Draw(4, 2, polygonelements);
-       GL_LockArrays(0, 0);
-       R_Mesh_Finish();
-       // refresh
-       VID_Finish();
 }
 
-/*
-==================
-SCR_UpdateScreen
-
-This is called every frame, and can also be called explicitly to flush
-text to the screen.
-==================
-*/
-void SCR_UpdateScreen (void)
+void R_Mesh_Draw_ShowTris(int firstvertex, int numvertices, int numtriangles, const int *elements)
 {
-       if (vid_hidden)
-               return;
-
-       if (r_textureunits.integer > gl_textureunits)
-               Cvar_SetValueQuick(&r_textureunits, gl_textureunits);
-       if (r_textureunits.integer < 1)
-               Cvar_SetValueQuick(&r_textureunits, 1);
-
-       if (gl_combine.integer && (!gl_combine_extension || r_textureunits.integer < 2))
-               Cvar_SetValueQuick(&gl_combine, 0);
-
-       CHECKGLERROR
-       qglViewport(0, 0, vid.realwidth, vid.realheight);
-       qglDisable(GL_SCISSOR_TEST);
-       qglDepthMask(1);
-       qglColorMask(1,1,1,1);
-       qglClearColor(0,0,0,0);
-       qglClear(GL_COLOR_BUFFER_BIT);
        CHECKGLERROR
-
-       R_TimeReport("clear");
-
-       if (r_stereo_redblue.integer || r_stereo_redgreen.integer || r_stereo_redcyan.integer || r_stereo_sidebyside.integer)
-       {
-               matrix4x4_t originalmatrix = r_refdef.viewentitymatrix;
-               r_refdef.viewentitymatrix.m[0][3] = originalmatrix.m[0][3] + r_stereo_separation.value * -0.5f * r_refdef.viewentitymatrix.m[0][1];
-               r_refdef.viewentitymatrix.m[1][3] = originalmatrix.m[1][3] + r_stereo_separation.value * -0.5f * r_refdef.viewentitymatrix.m[1][1];
-               r_refdef.viewentitymatrix.m[2][3] = originalmatrix.m[2][3] + r_stereo_separation.value * -0.5f * r_refdef.viewentitymatrix.m[2][1];
-
-               if (r_stereo_sidebyside.integer)
-                       r_stereo_side = 0;
-
-               if (r_stereo_redblue.integer || r_stereo_redgreen.integer || r_stereo_redcyan.integer)
-               {
-                       r_refdef.colormask[0] = 1;
-                       r_refdef.colormask[1] = 0;
-                       r_refdef.colormask[2] = 0;
-               }
-
-               SCR_DrawScreen();
-
-               r_refdef.viewentitymatrix.m[0][3] = originalmatrix.m[0][3] + r_stereo_separation.value * 0.5f * r_refdef.viewentitymatrix.m[0][1];
-               r_refdef.viewentitymatrix.m[1][3] = originalmatrix.m[1][3] + r_stereo_separation.value * 0.5f * r_refdef.viewentitymatrix.m[1][1];
-               r_refdef.viewentitymatrix.m[2][3] = originalmatrix.m[2][3] + r_stereo_separation.value * 0.5f * r_refdef.viewentitymatrix.m[2][1];
-
-               if (r_stereo_sidebyside.integer)
-                       r_stereo_side = 1;
-
-               if (r_stereo_redblue.integer || r_stereo_redgreen.integer || r_stereo_redcyan.integer)
-               {
-                       r_refdef.colormask[0] = 0;
-                       r_refdef.colormask[1] = r_stereo_redcyan.integer || r_stereo_redgreen.integer;
-                       r_refdef.colormask[2] = r_stereo_redcyan.integer || r_stereo_redblue.integer;
-               }
-
-               SCR_DrawScreen();
-
-               r_refdef.viewentitymatrix = originalmatrix;
-       }
-       else
-       {
-               r_showtrispass = false;
-               SCR_DrawScreen();
-
-               if (r_showtris.value > 0)
-               {
-                       rmeshstate_t m;
-                       GL_BlendFunc(GL_ONE, GL_ONE);
-                       GL_DepthTest(GL_FALSE);
-                       GL_DepthMask(GL_FALSE);
-                       memset(&m, 0, sizeof(m));
-                       R_Mesh_State(&m);
-                       r_showtrispass = true;
-                       GL_ShowTrisColor(0.2,0.2,0.2,1);
-                       SCR_DrawScreen();
-                       r_showtrispass = false;
-               }
-       }
-
-       VID_Finish();
-       R_TimeReport("finish");
-}
-
-
-//===========================================================================
-// dynamic vertex array buffer subsystem
-//===========================================================================
-
-// FIXME: someday this should be dynamically allocated and resized?
