]> de.git.xonotic.org Git - xonotic/darkplaces.git/blobdiff - collision.c
implemented a new preallocated "boxbrush" type for use with
[xonotic/darkplaces.git] / collision.c
index e6cdf0d5479b7f9f5214629cffcff54f81e6497c..e2bd242835267e01657a9e7f35895cc870b97ab8 100644 (file)
@@ -2,7 +2,8 @@
 #include "quakedef.h"
 #include "polygon.h"
 
-#define COLLISION_EDGEDIR_DIST_EPSILON (1.0f / 1048576.0f)
+#define COLLISION_EDGEDIR_DOT_EPSILON (0.999f)
+#define COLLISION_EDGECROSS_MINLENGTH2 (1.0f / 4194304.0f)
 #define COLLISION_SNAPSCALE (32.0f)
 #define COLLISION_SNAP (1.0f / COLLISION_SNAPSCALE)
 #define COLLISION_SNAP2 (2.0f / COLLISION_SNAPSCALE)
@@ -148,11 +149,12 @@ void Collision_CalcEdgeDirsForPolygonBrushFloat(colbrushf_t *brush)
                VectorSubtract(brush->points[i].v, brush->points[j].v, brush->edgedirs[j].v);
 }
 
-colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const colplanef_t *originalplanes, int supercontents, int q3surfaceflags, texture_t *texture)
+colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const colplanef_t *originalplanes, int supercontents, int q3surfaceflags, texture_t *texture, int hasaabbplanes)
 {
        // TODO: planesbuf could be replaced by a remapping table
        int j, k, l, m, w, xyzflags;
        int numpointsbuf = 0, maxpointsbuf = 256, numedgedirsbuf = 0, maxedgedirsbuf = 256, numplanesbuf = 0, maxplanesbuf = 256, numelementsbuf = 0, maxelementsbuf = 256;
+       int isaabb = true;
        double maxdist;
        colbrushf_t *brush;
        colpointf_t pointsbuf[256];
@@ -172,6 +174,14 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
        memset(polypointbuf, 0, sizeof(polypointbuf));
        memset(p, 0, sizeof(p));
 #endif
+
+       // check if there are too many planes and skip the brush
+       if (numoriginalplanes >= maxplanesbuf)
+       {
+               Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many planes for buffer\n");
+               return NULL;
+       }
+
        // figure out how large a bounding box we need to properly compute this brush
        maxdist = 0;
        for (j = 0;j < numoriginalplanes;j++)
@@ -183,20 +193,6 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
        // whose polygon is clipped away by the other planes)
        for (j = 0;j < numoriginalplanes;j++)
        {
-               // add the plane uniquely (no duplicates)
-               for (k = 0;k < numplanesbuf;k++)
-                       if (VectorCompare(planesbuf[k].normal, originalplanes[j].normal) && planesbuf[k].dist == originalplanes[j].dist)
-                               break;
-               // if the plane is a duplicate, skip it
-               if (k < numplanesbuf)
-                       continue;
-               // check if there are too many and skip the brush
-               if (numplanesbuf >= maxplanesbuf)
-               {
-                       Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many planes for buffer\n");
-                       return NULL;
-               }
-
                // add the new plane
                VectorCopy(originalplanes[j].normal, planesbuf[numplanesbuf].normal);
                planesbuf[numplanesbuf].dist = originalplanes[j].dist;
@@ -308,9 +304,18 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
 
                        // check if there is already a matching edgedir (no duplicates)
                        for (m = 0;m < numedgedirsbuf;m++)
-                               if (VectorDistance2(dir, edgedirsbuf[m].v) < COLLISION_EDGEDIR_DIST_EPSILON)
+                               if (DotProduct(dir, edgedirsbuf[m].v) >= COLLISION_EDGEDIR_DOT_EPSILON)
                                        break;
+                       // skip this if there is
+                       if (m < numedgedirsbuf)
+                               continue;
 
+                       // try again with negated edgedir
+                       VectorNegate(dir, dir);
+                       // check if there is already a matching edgedir (no duplicates)
+                       for (m = 0;m < numedgedirsbuf;m++)
+                               if (DotProduct(dir, edgedirsbuf[m].v) >= COLLISION_EDGEDIR_DOT_EPSILON)
+                                       break;
                        // if there is no match, add a new one
                        if (m == numedgedirsbuf)
                        {
@@ -325,6 +330,10 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
                                numedgedirsbuf++;
                        }
                }
+
+               // if any normal is not purely axial, it's not an axis-aligned box
+               if (isaabb && (originalplanes[j].normal[0] == 0) + (originalplanes[j].normal[1] == 0) + (originalplanes[j].normal[2] == 0) < 2)
+                       isaabb = false;
        }
 
