]> de.git.xonotic.org Git - xonotic/darkplaces.git/blobdiff - collision.c
implemented sv_gameplayfix_nudgeoutofsolid
[xonotic/darkplaces.git] / collision.c
index 92fb13ca2b29c09bf97d8c5842b88ade972fac02..d7fe855e70d28977e85e67e9c000ef4d1b48fe78 100644 (file)
@@ -2,6 +2,7 @@
 #include "quakedef.h"
 #include "polygon.h"
 
+#define COLLISION_EDGEDIR_DIST_EPSILON (1.0f / 1048576.0f)
 #define COLLISION_SNAPSCALE (32.0f)
 #define COLLISION_SNAP (1.0f / COLLISION_SNAPSCALE)
 #define COLLISION_SNAP2 (2.0f / COLLISION_SNAPSCALE)
@@ -140,15 +141,22 @@ float furthestplanedist_float(const float *normal, const colpointf_t *points, in
        return bestdist;
 }
 
+void Collision_CalcEdgeDirsForPolygonBrushFloat(colbrushf_t *brush)
+{
+       int i, j;
+       for (i = 0, j = brush->numpoints - 1;i < brush->numpoints;j = i, i++)
+               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)
+colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const colplanef_t *originalplanes, int supercontents, int q3surfaceflags, texture_t *texture)
 {
        // TODO: planesbuf could be replaced by a remapping table
-       int j, k, m, w, xyzflags;
-       int numpointsbuf = 0, maxpointsbuf = 256, numplanesbuf = 0, maxplanesbuf = 256, numelementsbuf = 0, maxelementsbuf = 256;
+       int j, k, l, m, w, xyzflags;
+       int numpointsbuf = 0, maxpointsbuf = 256, numedgedirsbuf = 0, maxedgedirsbuf = 256, numplanesbuf = 0, maxplanesbuf = 256, numelementsbuf = 0, maxelementsbuf = 256;
        double maxdist;
        colbrushf_t *brush;
        colpointf_t pointsbuf[256];
+       colpointf_t edgedirsbuf[256];
        colplanef_t planesbuf[256];
        int elementsbuf[1024];
        int polypointbuf[256];
@@ -156,8 +164,9 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
        int pnumpoints;
        double p[2][3*64];
 #if 0
-       // enable these if debugging to avoid seeing garbage in unused data
+       // enable these if debugging to avoid seeing garbage in unused data-
        memset(pointsbuf, 0, sizeof(pointsbuf));
+       memset(edgedirsbuf, 0, sizeof(edgedirsbuf));
        memset(planesbuf, 0, sizeof(planesbuf));
        memset(elementsbuf, 0, sizeof(elementsbuf));
        memset(polypointbuf, 0, sizeof(polypointbuf));
@@ -250,6 +259,7 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
                        return NULL;
                }
 
+               // add the unique points for this polygon
                for (k = 0;k < pnumpoints;k++)
                {
                        float v[3];
@@ -287,6 +297,34 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
                        elementsbuf[numelementsbuf++] = polypointbuf[k + 1];
                        elementsbuf[numelementsbuf++] = polypointbuf[k + 2];
                }
+
+               // add the unique edgedirs for this polygon
+               for (k = 0, l = pnumpoints-1;k < pnumpoints;l = k, k++)
+               {
+                       float dir[3];
+                       // downgrade to float precision before comparing
+                       VectorSubtract(&p[w][k*3], &p[w][l*3], dir);
+                       VectorNormalize(dir);
+
+                       // 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)
+                                       break;
+
+                       // if there is no match, add a new one
+                       if (m == numedgedirsbuf)
+                       {
+                               // check if there are too many and skip the brush
+                               if (numedgedirsbuf >= maxedgedirsbuf)
+                               {
+                                       Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many edgedirs for buffer\n");
+                                       return NULL;
+                               }
+                               // add the new one
+                               VectorCopy(dir, edgedirsbuf[numedgedirsbuf].v);
+                               numedgedirsbuf++;
+                       }
+               }
        }
 
        // if nothing is left, there's nothing to allocate
@@ -309,20 +347,30 @@ 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(colplanef_t) * numplanesbuf + sizeof(int) * numelementsbuf);
+       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->supercontents = supercontents;
        brush->numplanes = numplanesbuf;
+       brush->numedgedirs = numedgedirsbuf;
        brush->numpoints = numpointsbuf;
        brush->numtriangles = numelementsbuf / 3;
        brush->planes = (colplanef_t *)(brush + 1);
        brush->points = (colpointf_t *)(brush->planes + brush->numplanes);
+       brush->edgedirs = (colpointf_t *)(brush->points + brush->numpoints);
        brush->elements = (int *)(brush->points + brush->numpoints);
+       brush->q3surfaceflags = q3surfaceflags;
+       brush->texture = texture;
        for (j = 0;j < brush->numpoints;j++)
        {
                brush->points[j].v[0] = pointsbuf[j].v[0];
                brush->points[j].v[1] = pointsbuf[j].v[1];
                brush->points[j].v[2] = pointsbuf[j].v[2];
        }
+       for (j = 0;j < brush->numedgedirs;j++)
+       {
+               brush->edgedirs[j].v[0] = edgedirsbuf[j].v[0];
+               brush->edgedirs[j].v[1] = edgedirsbuf[j].v[1];
+               brush->edgedirs[j].v[2] = edgedirsbuf[j].v[2];
+       }
        for (j = 0;j < brush->numplanes;j++)
        {
                brush->planes[j].normal[0] = planesbuf[j].normal[0];
@@ -395,6 +443,7 @@ void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
                else
                {
                        brush->numplanes = 5;
+                       brush->numedgedirs = 3;
                        VectorNormalize(brush->planes[0].normal);
                        brush->planes[0].dist = DotProduct(brush->points->v, brush->planes[0].normal);
                        VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
@@ -402,6 +451,9 @@ void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
                        VectorSubtract(brush->points[2].v, brush->points[0].v, edge0);
                        VectorSubtract(brush->points[0].v, brush->points[1].v, edge1);
                        VectorSubtract(brush->points[1].v, brush->points[2].v, edge2);
+                       VectorCopy(edge0, brush->edgedirs[0].v);
+                       VectorCopy(edge1, brush->edgedirs[1].v);
+                       VectorCopy(edge2, brush->edgedirs[2].v);
 #if 1
                        {
                                float projectionnormal[3], projectionedge0[3], projectionedge1[3], projectionedge2[3];
@@ -544,83 +596,114 @@ void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
        }
 }
 
-colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points, int supercontents)
+colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points, int supercontents, int q3surfaceflags, texture_t *texture)
 {
        colbrushf_t *brush;
-       brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2));
+       brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2) + sizeof(colpointf_t) * numpoints);
        brush->supercontents = supercontents;
        brush->numpoints = numpoints;
+       brush->numedgedirs = numpoints;
        brush->numplanes = numpoints + 2;
        brush->planes = (colplanef_t *)(brush + 1);
        brush->points = (colpointf_t *)points;
+       brush->edgedirs = (colpointf_t *)(brush->planes + brush->numplanes);
+       brush->q3surfaceflags = q3surfaceflags;
+       brush->texture = texture;
        Sys_Error("Collision_AllocBrushFromPermanentPolygonFloat: FIXME: this code needs to be updated to generate a mesh...");
        return brush;
 }
 
 // NOTE: start and end of each brush pair must have same numplanes/numpoints
-void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end)
+void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *trace_start, const colbrushf_t *trace_end, const colbrushf_t *other_start, const colbrushf_t *other_end)
 {
-       int nplane, nplane2, hitq3surfaceflags = 0;
-       float enterfrac = -1, leavefrac = 1, d1, d2, f, imove, newimpactnormal[3], enterfrac2 = -1;
-       const colplanef_t *startplane, *endplane;
+       int nplane, nplane2, nedge1, nedge2, hitq3surfaceflags = 0;
+       int tracenumedgedirs = trace_start->numedgedirs;
+       //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 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;
-
-       VectorClear(newimpactnormal);
-
-       for (nplane = 0;nplane < thatbrush_start->numplanes + thisbrush_start->numplanes;nplane++)
+       vec_t startdepth = 1;
+       vec3_t startdepthnormal;
+
+       VectorClear(startdepthnormal);
+       Vector4Clear(newimpactplane);
+
+       // Separating Axis Theorem:
+       // if a supporting vector (plane normal) can be found that separates two
+       // objects, they are not colliding.
+       //
+       // Minkowski Sum:
+       // reduce the size of one object to a point while enlarging the other to
+       // represent the space that point can not occupy.
+       //
+       // try every plane we can construct between the two brushes and measure
+       // the distance between them.
+       for (nplane = 0;nplane < numplanes3;nplane++)
        {
-               nplane2 = nplane;
-               if (nplane2 >= thatbrush_start->numplanes)
+               if (nplane < numplanes1)
                {
-                       nplane2 -= thatbrush_start->numplanes;
-                       startplane = thisbrush_start->planes + nplane2;
-                       endplane = thisbrush_end->planes + nplane2;
-                       if (developer.integer >= 100)
-                       {
-                               // any brush with degenerate planes is not worth handling
-                               if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
-                               {
-                                       Con_Print("Collision_TraceBrushBrushFloat: degenerate thisbrush plane!\n");
-                                       return;
-                               }
-                               f = furthestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints);
-                               if (fabs(f - startplane->dist) > COLLISION_PLANE_DIST_EPSILON)
-                                       Con_Printf("startplane->dist %f != calculated %f (thisbrush_start)\n", startplane->dist, f);
-                       }
-                       d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints) - collision_startnudge.value;
-                       d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - furthestplanedist_float(endplane->normal, thatbrush_end->points, thatbrush_end->numpoints) - collision_endnudge.value;
+                       nplane2 = nplane;
+                       VectorCopy(trace_start->planes[nplane2].normal, startplane);
+                       VectorCopy(trace_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);
                }
                else
                {
-                       startplane = thatbrush_start->planes + nplane2;
-                       endplane = thatbrush_end->planes + nplane2;
-                       if (developer.integer >= 100)
+                       // pick an edgedir from each brush and cross them
+                       nplane2 = nplane - numplanes2;
+                       nedge1 = nplane2 >> 1;
+                       nedge2 = nedge1 / tracenumedgedirs;
+                       nedge1 -= nedge2 * tracenumedgedirs;
+                       if (nplane2 & 1)
                        {
-                               // any brush with degenerate planes is not worth handling
-                               if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
-                               {
-                                       Con_Print("Collision_TraceBrushBrushFloat: degenerate thatbrush plane!\n");
-                                       return;
-                               }
-                               f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
-                               if (fabs(f - startplane->dist) > COLLISION_PLANE_DIST_EPSILON)
-                                       Con_Printf("startplane->dist %f != calculated %f (thatbrush_start)\n", startplane->dist, f);
+                               CrossProduct(trace_start->edgedirs[nedge1].v, other_start->edgedirs[nedge2].v, startplane);
+                               CrossProduct(trace_end->edgedirs[nedge1].v, other_end->edgedirs[nedge2].v, endplane);
                        }
-                       d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - startplane->dist - collision_startnudge.value;
-                       d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - endplane->dist - collision_endnudge.value;
+                       else
+                       {
+                               CrossProduct(other_start->edgedirs[nedge2].v, trace_start->edgedirs[nedge1].v, startplane);
+                               CrossProduct(other_end->edgedirs[nedge2].v, trace_end->edgedirs[nedge1].v, endplane);
+                       }
+                       VectorNormalize(startplane);
+                       VectorNormalize(endplane);
+               }
+               startplane[3] = furthestplanedist_float(startplane, other_start->points, othernumpoints);
+               endplane[3] = furthestplanedist_float(startplane, other_end->points, othernumpoints);
+               startdist = nearestplanedist_float(startplane, trace_start->points, tracenumpoints) - startplane[3] - collision_startnudge.value;
+               enddist = nearestplanedist_float(endplane, trace_end->points, tracenumpoints) - endplane[3] - collision_endnudge.value;
+               //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 && (startdepth < startdist || startdepth == 1))
+               {
+                       startdepth = startdist;
+                       VectorCopy(startplane, startdepthnormal);
                }
-               //Con_Printf("%c%i: d1 = %f, d2 = %f, d1 / (d1 - d2) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, d1, d2, d1 / (d1 - d2));
 
