X-Git-Url: http://de.git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=blobdiff_plain;f=collision.c;h=73a1bd0a5b374fa1d2c1a847d0150242c8ffae74;hp=11300643e15966f6eba5fea4eb9826ff5f0c3f26;hb=7a96ec58916ceea50684acf4c00eaef551199fef;hpb=340c4d637bbc0346e545c0ef5f8509c651aa72c6

diff --git a/collision.c b/collision.c
index 11300643..73a1bd0a 100644
--- a/collision.c
+++ b/collision.c
@@ -1,296 +1,18 @@
 
 #include "quakedef.h"
-#include "winding.h"
+#include "polygon.h"
 
 #define COLLISION_SNAPSCALE (32.0f)
 #define COLLISION_SNAP (1.0f / COLLISION_SNAPSCALE)
+#define COLLISION_SNAP2 (2.0f / COLLISION_SNAPSCALE)
+#define COLLISION_PLANE_DIST_EPSILON (2.0f / COLLISION_SNAPSCALE)
 
-cvar_t collision_impactnudge = {0, "collision_impactnudge", "0.03125"};
-cvar_t collision_startnudge = {0, "collision_startnudge", "0"};
-cvar_t collision_endnudge = {0, "collision_endnudge", "0"};
-cvar_t collision_enternudge = {0, "collision_enternudge", "0"};
-cvar_t collision_leavenudge = {0, "collision_leavenudge", "0"};
-
-#if 0
-typedef struct
-{
-	// the hull we're tracing through
-	const hull_t *hull;
-
-	// the trace structure to fill in
-	trace_t *trace;
-
-	// start and end of the trace (in model space)
-	double start[3];
-	double end[3];
-
-	// end - start
-	double dist[3];
-
-	// overrides the CONTENTS_SOLID in the box bsp tree
-	int boxsupercontents;
-}
-RecursiveHullCheckTraceInfo_t;
-
-#define HULLCHECKSTATE_EMPTY 0
-#define HULLCHECKSTATE_SOLID 1
-#define HULLCHECKSTATE_DONE 2
-
-static int RecursiveHullCheck(RecursiveHullCheckTraceInfo_t *t, int num, double p1f, double p2f, double p1[3], double p2[3])
-{
-	// status variables, these don't need to be saved on the stack when
-	// recursing...  but are because this should be thread-safe
-	// (note: tracing against a bbox is not thread-safe, yet)
-	int ret;
-	mplane_t *plane;
-	double t1, t2;
-
-	// variables that need to be stored on the stack when recursing
-	dclipnode_t *node;
-	int side;
-	double midf, mid[3];
-
-	// LordHavoc: a goto!  everyone flee in terror... :)
-loc0:
-	// check for empty
-	if (num < 0)
-	{
-		num = Mod_Q1BSP_SuperContentsFromNativeContents(NULL, num);
-		if (!t->trace->startfound)
-		{
-			t->trace->startfound = true;
-			t->trace->startsupercontents |= num;
-		}
-		if (num & SUPERCONTENTS_LIQUIDSMASK)
-			t->trace->inwater = true;
-		if (num == 0)
-			t->trace->inopen = true;
-		if (num & t->trace->hitsupercontentsmask)
-		{
-			// if the first leaf is solid, set startsolid
-			if (t->trace->allsolid)
-				t->trace->startsolid = true;
-#if COLLISIONPARANOID >= 3
-			Con_Print("S");
-#endif
-			return HULLCHECKSTATE_SOLID;
-		}
-		else
-		{
-			t->trace->allsolid = false;
-#if COLLISIONPARANOID >= 3
-			Con_Print("E");
-#endif
-			return HULLCHECKSTATE_EMPTY;
-		}
-	}
-
-	// find the point distances
-	node = t->hull->clipnodes + num;
-
-	plane = t->hull->planes + node->planenum;
-	if (plane->type < 3)
-	{
-		t1 = p1[plane->type] - plane->dist;
-		t2 = p2[plane->type] - plane->dist;
-	}
-	else
-	{
-		t1 = DotProduct (plane->normal, p1) - plane->dist;
-		t2 = DotProduct (plane->normal, p2) - plane->dist;
-	}
-
-	if (t1 < 0)
-	{
-		if (t2 < 0)
-		{
-#if COLLISIONPARANOID >= 3
-			Con_Print("<");
-#endif
-			num = node->children[1];
-			goto loc0;
-		}
-		side = 1;
-	}
-	else
-	{
-		if (t2 >= 0)
-		{
-#if COLLISIONPARANOID >= 3
-			Con_Print(">");
-#endif
-			num = node->children[0];
-			goto loc0;
-		}
-		side = 0;
-	}
-
-	// the line intersects, find intersection point
-	// LordHavoc: this uses the original trace for maximum accuracy
-#if COLLISIONPARANOID >= 3
-	Con_Print("M");
-#endif
-	if (plane->type < 3)
-	{
-		t1 = t->start[plane->type] - plane->dist;
-		t2 = t->end[plane->type] - plane->dist;
-	}
-	else
-	{
-		t1 = DotProduct (plane->normal, t->start) - plane->dist;
-		t2 = DotProduct (plane->normal, t->end) - plane->dist;
-	}
-
-	midf = t1 / (t1 - t2);
-	midf = bound(p1f, midf, p2f);
-	VectorMA(t->start, midf, t->dist, mid);
-
-	// recurse both sides, front side first
-	ret = RecursiveHullCheck (t, node->children[side], p1f, midf, p1, mid);
-	// if this side is not empty, return what it is (solid or done)
-	if (ret != HULLCHECKSTATE_EMPTY)
-		return ret;
-
-	ret = RecursiveHullCheck (t, node->children[side ^ 1], midf, p2f, mid, p2);
-	// if other side is not solid, return what it is (empty or done)
-	if (ret != HULLCHECKSTATE_SOLID)
-		return ret;
-
-	// front is air and back is solid, this is the impact point...
-	if (side)
-	{
-		t->trace->plane.dist = -plane->dist;
-		VectorNegate (plane->normal, t->trace->plane.normal);
-	}
-	else
-	{
-		t->trace->plane.dist = plane->dist;
-		VectorCopy (plane->normal, t->trace->plane.normal);
-	}
-
-	// calculate the true fraction
-	t1 = DotProduct(t->trace->plane.normal, t->start) - t->trace->plane.dist - collision_startnudge.value;
-	t2 = DotProduct(t->trace->plane.normal, t->end) - t->trace->plane.dist - collision_endnudge.value;
-	midf = t1 / (t1 - t2);
-	t->trace->realfraction = bound(0, midf, 1);
-
-	// calculate the return fraction which is nudged off the surface a bit
-	midf = (t1 - collision_impactnudge.value) / (t1 - t2);
-	t->trace->fraction = bound(0, midf, 1);
-
-#if COLLISIONPARANOID >= 3
-	Con_Print("D");
-#endif
-	return HULLCHECKSTATE_DONE;
-}
-
-#if 0
-// used if start and end are the same
-static void RecursiveHullCheckPoint (RecursiveHullCheckTraceInfo_t *t, int num)
-{
-	// If you can read this, you understand BSP trees
-	while (num >= 0)
-		num = t->hull->clipnodes[num].children[((t->hull->planes[t->hull->clipnodes[num].planenum].type < 3) ? (t->start[t->hull->planes[t->hull->clipnodes[num].planenum].type]) : (DotProduct(t->hull->planes[t->hull->clipnodes[num].planenum].normal, t->start))) < t->hull->planes[t->hull->clipnodes[num].planenum].dist];
-
-	// check for empty
-	t->trace->endcontents = num;
-	if (t->trace->thiscontents)
-	{
-		if (num == t->trace->thiscontents)
-			t->trace->allsolid = false;
-		else
-		{
-			// if the first leaf is solid, set startsolid
-			if (t->trace->allsolid)
-				t->trace->startsolid = true;
-		}
-	}
-	else
-	{
-		if (num != CONTENTS_SOLID)
-		{
-			t->trace->allsolid = false;
-			if (num == CONTENTS_EMPTY)
-				t->trace->inopen = true;
-			else
-				t->trace->inwater = true;
-		}
-		else
-		{
-			// if the first leaf is solid, set startsolid
-			if (t->trace->allsolid)
-				t->trace->startsolid = true;
-		}
-	}
-}
-#endif
-
-static hull_t box_hull;
-static dclipnode_t box_clipnodes[6];
-static mplane_t box_planes[6];
-
-void Mod_Q1BSP_Collision_Init (void)
-{
-	int		i;
-	int		side;
-
-	//Set up the planes and clipnodes so that the six floats of a bounding box
-	//can just be stored out and get a proper hull_t structure.
-
-	box_hull.clipnodes = box_clipnodes;
-	box_hull.planes = box_planes;
-	box_hull.firstclipnode = 0;
-	box_hull.lastclipnode = 5;
-
-	for (i = 0;i < 6;i++)
-	{
-		box_clipnodes[i].planenum = i;
-
-		side = i&1;
-
-		box_clipnodes[i].children[side] = CONTENTS_EMPTY;
-		if (i != 5)
-			box_clipnodes[i].children[side^1] = i + 1;
-		else
-			box_clipnodes[i].children[side^1] = CONTENTS_SOLID;
-
-		box_planes[i].type = i>>1;
-		box_planes[i].normal[i>>1] = 1;
-	}
-}
-
-void Collision_ClipTrace_Box(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 boxsupercontents)
-{
-	RecursiveHullCheckTraceInfo_t rhc;
-	// fill in a default trace
-	memset(&rhc, 0, sizeof(rhc));
-	memset(trace, 0, sizeof(trace_t));
-	//To keep everything totally uniform, bounding boxes are turned into small
-	//BSP trees instead of being compared directly.
-	// create a temp hull from bounding box sizes
-	box_planes[0].dist = cmaxs[0] - mins[0];
-	box_planes[1].dist = cmins[0] - maxs[0];
-	box_planes[2].dist = cmaxs[1] - mins[1];
-	box_planes[3].dist = cmins[1] - maxs[1];
-	box_planes[4].dist = cmaxs[2] - mins[2];
-	box_planes[5].dist = cmins[2] - maxs[2];
-	// trace a line through the generated clipping hull
-	rhc.boxsupercontents = boxsupercontents;
-	rhc.hull = &box_hull;
-	rhc.trace = trace;
-	rhc.trace->hitsupercontentsmask = hitsupercontentsmask;
-	rhc.trace->fraction = 1;
-	rhc.trace->realfraction = 1;
-	rhc.trace->allsolid = true;
-	VectorCopy(start, rhc.start);
-	VectorCopy(end, rhc.end);
-	VectorSubtract(rhc.end, rhc.start, rhc.dist);
-	Mod_Q1BSP_RecursiveHullCheck(&rhc, rhc.hull->firstclipnode, 0, 1, rhc.start, rhc.end);
-	VectorMA(rhc.start, rhc.trace->fraction, rhc.dist, rhc.trace->endpos);
-	if (rhc.trace->startsupercontents)
-		rhc.trace->startsupercontents = boxsupercontents;
-}
-#endif
+cvar_t collision_impactnudge = {0, "collision_impactnudge", "0.03125", "how much to back off from the impact"};
+cvar_t collision_startnudge = {0, "collision_startnudge", "0", "how much to bias collision trace start"};
+cvar_t collision_endnudge = {0, "collision_endnudge", "0", "how much to bias collision trace end"};
+cvar_t collision_enternudge = {0, "collision_enternudge", "0", "how much to bias collision entry fraction"};
+cvar_t collision_leavenudge = {0, "collision_leavenudge", "0", "how much to bias collision exit fraction"};
+cvar_t collision_prefernudgedfraction = {0, "collision_prefernudgedfraction", "1", "whether to sort collision events by nudged fraction (1) or real fraction (0)"};
 
