#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])
+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
int ret;
mplane_t *plane;
double t1, t2;
- //double frac;
- //double mid[3];
// variables that need to be stored on the stack when recursing
dclipnode_t *node;
if (num < 0)
{
t->trace->endcontents = num;
- if (t->trace->startcontents)
+ if (t->trace->thiscontents)
{
- if (num == t->trace->startcontents)
+ if (num == t->trace->thiscontents)
t->trace->allsolid = false;
else
{
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->startcontents)
+ if (t->trace->thiscontents)
{
- if (num == t->trace->startcontents)
+ if (num == t->trace->thiscontents)
t->trace->allsolid = false;
else
{
}
}
}
-
-void Collision_RoundUpToHullSize(const model_t *cmodel, const vec3_t inmins, const vec3_t inmaxs, vec3_t outmins, vec3_t outmaxs)
-{
- vec3_t size;
- const hull_t *hull;
-
- VectorSubtract(inmaxs, inmins, size);
- if (cmodel->ishlbsp)
- {
- if (size[0] < 3)
- hull = &cmodel->hulls[0]; // 0x0x0
- else if (size[0] <= 32)
- {
- if (size[2] < 54) // pick the nearest of 36 or 72
- hull = &cmodel->hulls[3]; // 32x32x36
- else
- hull = &cmodel->hulls[1]; // 32x32x72
- }
- else
- hull = &cmodel->hulls[2]; // 64x64x64
- }
- else
- {
- if (size[0] < 3)
- hull = &cmodel->hulls[0]; // 0x0x0
- else if (size[0] <= 32)
- hull = &cmodel->hulls[1]; // 32x32x56
- else
- hull = &cmodel->hulls[2]; // 64x64x88
- }
- VectorCopy(inmins, outmins);
- VectorAdd(inmins, hull->clip_size, outmaxs);
-}
+#endif
static hull_t box_hull;
static dclipnode_t box_clipnodes[6];
}
}
+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)
+{
+ 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.hull = &box_hull;
+ rhc.trace = trace;
+ rhc.trace->fraction = 1;
+ rhc.trace->allsolid = true;
+ VectorCopy(start, rhc.start);
+ VectorCopy(end, rhc.end);
+ VectorSubtract(rhc.end, rhc.start, rhc.dist);
+ RecursiveHullCheck(&rhc, rhc.hull->firstclipnode, 0, 1, rhc.start, rhc.end);
+}
+
+
+
+
+
-static hull_t *HullForBBoxEntity (const vec3_t corigin, const vec3_t cmins, const vec3_t cmaxs, const vec3_t mins, const vec3_t maxs, vec3_t offset)
+
+
+
+
+
+
+
+
+
+void Collision_PrintBrushAsQHull(colbrushf_t *brush, const char *name)
{
- vec3_t hullmins, hullmaxs;
+ int i;
+ Con_Printf("3 %s\n%i\n", name, brush->numpoints);
+ for (i = 0;i < brush->numpoints;i++)
+ Con_Printf("%g %g %g\n", brush->points[i].v[0], brush->points[i].v[1], brush->points[i].v[2]);
+ // FIXME: optimize!
+ Con_Printf("4\n%i\n", brush->numplanes);
+ for (i = 0;i < brush->numplanes;i++)
+ Con_Printf("%g %g %g %g\n", brush->planes[i].normal[0], brush->planes[i].normal[1], brush->planes[i].normal[2], brush->planes[i].dist);
+}
- // create a temp hull from bounding box sizes
- VectorCopy (corigin, offset);
- VectorSubtract (cmins, maxs, hullmins);
- VectorSubtract (cmaxs, mins, hullmaxs);
- //To keep everything totally uniform, bounding boxes are turned into small
- //BSP trees instead of being compared directly.
