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Diffstat (limited to 'src/qcommon/cm_polylib.c')
| -rw-r--r-- | src/qcommon/cm_polylib.c | 738 |
1 files changed, 738 insertions, 0 deletions
diff --git a/src/qcommon/cm_polylib.c b/src/qcommon/cm_polylib.c new file mode 100644 index 0000000..1a93754 --- /dev/null +++ b/src/qcommon/cm_polylib.c @@ -0,0 +1,738 @@ +/* +=========================================================================== +Copyright (C) 1999-2005 Id Software, Inc. +Copyright (C) 2000-2006 Tim Angus + +This file is part of Tremulous. + +Tremulous is free software; you can redistribute it +and/or modify it under the terms of the GNU General Public License as +published by the Free Software Foundation; either version 2 of the License, +or (at your option) any later version. + +Tremulous is distributed in the hope that it will be +useful, but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with Tremulous; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +=========================================================================== +*/ + +// this is only used for visualization tools in cm_ debug functions + + +#include "cm_local.h" + + +// counters are only bumped when running single threaded, +// because they are an awful coherence problem +int c_active_windings; +int c_peak_windings; +int c_winding_allocs; +int c_winding_points; + +void pw(winding_t *w) +{ + int i; + for (i=0 ; i<w->numpoints ; i++) + printf ("(%5.1f, %5.1f, %5.1f)\n",w->p[i][0], w->p[i][1],w->p[i][2]); +} + + +/* +============= +AllocWinding +============= +*/ +winding_t *AllocWinding (int points) +{ + winding_t *w; + int s; + + c_winding_allocs++; + c_winding_points += points; + c_active_windings++; + if (c_active_windings > c_peak_windings) + c_peak_windings = c_active_windings; + + s = sizeof(vec_t)*3*points + sizeof(int); + w = Z_Malloc (s); + Com_Memset (w, 0, s); + return w; +} + +void FreeWinding (winding_t *w) +{ + if (*(unsigned *)w == 0xdeaddead) + Com_Error (ERR_FATAL, "FreeWinding: freed a freed winding"); + *(unsigned *)w = 0xdeaddead; + + c_active_windings--; + Z_Free (w); +} + +/* +============ +RemoveColinearPoints +============ +*/ +int c_removed; + +void RemoveColinearPoints (winding_t *w) +{ + int i, j, k; + vec3_t v1, v2; + int nump; + vec3_t p[MAX_POINTS_ON_WINDING]; + + nump = 0; + for (i=0 ; i<w->numpoints ; i++) + { + j = (i+1)%w->numpoints; + k = (i+w->numpoints-1)%w->numpoints; + VectorSubtract (w->p[j], w->p[i], v1); + VectorSubtract (w->p[i], w->p[k], v2); + VectorNormalize2(v1,v1); + VectorNormalize2(v2,v2); + if (DotProduct(v1, v2) < 0.999) + { + VectorCopy (w->p[i], p[nump]); + nump++; + } + } + + if (nump == w->numpoints) + return; + + c_removed += w->numpoints - nump; + w->numpoints = nump; + Com_Memcpy (w->p, p, nump*sizeof(p[0])); +} + +/* +============ +WindingPlane +============ +*/ +void WindingPlane (winding_t *w, vec3_t normal, vec_t *dist) +{ + vec3_t v1, v2; + + VectorSubtract (w->p[1], w->p[0], v1); + VectorSubtract (w->p[2], w->p[0], v2); + CrossProduct (v2, v1, normal); + VectorNormalize2(normal, normal); + *dist = DotProduct (w->p[0], normal); + +} + +/* +============= +WindingArea +============= +*/ +vec_t WindingArea (winding_t *w) +{ + int i; + vec3_t d1, d2, cross; + vec_t total; + + total = 0; + for (i=2 ; i<w->numpoints ; i++) + { + VectorSubtract (w->p[i-1], w->p[0], d1); + VectorSubtract (w->p[i], w->p[0], d2); + CrossProduct (d1, d2, cross); + total += 0.5 * VectorLength ( cross ); + } + return total; +} + +/* +============= +WindingBounds +============= +*/ +void WindingBounds (winding_t *w, vec3_t mins, vec3_t maxs) +{ + vec_t v; + int i,j; + + mins[0] = mins[1] = mins[2] = MAX_MAP_BOUNDS; + maxs[0] = maxs[1] = maxs[2] = -MAX_MAP_BOUNDS; + + for (i=0 ; i<w->numpoints ; i++) + { + for (j=0 ; j<3 ; j++) + { + v = w->p[i][j]; + if (v < mins[j]) + mins[j] = v; + if (v > maxs[j]) + maxs[j] = v; + } + } +} + +/* +============= +WindingCenter +============= +*/ +void WindingCenter (winding_t *w, vec3_t center) +{ + int i; + float scale; + + VectorCopy (vec3_origin, center); + for (i=0 ; i<w->numpoints ; i++) + VectorAdd (w->p[i], center, center); + + scale = 1.0/w->numpoints; + VectorScale (center, scale, center); +} + +/* +================= +BaseWindingForPlane +================= +*/ +winding_t *BaseWindingForPlane (vec3_t normal, vec_t dist) +{ + int i, x; + vec_t max, v; + vec3_t org, vright, vup; + winding_t *w; + +// find the major axis + + max = -MAX_MAP_BOUNDS; + x = -1; + for (i=0 ; i<3; i++) + { + v = fabs(normal[i]); + if (v > max) + { + x = i; + max = v; + } + } + if (x==-1) + Com_Error (ERR_DROP, "BaseWindingForPlane: no axis found"); + + VectorCopy (vec3_origin, vup); + switch (x) + { + case 0: + case 1: + vup[2] = 1; + break; + case 2: + vup[0] = 1; + break; + } + + v = DotProduct (vup, normal); + VectorMA (vup, -v, normal, vup); + VectorNormalize2(vup, vup); + + VectorScale (normal, dist, org); + + CrossProduct (vup, normal, vright); + + VectorScale (vup, MAX_MAP_BOUNDS, vup); + VectorScale (vright, MAX_MAP_BOUNDS, vright); + +// project a really big axis aligned box onto the plane + w = AllocWinding (4); + + VectorSubtract (org, vright, w->p[0]); + VectorAdd (w->p[0], vup, w->p[0]); + + VectorAdd (org, vright, w->p[1]); + VectorAdd (w->p[1], vup, w->p[1]); + + VectorAdd (org, vright, w->p[2]); + VectorSubtract (w->p[2], vup, w->p[2]); + + VectorSubtract (org, vright, w->p[3]); + VectorSubtract (w->p[3], vup, w->p[3]); + + w->numpoints = 4; + + return w; +} + +/* +================== +CopyWinding +================== +*/ +winding_t *CopyWinding (winding_t *w) +{ + unsigned long size; + winding_t *c; + + c = AllocWinding (w->numpoints); + size = (long)((winding_t *)0)->p[w->numpoints]; + Com_Memcpy (c, w, size); + return c; +} + +/* +================== +ReverseWinding +================== +*/ +winding_t *ReverseWinding (winding_t *w) +{ + int i; + winding_t *c; + + c = AllocWinding (w->numpoints); + for (i=0 ; i<w->numpoints ; i++) + { + VectorCopy (w->p[w->numpoints-1-i], c->p[i]); + } + c->numpoints = w->numpoints; + return c; +} + + +/* +============= +ClipWindingEpsilon +============= +*/ +void ClipWindingEpsilon (winding_t *in, vec3_t normal, vec_t dist, + vec_t epsilon, winding_t **front, winding_t **back) +{ + vec_t dists[MAX_POINTS_ON_WINDING+4]; + int sides[MAX_POINTS_ON_WINDING+4]; + int counts[3]; + static vec_t dot; // VC 4.2 optimizer bug if not static + int i, j; + vec_t *p1, *p2; + vec3_t mid; + winding_t *f, *b; + int maxpts; + + counts[0] = counts[1] = counts[2] = 0; + +// determine sides for each point + for (i=0 ; i<in->numpoints ; i++) + { + dot = DotProduct (in->p[i], normal); + dot -= dist; + dists[i] = dot; + if (dot > epsilon) + sides[i] = SIDE_FRONT; + else if (dot < -epsilon) + sides[i] = SIDE_BACK; + else + { + sides[i] = SIDE_ON; + } + counts[sides[i]]++; + } + sides[i] = sides[0]; + dists[i] = dists[0]; + + *front = *back = NULL; + + if (!counts[0]) + { + *back = CopyWinding (in); + return; + } + if (!counts[1]) + { + *front = CopyWinding (in); + return; + } + + maxpts = in->numpoints+4; // cant use counts[0]+2 because + // of fp grouping errors + + *front = f = AllocWinding (maxpts); + *back = b = AllocWinding (maxpts); + + for (i=0 ; i<in->numpoints ; i++) + { + p1 = in->p[i]; + + if (sides[i] == SIDE_ON) + { + VectorCopy (p1, f->p[f->numpoints]); + f->numpoints++; + VectorCopy (p1, b->p[b->numpoints]); + b->numpoints++; + continue; + } + + if (sides[i] == SIDE_FRONT) + { + VectorCopy (p1, f->p[f->numpoints]); + f->numpoints++; + } + if (sides[i] == SIDE_BACK) + { + VectorCopy (p1, b->p[b->numpoints]); + b->numpoints++; + } + + if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i]) + continue; + + // generate a split point + p2 = in->p[(i+1)%in->numpoints]; + + dot = dists[i] / (dists[i]-dists[i+1]); + for (j=0 ; j<3 ; j++) + { // avoid round off error when possible + if (normal[j] == 1) + mid[j] = dist; + else if (normal[j] == -1) + mid[j] = -dist; + else + mid[j] = p1[j] + dot*(p2[j]-p1[j]); + } + + VectorCopy (mid, f->p[f->numpoints]); + f->numpoints++; + VectorCopy (mid, b->p[b->numpoints]); + b->numpoints++; + } + + if (f->numpoints > maxpts || b->numpoints > maxpts) + Com_Error (ERR_DROP, "ClipWinding: points exceeded estimate"); + if (f->numpoints > MAX_POINTS_ON_WINDING || b->numpoints > MAX_POINTS_ON_WINDING) + Com_Error (ERR_DROP, "ClipWinding: MAX_POINTS_ON_WINDING"); +} + + +/* +============= +ChopWindingInPlace +============= +*/ +void ChopWindingInPlace (winding_t **inout, vec3_t normal, vec_t dist, vec_t epsilon) +{ + winding_t *in; + vec_t dists[MAX_POINTS_ON_WINDING+4]; + int sides[MAX_POINTS_ON_WINDING+4]; + int counts[3]; + static vec_t dot; // VC 4.2 optimizer bug if not static + int i, j; + vec_t *p1, *p2; + vec3_t mid; + winding_t *f; + int maxpts; + + in = *inout; + counts[0] = counts[1] = counts[2] = 0; + +// determine sides for each point + for (i=0 ; i<in->numpoints ; i++) + { + dot = DotProduct (in->p[i], normal); + dot -= dist; + dists[i] = dot; + if (dot > epsilon) + sides[i] = SIDE_FRONT; + else if (dot < -epsilon) + sides[i] = SIDE_BACK; + else + { + sides[i] = SIDE_ON; + } + counts[sides[i]]++; + } + sides[i] = sides[0]; + dists[i] = dists[0]; + + if (!counts[0]) + { + FreeWinding (in); + *inout = NULL; + return; + } + if (!counts[1]) + return; // inout stays the same + + maxpts = in->numpoints+4; // cant use counts[0]+2 because + // of fp grouping errors + + f = AllocWinding (maxpts); + + for (i=0 ; i<in->numpoints ; i++) + { + p1 = in->p[i]; + + if (sides[i] == SIDE_ON) + { + VectorCopy (p1, f->p[f->numpoints]); + f->numpoints++; + continue; + } + + if (sides[i] == SIDE_FRONT) + { + VectorCopy (p1, f->p[f->numpoints]); + f->numpoints++; + } + + if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i]) + continue; + + // generate a split point + p2 = in->p[(i+1)%in->numpoints]; + + dot = dists[i] / (dists[i]-dists[i+1]); + for (j=0 ; j<3 ; j++) + { // avoid round off error when possible + if (normal[j] == 1) + mid[j] = dist; + else if (normal[j] == -1) + mid[j] = -dist; + else + mid[j] = p1[j] + dot*(p2[j]-p1[j]); + } + + VectorCopy (mid, f->p[f->numpoints]); + f->numpoints++; + } + + if (f->numpoints > maxpts) + Com_Error (ERR_DROP, "ClipWinding: points exceeded estimate"); + if (f->numpoints > MAX_POINTS_ON_WINDING) + Com_Error (ERR_DROP, "ClipWinding: MAX_POINTS_ON_WINDING"); + + FreeWinding (in); + *inout = f; +} + + +/* +================= +ChopWinding + +Returns the fragment of in that is on the front side +of the cliping plane. The original is freed. +================= +*/ +winding_t *ChopWinding (winding_t *in, vec3_t normal, vec_t dist) +{ + winding_t *f, *b; + + ClipWindingEpsilon (in, normal, dist, ON_EPSILON, &f, &b); + FreeWinding (in); + if (b) + FreeWinding (b); + return f; +} + + +/* +================= +CheckWinding + +================= +*/ +void CheckWinding (winding_t *w) +{ + int i, j; + vec_t *p1, *p2; + vec_t d, edgedist; + vec3_t dir, edgenormal, facenormal; + vec_t area; + vec_t facedist; + + if (w->numpoints < 3) + Com_Error (ERR_DROP, "CheckWinding: %i points",w->numpoints); + + area = WindingArea(w); + if (area < 1) + Com_Error (ERR_DROP, "CheckWinding: %f area", area); + + WindingPlane (w, facenormal, &facedist); + + for (i=0 ; i<w->numpoints ; i++) + { + p1 = w->p[i]; + + for (j=0 ; j<3 ; j++) + if (p1[j] > MAX_MAP_BOUNDS || p1[j] < -MAX_MAP_BOUNDS) + Com_Error (ERR_DROP, "CheckFace: BUGUS_RANGE: %f",p1[j]); + + j = i+1 == w->numpoints ? 