 void Collision_Init (void)
 {
@@ -299,6 +21,7 @@ void Collision_Init (void)
 	Cvar_RegisterVariable(&collision_endnudge);
 	Cvar_RegisterVariable(&collision_enternudge);
 	Cvar_RegisterVariable(&collision_leavenudge);
+	Cvar_RegisterVariable(&collision_prefernudgedfraction);
 }
 
 
@@ -328,7 +51,7 @@ void Collision_PrintBrushAsQHull(colbrushf_t *brush, const char *name)
 
 void Collision_ValidateBrush(colbrushf_t *brush)
 {
-	int j, k, pointsoffplanes, printbrush;
+	int j, k, pointsoffplanes, pointonplanes, pointswithinsufficientplanes, printbrush;
 	float d;
 	printbrush = false;
 	if (!brush->numpoints)
@@ -347,21 +70,33 @@ void Collision_ValidateBrush(colbrushf_t *brush)
 	if (brush->numplanes)
 	{
 		pointsoffplanes = 0;
+		pointswithinsufficientplanes = 0;
 		for (k = 0;k < brush->numplanes;k++)
-		{
 			if (DotProduct(brush->planes[k].normal, brush->planes[k].normal) < 0.0001f)
 				Con_Printf("Collision_ValidateBrush: plane #%i (%f %f %f %f) is degenerate\n", k, brush->planes[k].normal[0], brush->planes[k].normal[1], brush->planes[k].normal[2], brush->planes[k].dist);
-			for (j = 0;j < brush->numpoints;j++)
+		for (j = 0;j < brush->numpoints;j++)
+		{
+			pointonplanes = 0;
+			for (k = 0;k < brush->numplanes;k++)
 			{
 				d = DotProduct(brush->points[j].v, brush->planes[k].normal) - brush->planes[k].dist;
-				if (d > (1.0f / 8.0f))
+				if (d > COLLISION_PLANE_DIST_EPSILON)
 				{
 					Con_Printf("Collision_ValidateBrush: point #%i (%f %f %f) infront of plane #%i (%f %f %f %f)\n", j, brush->points[j].v[0], brush->points[j].v[1], brush->points[j].v[2], k, brush->planes[k].normal[0], brush->planes[k].normal[1], brush->planes[k].normal[2], brush->planes[k].dist);
 					printbrush = true;
 				}
-				if (fabs(d) > 0.01f)
+				if (fabs(d) > COLLISION_PLANE_DIST_EPSILON)
 					pointsoffplanes++;
+				else
+					pointonplanes++;
 			}
+			if (pointonplanes < 3)
+				pointswithinsufficientplanes++;
+		}
+		if (pointswithinsufficientplanes)
+		{
+			Con_Print("Collision_ValidateBrush: some points have insufficient planes, every point must be on at least 3 planes to form a corner.\n");
+			printbrush = true;
 		}
 		if (pointsoffplanes == 0) // all points are on all planes
 		{
@@ -376,6 +111,8 @@ void Collision_ValidateBrush(colbrushf_t *brush)
 float nearestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 {
 	float dist, bestdist;
+	if (!numpoints)
+		return 0;
 	bestdist = DotProduct(points->v, normal);
 	points++;
 	while(--numpoints)
@@ -390,6 +127,8 @@ float nearestplanedist_float(const float *normal, const colpointf_t *points, int
 float furthestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
 {
 	float dist, bestdist;
+	if (!numpoints)
+		return 0;
 	bestdist = DotProduct(points->v, normal);
 	points++;
 	while(--numpoints)
@@ -402,145 +141,227 @@ float furthestplanedist_float(const float *normal, const colpointf_t *points, in
 }
 
