+++ /dev/null
-
-/*
- * Mesa 3-D graphics library
- * Version: 3.3
- * Copyright (C) 1995-2000 Brian Paul
- *
- * 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.
- */
-
-
-/*
- * This file is part of the polygon tesselation code contributed by
- * Bogdan Sikorski
- */
-
-
-#ifdef PC_HEADER
-#include "all.h"
-#else
-#include <math.h>
-#include <stdlib.h>
-#include "gluP.h"
-#include "tess.h"
-#endif
-
-
-
-static GLenum store_polygon_as_contour(GLUtriangulatorObj *);
-static void free_current_polygon(tess_polygon *);
-static void prepare_projection_info(GLUtriangulatorObj *);
-static GLdouble twice_the_polygon_area(tess_vertex *, tess_vertex *);
-static GLenum verify_edge_vertex_intersections(GLUtriangulatorObj *);
-void tess_find_contour_hierarchies(GLUtriangulatorObj *);
-static GLenum test_for_overlapping_contours(GLUtriangulatorObj *);
-static GLenum contours_overlap(tess_contour *, tess_polygon *);
-static GLenum is_contour_contained_in(tess_contour *, tess_contour *);
-static void add_new_exterior(GLUtriangulatorObj *, tess_contour *);
-static void add_new_interior(GLUtriangulatorObj *, tess_contour *,
- tess_contour *);
-static void add_interior_with_hierarchy_check(GLUtriangulatorObj *,
- tess_contour *, tess_contour *);
-static void reverse_hierarchy_and_add_exterior(GLUtriangulatorObj *,
- tess_contour *,
- tess_contour *);
-static GLboolean point_in_polygon(tess_contour *, GLdouble, GLdouble);
-static void shift_interior_to_exterior(GLUtriangulatorObj *, tess_contour *);
-static void add_exterior_with_check(GLUtriangulatorObj *, tess_contour *,
- tess_contour *);
-static GLenum cut_out_hole(GLUtriangulatorObj *, tess_contour *,
- tess_contour *);
-static GLenum merge_hole_with_contour(GLUtriangulatorObj *,
- tess_contour *, tess_contour *,
- tess_vertex *, tess_vertex *);
-
-static GLenum
-find_normal(GLUtriangulatorObj * tobj)
-{
- tess_polygon *polygon = tobj->current_polygon;
- tess_vertex *va, *vb, *vc;
- GLdouble A, B, C;
- GLdouble A0, A1, A2, B0, B1, B2;
-
- va = polygon->vertices;
- vb = va->next;
- A0 = vb->location[0] - va->location[0];
- A1 = vb->location[1] - va->location[1];
- A2 = vb->location[2] - va->location[2];
- for (vc = vb->next; vc != va; vc = vc->next) {
- B0 = vc->location[0] - va->location[0];
- B1 = vc->location[1] - va->location[1];
- B2 = vc->location[2] - va->location[2];
- A = A1 * B2 - A2 * B1;
- B = A2 * B0 - A0 * B2;
- C = A0 * B1 - A1 * B0;
- if (fabs(A) > EPSILON || fabs(B) > EPSILON || fabs(C) > EPSILON) {
- polygon->A = A;
- polygon->B = B;
- polygon->C = C;
- polygon->D =
- -A * va->location[0] - B * va->location[1] - C * va->location[2];
- return GLU_NO_ERROR;
- }
- }
- tess_call_user_error(tobj, GLU_TESS_ERROR7);
- return GLU_ERROR;
-}
-
-void
-tess_test_polygon(GLUtriangulatorObj * tobj)
-{
- tess_polygon *polygon = tobj->current_polygon;
-
- /* any vertices defined? */
- if (polygon->vertex_cnt < 3) {
- free_current_polygon(polygon);
- return;