- box_planes[0].dist = hullmaxs[0];
- box_planes[1].dist = hullmins[0];
- box_planes[2].dist = hullmaxs[1];
- box_planes[3].dist = hullmins[1];
- box_planes[4].dist = hullmaxs[2];
- box_planes[5].dist = hullmins[2];
- return &box_hull;
+colbrushf_t *Collision_AllocBrushFloat(mempool_t *mempool, int numpoints, int numplanes)
+{
+ colbrushf_t *brush;
+ brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colpointf_t) * numpoints + sizeof(colplanef_t) * numplanes);
+ brush->numpoints = numpoints;
+ brush->numplanes = numplanes;
+ brush->planes = (void *)(brush + 1);
+ brush->points = (void *)(brush->planes + brush->numplanes);
+ return brush;
}
-static const hull_t *HullForBrushModel (const model_t *cmodel, const vec3_t corigin, const vec3_t mins, const vec3_t maxs, vec3_t offset)
+void Collision_CalcPlanesForPolygonBrushFloat(colbrushf_t *brush)
{
- vec3_t size;
- const hull_t *hull;
+ int i;
+ float edge0[3], edge1[3], normal[3], dist, bestdist;
+ colpointf_t *p, *p2;
- // decide which clipping hull to use, based on the size
- // explicit hulls in the BSP model
- VectorSubtract (maxs, mins, size);
- // LordHavoc: FIXME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
- if (cmodel->ishlbsp)
+ // choose best surface normal for polygon's plane
+ bestdist = 0;
+ for (i = 0, p = brush->points + 1;i < brush->numpoints - 2;i++, p++)
{
- if (size[0] < 3)
- hull = &cmodel->hulls[0]; // 0x0x0
- else if (size[0] <= 32)
+ VectorSubtract(p[-1].v, p[0].v, edge0);
+ VectorSubtract(p[1].v, p[0].v, edge1);
+ CrossProduct(edge0, edge1, normal);
+ dist = DotProduct(normal, normal);
+ if (i == 0 || bestdist < dist)
{
- if (size[2] < 54) // pick the nearest of 36 or 72
- hull = &cmodel->hulls[3]; // 32x32x36
- else
- hull = &cmodel->hulls[1]; // 32x32x72
+ bestdist = dist;
+ VectorCopy(normal, brush->planes->normal);
}
- else
- hull = &cmodel->hulls[2]; // 64x64x64
}
- else
+
+ VectorNormalize(brush->planes->normal);
+ brush->planes->dist = DotProduct(brush->points->v, brush->planes->normal);
+
+ // negate plane to create other side
+ VectorNegate(brush->planes[0].normal, brush->planes[1].normal);
+ brush->planes[1].dist = -brush->planes[0].dist;
+ for (i = 0, p = brush->points + (brush->numpoints - 1), p2 = brush->points;i < brush->numpoints;i++, p = p2, p2++)
{
- if (size[0] < 3)
- hull = &cmodel->hulls[0]; // 0x0x0
- else if (size[0] <= 32)
- hull = &cmodel->hulls[1]; // 32x32x56
- else
- hull = &cmodel->hulls[2]; // 64x64x88
+ VectorSubtract(p->v, p2->v, edge0);
+ CrossProduct(edge0, brush->planes->normal, brush->planes[i + 2].normal);
+ VectorNormalize(brush->planes[i + 2].normal);
+ brush->planes[i + 2].dist = DotProduct(p->v, brush->planes[i + 2].normal);
}
- // calculate an offset value to center the origin
- VectorSubtract (hull->clip_mins, mins, offset);
- VectorAdd (offset, corigin, offset);
-
- return hull;
+#if 1
+ // validity check - will be disabled later
+ for (i = 0;i < brush->numplanes;i++)
+ {
+ 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))
+ Con_Printf("Error in brush plane generation, plane %i\n", i);
+ }
+#endif
}
-void Collision_ClipTrace (trace_t *trace, const void *cent, const model_t *cmodel, const vec3_t corigin, const vec3_t cangles, const vec3_t cmins, const vec3_t cmaxs, const vec3_t start, const vec3_t mins, const vec3_t maxs, const vec3_t end)
+colbrushf_t *Collision_AllocBrushFromPermanentPolygonFloat(mempool_t *mempool, int numpoints, float *points)
{
- RecursiveHullCheckTraceInfo_t rhc;