-float varray_vertex3f[65536*3];
-float varray_svector3f[65536*3];
-float varray_tvector3f[65536*3];
-float varray_normal3f[65536*3];
-float varray_color4f[65536*4];
-float varray_texcoord2f[4][65536*2];
-float varray_texcoord3f[4][65536*3];
-int earray_element3i[65536];
-float varray_vertex3f2[65536*3];
-
-//===========================================================================
-// vertex array caching subsystem
-//===========================================================================
-
-typedef struct rcachearraylink_s
-{
-       struct rcachearraylink_s *next, *prev;
-       struct rcachearrayitem_s *data;
-}
-rcachearraylink_t;
-
-typedef struct rcachearrayitem_s
-{
-       // the original request structure
-       rcachearrayrequest_t request;
-       // active
-       int active;
-       // offset into r_mesh_rcachedata
-       int offset;
-       // for linking this into the sequential list
-       rcachearraylink_t sequentiallink;
-       // for linking this into the lookup list
-       rcachearraylink_t hashlink;
-}
-rcachearrayitem_t;
-
-#define RCACHEARRAY_HASHSIZE 65536
-#define RCACHEARRAY_ITEMS 4096
-#define RCACHEARRAY_DEFAULTSIZE (4 << 20)
-
-// all active items are linked into this chain in sorted order
-static rcachearraylink_t r_mesh_rcachesequentialchain;
-// all inactive items are linked into this chain in unknown order
-static rcachearraylink_t r_mesh_rcachefreechain;
-// all active items are also linked into these chains (using their hashlink)
-static rcachearraylink_t r_mesh_rcachechain[RCACHEARRAY_HASHSIZE];
-
-// all items are stored here, whether active or inactive
-static rcachearrayitem_t r_mesh_rcacheitems[RCACHEARRAY_ITEMS];
-
-// size of data buffer
-static int r_mesh_rcachedata_size = RCACHEARRAY_DEFAULTSIZE;
-// data buffer
-static qbyte r_mesh_rcachedata[RCACHEARRAY_DEFAULTSIZE];
-
-// current state
-static int r_mesh_rcachedata_offset;
-static rcachearraylink_t *r_mesh_rcachesequentialchain_current;
-
-static void R_Mesh_CacheArray_Startup(void)
-{
-       int i;
-       rcachearraylink_t *l;
-       // prepare all the linked lists
-       l = &r_mesh_rcachesequentialchain;l->next = l->prev = l;l->data = NULL;
-       l = &r_mesh_rcachefreechain;l->next = l->prev = l;l->data = NULL;
-       memset(&r_mesh_rcachechain, 0, sizeof(r_mesh_rcachechain));
-       for (i = 0;i < RCACHEARRAY_HASHSIZE;i++)
-       {
-               l = &r_mesh_rcachechain[i];
-               l->next = l->prev = l;
-               l->data = NULL;
-       }
-       memset(&r_mesh_rcacheitems, 0, sizeof(r_mesh_rcacheitems));
-       for (i = 0;i < RCACHEARRAY_ITEMS;i++)
+       qglBegin(GL_LINES);
+       for (;numtriangles;numtriangles--, elements += 3)
        {
-               r_mesh_rcacheitems[i].hashlink.data = r_mesh_rcacheitems[i].sequentiallink.data = &r_mesh_rcacheitems[i];
-               l = &r_mesh_rcacheitems[i].sequentiallink;
-               l->next = &r_mesh_rcachefreechain;
-               l->prev = l->next->prev;
-               l->next->prev = l->prev->next = l;
+               qglArrayElement(elements[0]);qglArrayElement(elements[1]);
+               qglArrayElement(elements[1]);qglArrayElement(elements[2]);
+               qglArrayElement(elements[2]);qglArrayElement(elements[0]);
        }
-       // clear other state
-       r_mesh_rcachedata_offset = 0;
-       r_mesh_rcachesequentialchain_current = &r_mesh_rcachesequentialchain;
-}
-
-static void R_Mesh_CacheArray_Shutdown(void)
-{
-}
-
-/*
-static void R_Mesh_CacheArray_ValidateState(int num)
-{
-       rcachearraylink_t *l, *lhead;
-       lhead = &r_mesh_rcachesequentialchain;
-       if (r_mesh_rcachesequentialchain_current == lhead)
-               return;
-       for (l = lhead->next;l != lhead;l = l->next)
-               if (r_mesh_rcachesequentialchain_current == l)
-                       return;
-       Sys_Error("%i", num);
-}
-*/
-
-int R_Mesh_CacheArray(rcachearrayrequest_t *r)
-{
-       rcachearraylink_t *l, *lhead, *lnext;
-       rcachearrayitem_t *d;
-       int hashindex, offset, offsetend;
-
-       //R_Mesh_CacheArray_ValidateState(3);
-       // calculate a hashindex to choose a cache chain
-       r->data = NULL;
-       hashindex = CRC_Block((void *)r, sizeof(*r)) % RCACHEARRAY_HASHSIZE;
-
-       // is it already cached?
-       for (lhead = &r_mesh_rcachechain[hashindex], l = lhead->next;l != lhead;l = l->next)
-       {
-               if (!memcmp(&l->data->request, r, sizeof(l->data->request)))
-               {
-                       // we have it cached already
-                       r->data = r_mesh_rcachedata + l->data->offset;
-                       return false;
-               }
-       }
-
-       // we need to add a new cache item, this means finding a place for the new
-       // data and making sure we have a free item available, lots of work...