- }
- /* wrap pointers */
- polygon->last_vertex->next = polygon->vertices;
- polygon->vertices->previous = polygon->last_vertex;
- /* determine the normal */
- if (find_normal(tobj) == GLU_ERROR)
- return;
- /* compare the normals of previously defined contours and this one */
- /* first contour define ? */
- if (tobj->contours == NULL) {
- tobj->A = polygon->A;
- tobj->B = polygon->B;
- tobj->C = polygon->C;
- tobj->D = polygon->D;
- /* determine the best projection to use */
- if (fabs(polygon->A) > fabs(polygon->B))
- if (fabs(polygon->A) > fabs(polygon->C))
- tobj->projection = OYZ;
- else
- tobj->projection = OXY;
- else if (fabs(polygon->B) > fabs(polygon->C))
- tobj->projection = OXZ;
- else
- tobj->projection = OXY;
- }
- else {
- GLdouble a[3], b[3];
- tess_vertex *vertex = polygon->vertices;
-
- a[0] = tobj->A;
- a[1] = tobj->B;
- a[2] = tobj->C;
- b[0] = polygon->A;
- b[1] = polygon->B;
- b[2] = polygon->C;
-
- /* compare the normals */
- if (fabs(a[1] * b[2] - a[2] * b[1]) > EPSILON ||
- fabs(a[2] * b[0] - a[0] * b[2]) > EPSILON ||
- fabs(a[0] * b[1] - a[1] * b[0]) > EPSILON) {
- /* not coplanar */
- tess_call_user_error(tobj, GLU_TESS_ERROR9);
- return;
- }
- /* the normals are parallel - test for plane equation */
- if (fabs(a[0] * vertex->location[0] + a[1] * vertex->location[1] +
- a[2] * vertex->location[2] + tobj->D) > EPSILON) {
- /* not the same plane */
- tess_call_user_error(tobj, GLU_TESS_ERROR9);
- return;
- }
- }
- prepare_projection_info(tobj);
- if (verify_edge_vertex_intersections(tobj) == GLU_ERROR)
- return;
- if (test_for_overlapping_contours(tobj) == GLU_ERROR)
- return;
- if (store_polygon_as_contour(tobj) == GLU_ERROR)
- return;
-}
-
-static GLenum
-test_for_overlapping_contours(GLUtriangulatorObj * tobj)
-{
- tess_contour *contour;
- tess_polygon *polygon;
-
- polygon = tobj->current_polygon;
- for (contour = tobj->contours; contour != NULL; contour = contour->next)
- if (contours_overlap(contour, polygon) != GLU_NO_ERROR) {
- tess_call_user_error(tobj, GLU_TESS_ERROR5);
- return GLU_ERROR;
- }
- return GLU_NO_ERROR;
-}
-
-static GLenum
-store_polygon_as_contour(GLUtriangulatorObj * tobj)
-{
- tess_polygon *polygon = tobj->current_polygon;
- tess_contour *contour = tobj->contours;
-
- /* the first contour defined */
- if (contour == NULL) {
- if ((contour = (tess_contour *) malloc(sizeof(tess_contour))) == NULL) {
- tess_call_user_error(tobj, GLU_OUT_OF_MEMORY);
- free_current_polygon(polygon);
- return GLU_ERROR;
- }
- tobj->contours = tobj->last_contour = contour;
- contour->next = contour->previous = NULL;
- }
- else {
- if ((contour = (tess_contour *) malloc(sizeof(tess_contour))) == NULL) {
- tess_call_user_error(tobj, GLU_OUT_OF_MEMORY);
- free_current_polygon(polygon);
- return GLU_ERROR;
- }
- contour->previous = tobj->last_contour;
- tobj->last_contour->next = contour;
- tobj->last_contour = contour;
- contour->next = NULL;
- }