- vec3_t offset, forward, left, up;
- double startd[3], endd[3], tempd[3];
-
- // fill in a default trace
- memset (&rhc, 0, sizeof(rhc));
- memset (trace, 0, sizeof(trace_t));
-
- rhc.trace = trace;
+ colbrushf_t *brush;
+ brush = Mem_Alloc(mempool, sizeof(colbrushf_t) + sizeof(colplanef_t) * (numpoints + 2));
+ brush->numpoints = numpoints;
+ brush->numplanes = numpoints + 2;
+ brush->planes = (void *)(brush + 1);
+ brush->points = (colpointf_t *)points;
+ return brush;
+}
- rhc.trace->fraction = 1;
- rhc.trace->allsolid = true;
+float nearestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
+{
+ float dist, bestdist;
+ bestdist = DotProduct(points->v, normal);
+ points++;
+ while(--numpoints)
+ {
+ dist = DotProduct(points->v, normal);
+ if (bestdist > dist)
+ bestdist = dist;
+ points++;
+ }
+ return bestdist;
+}
- if (cmodel && cmodel->type == mod_brush)
+float furthestplanedist_float(const float *normal, const colpointf_t *points, int numpoints)
+{
+ float dist, bestdist;
+ bestdist = DotProduct(points->v, normal);
+ points++;
+ while(--numpoints)
{
- // brush model
+ dist = DotProduct(points->v, normal);
+ if (bestdist < dist)
+ bestdist = dist;
+ points++;
+ }
+ return bestdist;
+}
- // get the clipping hull
- rhc.hull = HullForBrushModel (cmodel, corigin, mins, maxs, offset);
+#define COLLISIONEPSILON (1.0f / 32.0f)
+#define COLLISIONEPSILON2 0//(1.0f / 32.0f)
+
+// 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;
+ float enterfrac, leavefrac, d1, d2, f, newimpactnormal[3];
+ const colplanef_t *startplane, *endplane;
- VectorSubtract(start, offset, startd);
- VectorSubtract(end, offset, endd);
+ enterfrac = -1;
+ leavefrac = 1;
+ fstartsolid = true;
+ fendsolid = true;
- // rotate start and end into the model's frame of reference
- if (cangles[0] || cangles[1] || cangles[2])
+ for (nplane = 0;nplane < thatbrush_start->numplanes + thisbrush_start->numplanes;nplane++)
+ {
+ nplane2 = nplane;
+ if (nplane2 >= thatbrush_start->numplanes)
{
- AngleVectorsFLU (cangles, forward, left, up);
- VectorCopy(startd, tempd);
- startd[0] = DotProduct (tempd, forward);
- startd[1] = DotProduct (tempd, left);
- startd[2] = DotProduct (tempd, up);
- VectorCopy(endd, tempd);
- endd[0] = DotProduct (tempd, forward);
- endd[1] = DotProduct (tempd, left);
- endd[2] = DotProduct (tempd, up);
+ nplane2 -= thatbrush_start->numplanes;
+ startplane = thisbrush_start->planes + nplane2;
+ endplane = thisbrush_end->planes + nplane2;
}
-
- // trace a line through the appropriate clipping hull
- VectorCopy(startd, rhc.start);
- VectorCopy(endd, rhc.end);
- VectorCopy(rhc.end, rhc.trace->endpos);
- VectorSubtract(rhc.end, rhc.start, rhc.dist);
- if (DotProduct(rhc.dist, rhc.dist) > 0.00001)
- RecursiveHullCheck (&rhc, rhc.hull->firstclipnode, 0, 1, rhc.start, rhc.end);
else
- RecursiveHullCheckPoint (&rhc, rhc.hull->firstclipnode);
+ {
+ startplane = thatbrush_start->planes + nplane2;
+ endplane = thatbrush_end->planes + nplane2;
+ }
+ d1 = nearestplanedist_float(startplane->normal, thisbrush_start->points, thisbrush_start->numpoints) - furthestplanedist_float(startplane->normal, thatbrush_start->points, thatbrush_start->numpoints);
+ d2 = nearestplanedist_float(endplane->normal, thisbrush_end->points, thisbrush_end->numpoints) - furthestplanedist_float(endplane->normal, thatbrush_end->points, thatbrush_end->numpoints) - COLLISIONEPSILON2;
+ //Con_Printf("%c%i: d1 = %f, d2 = %f, d1 / (d1 - d2) = %f\n", nplane2 != nplane ? 'b' : 'a', nplane2, d1, d2, d1 / (d1 - d2));