-
-       // check if buffer needs to wrap
-       if (r_mesh_rcachedata_offset + r->data_size > r_mesh_rcachedata_size)
-       {
-               /*
-               if (r->data_size * 10 > r_mesh_rcachedata_size)
-               {
-                       // realloc whole cache
-               }
-               */
-               // reset back to start
-               r_mesh_rcachedata_offset = 0;
-               r_mesh_rcachesequentialchain_current = &r_mesh_rcachesequentialchain;
-       }
-       offset = r_mesh_rcachedata_offset;
-       r_mesh_rcachedata_offset += r->data_size;
-       offsetend = r_mesh_rcachedata_offset;
-       //R_Mesh_CacheArray_ValidateState(4);
-
-       /*
-       {
-               int n;
-               for (lhead = &r_mesh_rcachesequentialchain, l = lhead->next, n = 0;l != lhead;l = l->next, n++);
-               Con_Printf("R_Mesh_CacheArray: new data range %i:%i, %i items are already linked\n", offset, offsetend, n);
-       }
-       */
-
-       // make room for the new data (remove old items)
-       lhead = &r_mesh_rcachesequentialchain;
-       l = r_mesh_rcachesequentialchain_current;
-       if (l == lhead)
-               l = l->next;
-       while (l != lhead && l->data->offset < offsetend && l->data->offset + l->data->request.data_size > offset)
-       {
-       //r_mesh_rcachesequentialchain_current = l;
-       //R_Mesh_CacheArray_ValidateState(8);
-               lnext = l->next;
-               // if at the end of the chain, wrap around
-               if (lnext == lhead)
-                       lnext = lnext->next;
-       //r_mesh_rcachesequentialchain_current = lnext;
-       //R_Mesh_CacheArray_ValidateState(10);
-
-               // unlink from sequential chain
-               l->next->prev = l->prev;
-               l->prev->next = l->next;
-       //R_Mesh_CacheArray_ValidateState(11);
-               // link into free chain
-               l->next = &r_mesh_rcachefreechain;
-               l->prev = l->next->prev;
-               l->next->prev = l->prev->next = l;
-       //R_Mesh_CacheArray_ValidateState(12);
-
-               l = &l->data->hashlink;
-               // unlink from hash chain
-               l->next->prev = l->prev;
-               l->prev->next = l->next;
-
-               l = lnext;
-       //r_mesh_rcachesequentialchain_current = l;
-       //R_Mesh_CacheArray_ValidateState(9);
-       }
-       //r_mesh_rcachesequentialchain_current = l;
-       //R_Mesh_CacheArray_ValidateState(5);
-       // gobble an extra item if we have no free items available
-       if (r_mesh_rcachefreechain.next == &r_mesh_rcachefreechain)
-       {
-               lnext = l->next;
-
-               // unlink from sequential chain
-               l->next->prev = l->prev;
-               l->prev->next = l->next;
-               // link into free chain
-               l->next = &r_mesh_rcachefreechain;
-               l->prev = l->next->prev;
-               l->next->prev = l->prev->next = l;
-
-               l = &l->data->hashlink;
-               // unlink from hash chain
-               l->next->prev = l->prev;
-               l->prev->next = l->next;
-
-               l = lnext;
-       }
-       r_mesh_rcachesequentialchain_current = l;
-       //R_Mesh_CacheArray_ValidateState(6);
-
-       // now take an item from the free chain
-       l = r_mesh_rcachefreechain.next;
-       // set it up
-       d = l->data;
-       d->request = *r;
-       d->offset = offset;
-       // unlink
-       l->next->prev = l->prev;
-       l->prev->next = l->next;
-       // relink to sequential
-       l->next = r_mesh_rcachesequentialchain_current->prev;
-       l->prev = l->next->prev;
-       while (l->next->data && l->data && l->next->data->offset <= d->offset)
-       {
-               //Con_Print(">\n");
-               l->next = l->next->next;
-               l->prev = l->prev->next;
-       }
-       while (l->prev->data && l->data && l->prev->data->offset >= d->offset)
-       {
-               //Con_Print("<\n");
-               l->prev = l->prev->prev;
-               l->next = l->next->prev;
-       }
-       l->next->prev = l->prev->next = l;
-       // also link into hash chain
-       l = &l->data->hashlink;
-       l->next = &r_mesh_rcachechain[hashindex];
-       l->prev = l->next->prev;
-       l->prev->next = l;
-       l->next->prev = l->prev->next = l;
-
-
-       //r_mesh_rcachesequentialchain_current = d->sequentiallink.next;
-
-       //R_Mesh_CacheArray_ValidateState(7);
-       // and finally set the data pointer
-       r->data = r_mesh_rcachedata + d->offset;
-       // and tell the caller to fill the array
-       return true;
+       qglEnd();
+       CHECKGLERROR
 }
-