0 : i+1; + + // check the point is on the face plane + d = DotProduct (p1, facenormal) - facedist; + if (d < -ON_EPSILON || d > ON_EPSILON) + Com_Error (ERR_DROP, "CheckWinding: point off plane"); + + // check the edge isnt degenerate + p2 = w->p[j]; + VectorSubtract (p2, p1, dir); + + if (VectorLength (dir) < ON_EPSILON) + Com_Error (ERR_DROP, "CheckWinding: degenerate edge"); + + CrossProduct (facenormal, dir, edgenormal); + VectorNormalize2 (edgenormal, edgenormal); + edgedist = DotProduct (p1, edgenormal); + edgedist += ON_EPSILON; + + // all other points must be on front side + for (j=0 ; j<w->numpoints ; j++) + { + if (j == i) + continue; + d = DotProduct (w->p[j], edgenormal); + if (d > edgedist) + Com_Error (ERR_DROP, "CheckWinding: non-convex"); + } + } +} + + +/* +============ +WindingOnPlaneSide +============ +*/ +int WindingOnPlaneSide (winding_t *w, vec3_t normal, vec_t dist) +{ + qboolean front, back; + int i; + vec_t d; + + front = qfalse; + back = qfalse; + for (i=0 ; i<w->numpoints ; i++) + { + d = DotProduct (w->p[i], normal) - dist; + if (d < -ON_EPSILON) + { + if (front) + return SIDE_CROSS; + back = qtrue; + continue; + } + if (d > ON_EPSILON) + { + if (back) + return SIDE_CROSS; + front = qtrue; + continue; + } + } + + if (back) + return SIDE_BACK; + if (front) + return SIDE_FRONT; + return SIDE_ON; +} + + +/* +================= +AddWindingToConvexHull + +Both w and *hull are on the same plane +================= +*/ +#define MAX_HULL_POINTS 128 +void AddWindingToConvexHull( winding_t *w, winding_t **hull, vec3_t normal ) { + int i, j, k; + float *p, *copy; + vec3_t dir; + float d; + int numHullPoints, numNew; + vec3_t hullPoints[MAX_HULL_POINTS]; + vec3_t newHullPoints[MAX_HULL_POINTS]; + vec3_t hullDirs[MAX_HULL_POINTS]; + qboolean hullSide[MAX_HULL_POINTS]; + qboolean outside; + + if ( !*hull ) { + *hull = CopyWinding( w ); + return; + } + + numHullPoints = (*hull)->numpoints; + Com_Memcpy( hullPoints, (*hull)->p, numHullPoints * sizeof(vec3_t) ); + + for ( i = 0 ; i < w->numpoints ; i++ ) { + p = w->p[i]; + + // calculate hull side vectors + for ( j = 0 ; j < numHullPoints ; j++ ) { + k = ( j + 1 ) % numHullPoints; + + VectorSubtract( hullPoints[k], hullPoints[j], dir ); + VectorNormalize2( dir, dir ); + CrossProduct( normal, dir, hullDirs[j] ); + } + + outside = qfalse; + for ( j = 0 ; j < numHullPoints ; j++ ) { + VectorSubtract( p, hullPoints[j], dir ); + d = DotProduct( dir, hullDirs[j] ); + if ( d >= ON_EPSILON ) { + outside = qtrue; + } + if ( d >= -ON_EPSILON ) { + hullSide[j] = qtrue; + } else { + hullSide[j] = qfalse; + } + } + + // if the point is effectively inside, do nothing + if ( !outside ) { + continue; + } + + // find the back side to front side transition + for ( j = 0 ; j < numHullPoints ; j++ ) { + if ( !hullSide[ j % numHullPoints ] && hullSide[ (j + 1) % numHullPoints ] ) { + break; + } + } + if ( j == numHullPoints ) { + continue; + } + + // insert the point here + VectorCopy( p, newHullPoints[0] ); + numNew = 1; + + // copy over all points that aren't double fronts + j = (j+1)%numHullPoints; + for ( k = 0 ; k < numHullPoints ; k++ ) { + if ( hullSide[ (j+k) % numHullPoints ] && hullSide[ (j+k+1) % numHullPoints ] ) { + continue; + } + copy = hullPoints[ (j+k+1) % numHullPoints ]; + VectorCopy( copy, newHullPoints[numNew] ); + numNew++; + } + + numHullPoints = numNew; + Com_Memcpy( hullPoints, newHullPoints, numHullPoints * sizeof(vec3_t) ); + } + + FreeWinding( *hull ); + w = AllocWinding( numHullPoints ); + w->numpoints = numHullPoints; + *hull = w; + Com_Memcpy( w->p, hullPoints, numHullPoints * sizeof(vec3_t) ); +} + + |