-               if (d1 > d2)
+               if (startdist > enddist)
                {
                        // moving into brush
-                       if (d2 > 0)
+                       if (enddist >= collision_enternudge.value)
                                return;
-                       if (d1 > 0)
+                       if (startdist > 0)
                        {
                                // enter
-                               imove = 1 / (d1 - d2);
-                               f = (d1 - collision_enternudge.value) * imove;
+                               imove = 1 / (startdist - enddist);
+                               f = (startdist - collision_enternudge.value) * imove;
+                               if (f < 0)
+                                       f = 0;
                                // check if this will reduce the collision time range
                                if (enterfrac < f)
                                {
@@ -636,22 +719,45 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush
                                                return;
                                        // calculate the nudged fraction and impact normal we'll
                                        // need if we accept this collision later
-                                       enterfrac2 = f - collision_impactnudge.value * imove;
-                                       VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
-                                       hitq3surfaceflags = startplane->q3surfaceflags;
-                                       hittexture = startplane->texture;
+                                       enterfrac2 = (startdist - collision_impactnudge.value) * imove;
+                                       ie = 1.0f - enterfrac;
+                                       newimpactplane[0] = startplane[0] * ie + endplane[0] * enterfrac;
+                                       newimpactplane[1] = startplane[1] * ie + endplane[1] * enterfrac;
+                                       newimpactplane[2] = startplane[2] * ie + endplane[2] * enterfrac;
+                                       newimpactplane[3] = startplane[3] * ie + endplane[3] * enterfrac;
+                                       if (nplane < numplanes1)
+                                       {
+                                               // use the plane from trace
+                                               nplane2 = nplane;
+                                               hitq3surfaceflags = trace_start->planes[nplane2].q3surfaceflags;
+                                               hittexture = trace_start->planes[nplane2].texture;
+                                       }
+                                       else if (nplane < numplanes2)
+                                       {
+                                               // use the plane from other
+                                               nplane2 = nplane - numplanes1;
+                                               hitq3surfaceflags = other_start->planes[nplane2].q3surfaceflags;
+                                               hittexture = other_start->planes[nplane2].texture;
+                                       }
+                                       else
+                                       {
+                                               hitq3surfaceflags = other_start->q3surfaceflags;
+                                               hittexture = other_start->texture;
+                                       }
                                }
                        }
                }
                else
                {
                        // moving out of brush
-                       if (d1 > 0)
+                       if (startdist > 0)
                                return;
-                       if (d2 > 0)
+                       if (enddist > 0)
                        {
                                // leave
-                               f = (d1 + collision_leavenudge.value) / (d1 - d2);
+                               f = (startdist + collision_leavenudge.value) / (startdist - enddist);
+                               if (f > 1)
+                                       f = 1;
                                // check if this will reduce the collision time range
                                if (leavefrac > f)
                                {
@@ -668,76 +774,99 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush
        // at this point we know the trace overlaps the brush because it was not
        // rejected at any point in the loop above
 
