]> de.git.xonotic.org Git - xonotic/darkplaces.git/blobdiff - collision.c
changed a lot of Host_Error calls to Con_Printf or Sys_Error according to severity
[xonotic/darkplaces.git] / collision.c
index 2306aded1529a7164634408b482c09a9888776e0..30f4d7662acdae19488a51c9d22811a30c4c901f 100644 (file)
@@ -2,7 +2,7 @@
 #include "quakedef.h"
 #include "polygon.h"
 
-#define COLLISION_SNAPSCALE (32.0f)
+#define COLLISION_SNAPSCALE (8.0f)
 #define COLLISION_SNAP (1.0f / COLLISION_SNAPSCALE)
 
 cvar_t collision_impactnudge = {0, "collision_impactnudge", "0.03125"};
@@ -11,287 +11,6 @@ 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
-
 void Collision_Init (void)
 {
        Cvar_RegisterVariable(&collision_impactnudge);
@@ -449,7 +168,7 @@ colbrushf_t *Collision_NewBrushFromPlanes(mempool_t *mempool, int numoriginalpla
                // check if there are too many and skip the brush
                if (numplanesbuf >= maxplanesbuf)
                {
-                       Con_Print("Mod_Q3BSP_LoadBrushes: failed to build collision brush: too many planes for buffer\n");
+                       Con_Print("Collision_NewBrushFromPlanes: failed to build collision brush: too many planes for buffer\n");
                        return NULL;
                }
 
@@ -620,6 +339,7 @@ void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
        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
@@ -791,7 +511,7 @@ colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, i
        brush->numplanes = numpoints + 2;
        brush->planes = (void *)(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...\n");
        return brush;
 }
 
@@ -799,7 +519,7 @@ colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, i
 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;
+       float enterfrac, leavefrac, d1, d2, f, imove, newimpactnormal[3], enterfrac2;
        const colplanef_t *startplane, *endplane;
 
        enterfrac = -1;
@@ -825,7 +545,7 @@ 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) > 0.125f)
                                        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;
@@ -844,7 +564,7 @@ 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) > 0.125f)
                                        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;
@@ -852,46 +572,38 @@ 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 > 0)
                                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
+                               fstartsolid = false;
+                               imove = 1 / (d1 - d2);
+                               f = (d1 - collision_enternudge.value) * imove;
+                               if (enterfrac < f)
+                               {
+                                       enterfrac = f;
+                                       enterfrac2 = f - collision_impactnudge.value * imove;
+                                       VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
+                               }
                        }
                }
-               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
-                       if (d1 > 0)
+                       // moving out of brush
+                       if(d1 > 0)
                                return;
+                       if(d2 > 0)
+                       {
+                               // leave
+                               fendsolid = false;
+                               f = (d1 + collision_leavenudge.value) / (d1 - d2);
+                               if (leavefrac > f)
+                                       leavefrac = f;
+                       }
                }
        }
 
@@ -947,7 +659,7 @@ void Collision_TraceBrushBrushFloat(trace_t *trace, const colbrushf_t *thisbrush
 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;
+       float enterfrac, leavefrac, d1, d2, f, imove, newimpactnormal[3], enterfrac2;
        const colplanef_t *startplane, *endplane;
 
        enterfrac = -1;
@@ -973,42 +685,43 @@ 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) > 0.125f)
                                        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 > 0)
                                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
+                               fstartsolid = false;
+                               imove = 1 / (d1 - d2);
+                               f = (d1 - collision_enternudge.value) * imove;
+                               if (enterfrac < f)
+                               {
+                                       enterfrac = f;
+                                       enterfrac2 = f - collision_impactnudge.value * imove;
+                                       VectorLerp(startplane->normal, enterfrac, endplane->normal, newimpactnormal);
+                               }
                        }
                }
                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
+                               fendsolid = false;
+                               f = (d1 + collision_leavenudge.value) / (d1 - d2);
+                               if (leavefrac > f)
+                                       leavefrac = f;
+                       }
                }
        }
 
@@ -1267,6 +980,7 @@ colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins,
        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
@@ -1411,7 +1125,18 @@ float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double
 
 void Collision_TraceLineTriangleFloat(trace_t *trace, const vec3_t linestart, const vec3_t lineend, const float *point0, const float *point1, const float *point2)
 {
-       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...
@@ -1419,23 +1144,122 @@ 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;
+
+       // 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;
+#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)
@@ -1464,7 +1288,7 @@ 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))
@@ -1483,9 +1307,19 @@ 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
@@ -1493,11 +1327,7 @@ 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;
+#endif
 }
 
 typedef struct colbspnode_s