        // if nothing is left, there's nothing to allocate
@@ -348,6 +357,8 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
 
        // allocate the brush and copy to it
        brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpointsbuf + sizeof(colpointf_t) * numedgedirsbuf + sizeof(colplanef_t) * numplanesbuf + sizeof(int) * numelementsbuf);
+       brush->isaabb = isaabb;
+       brush->hasaabbplanes = hasaabbplanes;
        brush->supercontents = supercontents;
        brush->numplanes = numplanesbuf;
        brush->numedgedirs = numedgedirsbuf;
@@ -600,6 +611,8 @@ colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, i
 {
        colbrushf_t *brush;
        brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2) + sizeof(colpointf_t) * numpoints);
+       brush->isaabb = false;
+       brush->hasaabbplanes = false;
        brush->supercontents = supercontents;
        brush->numpoints = numpoints;
        brush->numedgedirs = numpoints;
@@ -621,20 +634,24 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *trace_sta
        //int othernumedgedirs = other_start->numedgedirs;
        int tracenumpoints = trace_start->numpoints;
        int othernumpoints = other_start->numpoints;
-       int numplanes1 = trace_start->numplanes;
-       int numplanes2 = numplanes1 + other_start->numplanes;
+       int numplanes1 = other_start->numplanes;
+       int numplanes2 = numplanes1 + trace_start->numplanes;
        int numplanes3 = numplanes2 + trace_start->numedgedirs * other_start->numedgedirs * 2;
        vec_t enterfrac = -1, leavefrac = 1, startdist, enddist, ie, f, imove, enterfrac2 = -1;
        vec4_t startplane;
        vec4_t endplane;
        vec4_t newimpactplane;
        texture_t *hittexture = NULL;
-       vec_t startdepth = trace->startdepth;
+       vec_t startdepth = 1;
        vec3_t startdepthnormal;
 
-       VectorCopy(trace->startdepthnormal, startdepthnormal);
+       VectorClear(startdepthnormal);
        Vector4Clear(newimpactplane);
 
+       // fast case for AABB vs compiled brushes (which begin with AABB planes and also have precomputed bevels for AABB collisions)
+       if (trace_start->isaabb && other_start->hasaabbplanes)
+               numplanes3 = numplanes2 = numplanes1;
+
        // Separating Axis Theorem:
        // if a supporting vector (plane normal) can be found that separates two
        // objects, they are not colliding.
@@ -650,14 +667,14 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *trace_sta
                if (nplane < numplanes1)
                {
                        nplane2 = nplane;
-                       VectorCopy(trace_start->planes[nplane2].normal, startplane);
-                       VectorCopy(trace_end->planes[nplane2].normal, endplane);
+                       VectorCopy(other_start->planes[nplane2].normal, startplane);
+                       VectorCopy(other_end->planes[nplane2].normal, endplane);
                }
                else if (nplane < numplanes2)
                {
                        nplane2 = nplane - numplanes1;
-                       VectorCopy(other_start->planes[nplane2].normal, startplane);
-                       VectorCopy(other_end->planes[nplane2].normal, endplane);
+                       VectorCopy(trace_start->planes[nplane2].normal, startplane);
+                       VectorCopy(trace_end->planes[nplane2].normal, endplane);
                }
                else
                {
@@ -669,12 +686,20 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *trace_sta
                        if (nplane2 & 1)
                        {
                                CrossProduct(trace_start->edgedirs[nedge1].v, other_start->edgedirs[nedge2].v, startplane);
+                               if (VectorLength2(startplane) < COLLISION_EDGECROSS_MINLENGTH2)
+                                       continue; // degenerate crossproduct
                                CrossProduct(trace_end->edgedirs[nedge1].v, other_end->edgedirs[nedge2].v, endplane);
+                               if (VectorLength2(endplane) < COLLISION_EDGECROSS_MINLENGTH2)
+                                       continue; // degenerate crossproduct
                        }
                        else
                        {
                                CrossProduct(other_start->edgedirs[nedge2].v, trace_start->edgedirs[nedge1].v, startplane);
+                               if (VectorLength2(startplane) < COLLISION_EDGECROSS_MINLENGTH2)
+                                       continue; // degenerate crossproduct
                                CrossProduct(other_end->edgedirs[nedge2].v, trace_end->edgedirs[nedge1].v, endplane);
+                               if (VectorLength2(endplane) < COLLISION_EDGECROSS_MINLENGTH2)
+                                       continue; // degenerate crossproduct
                        }
                        VectorNormalize(startplane);
                        VectorNormalize(endplane);
@@ -686,10 +711,10 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *trace_sta
                //Con_Printf("%c%i: startdist = %f, enddist = %f, startdist / (startdist - enddist) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, startdist, enddist, startdist / (startdist - enddist));
 