-       // see if this brush can block the trace or not according to contents
-       if (trace->hitsupercontentsmask & thatbrush_start->supercontents)
+       // see if the trace started outside the brush or not
+       if (enterfrac > -1)
        {
-               if (enterfrac == -1)
+               // started outside, and overlaps, therefore there is a collision here
+               // store out the impact information
+               if (trace->hitsupercontentsmask & other_start->supercontents)
                {
-                       trace->startsupercontents |= thatbrush_start->supercontents;
-                       trace->startsolid = true;
-                       if (leavefrac < 1)
-                               trace->allsolid = true;
+                       trace->hitsupercontents = other_start->supercontents;
+                       trace->hitq3surfaceflags = hitq3surfaceflags;
+                       trace->hittexture = hittexture;
+                       trace->realfraction = bound(0, enterfrac, 1);
+                       trace->fraction = bound(0, enterfrac2, 1);
+                       if (collision_prefernudgedfraction.integer)
+                               trace->realfraction = trace->fraction;
+                       VectorCopy(newimpactplane, trace->plane.normal);
+                       trace->plane.dist = newimpactplane[3];
                }
-               // store out the impact information
-               trace->hitsupercontents = thatbrush_start->supercontents;
-               trace->hitq3surfaceflags = hitq3surfaceflags;
-               trace->hittexture = hittexture;
-               trace->realfraction = bound(0, enterfrac, 1);
-               trace->fraction = bound(0, enterfrac2, 1);
-               if (collision_prefernudgedfraction.integer)
-                       trace->realfraction = trace->fraction;
-               VectorCopy(newimpactnormal, trace->plane.normal);
        }
        else
        {
-               // this brush can not block the trace, but it can update start contents
-               if (enterfrac == -1)
-                       trace->startsupercontents |= thatbrush_start->supercontents;
+               // started inside, update startsolid and friends
+               trace->startsupercontents |= other_start->supercontents;
+               if (trace->hitsupercontentsmask & other_start->supercontents)
+               {
+                       trace->startsolid = true;
+                       if (leavefrac < 1)
+                               trace->allsolid = true;
+                       VectorCopy(newimpactplane, trace->plane.normal);
+                       trace->plane.dist = newimpactplane[3];
+                       if (trace->startdepth > startdepth)
+                       {
+                               trace->startdepth = startdepth;
+                               VectorCopy(startdepthnormal, trace->startdepthnormal);
+                       }
+               }
        }
 }
 
-// NOTE: start and end brush pair must have same numplanes/numpoints
-void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const colbrushf_t *thatbrush_start, const colbrushf_t *thatbrush_end)
+// NOTE: start and end of each brush pair must have same numplanes/numpoints
+void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const colbrushf_t *other_start, const colbrushf_t *other_end)
 {
        int nplane, hitq3surfaceflags = 0;
-       float enterfrac = -1, leavefrac = 1, d1, d2, f, imove, newimpactnormal[3], enterfrac2 = -1;
-       const colplanef_t *startplane, *endplane;
+       int numplanes = other_start->numplanes;
+       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;
-
-       VectorClear(newimpactnormal);
-
-       for (nplane = 0;nplane < thatbrush_start->numplanes;nplane++)
+       vec_t startdepth = 1;
+       vec3_t startdepthnormal;
+
+       VectorClear(startdepthnormal);
+       Vector4Clear(newimpactplane);
+
+       // Separating Axis Theorem:
+       // if a supporting vector (plane normal) can be found that separates two
+       // objects, they are not colliding.
+       //
+       // Minkowski Sum:
+       // reduce the size of one object to a point while enlarging the other to
+       // represent the space that point can not occupy.
+       //
+       // try every plane we can construct between the two brushes and measure
+       // the distance between them.
+       for (nplane = 0;nplane < numplanes;nplane++)
        {
-               startplane = thatbrush_start->planes + nplane;
-               endplane = thatbrush_end->planes + nplane;
-               d1 = DotProduct(startplane->normal, linestart) - startplane->dist - collision_startnudge.value;
-               d2 = DotProduct(endplane->normal, lineend) - endplane->dist - collision_endnudge.value;
-               if (developer.integer >= 100)
+               VectorCopy(other_start->planes[nplane].normal, startplane);
+               startplane[3] = other_start->planes[nplane].dist;
+               VectorCopy(other_end->planes[nplane].normal, endplane);
+               endplane[3] = other_end->planes[nplane].dist;
+               startdist = DotProduct(linestart, startplane) - startplane[3] - collision_startnudge.value;
+               enddist = DotProduct(lineend, endplane) - endplane[3] - collision_endnudge.value;
+               //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 && (startdepth < startdist || startdepth == 1))
                {
-                       // any brush with degenerate planes is not worth handling
-                       if (DotProduct(startplane->normal, startplane->normal) < 0.9f || DotProduct(endplane->normal, endplane->normal) < 0.9f)
-                       {
-                               Con_Print("Collision_TraceLineBrushFloat: degenerate plane!\n");
-                               return;
-                       }
-                       if (thatbrush_start->numpoints)
-                       {
-                               f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
-                               if (fabs(f - startplane->dist) > COLLISION_PLANE_DIST_EPSILON)
-                                       Con_Printf("startplane->dist %f != calculated %f\n", startplane->dist, f);
-                       }
+                       startdepth = startdist;
+                       VectorCopy(startplane, startdepthnormal);
                }
 