- // if we hit, unrotate endpos and normal, and store the entity we hit
- if (rhc.trace->fraction != 1)
+ f = d1 - d2;
+ if (f >= 0)
{
- // rotate endpos back to world frame of reference
- if (cangles[0] || cangles[1] || cangles[2])
+ // moving into brush
+ if (d2 > 0)
+ return;
+ if (d1 < 0)
+ continue;
+ // enter
+ fstartsolid = false;
+ f = (d1 - COLLISIONEPSILON) / f;
+ f = bound(0, f, 1);
+ if (enterfrac < f)
{
- VectorNegate (cangles, offset);
- AngleVectorsFLU (offset, forward, left, up);
-
- VectorCopy (rhc.trace->endpos, tempd);
- rhc.trace->endpos[0] = DotProduct (tempd, forward);
- rhc.trace->endpos[1] = DotProduct (tempd, left);
- rhc.trace->endpos[2] = DotProduct (tempd, up);
-
- VectorCopy (rhc.trace->plane.normal, tempd);
- rhc.trace->plane.normal[0] = DotProduct (tempd, forward);
- rhc.trace->plane.normal[1] = DotProduct (tempd, left);
- rhc.trace->plane.normal[2] = DotProduct (tempd, up);
+ enterfrac = f;
+ VectorBlend(startplane->normal, endplane->normal, enterfrac, newimpactnormal);
}
- // fix offset
- VectorAdd (rhc.trace->endpos, offset, rhc.trace->endpos);
- rhc.trace->ent = (void *) cent;
}
- else if (rhc.trace->allsolid || rhc.trace->startsolid)
- rhc.trace->ent = (void *) cent;
+ else if (f < 0)
+ {
+ // moving out of brush
+ if (d1 > 0)
+ return;
+ if (d2 < 0)
+ continue;
+ // leave
+ fendsolid = false;
+ f = (d1 + COLLISIONEPSILON) / f;
+ f = bound(0, f, 1);
+ if (leavefrac > f)
+ leavefrac = f;
+ }
}
- else
+
+ if (fstartsolid)
{
- // bounding box
+ trace->startsolid = true;
+ if (fendsolid)
+ trace->allsolid = true;
+ }
- rhc.hull = HullForBBoxEntity (corigin, cmins, cmaxs, mins, maxs, offset);
+ // 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 (enterfrac > -1 && enterfrac < trace->fraction && enterfrac - (1.0f / 1024.0f) <= leavefrac)
+ {
+ trace->fraction = bound(0, enterfrac, 1);
+ VectorCopy(newimpactnormal, trace->plane.normal);
+ }
+}
- // trace a line through the generated clipping hull
- VectorCopy(startd, rhc.start);
- VectorCopy(endd, rhc.end);
- VectorCopy(rhc.end, rhc.trace->endpos);
- VectorSubtract(rhc.end, rhc.start, rhc.dist);
- if (DotProduct(rhc.dist, rhc.dist) > 0.00001)
- RecursiveHullCheck (&rhc, rhc.hull->firstclipnode, 0, 1, rhc.start, rhc.end);
- else
- RecursiveHullCheckPoint (&rhc, rhc.hull->firstclipnode);
+static colplanef_t polyf_planes[256 + 2];
+static colbrushf_t polyf_brush;
- // if we hit, store the entity we hit
- if (rhc.trace->fraction != 1)
- {
- // fix offset
- VectorAdd (rhc.trace->endpos, offset, rhc.trace->endpos);
- rhc.trace->ent = (void *) cent;
- }
- else if (rhc.trace->allsolid || rhc.trace->startsolid)
- rhc.trace->ent = (void *) cent;
+void Collision_TraceBrushPolygonFloat(trace_t *trace, const colbrushf_t *thisbrush_start, const colbrushf_t *thisbrush_end, int numpoints, const float *points)
+{
+ if (numpoints > 256)
+ {
+ Con_Printf("Polygon with more than 256 points not supported yet (fixme!)\n");
+ return;
}
+ polyf_brush.numpoints = numpoints;
+ polyf_brush.numplanes = numpoints + 2;
+ polyf_brush.points = (colpointf_t *)points;
+ polyf_brush.planes = polyf_planes;
+ Collision_CalcPlanesForPolygonBrushFloat(&polyf_brush);
+ //Collision_PrintBrushAsQHull(&polyf_brush, "polyf_brush");
+ Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brush, &polyf_brush);
}
+
+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 i;
+ if (numpoints > 256)
+ {
+ Con_Printf("Polygon with more than 256 points not supported yet (fixme!)\n");