                // aside from collisions, this is also used for error correction
-               if (startdist < 0 && trace->startdepth < startdist)
+               if (startdist < 0 && (startdepth < startdist || startdepth == 1))
                {
-                       trace->startdepth = startdist;
-                       VectorCopy(startplane, trace->startdepthnormal);
+                       startdepth = startdist;
+                       VectorCopy(startplane, startdepthnormal);
                }
 
                if (startdist > enddist)
@@ -727,17 +752,17 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *trace_sta
                                        newimpactplane[3] = startplane[3] * ie + endplane[3] * enterfrac;
                                        if (nplane < numplanes1)
                                        {
-                                               // use the plane from trace
+                                               // use the plane from other
                                                nplane2 = nplane;
-                                               hitq3surfaceflags = trace_start->planes[nplane2].q3surfaceflags;
-                                               hittexture = trace_start->planes[nplane2].texture;
+                                               hitq3surfaceflags = other_start->planes[nplane2].q3surfaceflags;
+                                               hittexture = other_start->planes[nplane2].texture;
                                        }
                                        else if (nplane < numplanes2)
                                        {
-                                               // use the plane from other
+                                               // use the plane from trace
                                                nplane2 = nplane - numplanes1;
-                                               hitq3surfaceflags = other_start->planes[nplane2].q3surfaceflags;
-                                               hittexture = other_start->planes[nplane2].texture;
+                                               hitq3surfaceflags = trace_start->planes[nplane2].q3surfaceflags;
+                                               hittexture = trace_start->planes[nplane2].texture;
                                        }
                                        else
                                        {
@@ -803,7 +828,7 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *trace_sta
                                trace->allsolid = true;
                        VectorCopy(newimpactplane, trace->plane.normal);
                        trace->plane.dist = newimpactplane[3];
-                       if (trace->startdepth < startdepth)
+                       if (trace->startdepth > startdepth)
                        {
                                trace->startdepth = startdepth;
                                VectorCopy(startdepthnormal, trace->startdepthnormal);
@@ -822,10 +847,10 @@ void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const
        vec4_t endplane;
        vec4_t newimpactplane;
        texture_t *hittexture = NULL;
-       vec_t startdepth = trace->startdepth;
+       vec_t startdepth = 1;
        vec3_t startdepthnormal;
 
-       VectorCopy(trace->startdepthnormal, startdepthnormal);
+       VectorClear(startdepthnormal);
        Vector4Clear(newimpactplane);
 
        // Separating Axis Theorem:
@@ -849,10 +874,10 @@ void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const
                //Con_Printf("%c%i: startdist = %f, enddist = %f, startdist / (startdist - enddist) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, startdist, enddist, startdist / (startdist - enddist));
 
                // aside from collisions, this is also used for error correction
-               if (startdist < 0 && trace->startdepth < startdist)
+               if (startdist < 0 && (startdepth < startdist || startdepth == 1))
                {
-                       trace->startdepth = startdist;
-                       VectorCopy(startplane, trace->startdepthnormal);
+                       startdepth = startdist;
+                       VectorCopy(startplane, startdepthnormal);
                }
 
                if (startdist > enddist)
@@ -949,7 +974,7 @@ void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const
                                trace->allsolid = true;
                        VectorCopy(newimpactplane, trace->plane.normal);
                        trace->plane.dist = newimpactplane[3];
-                       if (trace->startdepth < startdepth)
+                       if (trace->startdepth > startdepth)
                        {
                                trace->startdepth = startdepth;
                                VectorCopy(startdepthnormal, trace->startdepthnormal);
@@ -984,11 +1009,6 @@ void Collision_TracePointBrushFloat(trace_t *trace, const vec3_t point, const co
        }
 }
 
-static colpointf_t polyf_points[256];
-static colpointf_t polyf_edgedirs[256];
-static colplanef_t polyf_planes[256 + 2];
-static colbrushf_t polyf_brush;
-
 void Collision_SnapCopyPoints(int numpoints, const colpointf_t *in, colpointf_t *out, float fractionprecision, float invfractionprecision)
 {
        int i;
@@ -1000,46 +1020,29 @@ void Collision_SnapCopyPoints(int numpoints, const colpointf_t *in, colpointf_t
        }
 }
 