-               if (d1 > d2)
+               if (startdist > enddist)
                {
                        // moving into brush
-                       if (d2 > 0)
+                       if (enddist >= collision_enternudge.value)
                                return;
-                       if (d1 > 0)
+                       if (startdist > 0)
                        {
                                // enter
-                               imove = 1 / (d1 - d2);
-                               f = (d1 - collision_enternudge.value) * imove;
+                               imove = 1 / (startdist - enddist);
+                               f = (startdist - collision_enternudge.value) * imove;
+                               if (f < 0)
+                                       f = 0;
                                // check if this will reduce the collision time range
                                if (enterfrac < f)
                                {
@@ -753,22 +882,28 @@ void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const
                                                return;
                                        // calculate the nudged fraction and impact normal we'll
                                        // need if we accept this collision later
-                                       enterfrac2 = f - collision_impactnudge.value * imove;
-                                       VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
-                                       hitq3surfaceflags = startplane->q3surfaceflags;
-                                       hittexture = startplane->texture;
+                                       enterfrac2 = (startdist - collision_impactnudge.value) * imove;
+                                       ie = 1.0f - enterfrac;
+                                       newimpactplane[0] = startplane[0] * ie + endplane[0] * enterfrac;
+                                       newimpactplane[1] = startplane[1] * ie + endplane[1] * enterfrac;
+                                       newimpactplane[2] = startplane[2] * ie + endplane[2] * enterfrac;
+                                       newimpactplane[3] = startplane[3] * ie + endplane[3] * enterfrac;
+                                       hitq3surfaceflags = other_start->planes[nplane].q3surfaceflags;
+                                       hittexture = other_start->planes[nplane].texture;
                                }
                        }
                }
                else
                {
                        // moving out of brush
-                       if (d1 > 0)
+                       if (startdist > 0)
                                return;
-                       if (d2 > 0)
+                       if (enddist > 0)
                        {
                                // leave
-                               f = (d1 + collision_leavenudge.value) / (d1 - d2);
+                               f = (startdist + collision_leavenudge.value) / (startdist - enddist);
+                               if (f > 1)
+                                       f = 1;
                                // check if this will reduce the collision time range
                                if (leavefrac > f)
                                {
@@ -785,42 +920,61 @@ void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const
        // at this point we know the trace overlaps the brush because it was not
        // rejected at any point in the loop above
 
-       // see if this brush can block the trace or not according to contents
-       if (trace->hitsupercontentsmask & thatbrush_start->supercontents)
+       // see if the trace started outside the brush or not
+       if (enterfrac > -1)
        {
-               if (enterfrac == -1)
+               // started outside, and overlaps, therefore there is a collision here
+               // store out the impact information
+               if (trace->hitsupercontentsmask & other_start->supercontents)
                {
-                       trace->startsupercontents |= thatbrush_start->supercontents;
-                       trace->startsolid = true;
-                       if (leavefrac < 1)
-                               trace->allsolid = true;
+                       trace->hitsupercontents = other_start->supercontents;
+                       trace->hitq3surfaceflags = hitq3surfaceflags;
+                       trace->hittexture = hittexture;
+                       trace->realfraction = bound(0, enterfrac, 1);
+                       trace->fraction = bound(0, enterfrac2, 1);
+                       if (collision_prefernudgedfraction.integer)
+                               trace->realfraction = trace->fraction;
+                       VectorCopy(newimpactplane, trace->plane.normal);
+                       trace->plane.dist = newimpactplane[3];
                }
-               // store out the impact information
-               trace->hitsupercontents = thatbrush_start->supercontents;
-               trace->hitq3surfaceflags = hitq3surfaceflags;
-               trace->hittexture = hittexture;
-               trace->realfraction = bound(0, enterfrac, 1);
-               trace->fraction = bound(0, enterfrac2, 1);
-               if (collision_prefernudgedfraction.integer)
-                       trace->realfraction = trace->fraction;
-               VectorCopy(newimpactnormal, trace->plane.normal);
        }
        else
        {
-               // this brush can not block the trace, but it can update start contents
-               if (enterfrac == -1)
-                       trace->startsupercontents |= thatbrush_start->supercontents;
+               // started inside, update startsolid and friends
+               trace->startsupercontents |= other_start->supercontents;
+               if (trace->hitsupercontentsmask & other_start->supercontents)
+               {
+                       trace->startsolid = true;
+                       if (leavefrac < 1)
+                               trace->allsolid = true;
+                       VectorCopy(newimpactplane, trace->plane.normal);
+                       trace->plane.dist = newimpactplane[3];
+                       if (trace->startdepth > startdepth)
+                       {
+                               trace->startdepth = startdepth;
+                               VectorCopy(startdepthnormal, trace->startdepthnormal);
+                       }
+               }
        }
 }
 
-void Collision_TracePointBrushFloat(trace_t *trace, const vec3_t point, const colbrushf_t *thatbrush)
+qboolean Collision_PointInsideBrushFloat(const vec3_t point, const colbrushf_t *brush)
 {
        int nplane;
        const colplanef_t *plane;
 
