709 lines
13 KiB
C
709 lines
13 KiB
C
/***
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*
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* Copyright (c) 1996-2002, Valve LLC. All rights reserved.
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*
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* This product contains software technology licensed from Id
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* Software, Inc. ("Id Technology"). Id Technology (c) 1996 Id Software, Inc.
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* All Rights Reserved.
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*
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****/
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#include "cmdlib.h"
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#include "mathlib.h"
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#include "polylib.h"
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int c_active_windings;
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int c_peak_windings;
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int c_winding_allocs;
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int c_winding_points;
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#define BOGUS_RANGE 8192
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void pw(winding_t *w)
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{
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int i;
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for (i=0 ; i<w->numpoints ; i++)
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printf ("(%5.1f, %5.1f, %5.1f)\n",w->p[i][0], w->p[i][1],w->p[i][2]);
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}
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/*
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=============
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AllocWinding
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=============
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*/
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winding_t *AllocWinding (int points)
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{
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winding_t *w;
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int s;
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c_winding_allocs++;
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c_winding_points += points;
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c_active_windings++;
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if (c_active_windings > c_peak_windings)
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c_peak_windings = c_active_windings;
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s = sizeof(vec_t)*3*points + sizeof(int);
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s += sizeof(vec_t) - sizeof(w->numpoints); // padding
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w = malloc (s);
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memset (w, 0, s);
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return w;
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}
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void FreeWinding (winding_t *w)
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{
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c_active_windings--;
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free (w);
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}
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/*
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============
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RemoveColinearPoints
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============
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*/
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int c_removed;
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void RemoveColinearPoints (winding_t *w)
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{
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int i, j, k;
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vec3_t v1, v2;
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int nump;
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vec3_t p[MAX_POINTS_ON_WINDING];
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nump = 0;
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for (i=0 ; i<w->numpoints ; i++)
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{
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j = (i+1)%w->numpoints;
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k = (i+w->numpoints-1)%w->numpoints;
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VectorSubtract (w->p[j], w->p[i], v1);
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VectorSubtract (w->p[i], w->p[k], v2);
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VectorNormalize(v1);
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VectorNormalize(v2);
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if (DotProduct(v1, v2) < 1.0-ON_EPSILON)
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{
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VectorCopy (w->p[i], p[nump]);
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nump++;
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}
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}
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if (nump == w->numpoints)
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return;
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c_removed += w->numpoints - nump;
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w->numpoints = nump;
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memcpy (w->p, p, nump*sizeof(p[0]));
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}
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/*
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============
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WindingPlane
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============
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*/
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void WindingPlane (winding_t *w, vec3_t normal, vec_t *dist)
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{
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vec3_t v1, v2;
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VectorSubtract (w->p[1], w->p[0], v1);
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VectorSubtract (w->p[2], w->p[0], v2);
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CrossProduct (v2, v1, normal);
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VectorNormalize (normal);
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*dist = DotProduct (w->p[0], normal);
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}
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/*
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=============
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WindingArea
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=============
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*/
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vec_t WindingArea (winding_t *w)
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{
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int i;
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vec3_t d1, d2, cross;
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vec_t total;
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total = 0;
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for (i=2 ; i<w->numpoints ; i++)
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{
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VectorSubtract (w->p[i-1], w->p[0], d1);
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VectorSubtract (w->p[i], w->p[0], d2);
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CrossProduct (d1, d2, cross);
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total += 0.5 * VectorLength ( cross );
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}
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return total;
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}
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void WindingBounds (winding_t *w, vec3_t mins, vec3_t maxs)
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{
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vec_t v;
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int i,j;
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mins[0] = mins[1] = mins[2] = 99999;
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maxs[0] = maxs[1] = maxs[2] = -99999;
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for (i=0 ; i<w->numpoints ; i++)
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{
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for (j=0 ; j<3 ; j++)
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{
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v = w->p[i][j];
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if (v < mins[j])
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mins[j] = v;
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if (v > maxs[j])
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maxs[j] = v;
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}
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}
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}
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/*
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=============
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WindingCenter
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=============
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*/
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void WindingCenter (winding_t *w, vec3_t center)
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{
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int i;
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vec3_t d1, d2, cross;
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float scale;
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VectorCopy (vec3_origin, center);
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for (i=0 ; i<w->numpoints ; i++)
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VectorAdd (w->p[i], center, center);
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scale = 1.0/w->numpoints;
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VectorScale (center, scale, center);
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}
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/*
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=================
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BaseWindingForPlane
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=================
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*/
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winding_t *BaseWindingForPlane (vec3_t normal, float dist)
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{
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int i, x;
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vec_t max, v;
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vec3_t org, vright, vup;
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winding_t *w;
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// find the major axis