-void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, int supercontents, int q3surfaceflags, texture_t *texture)
-{
-       if (numpoints > 256)
-       {
-               Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
-               return;
-       }
-       polyf_brush.numpoints = numpoints;
-       polyf_brush.numedgedirs = numpoints;
-       polyf_brush.numplanes = numpoints + 2;
-       //polyf_brush.points = (colpointf_t *)points;
-       polyf_brush.planes = polyf_planes;
-       polyf_brush.edgedirs = polyf_edgedirs;
-       polyf_brush.supercontents = supercontents;
-       polyf_brush.points = polyf_points;
-       polyf_brush.q3surfaceflags = q3surfaceflags;
-       polyf_brush.texture = texture;
-       Collision_SnapCopyPoints(polyf_brush.numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
-       Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
-       Collision_CalcEdgeDirsForPolygonBrushFloat(&polyf_brush);
-       //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
-       Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
-}
-
 void Collision_TraceBrushTriangleMeshFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numtriangles, const int *element3i, const float *vertex3f, int stride, float *bbox6f, int supercontents, int q3surfaceflags, texture_t *texture, const vec3_t segmentmins, const vec3_t segmentmaxs)
 {
        int i;
-       polyf_brush.numpoints = 3;
-       polyf_brush.numedgedirs = 3;
-       polyf_brush.numplanes = 5;
-       polyf_brush.points = polyf_points;
-       polyf_brush.edgedirs = polyf_edgedirs;
-       polyf_brush.planes = polyf_planes;
-       polyf_brush.supercontents = supercontents;
-       polyf_brush.q3surfaceflags = q3surfaceflags;
-       polyf_brush.texture = texture;
-       for (i = 0;i < polyf_brush.numplanes;i++)
+       colpointf_t points[3];
+       colpointf_t edgedirs[3];
+       colplanef_t planes[5];
+       colbrushf_t brush;
+       memset(&brush, 0, sizeof(brush));
+       brush.isaabb = false;
+       brush.hasaabbplanes = false;
+       brush.numpoints = 3;
+       brush.numedgedirs = 3;
+       brush.numplanes = 5;
+       brush.points = points;
+       brush.edgedirs = edgedirs;
+       brush.planes = planes;
+       brush.supercontents = supercontents;
+       brush.q3surfaceflags = q3surfaceflags;
+       brush.texture = texture;
+       for (i = 0;i < brush.numplanes;i++)
        {
-               polyf_brush.planes[i].q3surfaceflags = q3surfaceflags;
-               polyf_brush.planes[i].texture = texture;
+               brush.planes[i].q3surfaceflags = q3surfaceflags;
+               brush.planes[i].texture = texture;
        }
        if(stride)
        {
@@ -1054,14 +1057,14 @@ void Collision_TraceBrushTriangleMeshFloat(trace_t *trace, const colbrushf_t *th
                                        tri = i * stride + k;
                                        if(tri >= numtriangles)
                                                break;
-                                       VectorCopy(vertex3f + element3i[tri * 3 + 0] * 3, polyf_points[0].v);
-                                       VectorCopy(vertex3f + element3i[tri * 3 + 1] * 3, polyf_points[1].v);
-                                       VectorCopy(vertex3f + element3i[tri * 3 + 2] * 3, polyf_points[2].v);
-                                       Collision_SnapCopyPoints(polyf_brush.numpoints, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
-                                       Collision_CalcEdgeDirsForPolygonBrushFloat(&polyf_brush);
-                                       Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
-                                       //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
-                                       Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
+                                       VectorCopy(vertex3f + element3i[tri * 3 + 0] * 3, points[0].v);
+                                       VectorCopy(vertex3f + element3i[tri * 3 + 1] * 3, points[1].v);
+                                       VectorCopy(vertex3f + element3i[tri * 3 + 2] * 3, points[2].v);
+                                       Collision_SnapCopyPoints(brush.numpoints, points, points, COLLISION_SNAPSCALE, COLLISION_SNAP);
+                                       Collision_CalcEdgeDirsForPolygonBrushFloat(&brush);
+                                       Collision_CalcPlanesForPolygonBrushFloat(&brush);
+                                       //Collision_PrintBrushAsQHull(&brush, "brush");
+                                       Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &brush, &brush);
                                }
                        }
                }
@@ -1072,43 +1075,19 @@ void Collision_TraceBrushTriangleMeshFloat(trace_t *trace, const colbrushf_t *th
                {
                        if (TriangleOverlapsBox(vertex3f + element3i[0]*3, vertex3f + element3i[1]*3, vertex3f + element3i[2]*3, segmentmins, segmentmaxs))
                        {
-                               VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
-                               VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
-                               VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
-                               Collision_SnapCopyPoints(polyf_brush.numpoints, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
-                               Collision_CalcEdgeDirsForPolygonBrushFloat(&polyf_brush);
-                               Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
-                               //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
-                               Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
+                               VectorCopy(vertex3f + element3i[0] * 3, points[0].v);
+                               VectorCopy(vertex3f + element3i[1] * 3, points[1].v);
+                               VectorCopy(vertex3f + element3i[2] * 3, points[2].v);
+                               Collision_SnapCopyPoints(brush.numpoints, points, points, COLLISION_SNAPSCALE, COLLISION_SNAP);
+                               Collision_CalcEdgeDirsForPolygonBrushFloat(&brush);
+                               Collision_CalcPlanesForPolygonBrushFloat(&brush);
+                               //Collision_PrintBrushAsQHull(&brush, "brush");
+                               Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &brush, &brush);
                        }
                }
        }
 }
 