 
-colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const mplane_t *originalplanes, int supercontents, winding_t *temp1, winding_t *temp2)
+colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalplanes, const colplanef_t *originalplanes, int supercontents)
 {
-	int j, k, m;
-	int numpoints, maxpoints, numplanes, maxplanes, numelements, maxelements, numtriangles, numpolypoints, maxpolypoints;
-	winding_t *w, *temp, *othertemp;
+	// 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;
+	double maxdist;
 	colbrushf_t *brush;
 	colpointf_t pointsbuf[256];
 	colplanef_t planesbuf[256];
 	int elementsbuf[1024];
 	int polypointbuf[256];
+	int pmaxpoints = 64;
+	int pnumpoints;
+	double p[2][3*64];
+#if 0
+	// enable these if debugging to avoid seeing garbage in unused data
+	memset(pointsbuf, 0, sizeof(pointsbuf));
+	memset(planesbuf, 0, sizeof(planesbuf));
+	memset(elementsbuf, 0, sizeof(elementsbuf));
+	memset(polypointbuf, 0, sizeof(polypointbuf));
+	memset(p, 0, sizeof(p));
+#endif
+	// figure out how large a bounding box we need to properly compute this brush
+	maxdist = 0;
+	for (j = 0;j < numoriginalplanes;j++)
+		maxdist = max(maxdist, fabs(originalplanes[j].dist));
+	// now make it large enough to enclose the entire brush, and round it off to a reasonable multiple of 1024
+	maxdist = floor(maxdist * (4.0 / 1024.0) + 2) * 1024.0;
 	// construct a collision brush (points, planes, and renderable mesh) from
 	// a set of planes, this also optimizes out any unnecessary planes (ones
 	// whose polygon is clipped away by the other planes)
-	numpoints = 0;maxpoints = 256;
-	numplanes = 0;maxplanes = 256;
-	numelements = 0;maxelements = 1024;
-	numtriangles = 0;
-	maxpolypoints = 256;
 	for (j = 0;j < numoriginalplanes;j++)
 	{
 		// add the plane uniquely (no duplicates)
-		for (k = 0;k < numplanes;k++)
+		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 < numplanes)
+		if (k < numplanesbuf)
 			continue;
 		// check if there are too many and skip the brush
-		if (numplanes >= 256)
+		if (numplanesbuf >= maxplanesbuf)
 		{
-			Con_Print("Mod_Q3BSP_LoadBrushes: failed to build collision brush: too many planes for buffer\n");
+			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;
+		planesbuf[numplanesbuf].q3surfaceflags = originalplanes[j].q3surfaceflags;
+		planesbuf[numplanesbuf].texture = originalplanes[j].texture;
+		numplanesbuf++;
+
 		// create a large polygon from the plane
-		w = temp1;
-		othertemp = temp2;
-		BufWinding_NewFromPlane(w, originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist);
+		w = 0;
+		PolygonD_QuadForPlane(p[w], originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist, maxdist);
+		pnumpoints = 4;
 		// clip it by all other planes
-		for (k = 0;k < numoriginalplanes && w->numpoints;k++)
+		for (k = 0;k < numoriginalplanes && pnumpoints >= 3 && pnumpoints <= pmaxpoints;k++)
 		{
+			// skip the plane this polygon
+			// (nothing happens if it is processed, this is just an optimization)
 			if (k != j)
 			{
 				// we want to keep the inside of the brush plane so we flip
 				// the cutting plane
-				BufWinding_Divide(w, -originalplanes[k].normal[0], -originalplanes[k].normal[1], -originalplanes[k].normal[2], -originalplanes[k].dist, othertemp, NULL, NULL, NULL);
-				temp = w;
-				w = othertemp;
-				othertemp = temp;
+				PolygonD_Divide(pnumpoints, p[w], -originalplanes[k].normal[0], -originalplanes[k].normal[1], -originalplanes[k].normal[2], -originalplanes[k].dist, COLLISION_PLANE_DIST_EPSILON, pmaxpoints, p[!w], &pnumpoints, 0, NULL, NULL, NULL);
+				w = !w;
 			}
 		}
+
 		// if nothing is left, skip it
-		if (!w->numpoints)
+		if (pnumpoints < 3)
+		{
+			//Con_DPrintf("Collision_NewBrushFromPlanes: warning: polygon for plane %f %f %f %f clipped away\n", originalplanes[j].normal[0], originalplanes[j].normal[1], originalplanes[j].normal[2], originalplanes[j].dist);
 			continue;
+		}
 
-		// copy off the number of points for later when the winding is freed
-		numpolypoints = w->numpoints;
+		for (k = 0;k < pnumpoints;k++)
+		{
+			int l, m;
+			m = 0;
+			for (l = 0;l < numoriginalplanes;l++)
+				if (fabs(DotProduct(&p[w][k*3], originalplanes[l].normal) - originalplanes[l].dist) < COLLISION_PLANE_DIST_EPSILON)
+					m++;
+			if (m < 3)
+				break;
+		}
+		if (k < pnumpoints)
+		{
+			Con_DPrintf("Collision_NewBrushFromPlanes: warning: polygon point does not lie on at least 3 planes\n");
+			//return NULL;
+		}
 
 		// check if there are too many polygon vertices for buffer
-		if (numpolypoints > maxpolypoints)
+		if (pnumpoints > pmaxpoints)
 		{
-			Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
+			Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 			return NULL;
 		}
 
 		// check if there are too many triangle elements for buffer
-		if (numelements + (w->numpoints - 2) * 3 > maxelements)
+		if (numelementsbuf + (pnumpoints - 2) * 3 > maxelementsbuf)
 		{
-			Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many triangle elements for buffer\n");
+			Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many triangle elements for buffer\n");
 			return NULL;
 		}
 
-		for (k = 0;k < w->numpoints;k++)
+		for (k = 0;k < pnumpoints;k++)
 		{
+			float v[3];
+			// downgrade to float precision before comparing
+			VectorCopy(&p[w][k*3], v);
+
 			// check if there is already a matching point (no duplicates)
-			for (m = 0;m < numpoints;m++)
-				if (VectorDistance2(w->points[k], pointsbuf[m].v) < COLLISION_SNAP)
+			for (m = 0;m < numpointsbuf;m++)
+				if (VectorDistance2(v, pointsbuf[m].v) < COLLISION_SNAP2)
 					break;
 
 			// if there is no match, add a new one
-			if (m == numpoints)
+			if (m == numpointsbuf)
 			{
 				// check if there are too many and skip the brush
-				if (numpoints >= 256)
+				if (numpointsbuf >= maxpointsbuf)
 				{
-					Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
-					Winding_Free(w);
+					Con_DPrint("Collision_NewBrushFromPlanes: failed to build collision brush: too many points for buffer\n");
 					return NULL;
 				}
 				// add the new one
-				VectorCopy(w->points[k], pointsbuf[numpoints].v);
-				numpoints++;
+				VectorCopy(&p[w][k*3], pointsbuf[numpointsbuf].v);
+				numpointsbuf++;
 			}
 
 			// store the index into a buffer
 			polypointbuf[k] = m;
 		}
-		w = NULL;
-		othertemp = NULL;
-		temp = NULL;
 
 		// add the triangles for the polygon
 		// (this particular code makes a triangle fan)
-		for (k = 0;k < numpolypoints - 2;k++)
+		for (k = 0;k < pnumpoints - 2;k++)
 		{
-			numtriangles++;
-			elementsbuf[numelements++] = polypointbuf[0];
-			elementsbuf[numelements++] = polypointbuf[k + 1];
-			elementsbuf[numelements++] = polypointbuf[k + 2];
+			elementsbuf[numelementsbuf++] = polypointbuf[0];
+			elementsbuf[numelementsbuf++] = polypointbuf[k + 1];
+			elementsbuf[numelementsbuf++] = polypointbuf[k + 2];
 		}
-
-		// add the new plane
-		VectorCopy(originalplanes[j].normal, planesbuf[numplanes].normal);
-		planesbuf[numplanes].dist = originalplanes[j].dist;
-		numplanes++;
 	}
 
 	// if nothing is left, there's nothing to allocate
-	if (numtriangles < 4 || numplanes < 4 || numpoints < 4)
+	if (numplanesbuf < 4)
+	{
+		Con_DPrintf("Collision_NewBrushFromPlanes: failed to build collision brush: %i triangles, %i planes (input was %i planes), %i vertices\n", numelementsbuf / 3, numplanesbuf, numoriginalplanes, numpointsbuf);
 		return NULL;
+	}
+
+	// if no triangles or points could be constructed, then this routine failed but the brush is not discarded
+	if (numelementsbuf < 12 || numpointsbuf < 4)
+		Con_DPrintf("Collision_NewBrushFromPlanes: unable to rebuild triangles/points for collision brush: %i triangles, %i planes (input was %i planes), %i vertices\n", numelementsbuf / 3, numplanesbuf, numoriginalplanes, numpointsbuf);
+
+	// validate plane distances
+	for (j = 0;j < numplanesbuf;j++)
+	{
+		float d = furthestplanedist_float(planesbuf[j].normal, pointsbuf, numpointsbuf);
+		if (fabs(planesbuf[j].dist - d) > COLLISION_PLANE_DIST_EPSILON)
+			Con_DPrintf("plane %f %f %f %f mismatches dist %f\n", planesbuf[j].normal[0], planesbuf[j].normal[1], planesbuf[j].normal[2], planesbuf[j].dist, d);
+	}
 