- /* mark all vertices in new contour as not special */
- /* and all are boundary edges */
- {
- tess_vertex *vertex;
- GLuint vertex_cnt, i;
-
- for (vertex = polygon->vertices, i = 0, vertex_cnt =
- polygon->vertex_cnt; i < vertex_cnt; vertex = vertex->next, i++) {
- vertex->shadow_vertex = NULL;
- vertex->edge_flag = GL_TRUE;
- }
- }
- contour->vertex_cnt = polygon->vertex_cnt;
- contour->area = polygon->area;
- contour->orientation = polygon->orientation;
- contour->type = GLU_UNKNOWN;
- contour->vertices = polygon->vertices;
- contour->last_vertex = polygon->last_vertex;
- polygon->vertices = polygon->last_vertex = NULL;
- polygon->vertex_cnt = 0;
- ++(tobj->contour_cnt);
- return GLU_NO_ERROR;
-}
-
-static void
-free_current_polygon(tess_polygon * polygon)
-{
- tess_vertex *vertex, *vertex_tmp;
- GLuint i;
-
- /* free current_polygon structures */
- for (vertex = polygon->vertices, i = 0; i < polygon->vertex_cnt; i++) {
- vertex_tmp = vertex->next;
- free(vertex);
- vertex = vertex_tmp;
- }
- polygon->vertices = polygon->last_vertex = NULL;
- polygon->vertex_cnt = 0;
-}
-
-static void
-prepare_projection_info(GLUtriangulatorObj * tobj)
-{
- tess_polygon *polygon = tobj->current_polygon;
- tess_vertex *vertex, *last_vertex_ptr;
- GLdouble area;
-
- last_vertex_ptr = polygon->last_vertex;
- switch (tobj->projection) {
- case OXY:
- for (vertex = polygon->vertices; vertex != last_vertex_ptr;
- vertex = vertex->next) {
- vertex->x = vertex->location[0];
- vertex->y = vertex->location[1];
- }
- last_vertex_ptr->x = last_vertex_ptr->location[0];
- last_vertex_ptr->y = last_vertex_ptr->location[1];
- break;
- case OXZ:
- for (vertex = polygon->vertices; vertex != last_vertex_ptr;
- vertex = vertex->next) {
- vertex->x = vertex->location[0];
- vertex->y = vertex->location[2];
- }
- last_vertex_ptr->x = last_vertex_ptr->location[0];
- last_vertex_ptr->y = last_vertex_ptr->location[2];
- break;
- case OYZ:
- for (vertex = polygon->vertices; vertex != last_vertex_ptr;
- vertex = vertex->next) {
- vertex->x = vertex->location[1];
- vertex->y = vertex->location[2];
- }
- last_vertex_ptr->x = last_vertex_ptr->location[1];
- last_vertex_ptr->y = last_vertex_ptr->location[2];
- break;
- }
- area = twice_the_polygon_area(polygon->vertices, polygon->last_vertex);
- if (area >= 0.0) {
- polygon->orientation = GLU_CCW;
- polygon->area = area;
- }
- else {
- polygon->orientation = GLU_CW;
- polygon->area = -area;
- }
-}
-
-static GLdouble
-twice_the_polygon_area(tess_vertex * vertex, tess_vertex * last_vertex)
-{
- tess_vertex *next;
- GLdouble area, x, y;
-
- area = 0.0;
- x = vertex->x;
- y = vertex->y;
- vertex = vertex->next;
- for (; vertex != last_vertex; vertex = vertex->next) {
- next = vertex->next;
- area +=
- (vertex->x - x) * (next->y - y) - (vertex->y - y) * (next->x - x);
- }
- return area;
-}
-
-/* test if edges ab and cd intersect */
-/* if not return GLU_NO_ERROR, else if cross return GLU_TESS_ERROR8, */