-void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numpoints, const float *points, int supercontents, int q3surfaceflags, texture_t *texture)
-{
-       if (numpoints > 256)
-       {
-               Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
-               return;
-       }
-       polyf_brush.numpoints = numpoints;
-       polyf_brush.numedgedirs = numpoints;
-       polyf_brush.numplanes = numpoints + 2;
-       //polyf_brush.points = (colpointf_t *)points;
-       polyf_brush.points = polyf_points;
-       Collision_SnapCopyPoints(polyf_brush.numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
-       polyf_brush.edgedirs = polyf_edgedirs;
-       polyf_brush.planes = polyf_planes;
-       polyf_brush.supercontents = supercontents;
-       polyf_brush.q3surfaceflags = q3surfaceflags;
-       polyf_brush.texture = texture;
-       //Collision_CalcEdgeDirsForPolygonBrushFloat(&polyf_brush);
-       Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
-       //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
-       Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
-}
-
 void Collision_TraceLineTriangleMeshFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numtriangles, const int *element3i, const float *vertex3f, int stride, float *bbox6f, int supercontents, int q3surfaceflags, texture_t *texture, const vec3_t segmentmins, const vec3_t segmentmaxs)
 {
        int i;
@@ -1138,191 +1117,104 @@ void Collision_TraceLineTriangleMeshFloat(trace_t *trace, const vec3_t linestart
                        Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[0] * 3, vertex3f + element3i[1] * 3, vertex3f + element3i[2] * 3, supercontents, q3surfaceflags, texture);
        }
 #else
-       polyf_brush.numpoints = 3;
-       polyf_brush.numedgedirs = 3;
-       polyf_brush.numplanes = 5;
-       polyf_brush.points = polyf_points;
-       polyf_brush.edgedirs = polyf_edgedirs;
-       polyf_brush.planes = polyf_planes;
-       polyf_brush.supercontents = supercontents;
-       polyf_brush.q3surfaceflags = q3surfaceflags;
-       polyf_brush.texture = texture;
-       for (i = 0;i < polyf_brush.numplanes;i++)
+       colpointf_t points[3];
+       colpointf_t edgedirs[3];
+       colplanef_t planes[5];
+       colbrushf_t brush;
+       memset(&brush, 0, sizeof(brush));
+       brush.isaabb = false;
+       brush.hasaabbplanes = false;
+       brush.numpoints = 3;
+       brush.numedgedirs = 3;
+       brush.numplanes = 5;
+       brush.points = points;
+       brush.edgedirs = edgedirs;
+       brush.planes = planes;
+       brush.supercontents = supercontents;
+       brush.q3surfaceflags = q3surfaceflags;
+       brush.texture = texture;
+       for (i = 0;i < brush.numplanes;i++)
        {
-               polyf_brush.planes[i].supercontents = supercontents;
-               polyf_brush.planes[i].q3surfaceflags = q3surfaceflags;
-               polyf_brush.planes[i].texture = texture;
+               brush.planes[i].q3surfaceflags = q3surfaceflags;
+               brush.planes[i].texture = texture;
        }
        for (i = 0;i < numtriangles;i++, element3i += 3)
        {
                if (TriangleOverlapsBox(vertex3f + element3i[0]*3, vertex3 + [element3i[1]*3, vertex3f + element3i[2]*3, segmentmins, segmentmaxs))
                {
-                       VectorCopy(vertex3f + element3i[0] * 3, polyf_points[0].v);
-                       VectorCopy(vertex3f + element3i[1] * 3, polyf_points[1].v);
-                       VectorCopy(vertex3f + element3i[2] * 3, polyf_points[2].v);
-                       Collision_SnapCopyPoints(polyf_brush.numpoints, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
-                       Collision_CalcEdgeDirsForPolygonBrushFloat(&polyf_brush);
-                       Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
-                       //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
-                       Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
+                       VectorCopy(vertex3f + element3i[0] * 3, points[0].v);
+                       VectorCopy(vertex3f + element3i[1] * 3, points[1].v);
+                       VectorCopy(vertex3f + element3i[2] * 3, points[2].v);
+                       Collision_SnapCopyPoints(brush.numpoints, points, points, COLLISION_SNAPSCALE, COLLISION_SNAP);
+                       Collision_CalcEdgeDirsForPolygonBrushFloat(&brush);
+                       Collision_CalcPlanesForPolygonBrushFloat(&brush);
+                       //Collision_PrintBrushAsQHull(&brush, "brush");
+                       Collision_TraceLineBrushFloat(trace, linestart, lineend, &brush, &brush);
                }
        }
 #endif
 }
 