 	// allocate the brush and copy to it
-	brush = Collision_AllocBrushFloat(mempool, numpoints, numplanes, numtriangles, supercontents);
-	memcpy(brush->points, pointsbuf, numpoints * sizeof(colpointf_t));
-	memcpy(brush->planes, planesbuf, numplanes * sizeof(colplanef_t));
-	memcpy(brush->elements, elementsbuf, numtriangles * sizeof(int[3]));
-	// recalc distances
+	brush = (colbrushf_t *)Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpointsbuf + sizeof(colplanef_t) * numplanesbuf + sizeof(int) * numelementsbuf);
+	brush->supercontents = supercontents;
+	brush->numplanes = numplanesbuf;
+	brush->numpoints = numpointsbuf;
+	brush->numtriangles = numelementsbuf / 3;
+	brush->planes = (colplanef_t *)(brush + 1);
+	brush->points = (colpointf_t *)(brush->planes + brush->numplanes);
+	brush->elements = (int *)(brush->points + brush->numpoints);
+	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->numplanes;j++)
-		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->planes[j].normal[0] = planesbuf[j].normal[0];
+		brush->planes[j].normal[1] = planesbuf[j].normal[1];
+		brush->planes[j].normal[2] = planesbuf[j].normal[2];
+		brush->planes[j].dist = planesbuf[j].dist;
+		brush->planes[j].q3surfaceflags = planesbuf[j].q3surfaceflags;
+		brush->planes[j].texture = planesbuf[j].texture;
+	}
+	for (j = 0;j < brush->numtriangles * 3;j++)
+		brush->elements[j] = elementsbuf[j];
+
+	xyzflags = 0;
+	VectorClear(brush->mins);
+	VectorClear(brush->maxs);
+	for (j = 0;j < min(6, numoriginalplanes);j++)
+	{
+		     if (originalplanes[j].normal[0] ==  1) {xyzflags |=  1;brush->maxs[0] =  originalplanes[j].dist;}
+		else if (originalplanes[j].normal[0] == -1) {xyzflags |=  2;brush->mins[0] = -originalplanes[j].dist;}
+		else if (originalplanes[j].normal[1] ==  1) {xyzflags |=  4;brush->maxs[1] =  originalplanes[j].dist;}
+		else if (originalplanes[j].normal[1] == -1) {xyzflags |=  8;brush->mins[1] = -originalplanes[j].dist;}
+		else if (originalplanes[j].normal[2] ==  1) {xyzflags |= 16;brush->maxs[2] =  originalplanes[j].dist;}
+		else if (originalplanes[j].normal[2] == -1) {xyzflags |= 32;brush->mins[2] = -originalplanes[j].dist;}
+	}
+	// if not all xyzflags were set, then this is not a brush from q3map/q3map2, and needs reconstruction of the bounding box
+	// (this case works for any brush with valid points, but sometimes brushes are not reconstructed properly and hence the points are not valid, so this is reserved as a fallback case)
+	if (xyzflags != 63)
+	{
+		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;
@@ -554,26 +375,13 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
 
 
 
-colbrushf_t *Collision_AllocBrushFloat(mempool_t *mempool, int numpoints, int numplanes, int numtriangles, int supercontents)
-{
-	colbrushf_t *brush;
-	brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpoints + sizeof(colplanef_t) * numplanes + sizeof(int[3]) * numtriangles);
-	brush->supercontents = supercontents;
-	brush->numplanes = numplanes;
-	brush->numpoints = numpoints;
-	brush->numtriangles = numtriangles;
-	brush->planes = (void *)(brush + 1);
-	brush->points = (void *)(brush->planes + brush->numplanes);
-	brush->elements = (void *)(brush->points + brush->numpoints);
-	return brush;
-}
-
 void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 {
 	int i;
-	float edge0[3], edge1[3], edge2[3], normal[3], dist, bestdist, temp[3];
+	float edge0[3], edge1[3], edge2[3], normal[3], dist, bestdist;
 	colpointf_t *p, *p2;
 
+	// FIXME: these probably don't actually need to be normalized if the collision code does not care
 	if (brush->numpoints == 3)
 	{
 		// optimized triangle case
@@ -637,10 +445,12 @@ void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 			brush->planes[3].dist = DotProduct(brush->points[0].v, brush->planes[3].normal);
 			brush->planes[4].dist = DotProduct(brush->points[1].v, brush->planes[4].normal);
 
-			if (developer.integer)
+			if (developer.integer >= 100)
 			{
 				// validation code
 #if 0
+				float temp[3];
+
 				VectorSubtract(brush->points[0].v, brush->points[1].v, edge0);
 				VectorSubtract(brush->points[2].v, brush->points[1].v, edge1);
 				CrossProduct(edge0, edge1, normal);
@@ -720,7 +530,7 @@ void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 		}
 	}
 
-	if (developer.integer)
+	if (developer.integer >= 100)
 	{
 		// validity check - will be disabled later
 		Collision_ValidateBrush(brush);
@@ -728,7 +538,7 @@ void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 		{
 			int j;
 			for (j = 0, p = brush->points;j < brush->numpoints;j++, p++)
-				if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + (1.0 / 32.0))
+				if (DotProduct(p->v, brush->planes[i].normal) > brush->planes[i].dist + COLLISION_PLANE_DIST_EPSILON)
 					Con_Printf("Error in brush plane generation, plane %i\n", i);
 		}
 	}
@@ -737,28 +547,25 @@ void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
 colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points, int supercontents)
 {
 	colbrushf_t *brush;
-	brush = 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));
 	brush->supercontents = supercontents;
 	brush->numpoints = numpoints;
 	brush->numplanes = numpoints + 2;
-	brush->planes = (void *)(brush + 1);
+	brush->planes = (colplanef_t *)(brush + 1);
 	brush->points = (colpointf_t *)points;
-	Host_Error("Collision_AllocBrushFromPermanentPolygonFloat: FIXME: this code needs to be updated to generate a mesh...\n");
+	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)
 {
-	int nplane, nplane2, fstartsolid, fendsolid, brushsolid;
-	float enterfrac, leavefrac, d1, d2, f, move, imove, newimpactnormal[3], enterfrac2;
+	int nplane, nplane2, hitq3surfaceflags = 0;
+	float enterfrac = -1, leavefrac = 1, d1, d2, f, imove, newimpactnormal[3], enterfrac2 = -1;
 	const colplanef_t *startplane, *endplane;
+	texture_t *hittexture = NULL;
 
-	enterfrac = -1;
-	enterfrac2 = -1;
-	leavefrac = 1;
-	fstartsolid = true;
-	fendsolid = true;
+	VectorClear(newimpactnormal);
 
 	for (nplane = 0;nplane < thatbrush_start->numplanes + thisbrush_start->numplanes;nplane++)
 	{
@@ -768,7 +575,7 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush
 			nplane2 -= thatbrush_start->numplanes;
 			startplane = thisbrush_start->planes + nplane2;
 			endplane = thisbrush_end->planes + nplane2;
-			if (developer.integer)
+			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)
@@ -777,7 +584,7 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush
 					return;
 				}
 				f = furthestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints);
-				if (fabs(f - startplane->dist) > 0.01f)
+				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;
@@ -787,7 +594,7 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush
 		{
 			startplane = thatbrush_start->planes + nplane2;
 			endplane = thatbrush_end->planes + nplane2;
-			if (developer.integer)
+			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)
@@ -796,7 +603,7 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush
 					return;
 				}
 				f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
-				if (fabs(f - startplane->dist) > 0.01f)
+				if (fabs(f - startplane->dist) > COLLISION_PLANE_DIST_EPSILON)
 					Con_Printf("startplane->dist %f != calculated %f (thatbrush_start)\n", startplane->dist, f);
 			}
 			d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - startplane->dist - collision_startnudge.value;
@@ -804,109 +611,106 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush
 		}
 		//Con_Printf("%c%i: d1 = %f, d2 = %f, d1 / (d1 - d2) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, d1, d2, d1 / (d1 - d2));
 