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max = -BOGUS_RANGE;
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x = -1;
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for (i=0 ; i<3; i++)
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{
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v = fabs(normal[i]);
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if (v > max)
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{
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x = i;
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max = v;
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}
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}
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if (x==-1)
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Error ("BaseWindingForPlane: no axis found");
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VectorCopy (vec3_origin, vup);
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switch (x)
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{
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case 0:
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case 1:
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vup[2] = 1;
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break;
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case 2:
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vup[0] = 1;
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break;
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}
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v = DotProduct (vup, normal);
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VectorMA (vup, -v, normal, vup);
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VectorNormalize (vup);
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VectorScale (normal, dist, org);
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CrossProduct (vup, normal, vright);
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VectorScale (vup, 9000, vup);
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VectorScale (vright, 9000, vright);
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// project a really big axis aligned box onto the plane
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w = AllocWinding (4);
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VectorSubtract (org, vright, w->p[0]);
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VectorAdd (w->p[0], vup, w->p[0]);
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VectorAdd (org, vright, w->p[1]);
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VectorAdd (w->p[1], vup, w->p[1]);
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VectorAdd (org, vright, w->p[2]);
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VectorSubtract (w->p[2], vup, w->p[2]);
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VectorSubtract (org, vright, w->p[3]);
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VectorSubtract (w->p[3], vup, w->p[3]);
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w->numpoints = 4;
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return w;
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}
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/*
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==================
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CopyWinding
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==================
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*/
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winding_t *CopyWinding (winding_t *w)
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{
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int size;
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winding_t *c;
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size = (int)((winding_t *)0)->p[w->numpoints];
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c = malloc (size);
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memcpy (c, w, size);
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return c;
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}
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/*
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=============
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ClipWinding
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=============
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*/
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void ClipWinding (winding_t *in, vec3_t normal, vec_t dist,
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winding_t **front, winding_t **back)
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{
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vec_t dists[MAX_POINTS_ON_WINDING+4];
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int sides[MAX_POINTS_ON_WINDING+4];
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int counts[3];
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vec_t dot;
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int i, j;
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vec_t *p1, *p2;
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vec3_t mid;
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winding_t *f, *b;
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int maxpts;
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counts[0] = counts[1] = counts[2] = 0;
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// determine sides for each point
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for (i=0 ; i<in->numpoints ; i++)
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{
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dot = DotProduct (in->p[i], normal);
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dot -= dist;
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dists[i] = dot;
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if (dot > ON_EPSILON)
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sides[i] = SIDE_FRONT;
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else if (dot < -ON_EPSILON)
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sides[i] = SIDE_BACK;
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else
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{
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sides[i] = SIDE_ON;
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}
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counts[sides[i]]++;
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}
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sides[i] = sides[0];
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dists[i] = dists[0];
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*front = *back = NULL;
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if (!counts[0])
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{
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*back = CopyWinding (in);
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return;
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}
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if (!counts[1])
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{
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*front = CopyWinding (in);
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return;
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}
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maxpts = in->numpoints+4; // can't use counts[0]+2 because
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// of fp grouping errors
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*front = f = AllocWinding (maxpts);
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*back = b = AllocWinding (maxpts);
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for (i=0 ; i<in->numpoints ; i++)
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{
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p1 = in->p[i];
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if (sides[i] == SIDE_ON)
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{
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VectorCopy (p1, f->p[f->numpoints]);
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f->numpoints++;
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VectorCopy (p1, b->p[b->numpoints]);
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b->numpoints++;
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continue;
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}
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if (sides[i] == SIDE_FRONT)
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{
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VectorCopy (p1, f->p[f->numpoints]);
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f->numpoints++;
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}
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if (sides[i] == SIDE_BACK)
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{
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VectorCopy (p1, b->p[b->numpoints]);
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b->numpoints++;
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}
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if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
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continue;
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// generate a split point
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p2 = in->p[(i+1)%in->numpoints];
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dot = dists[i] / (dists[i]-dists[i+1]);
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for (j=0 ; j<3 ; j++)
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{ // avoid round off error when possible
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if (normal[j] == 1)
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mid[j] = dist;
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else if (normal[j] == -1)
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mid[j] = -dist;
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else
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mid[j] = p1[j] + dot*(p2[j]-p1[j]);
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}
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VectorCopy (mid, f->p[f->numpoints]);
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f->numpoints++;
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VectorCopy (mid, b->p[b->numpoints]);
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b->numpoints++;
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}
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if (f->numpoints > maxpts || b->numpoints > maxpts)
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Error ("ClipWinding: points exceeded estimate");
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if (f->numpoints > MAX_POINTS_ON_WINDING || b->numpoints > MAX_POINTS_ON_WINDING)
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Error ("ClipWinding: MAX_POINTS_ON_WINDING");
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}
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/*
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=============
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ClipWindingNoCopy
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=============
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*/