-
-static colpointf_t polyf_pointsstart[256], polyf_pointsend[256];
-static colplanef_t polyf_planesstart[256 + 2], polyf_planesend[256 + 2];
-static colbrushf_t polyf_brushstart, polyf_brushend;
-
-void Collision_TraceBrushPolygonTransformFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, const matrix4x4_t *polygonmatrixstart, const matrix4x4_t *polygonmatrixend, int supercontents, int q3surfaceflags, texture_t *texture)
-{
-       int i;
-       if (numpoints > 256)
-       {
-               Con_Print("Polygon with more than 256 points not supported yet (fixme!)\n");
-               return;
-       }
-       polyf_brushstart.numpoints = numpoints;
-       polyf_brushstart.numedgedirs = numpoints;
-       polyf_brushstart.numplanes = numpoints + 2;
-       polyf_brushstart.points = polyf_pointsstart;//(colpointf_t *)points;
-       polyf_brushstart.planes = polyf_planesstart;
-       polyf_brushstart.supercontents = supercontents;
-       polyf_brushstart.q3surfaceflags = q3surfaceflags;
-       polyf_brushstart.texture = texture;
-       for (i = 0;i < numpoints;i++)
-               Matrix4x4_Transform(polygonmatrixstart, points + i * 3, polyf_brushstart.points[i].v);
-       polyf_brushend.numpoints = numpoints;
-       polyf_brushend.numedgedirs = numpoints;
-       polyf_brushend.numplanes = numpoints + 2;
-       polyf_brushend.points = polyf_pointsend;//(colpointf_t *)points;
-       polyf_brushend.planes = polyf_planesend;
-       polyf_brushend.supercontents = supercontents;
-       polyf_brushend.q3surfaceflags = q3surfaceflags;
-       polyf_brushend.texture = texture;
-       for (i = 0;i < numpoints;i++)
-               Matrix4x4_Transform(polygonmatrixend, points + i * 3, polyf_brushend.points[i].v);
-       for (i = 0;i < polyf_brushstart.numplanes;i++)
-       {
-               polyf_brushstart.planes[i].q3surfaceflags = q3surfaceflags;
-               polyf_brushstart.planes[i].texture = texture;
-       }
-       Collision_SnapCopyPoints(polyf_brushstart.numpoints, polyf_pointsstart, polyf_pointsstart, COLLISION_SNAPSCALE, COLLISION_SNAP);
-       Collision_SnapCopyPoints(polyf_brushend.numpoints, polyf_pointsend, polyf_pointsend, COLLISION_SNAPSCALE, COLLISION_SNAP);
-       Collision_CalcEdgeDirsForPolygonBrushFloat(&polyf_brushstart);
-       Collision_CalcEdgeDirsForPolygonBrushFloat(&polyf_brushend);
-       Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushstart);
-       Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushend);
-
-       //Collision_PrintBrushAsQHull(&polyf_brushstart, "polyf_brushstart");
-       //Collision_PrintBrushAsQHull(&polyf_brushend, "polyf_brushend");
-
-       Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brushstart, &polyf_brushend);
-}
-
-
-
-#define MAX_BRUSHFORBOX 16
-static unsigned int brushforbox_index = 0;
-// note: this relies on integer overflow to be consistent with modulo
-// MAX_BRUSHFORBOX, or in other words, MAX_BRUSHFORBOX must be a power of two!
-static colpointf_t brushforbox_point[MAX_BRUSHFORBOX*8];
-static colpointf_t brushforbox_edgedir[MAX_BRUSHFORBOX*6];
-static colplanef_t brushforbox_plane[MAX_BRUSHFORBOX*6];
-static colbrushf_t brushforbox_brush[MAX_BRUSHFORBOX];
-static colbrushf_t brushforpoint_brush[MAX_BRUSHFORBOX];
-
-void Collision_InitBrushForBox(void)
+void Collision_BrushForBox(colboxbrushf_t *boxbrush, const vec3_t mins, const vec3_t maxs, int supercontents, int q3surfaceflags, texture_t *texture)
 {
        int i;
-       for (i = 0;i < MAX_BRUSHFORBOX;i++)
-       {
-               brushforbox_brush[i].numpoints = 8;
-               brushforbox_brush[i].numedgedirs = 6;
-               brushforbox_brush[i].numplanes = 6;
-               brushforbox_brush[i].points = brushforbox_point + i * 8;
-               brushforbox_brush[i].edgedirs = brushforbox_edgedir + i * 6;
-               brushforbox_brush[i].planes = brushforbox_plane + i * 6;
-               brushforpoint_brush[i].numpoints = 1;
-               brushforpoint_brush[i].numedgedirs = 0;
-               brushforpoint_brush[i].numplanes = 0;
-               brushforpoint_brush[i].points = brushforbox_point + i * 8;
-               brushforpoint_brush[i].edgedirs = brushforbox_edgedir + i * 6;
-               brushforpoint_brush[i].planes = brushforbox_plane + i * 6;
-       }
-}
-
-colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins, const vec3_t maxs, int supercontents, int q3surfaceflags, texture_t *texture)
-{
-       int i, j;
-       vec3_t v;
-       colbrushf_t *brush;
-       if (brushforbox_brush[0].numpoints == 0)
-               Collision_InitBrushForBox();
-       // FIXME: these probably don't actually need to be normalized if the collision code does not care
+       memset(boxbrush, 0, sizeof(*boxbrush));
+       boxbrush->brush.points = boxbrush->points;
+       boxbrush->brush.edgedirs = boxbrush->edgedirs;
+       boxbrush->brush.planes = boxbrush->planes;
+       boxbrush->brush.supercontents = supercontents;
+       boxbrush->brush.q3surfaceflags = q3surfaceflags;
+       boxbrush->brush.texture = texture;
        if (VectorCompare(mins, maxs))
        {