-		move = d1 - d2;
-		if (move > 0)
+		if (d1 > d2)
 		{
 			// moving into brush
-			if (d2 > collision_enternudge.value)
+			if (d2 >= collision_enternudge.value)
 				return;
-			if (d1 < 0)
-				continue;
-			// enter
-			fstartsolid = false;
-			imove = 1 / move;
-			f = (d1 - collision_enternudge.value) * imove;
-			f = bound(0, f, 1);
-			if (enterfrac < f)
+			if (d1 > 0)
 			{
-				enterfrac = f;
-				enterfrac2 = f - collision_impactnudge.value * imove;
-				enterfrac2 = bound(0, enterfrac2, 1);
-				VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
+				// enter
+				imove = 1 / (d1 - d2);
+				f = (d1 - collision_enternudge.value) * imove;
+				if (f < 0)
+					f = 0;
+				// check if this will reduce the collision time range
+				if (enterfrac < f)
+				{
+					// reduced collision time range
+					enterfrac = f;
+					// if the collision time range is now empty, no collision
+					if (enterfrac > leavefrac)
+						return;
+					// if the collision would be further away than the trace's
+					// existing collision data, we don't care about this
+					// collision
+					if (enterfrac > trace->realfraction)
+						return;
+					// calculate the nudged fraction and impact normal we'll
+					// need if we accept this collision later
+					enterfrac2 = (d1 - collision_impactnudge.value) * imove;
+					VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
+					hitq3surfaceflags = startplane->q3surfaceflags;
+					hittexture = startplane->texture;
+				}
 			}
 		}
-		else if (move < 0)
-		{
-			// moving out of brush
-			if (d1 > collision_leavenudge.value)
-				return;
-			if (d2 < 0)
-				continue;
-			// leave
-			fendsolid = false;
-			f = (d1 + collision_leavenudge.value) / move;
-			f = bound(0, f, 1);
-			if (leavefrac > f)
-				leavefrac = f;
-		}
 		else
 		{
-			// sliding along plane
+			// moving out of brush
 			if (d1 > 0)
 				return;
+			if (d2 > 0)
+			{
+				// leave
+				f = (d1 + collision_leavenudge.value) / (d1 - d2);
+				if (f > 1)
+					f = 1;
+				// check if this will reduce the collision time range
+				if (leavefrac > f)
+				{
+					// reduced collision time range
+					leavefrac = f;
+					// if the collision time range is now empty, no collision
+					if (enterfrac > leavefrac)
+						return;
+				}
+			}
 		}
 	}
 
-	brushsolid = trace->hitsupercontentsmask & thatbrush_start->supercontents;
-	if (fstartsolid)
-	{
-		trace->startsupercontents |= thatbrush_start->supercontents;
-		if (brushsolid)
-		{
-			trace->startsolid = true;
-			if (fendsolid)
-				trace->allsolid = true;
-		}
-	}
+	// at this point we know the trace overlaps the brush because it was not
+	// rejected at any point in the loop above
 
-	// LordHavoc: we need an epsilon nudge here because for a point trace the
-	// penetrating line segment is normally zero length if this brush was
-	// generated from a polygon (infinitely thin), and could even be slightly
-	// positive or negative due to rounding errors in that case.
-	if (brushsolid && enterfrac > -1 && enterfrac < trace->realfraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
+	// see if the trace started outside the brush or not
+	if (enterfrac > -1)
 	{
-#if 0
-		// broken
-		if (thatbrush_start->ispolygon)
-		{
-			d1 = nearestplanedist_float(thatbrush_start->planes[0].normal, thisbrush_start->points, thisbrush_start->numpoints) - thatbrush_start->planes[0].dist - collision_startnudge.value;
-			d2 = nearestplanedist_float(thatbrush_end->planes[0].normal, thisbrush_end->points, thisbrush_end->numpoints) - thatbrush_end->planes[0].dist - collision_endnudge.value;
-			move = d1 - d2;
-			if (move <= 0 || d2 > collision_enternudge.value || d1 < 0)
-				return;
-			// enter
-			imove = 1 / move;
-			enterfrac = (d1 - collision_enternudge.value) * imove;
-			if (enterfrac < trace->realfraction)
-			{
-				enterfrac2 = enterfrac - collision_impactnudge.value * imove;
-				trace->realfraction = bound(0, enterfrac, 1);
-				trace->fraction = bound(0, enterfrac2, 1);
-				VectorLerp(thatbrush_start->planes[0].normal, enterfrac, thatbrush_end->planes[0].normal, trace->plane.normal);
-			}
-		}
-		else
-#endif
+		// started outside, and overlaps, therefore there is a collision here
+		// store out the impact information
+		if (trace->hitsupercontentsmask & thatbrush_start->supercontents)
 		{
+			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
+	{
+		// started inside, update startsolid and friends
+		trace->startsupercontents |= thatbrush_start->supercontents;
+		if (trace->hitsupercontentsmask & thatbrush_start->supercontents)
+		{
+			trace->startsolid = true;
+			if (leavefrac < 1)
+				trace->allsolid = true;
+		}
+	}
 }
 
 // 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)
 {
-	int nplane, fstartsolid, fendsolid, brushsolid;
-	float enterfrac, leavefrac, d1, d2, f, move, imove, newimpactnormal[3], enterfrac2;
+	int nplane, hitq3surfaceflags = 0;
+	float enterfrac = -1, leavefrac = 1, d1, d2, f, imove, newimpactnormal[3], enterfrac2 = -1;
 	const colplanef_t *startplane, *endplane;
+	texture_t *hittexture = NULL;
 
-	enterfrac = -1;
-	enterfrac2 = -1;
-	leavefrac = 1;
-	fstartsolid = true;
-	fendsolid = true;
+	VectorClear(newimpactnormal);
 
 	for (nplane = 0;nplane < thatbrush_start->numplanes;nplane++)
 	{
@@ -914,7 +718,7 @@ void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const
 		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)
+		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)
@@ -925,101 +729,117 @@ void Collision_TraceLineBrushFloat(trace_t *trace, const vec3_t linestart, const
 			if (thatbrush_start->numpoints)
 			{
 				f = furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
-				if (fabs(f - startplane->dist) > 0.01f)
+				if (fabs(f - startplane->dist) > COLLISION_PLANE_DIST_EPSILON)
 					Con_Printf("startplane->dist %f != calculated %f\n", startplane->dist, f);
 			}
 		}
 
-		move = d1 - d2;
-		if (move > 0)
+		if (d1 > d2)
 		{
 			// moving into brush
-			if (d2 >= 0)
+			if (d2 >= collision_enternudge.value)
 				return;
-			if (d1 <= 0)
-				continue;
-			// enter
-			fstartsolid = false;
-			imove = 1 / move;
-			f = (d1 - collision_enternudge.value) * imove;
-			if (enterfrac < f)
+			if (d1 > 0)
 			{
-				enterfrac = f;
-				enterfrac2 = f - collision_impactnudge.value * imove;
-				VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
+				// enter
+				imove = 1 / (d1 - d2);
+				f = (d1 - collision_enternudge.value) * imove;
+				if (f < 0)
+					f = 0;
+				// check if this will reduce the collision time range
+				if (enterfrac < f)
+				{
+					// reduced collision time range
+					enterfrac = f;
+					// if the collision time range is now empty, no collision
+					if (enterfrac > leavefrac)
+						return;
+					// if the collision would be further away than the trace's
+					// existing collision data, we don't care about this
+					// collision
+					if (enterfrac > trace->realfraction)
+						return;
+					// calculate the nudged fraction and impact normal we'll
+					// need if we accept this collision later
+					enterfrac2 = (d1 - collision_impactnudge.value) * imove;
+					VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
+					hitq3surfaceflags = startplane->q3surfaceflags;
+					hittexture = startplane->texture;
+				}
 			}
 		}
 		else
 		{
 			// moving out of brush
-			if (d1 >= 0)
+			if (d1 > 0)
 				return;
-			if (d2 <= 0)
-				continue;
-			// leave
-			fendsolid = false;
-			f = (d1 - collision_leavenudge.value) / move;
-			if (leavefrac > f)
-				leavefrac = f;
+			if (d2 > 0)
+			{
+				// leave
+				f = (d1 + collision_leavenudge.value) / (d1 - d2);
+				// check if this will reduce the collision time range
+				if (leavefrac > f)
+				{
+					// reduced collision time range
+					leavefrac = f;
+					// if the collision time range is now empty, no collision
+					if (enterfrac > leavefrac)
+						return;
+				}
+			}
 		}
 	}
 