+ return;
+ }
+ polyf_brushstart.numpoints = numpoints;
+ polyf_brushstart.numplanes = numpoints + 2;
+ polyf_brushstart.points = polyf_pointsstart;//(colpointf_t *)points;
+ polyf_brushstart.planes = polyf_planesstart;
+ for (i = 0;i < numpoints;i++)
+ Matrix4x4_Transform(polygonmatrixstart, points + i * 3, polyf_brushstart.points[i].v);
+ polyf_brushend.numpoints = numpoints;
+ polyf_brushend.numplanes = numpoints + 2;
+ polyf_brushend.points = polyf_pointsend;//(colpointf_t *)points;
+ polyf_brushend.planes = polyf_planesend;
+ for (i = 0;i < numpoints;i++)
+ Matrix4x4_Transform(polygonmatrixend, points + i * 3, polyf_brushend.points[i].v);
+ Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushstart);
+ Collision_CalcPlanesForPolygonBrushFloat(&polyf_brushend);
+
+ //Collision_PrintBrushAsQHull(&polyf_brushstart, "polyf_brushstart");
+ //Collision_PrintBrushAsQHull(&polyf_brushend, "polyf_brushend");
+
+ Collision_TraceBrushBrushFloat(trace, thisbrush_start, thisbrush_end, &polyf_brushstart, &polyf_brushend);
+}
+
+
+
+#define MAX_BRUSHFORBOX 16
+static int brushforbox_index = 0;
+static colpointf_t brushforbox_point[MAX_BRUSHFORBOX*8];
+static colplanef_t brushforbox_plane[MAX_BRUSHFORBOX*6];
+static colbrushf_t brushforbox_brush[MAX_BRUSHFORBOX];
+
+void Collision_InitBrushForBox(void)
+{
+ int i;
+ for (i = 0;i < MAX_BRUSHFORBOX;i++)
+ {
+ 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;
+ }
+}
+
+colbrushf_t *Collision_BrushForBox(const matrix4x4_t *matrix, const vec3_t mins, const vec3_t maxs)
+{
+ int i;
+ vec3_t v;
+ colbrushf_t *brush;
+ if (brushforbox_brush[0].numpoints == 0)
+ Collision_InitBrushForBox();
+ brush = brushforbox_brush + ((brushforbox_index++) % MAX_BRUSHFORBOX);
+ // FIXME: optimize
+ for (i = 0;i < 8;i++)
+ {
+ v[0] = i & 1 ? maxs[0] : mins[0];
+ v[1] = i & 2 ? maxs[1] : mins[1];
+ v[2] = i & 4 ? maxs[2] : mins[2];
+ Matrix4x4_Transform(matrix, v, brush->points[i].v);
+ }
+ // FIXME: optimize!
+ for (i = 0;i < 6;i++)
+ {
+ VectorClear(v);
+ v[i >> 1] = i & 1 ? 1 : -1;
+ Matrix4x4_Transform3x3(matrix, v, brush->planes[i].normal);
+ VectorNormalize(brush->planes[i].normal);
+ brush->planes[i].dist = furthestplanedist_float(brush->planes[i].normal, brush->points, brush->numpoints);
+ }
+ return brush;
+}
+
+// LordHavoc: currently unused and not yet 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)
+float Collision_ClipTrace_Line_Sphere(double *linestart, double *lineend, double *sphereorigin, double sphereradius, double *impactpoint, double *impactnormal)
+{
+ 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;
+ // calculate line direction
+ dir[0] = lineend[0] - linestart[0];
+ dir[1] = lineend[1] - linestart[1];
+ dir[2] = lineend[2] - linestart[2];
+ // normalize direction
+ linelength = sqrt(dir[0] * dir[0] + dir[1] * dir[1] + dir[2] * dir[2]);
+ if (linelength)
+ {
+ scale = 1.0 / linelength;
+ dir[0] *= scale;
+ dir[1] *= scale;
+ dir[2] *= scale;
+ }
+ // 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]);
+ // 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];
+ // 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);
+ 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];
+ // 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];
+ // 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;
+ }
+ // return fraction of movement distance
+ return impactdist / linelength;
+}
+
projects / xonotic / darkplaces.git / blobdiff