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gl2ps.c
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gl2ps.c
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/*
* GL2PS, an OpenGL to PostScript Printing Library
* Copyright (C) 1999-2002 Christophe Geuzaine
*
* $Id: gl2ps.c,v 1.2 2003/02/01 14:52:56 canacar Exp $
*
* E-mail: [email protected]
* URL: http://www.geuz.org/gl2ps/
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <string.h>
#include <sys/types.h>
#include <stdlib.h>
#include <stdarg.h>
#include <time.h>
#include "gl2ps.h"
#ifndef strlcpy
size_t strlcpy(char *dst, const char *src, size_t siz);
#endif
/* The gl2ps context. gl2ps is not thread safe (we should create a
local GL2PScontext during gl2psBeginPage). */
GL2PScontext *gl2ps = NULL;
/* Some 'system' utility routines */
void gl2psMsg(GLint level, char *fmt, ...){
va_list args;
if(!(gl2ps->options & GL2PS_SILENT)){
switch(level){
case GL2PS_INFO : fprintf(stderr, "GL2PS info: "); break;
case GL2PS_WARNING : fprintf(stderr, "GL2PS warning: "); break;
case GL2PS_ERROR : fprintf(stderr, "GL2PS error: "); break;
}
va_start(args, fmt);
vfprintf(stderr, fmt, args);
va_end (args);
fprintf(stderr, "\n");
}
if(level == GL2PS_ERROR) exit(1);
}
void *gl2psMalloc(size_t size){
void *ptr;
if(!size) return(NULL);
ptr = malloc(size);
if(!ptr) gl2psMsg(GL2PS_ERROR, "Couldn't allocate requested memory");
return(ptr);
}
void *gl2psRealloc(void *ptr, size_t size){
if(!size) return(NULL);
ptr = realloc(ptr, size);
if(!ptr) gl2psMsg(GL2PS_ERROR, "Couldn't reallocate requested memory");
return(ptr);
}
void gl2psFree(void *ptr){
if(!ptr) return;
free(ptr);
}
/* The list handling routines */
void gl2psListRealloc(GL2PSlist *list, GLint n){
if(n <= 0) return;
if(!list->array){
list->nmax = ((n - 1) / list->incr + 1) * list->incr;
list->array = (char *)gl2psMalloc(list->nmax * list->size);
}
else
if(n > list->nmax){
list->nmax = ((n - 1) / list->incr + 1) * list->incr;
list->array = (char *)gl2psRealloc(list->array,
list->nmax * list->size);
}
}
GL2PSlist *gl2psListCreate(GLint n, GLint incr, GLint size){
GL2PSlist *list;
if(n < 0) n = 0;
if(incr <= 0) incr = 1;
list = (GL2PSlist *)gl2psMalloc(sizeof(GL2PSlist));
list->nmax = 0;
list->incr = incr;
list->size = size;
list->n = 0;
list->array = NULL;
gl2psListRealloc(list, n);
return(list);
}
void gl2psListDelete(GL2PSlist *list){
gl2psFree(list->array);
gl2psFree(list);
}
void gl2psListAdd(GL2PSlist *list, void *data){
list->n++;
gl2psListRealloc(list, list->n);
memcpy(&list->array[(list->n - 1) * list->size], data, list->size);
}
GLint gl2psListNbr(GL2PSlist *list){
return(list->n);
}
void *gl2psListPointer(GL2PSlist *list, GLint index){
if((index < 0) || (index >= list->n))
gl2psMsg(GL2PS_ERROR, "Wrong list index in gl2psListPointer");
return(&list->array[index * list->size]);
}
void gl2psListSort(GL2PSlist *list,
int (*fcmp)(const void *a, const void *b)){
qsort(list->array, list->n, list->size, fcmp);
}
void gl2psListAction(GL2PSlist *list,
void (*action)(void *data, void *dummy)){
GLint i, dummy;
for(i = 0; i < gl2psListNbr(list); i++)
(*action)(gl2psListPointer(list, i), &dummy);
}
void gl2psListActionInverse(GL2PSlist *list,