                // point brush
-               brush = brushforpoint_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
-               VectorCopy(mins, brush->points->v);
+               boxbrush->brush.numpoints = 1;
+               boxbrush->brush.numedgedirs = 0;
+               boxbrush->brush.numplanes = 0;
+               VectorCopy(mins, boxbrush->brush.points[0].v);
        }
        else
        {
-               brush = brushforbox_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
-               // FIXME: optimize
-               for (i = 0;i < 8;i++)
-               {
-                       v[0] = i & 1 ? maxs[0] : mins[0];
-                       v[1] = i & 2 ? maxs[1] : mins[1];
-                       v[2] = i & 4 ? maxs[2] : mins[2];
-                       Matrix4x4_Transform(matrix, v, brush->points[i].v);
-               }
-               // FIXME: optimize!
+               boxbrush->brush.numpoints = 8;
+               boxbrush->brush.numedgedirs = 3;
+               boxbrush->brush.numplanes = 6;
+               // there are 8 points on a box
+               // there are 3 edgedirs on a box (both signs are tested in collision)
+               // there are 6 planes on a box
+               VectorSet(boxbrush->brush.points[0].v, mins[0], mins[1], mins[2]);
+               VectorSet(boxbrush->brush.points[1].v, maxs[0], mins[1], mins[2]);
+               VectorSet(boxbrush->brush.points[2].v, mins[0], maxs[1], mins[2]);
+               VectorSet(boxbrush->brush.points[3].v, maxs[0], maxs[1], mins[2]);
+               VectorSet(boxbrush->brush.points[4].v, mins[0], mins[1], maxs[2]);
+               VectorSet(boxbrush->brush.points[5].v, maxs[0], mins[1], maxs[2]);
+               VectorSet(boxbrush->brush.points[6].v, mins[0], maxs[1], maxs[2]);
+               VectorSet(boxbrush->brush.points[7].v, maxs[0], maxs[1], maxs[2]);
+               VectorSet(boxbrush->brush.edgedirs[0].v, 1, 0, 0);
+               VectorSet(boxbrush->brush.edgedirs[1].v, 0, 1, 0);
+               VectorSet(boxbrush->brush.edgedirs[2].v, 0, 0, 1);
+               VectorSet(boxbrush->brush.planes[0].normal, -1,  0,  0);boxbrush->brush.planes[0].dist = -mins[0];
+               VectorSet(boxbrush->brush.planes[1].normal,  1,  0,  0);boxbrush->brush.planes[1].dist =  maxs[0];
+               VectorSet(boxbrush->brush.planes[2].normal,  0, -1,  0);boxbrush->brush.planes[2].dist = -mins[1];
+               VectorSet(boxbrush->brush.planes[3].normal,  0,  1,  0);boxbrush->brush.planes[3].dist =  maxs[1];
+               VectorSet(boxbrush->brush.planes[4].normal,  0,  0, -1);boxbrush->brush.planes[4].dist = -mins[2];
+               VectorSet(boxbrush->brush.planes[5].normal,  0,  0,  1);boxbrush->brush.planes[5].dist =  maxs[2];
                for (i = 0;i < 6;i++)
                {
-                       VectorClear(v);
-                       v[i >> 1] = i & 1 ? 1 : -1;
-                       Matrix4x4_Transform3x3(matrix, v, brush->planes[i].normal);
-                       VectorNormalize(brush->planes[i].normal);
-                       brush->planes[i].q3surfaceflags = q3surfaceflags;
-                       brush->planes[i].texture = texture;
-                       VectorCopy(brush->planes[i].normal, brush->edgedirs[i].v);
+                       boxbrush->brush.planes[i].q3surfaceflags = q3surfaceflags;
+                       boxbrush->brush.planes[i].texture = texture;
                }
        }
-       brush->supercontents = supercontents;
-       brush->q3surfaceflags = q3surfaceflags;
-       brush->texture = texture;
-       for (j = 0;j < brush->numplanes;j++)
-       {
-               brush->planes[j].q3surfaceflags = q3surfaceflags;
-               brush->planes[j].texture = texture;
-               brush->planes[j].dist = furthestplanedist_float(brush->planes[j].normal, brush->points, brush->numpoints);
-       }
-       VectorCopy(brush->points[0].v, brush->mins);
-       VectorCopy(brush->points[0].v, brush->maxs);
-       for (j = 1;j < brush->numpoints;j++)
-       {
-               brush->mins[0] = min(brush->mins[0], brush->points[j].v[0]);
-               brush->mins[1] = min(brush->mins[1], brush->points[j].v[1]);
-               brush->mins[2] = min(brush->mins[2], brush->points[j].v[2]);
-               brush->maxs[0] = max(brush->maxs[0], brush->points[j].v[0]);
-               brush->maxs[1] = max(brush->maxs[1], brush->points[j].v[1]);
-               brush->maxs[2] = max(brush->maxs[2], brush->points[j].v[2]);
-       }
-       brush->mins[0] -= 1;
-       brush->mins[1] -= 1;
-       brush->mins[2] -= 1;
-       brush->maxs[0] += 1;
-       brush->maxs[1] += 1;
-       brush->maxs[2] += 1;
-       Collision_ValidateBrush(brush);
-       return brush;
+       boxbrush->brush.supercontents = supercontents;
+       boxbrush->brush.q3surfaceflags = q3surfaceflags;
+       boxbrush->brush.texture = texture;
+       VectorSet(boxbrush->brush.mins, mins[0] - 1, mins[1] - 1, mins[2] - 1);
+       VectorSet(boxbrush->brush.maxs, maxs[0] + 1, maxs[1] + 1, maxs[2] + 1);
+       Collision_ValidateBrush(&boxbrush->brush);
 }
 