-	brushsolid = trace->hitsupercontentsmask & thatbrush_start->supercontents;
-	if (fstartsolid)
-	{
-		trace->startsupercontents |= thatbrush_start->supercontents;
-		if (brushsolid)
-		{
-			trace->startsolid = true;
-			if (fendsolid)
-				trace->allsolid = true;
-		}
-	}
+	// at this point we know the trace overlaps the brush because it was not
+	// rejected at any point in the loop above
 
-	// LordHavoc: we need an epsilon nudge here because for a point trace the
-	// penetrating line segment is normally zero length if this brush was
-	// generated from a polygon (infinitely thin), and could even be slightly
-	// positive or negative due to rounding errors in that case.
-	if (brushsolid && enterfrac > -1 && enterfrac < trace->realfraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
+	// see if the trace started outside the brush or not
+	if (enterfrac > -1)
 	{
-#if 0
-		// broken
-		if (thatbrush_start->ispolygon)
-		{
-			d1 = DotProduct(thatbrush_start->planes[0].normal, linestart) - thatbrush_start->planes[0].dist - collision_startnudge.value;
-			d2 = DotProduct(thatbrush_end->planes[0].normal, lineend) - thatbrush_end->planes[0].dist - collision_endnudge.value;
-			move = d1 - d2;
-			if (move <= 0 || d2 > collision_enternudge.value || d1 < 0)
-				return;
-			// enter
-			imove = 1 / move;
-			enterfrac = (d1 - collision_enternudge.value) * imove;
-			if (enterfrac < trace->realfraction)
-			{
-				enterfrac2 = enterfrac - collision_impactnudge.value * imove;
-				trace->realfraction = bound(0, enterfrac, 1);
-				trace->fraction = bound(0, enterfrac2, 1);
-				VectorLerp(thatbrush_start->planes[0].normal, enterfrac, thatbrush_end->planes[0].normal, trace->plane.normal);
-			}
-		}
-		else
-#endif
+		// started outside, and overlaps, therefore there is a collision here
+		// store out the impact information
+		if (trace->hitsupercontentsmask & thatbrush_start->supercontents)
 		{
+			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
+	{
+		// started inside, update startsolid and friends
+		trace->startsupercontents |= thatbrush_start->supercontents;
+		if (trace->hitsupercontentsmask & thatbrush_start->supercontents)
+		{
+			trace->startsolid = true;
+			if (leavefrac < 1)
+				trace->allsolid = true;
+		}
+	}
 }
 
-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)
@@ -1035,11 +855,12 @@ static colbrushf_t polyf_brush;
 
 void Collision_SnapCopyPoints(int numpoints, const colpointf_t *in, colpointf_t *out, float fractionprecision, float invfractionprecision)
 {
-	while (numpoints--)
+	int i;
+	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;
 	}
 }
 
@@ -1056,35 +877,33 @@ void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbru
 	polyf_brush.planes = polyf_planes;
 	polyf_brush.supercontents = supercontents;
 	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);
 	Collision_CalcPlanesForPolygonBrushFloat(&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, 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 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.numplanes = 5;
 	polyf_brush.points = polyf_points;
 	polyf_brush.planes = polyf_planes;
 	polyf_brush.supercontents = supercontents;
+	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)
 	{
-		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])) - 1;
-		facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1])) - 1;
-		facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2])) - 1;
-		facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0])) + 1;
-		facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1])) + 1;
-		facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2])) + 1;
-		if (BoxesOverlap(segmentmins, segmentmaxs, facemins, facemaxs))
+		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_CalcPlanesForPolygonBrushFloat(&polyf_brush);
 			//Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
 			Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
@@ -1103,7 +922,7 @@ void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, con
 	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.planes = polyf_planes;
 	polyf_brush.supercontents = supercontents;
 	Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
@@ -1111,34 +930,33 @@ void Collision_TraceLinePolygonFloat(trace_t *trace, const vec3_t linestart, con
 	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, 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 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);
+		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.numplanes = 5;
 	polyf_brush.points = polyf_points;
 	polyf_brush.planes = polyf_planes;
 	polyf_brush.supercontents = supercontents;
+	for (i = 0;i < polyf_brush.numplanes;i++)
+	{
+		polyf_brush.planes[i].supercontents = supercontents;
+		polyf_brush.planes[i].q3surfaceflags = q3surfaceflags;
+		polyf_brush.planes[i].texture = texture;
+	}
 	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])) - 1;
-		facemins[1] = min(polyf_points[0].v[1], min(polyf_points[1].v[1], polyf_points[2].v[1])) - 1;
-		facemins[2] = min(polyf_points[0].v[2], min(polyf_points[1].v[2], polyf_points[2].v[2])) - 1;
-		facemaxs[0] = max(polyf_points[0].v[0], max(polyf_points[1].v[0], polyf_points[2].v[0])) + 1;
-		facemaxs[1] = max(polyf_points[0].v[1], max(polyf_points[1].v[1], polyf_points[2].v[1])) + 1;
-		facemaxs[2] = max(polyf_points[0].v[2], max(polyf_points[1].v[2], polyf_points[2].v[2])) + 1;
-		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_CalcPlanesForPolygonBrushFloat(&polyf_brush);
 			//Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
 			Collision_TraceLineBrushFloat(trace, linestart, lineend, &polyf_brush, &polyf_brush);
@@ -1152,7 +970,7 @@ 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)
+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)
@@ -1174,8 +992,13 @@ void Collision_TraceBrushPolygonTransformFloat(trace_t *trace, const colbrushf_t
 	polyf_brushend.supercontents = supercontents;
 	for (i = 0;i < numpoints;i++)
 		Matrix4x4_Transform(polygonmatrixend, points + i * 3, polyf_brushend.points[i].v);
-	Collision_SnapCopyPoints(numpoints, polyf_pointsstart, polyf_pointsstart, COLLISION_SNAPSCALE, COLLISION_SNAP);
-	Collision_SnapCopyPoints(numpoints, polyf_pointsend, polyf_pointsend, COLLISION_SNAPSCALE, COLLISION_SNAP);
+	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_CalcPlanesForPolygonBrushFloat(&polyf_brushstart);
 	Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushend);
 
@@ -1188,7 +1011,9 @@ 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 colplanef_t brushforbox_plane[MAX_BRUSHFORBOX*6];
 static colbrushf_t brushforbox_brush[MAX_BRUSHFORBOX];
@@ -1199,12 +1024,10 @@ void Collision_InitBrushForBox(void)
 	int i;
 	for (i = 0;i < MAX_BRUSHFORBOX;i++)
 	{
-		brushforbox_brush[i].supercontents = SUPERCONTENTS_SOLID;
 		brushforbox_brush[i].numpoints = 8;
 		brushforbox_brush[i].numplanes = 6;
 		brushforbox_brush[i].points = brushforbox_point + i * 8;
 		brushforbox_brush[i].planes = brushforbox_plane + i * 6;
-		brushforpoint_brush[i].supercontents = SUPERCONTENTS_SOLID;
 		brushforpoint_brush[i].numpoints = 1;
 		brushforpoint_brush[i].numplanes = 0;
 		brushforpoint_brush[i].points = brushforbox_point + i * 8;
@@ -1212,13 +1035,14 @@ void Collision_InitBrushForBox(void)
 	}
 }
 
-colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins, const vec3_t maxs)
+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
 	if (VectorCompare(mins, maxs))
 	{
 		// point brush
@@ -1245,8 +1069,13 @@ colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins,
 			VectorNormalize(brush->planes[i].normal);
 		}
 	}
+	brush->supercontents = supercontents;
 	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++)
@@ -1268,10 +1097,9 @@ colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins,
 	return 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)
+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;
-	matrix4x4_t identitymatrix;
 	vec3_t startmins, startmaxs, endmins, endmaxs;
 
 	// create brushes for the collision
@@ -1279,10 +1107,9 @@ 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);
-	Matrix4x4_CreateIdentity(&identitymatrix);
-	boxbrush = Collision_BrushForBox(&identitymatrix, cmins, cmaxs);
-	thisbrush_start = Collision_BrushForBox(&identitymatrix, startmins, startmaxs);
-	thisbrush_end = Collision_BrushForBox(&identitymatrix, endmins, 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);
 
 	memset(trace, 0, sizeof(trace_t));
 	trace->hitsupercontentsmask = hitsupercontentsmask;
@@ -1292,7 +1119,10 @@ void Collision_ClipTrace_BrushBox(trace_t *trace, const vec3_t cmins, const vec3
 	Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, boxbrush, boxbrush);
 }
 
-// LordHavoc: currently unused and not yet tested
+//pseudocode for detecting line/sphere overlap without calculating an impact point
+//linesphereorigin = sphereorigin - linestart;linediff = lineend - linestart;linespherefrac = DotProduct(linesphereorigin, linediff) / DotProduct(linediff, linediff);return VectorLength2(linesphereorigin - bound(0, linespherefrac, 1) * linediff) >= sphereradius*sphereradius;
+
+// LordHavoc: currently unused, but tested
 // note: this can be used for tracing a moving sphere vs a stationary sphere,
 // by simply adding the moving sphere's radius to the sphereradius parameter,
 // all the results are correct (impactpoint, impactnormal, and fraction)
@@ -1301,69 +1131,60 @@ float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double
 	double dir[3], scale, v[3], deviationdist, impactdist, linelength;
 	// make sure the impactpoint and impactnormal are valid even if there is
 	// no collision
-	impactpoint[0] = lineend[0];
-	impactpoint[1] = lineend[1];
-	impactpoint[2] = lineend[2];
-	impactnormal[0] = 0;
-	impactnormal[1] = 0;
-	impactnormal[2] = 0;
+	VectorCopy(lineend, impactpoint);
+	VectorClear(impactnormal);
 	// calculate line direction
-	dir[0] = lineend[0] - linestart[0];
-	dir[1] = lineend[1] - linestart[1];
-	dir[2] = lineend[2] - linestart[2];
+	VectorSubtract(lineend, linestart, dir);
 	// normalize direction
-	linelength = sqrt(dir[0] * dir[0] + dir[1] * dir[1] + dir[2] * dir[2]);
+	linelength = VectorLength(dir);
 	if (linelength)
 	{
 		scale = 1.0 / linelength;
-		dir[0] *= scale;
-		dir[1] *= scale;
-		dir[2] *= scale;
+		VectorScale(dir, scale, dir);
 	}
 	// this dotproduct calculates the distance along the line at which the
 	// sphere origin is (nearest point to the sphere origin on the line)
-	impactdist = dir[0] * (sphereorigin[0] - linestart[0]) + dir[1] * (sphereorigin[1] - linestart[1]) + dir[2] * (sphereorigin[2] - linestart[2]);
+	impactdist = DotProduct(sphereorigin, dir) - DotProduct(linestart, dir);
 	// calculate point on line at that distance, and subtract the
 	// sphereorigin from it, so we have a vector to measure for the distance
 	// of the line from the sphereorigin (deviation, how off-center it is)
-	v[0] = linestart[0] + impactdist * dir[0] - sphereorigin[0];
-	v[1] = linestart[1] + impactdist * dir[1] - sphereorigin[1];
-	v[2] = linestart[2] + impactdist * dir[2] - sphereorigin[2];
-	deviationdist = v[0] * v[0] + v[1] * v[1] + v[2] * v[2];
+	VectorMA(linestart, impactdist, dir, v);
+	VectorSubtract(v, sphereorigin, v);
+	deviationdist = VectorLength2(v);
 	// if outside the radius, it's a miss for sure
 	// (we do this comparison using squared radius to avoid a sqrt)
 	if (deviationdist > sphereradius*sphereradius)
 		return 1; // miss (off to the side)
 	// nudge back to find the correct impact distance
-	impactdist += (sqrt(deviationdist) - sphereradius);
+	impactdist -= sphereradius - deviationdist/sphereradius;
 	if (impactdist >= linelength)
 		return 1; // miss (not close enough)
 	if (impactdist < 0)
 		return 1; // miss (linestart is past or inside sphere)
 	// calculate new impactpoint
-	impactpoint[0] = linestart[0] + impactdist * dir[0];
-	impactpoint[1] = linestart[1] + impactdist * dir[1];
-	impactpoint[2] = linestart[2] + impactdist * dir[2];
+	VectorMA(linestart, impactdist, dir, impactpoint);
 	// calculate impactnormal (surface normal at point of impact)
-	impactnormal[0] = impactpoint[0] - sphereorigin[0];
-	impactnormal[1] = impactpoint[1] - sphereorigin[1];
-	impactnormal[2] = impactpoint[2] - sphereorigin[2];
+	VectorSubtract(impactpoint, sphereorigin, impactnormal);
 	// normalize impactnormal
-	scale = impactnormal[0] * impactnormal[0] + impactnormal[1] * impactnormal[1] + impactnormal[2] * impactnormal[2];
-	if (scale)
-	{
-		scale = 1.0 / sqrt(scale);
-		impactnormal[0] *= scale;
-		impactnormal[1] *= scale;
-		impactnormal[2] *= scale;
-	}
+	VectorNormalize(impactnormal);
 	// return fraction of movement distance
 	return impactdist / linelength;
 }
 
-void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const float *point0, const float *point1, const float *point2)
+void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const float *point0, const float *point1, const float *point2, int supercontents, int q3surfaceflags, texture_t *texture)
 {
-	float d1, d2, d, f, fnudged, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, edge[3];
+#if 1
+	// more optimized
+	float d1, d2, d, f, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, faceplanenormallength2, edge01[3], edge21[3], edge02[3];
+
+	// this function executes:
+	// 32 ops when line starts behind triangle
+	// 38 ops when line ends infront of triangle
+	// 43 ops when line fraction is already closer than this triangle
+	// 72 ops when line is outside edge 01
+	// 92 ops when line is outside edge 21
+	// 115 ops when line is outside edge 02
+	// 123 ops when line impacts triangle and updates trace results
 
 	// this code is designed for clockwise triangles, conversion to
 	// counterclockwise would require swapping some things around...
@@ -1371,23 +1192,129 @@ void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, co
 	// function when calling it than it is to rewire the internals.
 