void (*action)(void *data, void *dummy)){
GLint i, dummy;
for(i = gl2psListNbr(list); i > 0; i--)
(*action)(gl2psListPointer(list, i-1), &dummy);
}
/* The 3D sorting routines */
GLfloat gl2psComparePointPlane(GL2PSxyz point, GL2PSplane plane){
return(plane[0] * point[0] +
plane[1] * point[1] +
plane[2] * point[2] +
plane[3]);
}
GLfloat gl2psPsca(GLfloat *a, GLfloat *b){
return(a[0]*b[0] + a[1]*b[1] + a[2]*b[2]);
}
void gl2psPvec(GLfloat *a, GLfloat *b, GLfloat *c){
c[0] = a[1]*b[2] - a[2]*b[1];
c[1] = a[2]*b[0] - a[0]*b[2];
c[2] = a[0]*b[1] - a[1]*b[0];
}
GLfloat gl2psNorm(GLfloat *a){
return sqrt(a[0]*a[0] + a[1]*a[1] + a[2]*a[2]);
}
void gl2psGetNormal(GLfloat *a, GLfloat *b, GLfloat *c){
GLfloat norm;
gl2psPvec(a, b, c);
if(!GL2PS_ZERO(norm = gl2psNorm(c))){
c[0] = c[0] / norm;
c[1] = c[1] / norm;
c[2] = c[2] / norm;
}
else{
/* The plane is still wrong, despite our tests in
gl2psGetPlane... Let's return a dummy value (this is a hack: we
should do more tests in GetPlane): */
c[0] = c[1] = 0.;
c[2] = 1.;
}
}
void gl2psGetPlane(GL2PSprimitive *prim, GL2PSplane plane){
GL2PSxyz v = {0., 0., 0.}, w = {0., 0., 0.};
switch(prim->type){
case GL2PS_TRIANGLE :
case GL2PS_QUADRANGLE :
v[0] = prim->verts[1].xyz[0] - prim->verts[0].xyz[0];
v[1] = prim->verts[1].xyz[1] - prim->verts[0].xyz[1];
v[2] = prim->verts[1].xyz[2] - prim->verts[0].xyz[2];
w[0] = prim->verts[2].xyz[0] - prim->verts[0].xyz[0];
w[1] = prim->verts[2].xyz[1] - prim->verts[0].xyz[1];
w[2] = prim->verts[2].xyz[2] - prim->verts[0].xyz[2];
if((GL2PS_ZERO(v[0]) && GL2PS_ZERO(v[1]) && GL2PS_ZERO(v[2])) ||
(GL2PS_ZERO(w[0]) && GL2PS_ZERO(w[1]) && GL2PS_ZERO(w[2]))){
plane[0] = plane[1] = 0.;
plane[2] = 1.;
plane[3] = -prim->verts[0].xyz[2];
}
else{
gl2psGetNormal(v, w, plane);
plane[3] =
- plane[0] * prim->verts[0].xyz[0]
- plane[1] * prim->verts[0].xyz[1]
- plane[2] * prim->verts[0].xyz[2];
}
break;
case GL2PS_LINE :
v[0] = prim->verts[1].xyz[0] - prim->verts[0].xyz[0];
v[1] = prim->verts[1].xyz[1] - prim->verts[0].xyz[1];
v[2] = prim->verts[1].xyz[2] - prim->verts[0].xyz[2];
if(GL2PS_ZERO(v[0]) && GL2PS_ZERO(v[1]) && GL2PS_ZERO(v[2])){
plane[0] = plane[1] = 0.;
plane[2] = 1.;
plane[3] = -prim->verts[0].xyz[2];
}
else{
if(GL2PS_ZERO(v[0])) w[0] = 1.;
else if(GL2PS_ZERO(v[1])) w[1] = 1.;
else w[2] = 1.;
gl2psGetNormal(v, w, plane);
plane[3] =
- plane[0] * prim->verts[0].xyz[0]
- plane[1] * prim->verts[0].xyz[1]
- plane[2] * prim->verts[0].xyz[2];
}
break;
case GL2PS_POINT :
case GL2PS_TEXT :
plane[0] = plane[1] = 0.;
plane[2] = 1.;
plane[3] = -prim->verts[0].xyz[2];
break;
default :
gl2psMsg(GL2PS_ERROR, "Unknown primitive type in BSP tree");
}
}
void gl2psCutEdge(GL2PSvertex *a, GL2PSvertex *b, GL2PSplane plane,
GL2PSvertex *c){
GL2PSxyz v;
GLfloat sect;
v[0] = b->xyz[0] - a->xyz[0];
v[1] = b->xyz[1] - a->xyz[1];
v[2] = b->xyz[2] - a->xyz[2];
sect = - gl2psComparePointPlane(a->xyz, plane) / gl2psPsca(plane, v);
c->xyz[0] = a->xyz[0] + v[0] * sect;
c->xyz[1] = a->xyz[1] + v[1] * sect;
c->xyz[2] = a->xyz[2] + v[2] * sect;
c->rgba[0] = (1.-sect) * a->rgba[0] + sect * b->rgba[0];
c->rgba[1] = (1.-sect) * a->rgba[1] + sect * b->rgba[1];
c->rgba[2] = (1.-sect) * a->rgba[2] + sect * b->rgba[2];