-       for (nplane = 0, plane = thatbrush->planes;nplane < thatbrush->numplanes;nplane++, plane++)
+       if (!BoxesOverlap(point, point, brush->mins, brush->maxs))
+               return false;
+       for (nplane = 0, plane = brush->planes;nplane < brush->numplanes;nplane++, plane++)
                if (DotProduct(plane->normal, point) > plane->dist)
-                       return;
+                       return false;
+       return true;
+}
+
+void Collision_TracePointBrushFloat(trace_t *trace, const vec3_t point, const colbrushf_t *thatbrush)
+{
+       if (!Collision_PointInsideBrushFloat(point, thatbrush))
+               return;
 
        trace->startsupercontents |= thatbrush->supercontents;
        if (trace->hitsupercontentsmask & thatbrush->supercontents)
@@ -831,21 +985,22 @@ 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;
-       for (i = 0;i < numpoints;in++, out++)
+       for (i = 0;i < numpoints;i++)
        {
-               out->v[0] = floor(in->v[0] * fractionprecision + 0.5f) * invfractionprecision;
-               out->v[1] = floor(in->v[1] * fractionprecision + 0.5f) * invfractionprecision;
-               out->v[2] = floor(in->v[2] * fractionprecision + 0.5f) * invfractionprecision;
+               out[i].v[0] = floor(in[i].v[0] * fractionprecision + 0.5f) * invfractionprecision;
+               out[i].v[1] = floor(in[i].v[1] * fractionprecision + 0.5f) * invfractionprecision;
+               out[i].v[2] = floor(in[i].v[2] * fractionprecision + 0.5f) * invfractionprecision;
        }
 }
 
-void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points, int supercontents)
+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)
        {
@@ -853,53 +1008,84 @@ void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbru
                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;
-       Collision_SnapCopyPoints(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
+       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 supercontents, int q3surfaceflags, texture_t *texture, const vec3_t segmentmins, const vec3_t segmentmaxs)
+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;
-       float facemins[3], facemaxs[3];
        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++)
        {
                polyf_brush.planes[i].q3surfaceflags = q3surfaceflags;
                polyf_brush.planes[i].texture = texture;
        }
-       for (i = 0;i < numtriangles;i++, element3i += 3)
+       if(stride)
        {
-               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(3, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
-               facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0]));
-               facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1]));
-               facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2]));
-               facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0]));
-               facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1]));
-               facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2]));
-               if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
+               int k, cnt, tri;
+               cnt = (numtriangles + stride - 1) / stride;
+               for(i = 0; i < cnt; ++i)
                {
-                       Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
-                       //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
-                       Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
+                       if(BoxesOverlap(bbox6f + i * 6, bbox6f + i * 6 + 3, segmentmins, segmentmaxs))
+                       {
+                               for(k = 0; k < stride; ++k)
+                               {
+                                       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);
+                               }
+                       }
+               }
+       }
+       else
+       {
+               for (i = 0;i < numtriangles;i++, element3i += 3)
+               {
+                       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);
+                       }
                }
        }
 }
 
-void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, int numpoints, const float *points, int supercontents)
+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)
        {
@@ -907,30 +1093,60 @@ void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, con
                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(numpoints, (colpointf_t *)points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
+       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 supercontents, int q3surfaceflags, texture_t *texture, const vec3_t segmentmins, const vec3_t segmentmaxs)
+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;
 #if 1
        // FIXME: snap vertices?
-       for (i = 0;i < numtriangles;i++, element3i += 3)
-               Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[0] * 3, vertex3f + element3i[1] * 3, vertex3f + element3i[2] * 3, supercontents, q3surfaceflags, texture);
+       if(stride)
+       {
+               int k, cnt, tri;
+               cnt = (numtriangles + stride - 1) / stride;
+               for(i = 0; i < cnt; ++i)
+               {
+                       if(BoxesOverlap(bbox6f + i * 6, bbox6f + i * 6 + 3, segmentmins, segmentmaxs))
+                       {
+                               for(k = 0; k < stride; ++k)
+                               {
+                                       tri = i * stride + k;
+                                       if(tri >= numtriangles)
+                                               break;
+                                       Collision_TraceLineTriangleFloat(trace, linestart, lineend, vertex3f + element3i[tri * 3 + 0] * 3, vertex3f + element3i[tri * 3 + 1] * 3, vertex3f + element3i[tri * 3 + 2] * 3, supercontents, q3surfaceflags, texture);
+                               }
+                       }
+               }
+       }
+       else
+       {
+               for (i = 0;i < numtriangles;i++, element3i += 3)
+                       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++)
        {
                polyf_brush.planes[i].supercontents = supercontents;
@@ -939,19 +1155,13 @@ void Collision_TraceLineTriangleMeshFloat(trace_t *trace, const vec3_t linestart
        }
        for (i = 0;i < numtriangles;i++, element3i += 3)
        {
-               float facemins[3], facemaxs[3];
-               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(numpoints, polyf_points, polyf_points, COLLISION_SNAPSCALE, COLLISION_SNAP);
-               facemins[0] = min(polyf_points[0].v[0], min(polyf_points[1].v[0], polyf_points[2].v[0]));
-               facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1]));
-               facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2]));
-               facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0]));
-               facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1]));
-               facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2]));
-               if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
+               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);
@@ -974,17 +1184,23 @@ void Collision_TraceBrushPolygonTransformFloat(trace_t *trace, const colbrushf_t
                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++)
@@ -992,8 +1208,10 @@ void Collision_TraceBrushPolygonTransformFloat(trace_t *trace, const colbrushf_t
                polyf_brushstart.planes[i].q3surfaceflags = q3surfaceflags;
                polyf_brushstart.planes[i].texture = texture;
        }
-       Collision_SnapCopyPoints(numpoints, polyf_pointsstart, polyf_pointsstart, COLLISION_SNAPSCALE, COLLISION_SNAP);
-       Collision_SnapCopyPoints(numpoints, polyf_pointsend, polyf_pointsend, COLLISION_SNAPSCALE, COLLISION_SNAP);
+       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);
 