 void Collision_ClipTrace_BrushBox(trace_t *trace, const vec3_t cmins, const vec3_t cmaxs, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int hitsupercontentsmask, int supercontents, int q3surfaceflags, texture_t *texture)
 {
-       colbrushf_t *boxbrush, *thisbrush_start, *thisbrush_end;
+       colboxbrushf_t boxbrush, thisbrush_start, thisbrush_end;
        vec3_t startmins, startmaxs, endmins, endmaxs;
 
        // create brushes for the collision
@@ -1330,16 +1222,16 @@ void Collision_ClipTrace_BrushBox(trace_t *trace, const vec3_t cmins, const vec3
        VectorAdd(start, maxs, startmaxs);
        VectorAdd(end, mins, endmins);
        VectorAdd(end, maxs, endmaxs);
-       boxbrush = Collision_BrushForBox(&identitymatrix, cmins, cmaxs, supercontents, q3surfaceflags, texture);
-       thisbrush_start = Collision_BrushForBox(&identitymatrix, startmins, startmaxs, 0, 0, NULL);
-       thisbrush_end = Collision_BrushForBox(&identitymatrix, endmins, endmaxs, 0, 0, NULL);
+       Collision_BrushForBox(&boxbrush, cmins, cmaxs, supercontents, q3surfaceflags, texture);
+       Collision_BrushForBox(&thisbrush_start, startmins, startmaxs, 0, 0, NULL);
+       Collision_BrushForBox(&thisbrush_end, endmins, endmaxs, 0, 0, NULL);
 
        memset(trace, 0, sizeof(trace_t));
        trace->hitsupercontentsmask = hitsupercontentsmask;
        trace->fraction = 1;
        trace->realfraction = 1;
        trace->allsolid = true;
-       Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, boxbrush, boxbrush);
+       Collision_TraceBrushBrushFloat(trace, &thisbrush_start.brush, &thisbrush_end.brush, &boxbrush.brush, &boxbrush.brush);
 }
 
 //pseudocode for detecting line/sphere overlap without calculating an impact point
@@ -1806,6 +1698,11 @@ void Collision_CombineTraces(trace_t *cliptrace, const trace_t *trace, void *tou
                cliptrace->startsolid = true;
                if (cliptrace->realfraction == 1)
                        cliptrace->ent = touch;
+               if (cliptrace->startdepth > trace->startdepth)
+               {
+                       cliptrace->startdepth = trace->startdepth;
+                       VectorCopy(trace->startdepthnormal, cliptrace->startdepthnormal);
+               }
        }
        // don't set this except on the world, because it can easily confuse
        // monsters underwater if there's a bmodel involved in the trace