c->rgba[3] = (1.-sect) * a->rgba[3] + sect * b->rgba[3];
}
void gl2psCreateSplitPrimitive(GL2PSprimitive *parent, GL2PSplane plane,
GL2PSprimitive *child, GLshort numverts,
GLshort *index0, GLshort *index1){
GLshort i;
if(numverts > 4){
gl2psMsg(GL2PS_WARNING, "%d vertices in polygon", numverts);
numverts = 4;
}
switch(numverts){
case 1 : child->type = GL2PS_POINT; break;
case 2 : child->type = GL2PS_LINE; break;
case 3 : child->type = GL2PS_TRIANGLE; break;
case 4 : child->type = GL2PS_QUADRANGLE; break;
}
child->boundary = 0; /* not done! */
child->depth = parent->depth; /* should not be used in this case */
child->culled = parent->culled;
child->dash = parent->dash;
child->width = parent->width;
child->numverts = numverts;
child->verts = (GL2PSvertex *)gl2psMalloc(numverts * sizeof(GL2PSvertex));
for(i = 0; i < numverts; i++){
if(index1[i] < 0)
child->verts[i] = parent->verts[index0[i]];
else
gl2psCutEdge(&parent->verts[index0[i]], &parent->verts[index1[i]],
plane, &child->verts[i]);
}
}
void gl2psAddIndex(GLshort *index0, GLshort *index1, GLshort *nb,
GLshort i, GLshort j){
GLint k;
for(k = 0; k < *nb; k++)
if((index0[k] == i && index1[k] == j) ||
(index1[k] == i && index0[k] == j)) return;
index0[*nb] = i;
index1[*nb] = j;
(*nb)++;
}
GLshort gl2psGetIndex(GLshort i, GLshort num){
return(i < num-1) ? i+1 : 0;
}
GLint gl2psTestSplitPrimitive(GL2PSprimitive *prim, GL2PSplane plane){
GLint type = GL2PS_COINCIDENT;
GLshort i, j;
GLfloat d[5];
for(i = 0; i < prim->numverts; i++){
d[i] = gl2psComparePointPlane(prim->verts[i].xyz, plane);
}
if(prim->type == GL2PS_POINT)
return 0;
else{
for(i = 0; i < prim->numverts; i++){
j = gl2psGetIndex(i, prim->numverts);
if(d[j] > GL2PS_EPSILON){
if(type == GL2PS_COINCIDENT) type = GL2PS_IN_BACK_OF;
else if(type != GL2PS_IN_BACK_OF) return 1;
if(d[i] < -GL2PS_EPSILON) return 1;
}
else if(d[j] < -GL2PS_EPSILON){
if(type == GL2PS_COINCIDENT) type = GL2PS_IN_FRONT_OF;
else if(type != GL2PS_IN_FRONT_OF) return 1;
if(d[i] > GL2PS_EPSILON) return 1;
}
}
}
return 0;
}
GLint gl2psSplitPrimitive(GL2PSprimitive *prim, GL2PSplane plane,
GL2PSprimitive **front, GL2PSprimitive **back){
GLshort i, j, in=0, out=0, in0[5], in1[5], out0[5], out1[5];
GLint type;
GLfloat d[5];
type = GL2PS_COINCIDENT;
for(i = 0; i < prim->numverts; i++){
d[i] = gl2psComparePointPlane(prim->verts[i].xyz, plane);
}
switch(prim->type){
case GL2PS_POINT :
if(d[0] > GL2PS_EPSILON) type = GL2PS_IN_BACK_OF;
else if(d[0] < -GL2PS_EPSILON) type = GL2PS_IN_FRONT_OF;
else type = GL2PS_COINCIDENT;
break;
default :
for(i = 0; i < prim->numverts; i++){
j = gl2psGetIndex(i, prim->numverts);
if(d[j] > GL2PS_EPSILON){
if(type == GL2PS_COINCIDENT) type = GL2PS_IN_BACK_OF;
else if(type != GL2PS_IN_BACK_OF) type = GL2PS_SPANNING;
if(d[i] < -GL2PS_EPSILON){
gl2psAddIndex(in0, in1, &in, i, j);
gl2psAddIndex(out0, out1, &out, i, j);
type = GL2PS_SPANNING;
}
gl2psAddIndex(out0, out1, &out, j, -1);
}
else if(d[j] < -GL2PS_EPSILON){
if(type == GL2PS_COINCIDENT) type = GL2PS_IN_FRONT_OF;
else if(type != GL2PS_IN_FRONT_OF) type = GL2PS_SPANNING;
if(d[i] > GL2PS_EPSILON){
gl2psAddIndex(in0, in1, &in, i, j);
gl2psAddIndex(out0, out1, &out, i, j);
type = GL2PS_SPANNING;