@@ -1006,8 +1224,11 @@ void Collision_TraceBrushPolygonTransformFloat(trace_t *trace, const colbrushf_t
 
 
 #define MAX_BRUSHFORBOX 16
-static int brushforbox_index = 0;
+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];
@@ -1018,12 +1239,16 @@ void Collision_InitBrushForBox(void)
        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;
        }
 }
@@ -1060,9 +1285,14 @@ colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins,
                        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);
                }
        }
        brush->supercontents = supercontents;
+       brush->q3surfaceflags = q3surfaceflags;
+       brush->texture = texture;
        for (j = 0;j < brush->numplanes;j++)
        {
                brush->planes[j].q3surfaceflags = q3surfaceflags;
@@ -1149,7 +1379,7 @@ float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double
        if (deviationdist > sphereradius*sphereradius)
                return 1; // miss (off to the side)
        // nudge back to find the correct impact distance
-       impactdist += deviationdist - sphereradius;
+       impactdist -= sphereradius - deviationdist/sphereradius;
        if (impactdist >= linelength)
                return 1; // miss (not close enough)
        if (impactdist < 0)
@@ -1456,3 +1686,168 @@ void Collision_BoundingBoxOfBrushTraceSegment(const colbrushf_t *start, const co
        maxs[2] += 1;
 }
 
