--- /dev/null
+/*
+===========================================================================
+Copyright (C) 1997-2006 Id Software, Inc.
+
+This file is part of Quake 2 Tools source code.
+
+Quake 2 Tools source code 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.
+
+Quake 2 Tools source code 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 Quake 2 Tools source code; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+===========================================================================
+*/
+
+#include "cmdlib.h"
+#include "mathlib.h"
+#include "polylib.h"
+
+
+extern int numthreads;
+
+// counters are only bumped when running single threaded,
+// because they are an awefull coherence problem
+int c_active_windings;
+int c_peak_windings;
+int c_winding_allocs;
+int c_winding_points;
+
+#define BOGUS_RANGE 8192
+
+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;
+
+ if (numthreads == 1)
+ {
+ 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 = malloc (s);
+ memset (w, 0, s);
+ return w;
+}
+
+void FreeWinding (winding_t *w)
+{
+ if (*(unsigned *)w == 0xdeaddead)
+ Error ("FreeWinding: freed a freed winding");
+ *(unsigned *)w = 0xdeaddead;
+
+ if (numthreads == 1)
+ c_active_windings--;
+ 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);
+ VectorNormalize(v1,v1);
+ VectorNormalize(v2,v2);
+ if (DotProduct(v1, v2) < 0.999)
+ {
+ VectorCopy (w->p[i], p[nump]);
+ nump++;
+ }
+ }
+
+ if (nump == w->numpoints)
+ return;
+
+ if (numthreads == 1)
+ c_removed += w->numpoints - nump;
+ w->numpoints = nump;
+ 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);
+ VectorNormalize (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;
+}
+
+void WindingBounds (winding_t *w, vec3_t mins, vec3_t maxs)
+{
+ vec_t v;
+ int i,j;
+
+ mins[0] = mins[1] = mins[2] = 99999;
+ maxs[0] = maxs[1] = maxs[2] = -99999;
+
+ 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 = -BOGUS_RANGE;
+ x = -1;
+ for (i=0 ; i<3; i++)
+ {
+ v = fabs(normal[i]);
+ if (v > max)
+ {
+ x = i;
+ max = v;
+ }
+ }
+ if (x==-1)
+ Error ("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);
+ VectorNormalize (vup, vup);
+
+ VectorScale (normal, dist, org);
+
+ CrossProduct (vup, normal, vright);
+
+ VectorScale (vup, 8192, vup);
+ VectorScale (vright, 8192, 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)
+{
+ int size;
+ winding_t *c;
+
+ c = AllocWinding (w->numpoints);
+ size = (int)((winding_t *)0)->p[w->numpoints];
+ 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)
+ Error ("ClipWinding: points exceeded estimate");
+ if (f->numpoints > MAX_POINTS_ON_WINDING || b->numpoints > MAX_POINTS_ON_WINDING)
+ Error ("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)
+ Error ("ClipWinding: points exceeded estimate");
+ if (f->numpoints > MAX_POINTS_ON_WINDING)
+ Error ("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)
+ Error ("CheckWinding: %i points",w->numpoints);
+
+ area = WindingArea(w);
+ if (area < 1)
+ Error ("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] > BOGUS_RANGE || p1[j] < -BOGUS_RANGE)
+ Error ("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)
+ Error ("CheckWinding: point off plane");
+
+ // check the edge isnt degenerate
+ p2 = w->p[j];
+ VectorSubtract (p2, p1, dir);
+
+ if (VectorLength (dir) < ON_EPSILON)
+ Error ("CheckWinding: degenerate edge");
+
+ CrossProduct (facenormal, dir, edgenormal);
+ VectorNormalize (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)
+ Error ("CheckWinding: non-convex");
+ }
+ }
+}
+
+
+/*
+============
+WindingOnPlaneSide
+============
+*/
+int WindingOnPlaneSide (winding_t *w, vec3_t normal, vec_t dist)
+{
+ qboolean front, back;
+ int i;
+ vec_t d;
+
+ front = false;
+ back = false;
+ for (i=0 ; i<w->numpoints ; i++)
+ {
+ d = DotProduct (w->p[i], normal) - dist;
+ if (d < -ON_EPSILON)
+ {
+ if (front)
+ return SIDE_CROSS;
+ back = true;
+ continue;
+ }
+ if (d > ON_EPSILON)
+ {
+ if (back)
+ return SIDE_CROSS;
+ front = true;
+ continue;
+ }
+ }
+
+ if (back)
+ return SIDE_BACK;
+ if (front)
+ return SIDE_FRONT;
+ return SIDE_ON;
+}
+