}
gl2psAddIndex(in0, in1, &in, j, -1);
}
else{
gl2psAddIndex(in0, in1, &in, j, -1);
gl2psAddIndex(out0, out1, &out, j, -1);
}
}
break;
}
if(type == GL2PS_SPANNING){
*back = (GL2PSprimitive*)gl2psMalloc(sizeof(GL2PSprimitive));
*front = (GL2PSprimitive*)gl2psMalloc(sizeof(GL2PSprimitive));
gl2psCreateSplitPrimitive(prim, plane, *back, out, out0, out1);
gl2psCreateSplitPrimitive(prim, plane, *front, in, in0, in1);
}
return type;
}
void gl2psDivideQuad(GL2PSprimitive *quad,
GL2PSprimitive **t1, GL2PSprimitive **t2){
*t1 = (GL2PSprimitive*)gl2psMalloc(sizeof(GL2PSprimitive));
*t2 = (GL2PSprimitive*)gl2psMalloc(sizeof(GL2PSprimitive));
(*t1)->type = (*t2)->type = GL2PS_TRIANGLE;
(*t1)->numverts = (*t2)->numverts = 3;
(*t1)->depth = (*t2)->depth = quad->depth;
(*t1)->culled = (*t2)->culled = quad->culled;
(*t1)->dash = (*t2)->dash = quad->dash;
(*t1)->width = (*t2)->width = quad->width;
(*t1)->verts = (GL2PSvertex *)gl2psMalloc(3 * sizeof(GL2PSvertex));
(*t2)->verts = (GL2PSvertex *)gl2psMalloc(3 * sizeof(GL2PSvertex));
(*t1)->verts[0] = quad->verts[0];
(*t1)->verts[1] = quad->verts[1];
(*t1)->verts[2] = quad->verts[2];
(*t1)->boundary = ((quad->boundary & 1) ? 1 : 0) | ((quad->boundary & 2) ? 2 : 0);
(*t2)->verts[0] = quad->verts[0];
(*t2)->verts[1] = quad->verts[2];
(*t2)->verts[2] = quad->verts[3];
(*t1)->boundary = ((quad->boundary & 4) ? 2 : 0) | ((quad->boundary & 4) ? 2 : 0);
}
int gl2psCompareDepth(const void *a, const void *b){
GL2PSprimitive *q,*w;
GLfloat diff;
q = *(GL2PSprimitive**)a;
w = *(GL2PSprimitive**)b;
diff = q->depth - w->depth;
if(diff > 0.)
return 1;
else if(diff < 0.)
return -1;
else
return 0;
}
int gl2psTrianglesFirst(const void *a, const void *b){
GL2PSprimitive *q,*w;
q = *(GL2PSprimitive**)a;
w = *(GL2PSprimitive**)b;
return(q->type < w->type ? 1 : -1);
}
GLint gl2psFindRoot(GL2PSlist *primitives, GL2PSprimitive **root){
GLint i, j, count, best = 1000000, index = 0;
GL2PSprimitive *prim1, *prim2;
GL2PSplane plane;
GLint maxp;
if(gl2ps->options & GL2PS_BEST_ROOT){
*root = *(GL2PSprimitive**)gl2psListPointer(primitives, 0);
maxp = gl2psListNbr(primitives);
if(maxp > gl2ps->maxbestroot){
maxp = gl2ps->maxbestroot;
}
for(i = 0; i < maxp; i++){
prim1 = *(GL2PSprimitive**)gl2psListPointer(primitives, i);
gl2psGetPlane(prim1, plane);
count = 0;
for(j = 0; j < gl2psListNbr(primitives); j++){
if(j != i){
prim2 = *(GL2PSprimitive**)gl2psListPointer(primitives, j);
count += gl2psTestSplitPrimitive(prim2, plane);
}
if(count > best) break;
}
if(count < best){
best = count;
index = i;
*root = prim1;
if(!count) return index;
}
}
if(index) gl2psMsg(GL2PS_INFO, "GL2PS_BEST_ROOT was worth it: %d", index);
return index;
}
else{
*root = *(GL2PSprimitive**)gl2psListPointer(primitives, 0);
return 0;
}
}
void gl2psFreePrimitive(void *a, void *b){
GL2PSprimitive *q;
q = *(GL2PSprimitive**)a;
gl2psFree(q->verts);
if(q->type == GL2PS_TEXT){
gl2psFree(q->text->str);
gl2psFree(q->text->fontname);
gl2psFree(q->text);
}
gl2psFree(q);
}
void gl2psAddPrimitiveInList(GL2PSprimitive *prim, GL2PSlist *list){
GL2PSprimitive *t1, *t2;
if(prim->type != GL2PS_QUADRANGLE){
gl2psListAdd(list, &prim);
}
else{
gl2psDivideQuad(prim, &t1, &t2);