-/* else if adjacent return GLU_TESS_ERROR4 */
-static GLenum
-edge_edge_intersect(tess_vertex * a,
- tess_vertex * b, tess_vertex * c, tess_vertex * d)
-{
- GLdouble denom, r, s;
- GLdouble xba, ydc, yba, xdc, yac, xac;
-
- xba = b->x - a->x;
- yba = b->y - a->y;
- xdc = d->x - c->x;
- ydc = d->y - c->y;
- xac = a->x - c->x;
- yac = a->y - c->y;
- denom = xba * ydc - yba * xdc;
- r = yac * xdc - xac * ydc;
- /* parallel? */
- if (fabs(denom) < EPSILON) {
- if (fabs(r) < EPSILON) {
- /* colinear */
- if (fabs(xba) < EPSILON) {
- /* compare the Y coordinate */
- if (yba > 0.0) {
- if (
- (fabs(a->y - c->y) < EPSILON
- && fabs(c->y - b->y) < EPSILON)
- || (fabs(a->y - d->y) < EPSILON
- && fabs(d->y - b->y) <
- EPSILON)) return GLU_TESS_ERROR4;
-
- }
- else {
- if (
- (fabs(b->y - c->y) < EPSILON
- && fabs(c->y - a->y) < EPSILON)
- || (fabs(b->y - d->y) < EPSILON
- && fabs(d->y - a->y) <
- EPSILON)) return GLU_TESS_ERROR4;
- }
- }
- else {
- /* compare the X coordinate */
- if (xba > 0.0) {
- if (
- (fabs(a->x - c->x) < EPSILON
- && fabs(c->x - b->x) < EPSILON)
- || (fabs(a->x - d->x) < EPSILON
- && fabs(d->x - b->x) <
- EPSILON)) return GLU_TESS_ERROR4;
- }
- else {
- if (
- (fabs(b->x - c->x) < EPSILON
- && fabs(c->x - a->x) < EPSILON)
- || (fabs(b->x - d->x) < EPSILON
- && fabs(d->x - a->x) <
- EPSILON)) return GLU_TESS_ERROR4;
- }
- }
- }
- return GLU_NO_ERROR;
- }
- r /= denom;
- s = (yac * xba - xac * yba) / denom;
- /* test if one vertex lies on other edge */
- if (((fabs(r) < EPSILON || (r < 1.0 + EPSILON && r > 1.0 - EPSILON)) &&
- s > -EPSILON && s < 1.0 + EPSILON) ||
- ((fabs(s) < EPSILON || (s < 1.0 + EPSILON && s > 1.0 - EPSILON)) &&
- r > -EPSILON && r < 1.0 + EPSILON)) {
- return GLU_TESS_ERROR4;
- }
- /* test for crossing */
- if (r > -EPSILON && r < 1.0 + EPSILON && s > -EPSILON && s < 1.0 + EPSILON) {
- return GLU_TESS_ERROR8;
- }
- return GLU_NO_ERROR;
-}
-
-static GLenum
-verify_edge_vertex_intersections(GLUtriangulatorObj * tobj)
-{
- tess_polygon *polygon = tobj->current_polygon;
- tess_vertex *vertex1, *last_vertex, *vertex2;
- GLenum test;
-
- last_vertex = polygon->last_vertex;
- vertex1 = last_vertex;
- for (vertex2 = vertex1->next->next;
- vertex2->next != last_vertex; vertex2 = vertex2->next) {
- test = edge_edge_intersect(vertex1, vertex1->next, vertex2,
- vertex2->next);
- if (test != GLU_NO_ERROR) {
- tess_call_user_error(tobj, test);
- return GLU_ERROR;
- }
- }
- for (vertex1 = polygon->vertices;
- vertex1->next->next != last_vertex; vertex1 = vertex1->next) {
- for (vertex2 = vertex1->next->next;
- vertex2 != last_vertex; vertex2 = vertex2->next) {
- test = edge_edge_intersect(vertex1, vertex1->next, vertex2,
- vertex2->next);
- if (test != GLU_NO_ERROR) {
- tess_call_user_error(tobj, test);
- return GLU_ERROR;
- }
- }
- }
- return GLU_NO_ERROR;
-}
-
-static int
-#ifdef WIN32
- __cdecl
-#endif
-area_compare(const void *a, const void *b)
-{
- GLdouble area1, area2;
-