 	// calculate the faceplanenormal of the triangle, this represents the front side
-	TriangleNormal(point0, point1, point2, faceplanenormal);
+	// 15 ops
+	VectorSubtract(point0, point1, edge01);
+	VectorSubtract(point2, point1, edge21);
+	CrossProduct(edge01, edge21, faceplanenormal);
 	// there's no point in processing a degenerate triangle (GIGO - Garbage In, Garbage Out)
-	if (DotProduct(faceplanenormal, faceplanenormal) < 0.0001f)
+	// 6 ops
+	faceplanenormallength2 = DotProduct(faceplanenormal, faceplanenormal);
+	if (faceplanenormallength2 < 0.0001f)
 		return;
-	// normalize the normal
-	VectorNormalize(faceplanenormal);
 	// calculate the distance
+	// 5 ops
 	faceplanedist = DotProduct(point0, faceplanenormal);
 
+	// if start point is on the back side there is no collision
+	// (we don't care about traces going through the triangle the wrong way)
+
 	// calculate the start distance
+	// 6 ops
+	d1 = DotProduct(faceplanenormal, linestart);
+	if (d1 <= faceplanedist)
+		return;
+
+	// calculate the end distance
+	// 6 ops
+	d2 = DotProduct(faceplanenormal, lineend);
+	// if both are in front, there is no collision
+	if (d2 >= faceplanedist)
+		return;
+
+	// from here on we know d1 is >= 0 and d2 is < 0
+	// this means the line starts infront and ends behind, passing through it
+
+	// calculate the recipricol of the distance delta,
+	// so we can use it multiple times cheaply (instead of division)
+	// 2 ops
+	d = 1.0f / (d1 - d2);
+	// calculate the impact fraction by taking the start distance (> 0)
+	// and subtracting the face plane distance (this is the distance of the
+	// triangle along that same normal)
+	// then multiply by the recipricol distance delta
+	// 2 ops
+	f = (d1 - faceplanedist) * d;
+	// skip out if this impact is further away than previous ones
+	// 1 ops
+	if (f > trace->realfraction)
+		return;
+	// calculate the perfect impact point for classification of insidedness
+	// 9 ops
+	impact[0] = linestart[0] + f * (lineend[0] - linestart[0]);
+	impact[1] = linestart[1] + f * (lineend[1] - linestart[1]);
+	impact[2] = linestart[2] + f * (lineend[2] - linestart[2]);
+
+	// calculate the edge normal and reject if impact is outside triangle
+	// (an edge normal faces away from the triangle, to get the desired normal
+	//  a crossproduct with the faceplanenormal is used, and because of the way
+	// the insidedness comparison is written it does not need to be normalized)
+
+	// first use the two edges from the triangle plane math
+	// the other edge only gets calculated if the point survives that long
+
+	// 20 ops
+	CrossProduct(edge01, faceplanenormal, edgenormal);
+	if (DotProduct(impact, edgenormal) > DotProduct(point1, edgenormal))
+		return;
+
+	// 20 ops
+	CrossProduct(faceplanenormal, edge21, edgenormal);
+	if (DotProduct(impact, edgenormal) > DotProduct(point2, edgenormal))
+		return;
+
+	// 23 ops
+	VectorSubtract(point0, point2, edge02);
+	CrossProduct(faceplanenormal, edge02, edgenormal);
+	if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
+		return;
+
+	// 8 ops (rare)
+
+	// store the new trace fraction
+	trace->realfraction = f;
+
+	// calculate a nudged fraction to keep it out of the surface
+	// (the main fraction remains perfect)
+	trace->fraction = f - collision_impactnudge.value * d;
+
+	if (collision_prefernudgedfraction.integer)
+		trace->realfraction = trace->fraction;
+
+	// store the new trace plane (because collisions only happen from
+	// the front this is always simply the triangle normal, never flipped)
+	d = 1.0 / sqrt(faceplanenormallength2);
+	VectorScale(faceplanenormal, d, trace->plane.normal);
+	trace->plane.dist = faceplanedist * d;
+
+	trace->hitsupercontents = supercontents;
+	trace->hitq3surfaceflags = q3surfaceflags;
+	trace->hittexture = texture;
+#else
+	float d1, d2, d, f, fnudged, impact[3], edgenormal[3], faceplanenormal[3], faceplanedist, edge[3];
+
+	// this code is designed for clockwise triangles, conversion to
+	// counterclockwise would require swapping some things around...
+	// it is easier to simply swap the point0 and point2 parameters to this
+	// function when calling it than it is to rewire the internals.
+
+	// calculate the unnormalized faceplanenormal of the triangle,
+	// this represents the front side
+	TriangleNormal(point0, point1, point2, faceplanenormal);
+	// there's no point in processing a degenerate triangle
+	// (GIGO - Garbage In, Garbage Out)
+	if (DotProduct(faceplanenormal, faceplanenormal) < 0.0001f)
+		return;
+	// calculate the unnormalized distance
+	faceplanedist = DotProduct(point0, faceplanenormal);
+
+	// calculate the unnormalized start distance
 	d1 = DotProduct(faceplanenormal, linestart) - faceplanedist;
 	// if start point is on the back side there is no collision
 	// (we don't care about traces going through the triangle the wrong way)
-	if (d1 < 0)
+	if (d1 <= 0)
 		return;
 
-	// calculate the end distance
+	// calculate the unnormalized end distance
 	d2 = DotProduct(faceplanenormal, lineend) - faceplanedist;
 	// if both are in front, there is no collision
 	if (d2 >= 0)
@@ -1416,7 +1343,7 @@ void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, co
 	// (an edge normal faces away from the triangle, to get the desired normal
 	//  a crossproduct with the faceplanenormal is used, and because of the way
 	// the insidedness comparison is written it does not need to be normalized)
-	
+
 	VectorSubtract(point2, point0, edge);
 	CrossProduct(edge, faceplanenormal, edgenormal);
 	if (DotProduct(impact, edgenormal) > DotProduct(point0, edgenormal))
@@ -1435,9 +1362,19 @@ void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, co
 	// store the new trace fraction
 	trace->realfraction = bound(0, f, 1);
 
+	// store the new trace plane (because collisions only happen from
+	// the front this is always simply the triangle normal, never flipped)
+	VectorNormalize(faceplanenormal);
+	VectorCopy(faceplanenormal, trace->plane.normal);
+	trace->plane.dist = DotProduct(point0, faceplanenormal);
+
+	// calculate the normalized start and end distances
+	d1 = DotProduct(trace->plane.normal, linestart) - trace->plane.dist;
+	d2 = DotProduct(trace->plane.normal, lineend) - trace->plane.dist;
+
 	// calculate a nudged fraction to keep it out of the surface
 	// (the main fraction remains perfect)
-	fnudged = (d1 - collision_impactnudge.value) * d;
+	fnudged = (d1 - collision_impactnudge.value) / (d1 - d2);
 	trace->fraction = bound(0, fnudged, 1);
 
 	// store the new trace endpos
@@ -1445,11 +1382,10 @@ void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, co
 	//trace->endpos[0] = linestart[0] + fnudged * (lineend[0] - linestart[0]);
 	//trace->endpos[1] = linestart[1] + fnudged * (lineend[1] - linestart[1]);
 	//trace->endpos[2] = linestart[2] + fnudged * (lineend[2] - linestart[2]);
-
-	// store the new trace plane (because collisions only happen from
-	// the front this is always simply the triangle normal, never flipped)
-	VectorCopy(faceplanenormal, trace->plane.normal);
-	trace->plane.dist = faceplanedist;
+	trace->hitsupercontents = supercontents;
+	trace->hitq3surfaceflags = q3surfaceflags;
+	trace->hittexture = texture;
+#endif
 }
 
 typedef struct colbspnode_s
@@ -1476,9 +1412,9 @@ colbsp_t;
 colbsp_t *Collision_CreateCollisionBSP(mempool_t *mempool)
 {
 	colbsp_t *bsp;
-	bsp = Mem_Alloc(mempool, sizeof(colbsp_t));
+	bsp = (colbsp_t *)Mem_Alloc(mempool, sizeof(colbsp_t));
 	bsp->mempool = mempool;
-	bsp->nodes = Mem_Alloc(bsp->mempool, sizeof(colbspnode_t));
+	bsp->nodes = (colbspnode_t *)Mem_Alloc(bsp->mempool, sizeof(colbspnode_t));
 	return bsp;
 }
 
@@ -1527,3 +1463,79 @@ 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 tempnormal[3], starttransformed[3], endtransformed[3];
+
+	memset(trace, 0, sizeof(*trace));
+	trace->fraction = trace->realfraction = 1;
+	VectorCopy(end, trace->endpos);
+
+	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);
+
+	if (trace->fraction < 1)
+	{
+		VectorLerp(start, trace->fraction, end, trace->endpos);
+		VectorCopy(trace->plane.normal, tempnormal);
+		Matrix4x4_Transform3x3(matrix, tempnormal, trace->plane.normal);
+		// FIXME: should recalc trace->plane.dist
+	}
+}
+
+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_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;
+	}
+	// 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)
+	{
+		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;
+}