+//===========================================
+
+void Collision_ClipToGenericEntity(trace_t *trace, dp_model_t *model, int frame, const vec3_t bodymins, const vec3_t bodymaxs, int bodysupercontents, matrix4x4_t *matrix, matrix4x4_t *inversematrix, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int hitsupercontentsmask)
+{
+       float starttransformed[3], endtransformed[3];
+
+       memset(trace, 0, sizeof(*trace));
+       trace->fraction = trace->realfraction = 1;
+
+       Matrix4x4_Transform(inversematrix, start, starttransformed);
+       Matrix4x4_Transform(inversematrix, end, endtransformed);
+#if COLLISIONPARANOID >= 3
+       Con_Printf("trans(%f %f %f -> %f %f %f, %f %f %f -> %f %f %f)", start[0], start[1], start[2], starttransformed[0], starttransformed[1], starttransformed[2], end[0], end[1], end[2], endtransformed[0], endtransformed[1], endtransformed[2]);
+#endif
+
+       if (model && model->TraceBox)
+               model->TraceBox(model, bound(0, frame, (model->numframes - 1)), trace, starttransformed, mins, maxs, endtransformed, hitsupercontentsmask);
+       else
+               Collision_ClipTrace_Box(trace, bodymins, bodymaxs, starttransformed, mins, maxs, endtransformed, hitsupercontentsmask, bodysupercontents, 0, NULL);
+       trace->fraction = bound(0, trace->fraction, 1);
+       trace->realfraction = bound(0, trace->realfraction, 1);
+
+       VectorLerp(start, trace->fraction, end, trace->endpos);
+       // transform plane
+       // NOTE: this relies on plane.dist being directly after plane.normal
+       Matrix4x4_TransformPositivePlane(matrix, trace->plane.normal[0], trace->plane.normal[1], trace->plane.normal[2], trace->plane.dist, trace->plane.normal);
+}
+
+void Collision_ClipToWorld(trace_t *trace, dp_model_t *model, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end, int hitsupercontents)
+{
+       memset(trace, 0, sizeof(*trace));
+       trace->fraction = trace->realfraction = 1;
+       if (model && model->TraceBox)
+               model->TraceBox(model, 0, trace, start, mins, maxs, end, hitsupercontents);
+       trace->fraction = bound(0, trace->fraction, 1);
+       trace->realfraction = bound(0, trace->realfraction, 1);
+       VectorLerp(start, trace->fraction, end, trace->endpos);
+}
+
+void Collision_ClipLineToGenericEntity(trace_t *trace, dp_model_t *model, int frame, const vec3_t bodymins, const vec3_t bodymaxs, int bodysupercontents, matrix4x4_t *matrix, matrix4x4_t *inversematrix, const vec3_t start, const vec3_t end, int hitsupercontentsmask)
+{
+       float starttransformed[3], endtransformed[3];
+
+       memset(trace, 0, sizeof(*trace));
+       trace->fraction = trace->realfraction = 1;
+
+       Matrix4x4_Transform(inversematrix, start, starttransformed);
+       Matrix4x4_Transform(inversematrix, end, endtransformed);
+#if COLLISIONPARANOID >= 3
+       Con_Printf("trans(%f %f %f -> %f %f %f, %f %f %f -> %f %f %f)", start[0], start[1], start[2], starttransformed[0], starttransformed[1], starttransformed[2], end[0], end[1], end[2], endtransformed[0], endtransformed[1], endtransformed[2]);
+#endif
+
+       if (model && model->TraceLine)
+               model->TraceLine(model, bound(0, frame, (model->numframes - 1)), trace, starttransformed, endtransformed, hitsupercontentsmask);
+       else
+               Collision_ClipTrace_Box(trace, bodymins, bodymaxs, starttransformed, vec3_origin, vec3_origin, endtransformed, hitsupercontentsmask, bodysupercontents, 0, NULL);
+       trace->fraction = bound(0, trace->fraction, 1);
+       trace->realfraction = bound(0, trace->realfraction, 1);
+
+       VectorLerp(start, trace->fraction, end, trace->endpos);
+       // transform plane
+       // NOTE: this relies on plane.dist being directly after plane.normal
+       Matrix4x4_TransformPositivePlane(matrix, trace->plane.normal[0], trace->plane.normal[1], trace->plane.normal[2], trace->plane.dist, trace->plane.normal);
+}
+
+void Collision_ClipLineToWorld(trace_t *trace, dp_model_t *model, const vec3_t start, const vec3_t end, int hitsupercontents)
+{
+       memset(trace, 0, sizeof(*trace));
+       trace->fraction = trace->realfraction = 1;
+       if (model && model->TraceLine)
+               model->TraceLine(model, 0, trace, start, end, hitsupercontents);
+       trace->fraction = bound(0, trace->fraction, 1);
+       trace->realfraction = bound(0, trace->realfraction, 1);
+       VectorLerp(start, trace->fraction, end, trace->endpos);
+}
+
+void Collision_ClipPointToGenericEntity(trace_t *trace, dp_model_t *model, int frame, const vec3_t bodymins, const vec3_t bodymaxs, int bodysupercontents, matrix4x4_t *matrix, matrix4x4_t *inversematrix, const vec3_t start, int hitsupercontentsmask)
+{
+       float starttransformed[3];
+
+       memset(trace, 0, sizeof(*trace));
+       trace->fraction = trace->realfraction = 1;
+
+       Matrix4x4_Transform(inversematrix, start, starttransformed);
+#if COLLISIONPARANOID >= 3
+       Con_Printf("trans(%f %f %f -> %f %f %f)", start[0], start[1], start[2], starttransformed[0], starttransformed[1], starttransformed[2]);
+#endif
+
+       if (model && model->TracePoint)
+               model->TracePoint(model, bound(0, frame, (model->numframes - 1)), trace, starttransformed, hitsupercontentsmask);
+       else
+               Collision_ClipTrace_Point(trace, bodymins, bodymaxs, starttransformed, hitsupercontentsmask, bodysupercontents, 0, NULL);
+
+       VectorCopy(start, trace->endpos);
+       // transform plane
+       // NOTE: this relies on plane.dist being directly after plane.normal
+       Matrix4x4_TransformPositivePlane(matrix, trace->plane.normal[0], trace->plane.normal[1], trace->plane.normal[2], trace->plane.dist, trace->plane.normal);
+}
+
+void Collision_ClipPointToWorld(trace_t *trace, dp_model_t *model, const vec3_t start, int hitsupercontents)
+{
+       memset(trace, 0, sizeof(*trace));
+       trace->fraction = trace->realfraction = 1;
+       if (model && model->TracePoint)
+               model->TracePoint(model, 0, trace, start, hitsupercontents);
+       VectorCopy(start, trace->endpos);
+}
+
+void Collision_CombineTraces(trace_t *cliptrace, const trace_t *trace, void *touch, qboolean isbmodel)
+{
+       // take the 'best' answers from the new trace and combine with existing data
+       if (trace->allsolid)
+               cliptrace->allsolid = true;
+       if (trace->startsolid)
+       {
+               if (isbmodel)
+                       cliptrace->bmodelstartsolid = true;
+               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
+       // (inopen && inwater is how they check water visibility)
+       //if (trace->inopen)
+       //      cliptrace->inopen = true;
+       if (trace->inwater)
+               cliptrace->inwater = true;
+       if ((trace->realfraction <= cliptrace->realfraction) && (VectorLength2(trace->plane.normal) > 0))
+       {
+               cliptrace->fraction = trace->fraction;
+               cliptrace->realfraction = trace->realfraction;
+               VectorCopy(trace->endpos, cliptrace->endpos);
+               cliptrace->plane = trace->plane;
+               cliptrace->ent = touch;
+               cliptrace->hitsupercontents = trace->hitsupercontents;
+               cliptrace->hitq3surfaceflags = trace->hitq3surfaceflags;
+               cliptrace->hittexture = trace->hittexture;
+       }
+       cliptrace->startsupercontents |= trace->startsupercontents;
+}
+
+void Collision_ShortenTrace(trace_t *trace, float shorten_factor, const vec3_t end)
+{
+       // now undo our moving end 1 qu farther...
+       trace->fraction = bound(trace->fraction, trace->fraction / shorten_factor - 1e-6, 1); // we subtract 1e-6 to guard for roundoff errors
+       trace->realfraction = bound(trace->realfraction, trace->realfraction / shorten_factor - 1e-6, 1); // we subtract 1e-6 to guard for roundoff errors
+       if(trace->fraction >= 1) // trace would NOT hit if not expanded!
+       {
+               trace->fraction = 1;
+               trace->realfraction = 1;
+               VectorCopy(end, trace->endpos);
+               memset(&trace->plane, 0, sizeof(trace->plane));
+               trace->ent = NULL;
+               trace->hitsupercontentsmask = 0;
+               trace->hitsupercontents = 0;
+               trace->hitq3surfaceflags = 0;
+               trace->hittexture = NULL;
+       }
+}