halflife-photomode/utils/common/polylib.cpp

711 lines
13 KiB
C++

/***
*
* Copyright (c) 1996-2002, Valve LLC. All rights reserved.
*
* This product contains software technology licensed from Id
* Software, Inc. ("Id Technology"). Id Technology (c) 1996 Id Software, Inc.
* All Rights Reserved.
*
****/
#include "cmdlib.h"
#include "mathlib.h"
#include "polylib.h"
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;
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);
s += sizeof(vec_t) - sizeof(w->numpoints); // padding
w = reinterpret_cast<winding_t*>(malloc(s));
memset(w, 0, s);
return w;
}
void FreeWinding(winding_t* w)
{
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);
VectorNormalize(v2);
if (DotProduct(v1, v2) < 1.0 - ON_EPSILON)
{
VectorCopy(w->p[i], p[nump]);
nump++;
}
}
if (nump == w->numpoints)
return;
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);
*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, float 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);
VectorScale(normal, dist, org);
CrossProduct(vup, normal, vright);
VectorScale(vup, 9000, vup);
VectorScale(vright, 9000, 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;
size = (int)((winding_t*)0)->p[w->numpoints];
c = reinterpret_cast<winding_t*>(malloc(size));
memcpy(c, w, size);
return c;
}
/*
=============
ClipWinding
=============
*/
void ClipWinding(winding_t* in, vec3_t normal, vec_t dist,
winding_t** front, winding_t** back)
{
vec_t dists[MAX_POINTS_ON_WINDING + 4];
int sides[MAX_POINTS_ON_WINDING + 4];
int counts[3];
vec_t dot;
int i, j;
vec_t *p1, *p2;
vec3_t mid;
winding_t *f, *b;
int maxpts;
sides[0] = SIDE_FRONT;
dists[0] = 0;
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 > ON_EPSILON)
sides[i] = SIDE_FRONT;
else if (dot < -ON_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; // can't 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");
}
/*
=============
ClipWindingNoCopy
=============
*/
void ClipWindingNoCopy(winding_t* in, vec3_t normal, vec_t dist,
winding_t** front, winding_t** back)
{
vec_t dists[MAX_POINTS_ON_WINDING + 4];
int sides[MAX_POINTS_ON_WINDING + 4];
int counts[3];
vec_t dot;
int i, j;
vec_t *p1, *p2;
vec3_t mid;
winding_t *f, *b;
int maxpts;
sides[0] = SIDE_FRONT;
dists[0] = 0;
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 > ON_EPSILON)
sides[i] = SIDE_FRONT;
else if (dot < -ON_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 = in;
return;
}
if (!counts[1])
{
*front = in;
return;
}
maxpts = in->numpoints + 4; // can't 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");
}
/*
=============
ChopWindingNoFree
=============
*/
winding_t* ChopWindingNoFree(winding_t* in, vec3_t normal, vec_t dist)
{
vec_t dists[MAX_POINTS_ON_WINDING + 4];
int sides[MAX_POINTS_ON_WINDING + 4];
int counts[3];
vec_t dot;
int i, j;
vec_t *p1, *p2;
vec3_t mid;
winding_t* f;
int maxpts;
sides[0] = SIDE_FRONT;
dists[0] = 0;
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 > ON_EPSILON)
sides[i] = SIDE_FRONT;
else if (dot < -ON_EPSILON)
sides[i] = SIDE_BACK;
else
{
sides[i] = SIDE_ON;
}
counts[sides[i]]++;
}
sides[i] = sides[0];
dists[i] = dists[0];
if (!counts[0])
return NULL;
if (!counts[1])
return in;
maxpts = in->numpoints + 4; // can't 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");
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;
}