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void ClipWindingNoCopy (winding_t *in, vec3_t normal, vec_t dist,
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winding_t **front, winding_t **back)
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{
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vec_t dists[MAX_POINTS_ON_WINDING+4];
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int sides[MAX_POINTS_ON_WINDING+4];
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int counts[3];
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vec_t dot;
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int i, j;
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vec_t *p1, *p2;
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vec3_t mid;
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winding_t *f, *b;
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int maxpts;
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counts[0] = counts[1] = counts[2] = 0;
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// determine sides for each point
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for (i=0 ; i<in->numpoints ; i++)
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{
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dot = DotProduct (in->p[i], normal);
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dot -= dist;
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dists[i] = dot;
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if (dot > ON_EPSILON)
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sides[i] = SIDE_FRONT;
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else if (dot < -ON_EPSILON)
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sides[i] = SIDE_BACK;
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else
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{
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sides[i] = SIDE_ON;
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}
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counts[sides[i]]++;
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}
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sides[i] = sides[0];
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dists[i] = dists[0];
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*front = *back = NULL;
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if (!counts[0])
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{
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*back = in;
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return;
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}
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if (!counts[1])
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{
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*front = in;
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return;
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}
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maxpts = in->numpoints+4; // can't use counts[0]+2 because
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// of fp grouping errors
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*front = f = AllocWinding (maxpts);
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*back = b = AllocWinding (maxpts);
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for (i=0 ; i<in->numpoints ; i++)
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{
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p1 = in->p[i];
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if (sides[i] == SIDE_ON)
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{
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VectorCopy (p1, f->p[f->numpoints]);
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f->numpoints++;
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VectorCopy (p1, b->p[b->numpoints]);
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b->numpoints++;
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continue;
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}
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if (sides[i] == SIDE_FRONT)
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{
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VectorCopy (p1, f->p[f->numpoints]);
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f->numpoints++;
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}
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if (sides[i] == SIDE_BACK)
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{
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VectorCopy (p1, b->p[b->numpoints]);
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b->numpoints++;
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}
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if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
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continue;
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// generate a split point
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p2 = in->p[(i+1)%in->numpoints];
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dot = dists[i] / (dists[i]-dists[i+1]);
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for (j=0 ; j<3 ; j++)
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{ // avoid round off error when possible
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if (normal[j] == 1)
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mid[j] = dist;
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else if (normal[j] == -1)
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mid[j] = -dist;
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else
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mid[j] = p1[j] + dot*(p2[j]-p1[j]);
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}
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VectorCopy (mid, f->p[f->numpoints]);
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f->numpoints++;
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VectorCopy (mid, b->p[b->numpoints]);
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b->numpoints++;
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}
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if (f->numpoints > maxpts || b->numpoints > maxpts)
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Error ("ClipWinding: points exceeded estimate");
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if (f->numpoints > MAX_POINTS_ON_WINDING || b->numpoints > MAX_POINTS_ON_WINDING)
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Error ("ClipWinding: MAX_POINTS_ON_WINDING");
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}
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/*
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=============
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ChopWindingNoFree
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=============
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*/
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winding_t *ChopWindingNoFree (winding_t *in, vec3_t normal, vec_t dist)
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{
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vec_t dists[MAX_POINTS_ON_WINDING+4];
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int sides[MAX_POINTS_ON_WINDING+4];
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int counts[3];
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vec_t dot;
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int i, j;
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vec_t *p1, *p2;
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vec3_t mid;
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winding_t *f;
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int maxpts;
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counts[0] = counts[1] = counts[2] = 0;
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// determine sides for each point
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for (i=0 ; i<in->numpoints ; i++)
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{
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dot = DotProduct (in->p[i], normal);
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dot -= dist;
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dists[i] = dot;
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if (dot > ON_EPSILON)
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sides[i] = SIDE_FRONT;
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else if (dot < -ON_EPSILON)
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sides[i] = SIDE_BACK;
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else
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{
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sides[i] = SIDE_ON;
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}
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counts[sides[i]]++;
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}
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sides[i] = sides[0];
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dists[i] = dists[0];
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if (!counts[0])
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return NULL;
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if (!counts[1])
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return in;
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maxpts = in->numpoints+4; // can't use counts[0]+2 because
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// of fp grouping errors
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f = AllocWinding (maxpts);
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for (i=0 ; i<in->numpoints ; i++)
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{
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p1 = in->p[i];
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if (sides[i] == SIDE_ON)
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{
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VectorCopy (p1, f->p[f->numpoints]);
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f->numpoints++;
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continue;
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}
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if (sides[i] == SIDE_FRONT)
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{
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VectorCopy (p1, f->p[f->numpoints]);
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f->numpoints++;
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}
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if (sides[i+1] == SIDE_ON || sides[i+1] == sides[i])
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continue;
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// generate a split point
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p2 = in->p[(i+1)%in->numpoints];
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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");
|
|
|
|
return 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;
|
|
|
|
ClipWinding (in, normal, dist, &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 isn't degenerate
|
|
p2 = w->p[j];
|
|
VectorSubtract (p2, p1, dir);
|
|
|
|
if (VectorLength (dir) < ON_EPSILON)
|
|
Error ("CheckWinding: degenerate edge");
|
|
|
|
CrossProduct (facenormal, dir, edgenormal);
|
|
VectorNormalize (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;
|
|
}
|
|
|