gl2psListAdd(list, &t1);
gl2psListAdd(list, &t2);
gl2psFreePrimitive(&prim, NULL);
}
}
void gl2psFreeBspTree(GL2PSbsptree *tree){
if(tree->back){
gl2psFreeBspTree(tree->back);
gl2psFree(tree->back);
}
if(tree->primitives){
gl2psListAction(tree->primitives, gl2psFreePrimitive);
gl2psListDelete(tree->primitives);
}
if(tree->front){
gl2psFreeBspTree(tree->front);
gl2psFree(tree->front);
}
}
GLboolean gl2psGreater(GLfloat f1, GLfloat f2){
if(f1 > f2) return 1;
else return 0;
}
GLboolean gl2psLess(GLfloat f1, GLfloat f2){
if(f1 < f2) return 1;
else return 0;
}
void gl2psBuildBspTree(GL2PSbsptree *tree, GL2PSlist *primitives){
GL2PSprimitive *prim, *frontprim, *backprim;
GL2PSlist *frontlist, *backlist;
GLint i, index;
tree->front = NULL;
tree->back = NULL;
tree->primitives = gl2psListCreate(1, 2, sizeof(GL2PSprimitive*));
index = gl2psFindRoot(primitives, &prim);
gl2psGetPlane(prim, tree->plane);
gl2psAddPrimitiveInList(prim, tree->primitives);
frontlist = gl2psListCreate(1, 2, sizeof(GL2PSprimitive*));
backlist = gl2psListCreate(1, 2, sizeof(GL2PSprimitive*));
for(i = 0; i < gl2psListNbr(primitives); i++){
if(i != index){
prim = *(GL2PSprimitive**)gl2psListPointer(primitives,i);
switch(gl2psSplitPrimitive(prim, tree->plane, &frontprim, &backprim)){
case GL2PS_COINCIDENT:
gl2psAddPrimitiveInList(prim, tree->primitives);
break;
case GL2PS_IN_BACK_OF:
gl2psAddPrimitiveInList(prim, backlist);
break;
case GL2PS_IN_FRONT_OF:
gl2psAddPrimitiveInList(prim, frontlist);
break;
case GL2PS_SPANNING:
gl2psAddPrimitiveInList(backprim, backlist);
gl2psAddPrimitiveInList(frontprim, frontlist);
gl2psFreePrimitive(&prim, NULL);
break;
}
}
}
if(gl2psListNbr(tree->primitives))
gl2psListSort(tree->primitives, gl2psTrianglesFirst);
if(gl2psListNbr(frontlist)){
gl2psListSort(frontlist, gl2psTrianglesFirst);
tree->front = (GL2PSbsptree*)gl2psMalloc(sizeof(GL2PSbsptree));
gl2psBuildBspTree(tree->front, frontlist);
}
else
gl2psListDelete(frontlist);
if(gl2psListNbr(backlist)){
gl2psListSort(backlist, gl2psTrianglesFirst);
tree->back = (GL2PSbsptree*)gl2psMalloc(sizeof(GL2PSbsptree));
gl2psBuildBspTree(tree->back, backlist);
}
else
gl2psListDelete(backlist);
gl2psListDelete(primitives);
}
void gl2psTraverseBspTree(GL2PSbsptree *tree, GL2PSxyz eye, GLfloat epsilon,
GLboolean (*compare)(GLfloat f1, GLfloat f2),
void (*action)(void *data, void *dummy)){
GLfloat result;
if(!tree) return;
result = gl2psComparePointPlane(eye, tree->plane);
if(compare(result, epsilon)){
gl2psTraverseBspTree(tree->back, eye, epsilon, compare, action);
gl2psListAction(tree->primitives, action);
gl2psTraverseBspTree(tree->front, eye, epsilon, compare, action);
}
else if(compare(-epsilon, result)){
gl2psTraverseBspTree(tree->front, eye, epsilon, compare, action);
gl2psListAction(tree->primitives, action);
gl2psTraverseBspTree(tree->back, eye, epsilon, compare, action);
}
else{
gl2psTraverseBspTree(tree->front, eye, epsilon, compare, action);
gl2psTraverseBspTree(tree->back, eye, epsilon, compare, action);
}
}
/* The 2D sorting routines (for occlusion culling) */
GLint gl2psGetPlaneFromPoints(GL2PSxyz a, GL2PSxyz b, GL2PSplane plane){
GLfloat n;
plane[0] = b[1] - a[1];
plane[1] = a[0] - b[0];