- area1 = (*((tess_contour **) a))->area;
- area2 = (*((tess_contour **) b))->area;
- if (area1 < area2)
- return 1;
- if (area1 > area2)
- return -1;
- return 0;
-}
-
-void
-tess_find_contour_hierarchies(GLUtriangulatorObj * tobj)
-{
- tess_contour **contours; /* dinamic array of pointers */
- tess_contour *tmp_contour_ptr = tobj->contours;
- GLuint cnt, i;
- GLenum result;
- GLboolean hierarchy_changed;
-
- /* any contours? */
- if (tobj->contour_cnt < 2) {
- tobj->contours->type = GLU_EXTERIOR;
- return;
- }
- if ((contours = (tess_contour **)
- malloc(sizeof(tess_contour *) * (tobj->contour_cnt))) == NULL) {
- tess_call_user_error(tobj, GLU_OUT_OF_MEMORY);
- return;
- }
- for (tmp_contour_ptr = tobj->contours, cnt = 0;
- tmp_contour_ptr != NULL; tmp_contour_ptr = tmp_contour_ptr->next)
- contours[cnt++] = tmp_contour_ptr;
- /* now sort the contours in decreasing area size order */
- qsort((void *) contours, (size_t) cnt, (size_t) sizeof(tess_contour *),
- area_compare);
- /* we leave just the first contour - remove others from list */
- tobj->contours = contours[0];
- tobj->contours->next = tobj->contours->previous = NULL;
- tobj->last_contour = tobj->contours;
- tobj->contour_cnt = 1;
- /* first contour is the one with greatest area */
- /* must be EXTERIOR */
- tobj->contours->type = GLU_EXTERIOR;
- tmp_contour_ptr = tobj->contours;
- /* now we play! */
- for (i = 1; i < cnt; i++) {
- hierarchy_changed = GL_FALSE;
- for (tmp_contour_ptr = tobj->contours;
- tmp_contour_ptr != NULL; tmp_contour_ptr = tmp_contour_ptr->next) {
- if (tmp_contour_ptr->type == GLU_EXTERIOR) {
- /* check if contour completely contained in EXTERIOR */
- result = is_contour_contained_in(tmp_contour_ptr, contours[i]);
- switch (result) {
- case GLU_INTERIOR:
- /* now we have to check if contour is inside interiors */
- /* or not */
- /* any interiors? */
- if (tmp_contour_ptr->next != NULL &&
- tmp_contour_ptr->next->type == GLU_INTERIOR) {
- /* for all interior, check if inside any of them */
- /* if not inside any of interiors, its another */
- /* interior */
- /* or it may contain some interiors, then change */
- /* the contained interiors to exterior ones */
- add_interior_with_hierarchy_check(tobj,
- tmp_contour_ptr,
- contours[i]);
- }
- else {
- /* not in interior, add as new interior contour */
- add_new_interior(tobj, tmp_contour_ptr, contours[i]);
- }
- hierarchy_changed = GL_TRUE;
- break;
- case GLU_EXTERIOR:
- /* ooops, the marked as EXTERIOR (contours[i]) is */
- /* actually an interior of tmp_contour_ptr */
- /* reverse the local hierarchy */
- reverse_hierarchy_and_add_exterior(tobj, tmp_contour_ptr,
- contours[i]);
- hierarchy_changed = GL_TRUE;
- break;
- case GLU_NO_ERROR:
- break;
- default:
- abort();
- }
- }
- if (hierarchy_changed)
- break; /* break from for loop */
- }
- if (hierarchy_changed == GL_FALSE) {
- /* disjoint with all contours, add to contour list */
- add_new_exterior(tobj, contours[i]);
- }
- }