n = sqrt(plane[0]*plane[0] + plane[1]*plane[1]);
plane[2]=0.;
if(n != 0.){
plane[0] /= n;
plane[1] /= n;
plane[3] = -plane[0]*a[0]-plane[1]*a[1];
return 1;
}
else{
plane[0] = -1.0;
plane[1] = 0.;
plane[3] = a[0];
return 0;
}
}
void gl2psFreeBspImageTree(GL2PSbsptree2d **tree){
if(*tree){
if((*tree)->back) gl2psFreeBspImageTree(&(*tree)->back);
if((*tree)->front) gl2psFreeBspImageTree(&(*tree)->front);
gl2psFree(*tree);
*tree = NULL;
}
}
GLint gl2psCheckPoint(GL2PSxyz point, GL2PSplane plane){
GLfloat pt_dis;
pt_dis = gl2psComparePointPlane(point, plane);
if(pt_dis > GL2PS_EPSILON) return GL2PS_POINT_INFRONT;
else if(pt_dis < -GL2PS_EPSILON) return GL2PS_POINT_BACK;
else return GL2PS_POINT_COINCIDENT;
}
void gl2psAddPlanesInBspTreeImage(GL2PSprimitive *prim,
GL2PSbsptree2d **tree){
GLint ret = 0;
GLint i;
GLint offset = 0;
GL2PSbsptree2d *head = NULL, *cur = NULL;
if((*tree == NULL) && (prim->numverts > 2)){
head=(GL2PSbsptree2d*)gl2psMalloc(sizeof(GL2PSbsptree2d));
for(i = 0; i < prim->numverts-1; i++){
if(!gl2psGetPlaneFromPoints(prim->verts[i].xyz,
prim->verts[i+1].xyz,
head->plane)){
if(prim->numverts-i > 3)
offset++;
else{
gl2psFree(head);
return;
}
}
else break;
}
head->back = NULL;
head->front = NULL;
for(i = 2+offset; i < prim->numverts; i++){
ret = gl2psCheckPoint(prim->verts[i].xyz, head->plane);
if(ret != 0) break;
}
switch(ret){
case GL2PS_POINT_INFRONT :
cur = head;
for(i = 1+offset; i < (prim->numverts-1); i++){
if(cur->front == NULL)
cur->front = (GL2PSbsptree2d*)gl2psMalloc(sizeof(GL2PSbsptree2d));
if(gl2psGetPlaneFromPoints(prim->verts[i].xyz,
prim->verts[i+1].xyz,
cur->front->plane)){
cur = cur->front;
cur->front = NULL;
cur->back = NULL;
}
}
if(cur->front == NULL)
cur->front = (GL2PSbsptree2d*)gl2psMalloc(sizeof(GL2PSbsptree2d));
if(gl2psGetPlaneFromPoints(prim->verts[i].xyz,
prim->verts[offset].xyz,
cur->front->plane)){
cur->front->front = NULL;
cur->front->back = NULL;
}
else{
gl2psFree(cur->front);
cur = NULL;
}
break;
case GL2PS_POINT_BACK :
for(i = 0; i < 4; i++)
head->plane[i] = -head->plane[i];
cur = head;
for(i = 1+offset; i < (prim->numverts-1); i++){
if(cur->front == NULL)
cur->front = (GL2PSbsptree2d*)gl2psMalloc(sizeof(GL2PSbsptree2d));
if(gl2psGetPlaneFromPoints(prim->verts[i+1].xyz,
prim->verts[i].xyz,
cur->front->plane)){
cur = cur->front;
cur->front = NULL;
cur->back = NULL;
}
}
if(cur->front == NULL)
cur->front = (GL2PSbsptree2d*)gl2psMalloc(sizeof(GL2PSbsptree2d));
if(gl2psGetPlaneFromPoints(prim->verts[offset].xyz,
prim->verts[i].xyz,
cur->front->plane)){
cur->front->front = NULL;
cur->front->back = NULL;
}
else{
gl2psFree(cur->front);
cur = NULL;
}
break;
default:
gl2psFree(head);
return;
}
(*tree) = head;
}
}
GLint gl2psCheckPrimitive(GL2PSprimitive *prim, GL2PSplane plane){
GLint i;
GLint pos;
pos = gl2psCheckPoint(prim->verts[0].xyz, plane);
for(i = 1; i < prim->numverts; i++){
pos |= gl2psCheckPoint(prim->verts[i].xyz, plane);
if(pos == (GL2PS_POINT_INFRONT | GL2PS_POINT_BACK)) return GL2PS_SPANNING;
}
if(pos & GL2PS_POINT_INFRONT) return GL2PS_IN_FRONT_OF;
else if(pos & GL2PS_POINT_BACK) return GL2PS_IN_BACK_OF;
else return GL2PS_COINCIDENT;
}
GL2PSprimitive* gl2psCreateSplitPrimitive2D(GL2PSprimitive *parent,
GLint numverts,
GL2PSvertex *vertx){
GLint i;
GL2PSprimitive *child = (GL2PSprimitive*)gl2psMalloc(sizeof(GL2PSprimitive));
switch(numverts){
case 1 : child->type = GL2PS_POINT; break;
case 2 : child->type = GL2PS_LINE; break;
case 3 : child->type = GL2PS_TRIANGLE; break;
case 4 : child->type = GL2PS_QUADRANGLE; break;
}
child->boundary = 0; /* not done! */
child->depth = parent->depth;
child->culled = parent->culled;
child->dash = parent->dash;
child->width = parent->width;
child->numverts = numverts;
child->verts = (GL2PSvertex *)gl2psMalloc(numverts * sizeof(GL2PSvertex));
for(i = 0; i < numverts; i++)
child->verts[i] = vertx[i];
return child;
}
void gl2psSplitPrimitive2D(GL2PSprimitive *prim,
GL2PSplane plane,
GL2PSprimitive **front,
GL2PSprimitive **back){
/* cur will hold the position of current vertex
prev will holds the position of previous vertex
prev0 will holds the position of vertex number 0
v1 and v2 represent the current and previous vertexs respectively
flag will represents that should the current be checked against the plane */
GLint cur = -1, prev = -1, i, v1 = 0, v2 = 0, flag = 1, prev0 = -1;
/* list of vertexs which will go in front and back Primitive */
GL2PSvertex *front_list = NULL, *back_list = NULL;
/* number of vertex in front and back list */
GLint front_count = 0, back_count = 0;
for(i = 0; i <= prim->numverts; i++){
v1 = i;
if(v1 == prim->numverts){
if(prim->numverts < 3) break;
v1 = 0;
v2 = prim->numverts-1;
cur = prev0;
}
else if(flag){
cur = gl2psCheckPoint(prim->verts[v1].xyz, plane);
if(i == 0)
prev0 = cur;
}
if(((prev == -1) || (prev == cur) || (prev == 0) || (cur == 0)) &&
(i < prim->numverts)){
if(cur == GL2PS_POINT_INFRONT){
front_count++;
front_list = (GL2PSvertex*)gl2psRealloc(front_list,
sizeof(GL2PSvertex)*front_count);
front_list[front_count-1] = prim->verts[v1];
}
else if(cur == GL2PS_POINT_BACK){
back_count++;
back_list = (GL2PSvertex*)gl2psRealloc(back_list,
sizeof(GL2PSvertex)*back_count);
back_list[back_count-1] = prim->verts[v1];
}
else{
front_count++;
front_list = (GL2PSvertex*)gl2psRealloc(front_list,
sizeof(GL2PSvertex)*front_count);
front_list[front_count-1] = prim->verts[v1];
back_count++;
back_list = (GL2PSvertex*)gl2psRealloc(back_list,
sizeof(GL2PSvertex)*back_count);
back_list[back_count-1] = prim->verts[v1];
}
flag = 1;
}
else if((prev != cur) && (cur != 0) && (prev != 0)){
if(v1 != 0){
v2 = v1-1;
i--;
}
front_count++;
front_list = (GL2PSvertex*)gl2psRealloc(front_list,
sizeof(GL2PSvertex)*front_count);
gl2psCutEdge(&prim->verts[v2],
&prim->verts[v1],
plane,
&front_list[front_count-1]);
back_count++;
back_list = (GL2PSvertex*)gl2psRealloc(back_list,
sizeof(GL2PSvertex)*back_count);
back_list[back_count-1] = front_list[front_count-1];
flag = 0;
}
prev = cur;
}
*front = gl2psCreateSplitPrimitive2D(prim, front_count, front_list);
*back = gl2psCreateSplitPrimitive2D(prim, back_count, back_list);
gl2psFree(front_list);
gl2psFree(back_list);
}
GLint gl2psAddInImageTree(GL2PSprimitive *prim, GL2PSbsptree2d **tree){
GLint ret = 0;
GL2PSprimitive *frontprim = NULL, *backprim = NULL;
if(*tree == NULL){
gl2psAddPlanesInBspTreeImage(prim, tree);
return 1;
}
else{
switch(gl2psCheckPrimitive(prim, (*tree)->plane)){
case GL2PS_IN_BACK_OF: return gl2psAddInImageTree(prim, &(*tree)->back);
case GL2PS_IN_FRONT_OF:
if((*tree)->front != NULL) return gl2psAddInImageTree(prim, &(*tree)->front);
else return 0;
case GL2PS_SPANNING:
gl2psSplitPrimitive2D(prim, (*tree)->plane, &frontprim, &backprim);
ret = gl2psAddInImageTree(backprim, &(*tree)->back);
if((*tree)->front != NULL)
if(gl2psAddInImageTree(frontprim, &(*tree)->front))
ret = 1;
gl2psFree(frontprim->verts);
gl2psFree(frontprim);
gl2psFree(backprim->verts);
gl2psFree(backprim);
return ret;
case GL2PS_COINCIDENT:
if(prim->numverts < 3) return 1;
else return 0;
}
}
return 0;
}
void gl2psAddInImage(void *a, void *b){
GL2PSprimitive *prim;
prim = *(GL2PSprimitive **)a;
if(!gl2psAddInImageTree(prim, &gl2ps->image)){
prim->culled = 1;
}
}
/* Boundary contruction */
void gl2psAddBoundaryInList(GL2PSprimitive *prim, GL2PSlist *list){
GL2PSprimitive *b;
GLshort i;
GL2PSxyz c;
c[0] = c[1] = c[2] = 0.;
for(i = 0; i < prim->numverts; i++){
c[0] += prim->verts[i].xyz[0];
c[1] += prim->verts[i].xyz[1];
}
c[0] /= prim->numverts;
c[1] /= prim->numverts;
for(i = 0; i < prim->numverts; i++){
if(prim->boundary & (GLint)pow(2., i)){
b = (GL2PSprimitive*)gl2psMalloc(sizeof(GL2PSprimitive));
b->type = GL2PS_LINE;
b->dash = prim->dash;
b->depth = prim->depth; /* this is wrong */
b->culled = prim->culled;
b->width = prim->width;
b->boundary = 0;
b->numverts = 2;
b->verts = (GL2PSvertex *)gl2psMalloc(2 * sizeof(GL2PSvertex));
#define GL2PS_BOUNDARY_OFFSET 0
#if GL2PS_BOUNDARY_OFFSET
v[0] = c[0] - prim->verts[i].xyz[0];
v[1] = c[1] - prim->verts[i].xyz[1];
v[2] = 0.;
norm = gl2psNorm(v);
v[0] /= norm;
v[1] /= norm;
b->verts[0].xyz[0] = prim->verts[i].xyz[0] +0.1*v[0];
b->verts[0].xyz[1] = prim->verts[i].xyz[1] +0.1*v[1];
b->verts[0].xyz[2] = prim->verts[i].xyz[2];
v[0] = c[0] - prim->verts[gl2psGetIndex(i, prim->numverts)].xyz[0];
v[1] = c[1] - prim->verts[gl2psGetIndex(i, prim->numverts)].xyz[1];
norm = gl2psNorm(v);
v[0] /= norm;
v[1] /= norm;
b->verts[1].xyz[0] = prim->verts[gl2psGetIndex(i, prim->numverts)].xyz[0] +0.1*v[0];
b->verts[1].xyz[1] = prim->verts[gl2psGetIndex(i, prim->numverts)].xyz[1] +0.1*v[1];
b->verts[1].xyz[2] = prim->verts[gl2psGetIndex(i, prim->numverts)].xyz[2];
#else
b->verts[0].xyz[0] = prim->verts[i].xyz[0];
b->verts[0].xyz[1] = prim->verts[i].xyz[1];
b->verts[0].xyz[2] = prim->verts[i].xyz[2];
b->verts[1].xyz[0] = prim->verts[gl2psGetIndex(i, prim->numverts)].xyz[0];
b->verts[1].xyz[1] = prim->verts[gl2psGetIndex(i, prim->numverts)].xyz[1];
b->verts[1].xyz[2] = prim->verts[gl2psGetIndex(i, prim->numverts)].xyz[2];
#endif
b->verts[0].rgba[0] = 0.;
b->verts[0].rgba[1] = 0.;
b->verts[0].rgba[2] = 0.;
b->verts[0].rgba[3] = 0.;
b->verts[1].rgba[0] = 0.;
b->verts[1].rgba[1] = 0.;
b->verts[1].rgba[2] = 0.;
b->verts[1].rgba[3] = 0.;
gl2psListAdd(list, &b);
}
}
}
void gl2psBuildPolygonBoundary(GL2PSbsptree *tree){
GLint i, n;
GL2PSprimitive *prim;
if(!tree) return;
gl2psBuildPolygonBoundary(tree->back);
n = gl2psListNbr(tree->primitives);
for(i = 0; i < n; i++){
prim = *(GL2PSprimitive**)gl2psListPointer(tree->primitives, i);
if(prim->boundary) gl2psAddBoundaryInList(prim, tree->primitives);
}