- free(contours);
-}
-
-/* returns GLU_INTERIOR if inner is completey enclosed within outer */
-/* returns GLU_EXTERIOR if outer is completely enclosed within inner */
-/* returns GLU_NO_ERROR if contours are disjoint */
-static GLenum
-is_contour_contained_in(tess_contour * outer, tess_contour * inner)
-{
- GLenum relation_flag;
-
- /* set relation_flag to relation of containment of first inner vertex */
- /* regarding outer contour */
- if (point_in_polygon(outer, inner->vertices->x, inner->vertices->y))
- relation_flag = GLU_INTERIOR;
- else
- relation_flag = GLU_EXTERIOR;
- if (relation_flag == GLU_INTERIOR)
- return GLU_INTERIOR;
- if (point_in_polygon(inner, outer->vertices->x, outer->vertices->y))
- return GLU_EXTERIOR;
- return GLU_NO_ERROR;
-}
-
-static GLboolean
-point_in_polygon(tess_contour * contour, GLdouble x, GLdouble y)
-{
- tess_vertex *v1, *v2;
- GLuint i, vertex_cnt;
- GLdouble xp1, yp1, xp2, yp2;
- GLboolean tst;
-
- tst = GL_FALSE;
- v1 = contour->vertices;
- v2 = contour->vertices->previous;
- for (i = 0, vertex_cnt = contour->vertex_cnt; i < vertex_cnt; i++) {
- xp1 = v1->x;
- yp1 = v1->y;
- xp2 = v2->x;
- yp2 = v2->y;
- if ((((yp1 <= y) && (y < yp2)) || ((yp2 <= y) && (y < yp1))) &&
- (x < (xp2 - xp1) * (y - yp1) / (yp2 - yp1) + xp1))
- tst = (tst == GL_FALSE ? GL_TRUE : GL_FALSE);
- v2 = v1;
- v1 = v1->next;
- }
- return tst;
-}
-
-static GLenum
-contours_overlap(tess_contour * contour, tess_polygon * polygon)
-{
- tess_vertex *vertex1, *vertex2;
- GLuint vertex1_cnt, vertex2_cnt, i, j;
- GLenum test;
-
- vertex1 = contour->vertices;
- vertex2 = polygon->vertices;
- vertex1_cnt = contour->vertex_cnt;
- vertex2_cnt = polygon->vertex_cnt;
- for (i = 0; i < vertex1_cnt; vertex1 = vertex1->next, i++) {
- for (j = 0; j < vertex2_cnt; vertex2 = vertex2->next, j++)
- if ((test = edge_edge_intersect(vertex1, vertex1->next, vertex2,
- vertex2->next)) != GLU_NO_ERROR)
- return test;
- }
- return GLU_NO_ERROR;
-}
-
-static void
-add_new_exterior(GLUtriangulatorObj * tobj, tess_contour * contour)
-{
- contour->type = GLU_EXTERIOR;
- contour->next = NULL;
- contour->previous = tobj->last_contour;
- tobj->last_contour->next = contour;
- tobj->last_contour = contour;
-}
-
-static void
-add_new_interior(GLUtriangulatorObj * tobj,
- tess_contour * outer, tess_contour * contour)
-{
- contour->type = GLU_INTERIOR;
- contour->next = outer->next;
- contour->previous = outer;
- if (outer->next != NULL)
- outer->next->previous = contour;
- outer->next = contour;
- if (tobj->last_contour == outer)
- tobj->last_contour = contour;
-}
-
-static void
-add_interior_with_hierarchy_check(GLUtriangulatorObj * tobj,
- tess_contour * outer,
- tess_contour * contour)
-{
- tess_contour *ptr;
-
- /* for all interiors of outer check if they are interior of contour */
- /* if so, change that interior to exterior and move it of of the */
- /* interior sequence */
- if (outer->next != NULL && outer->next->type == GLU_INTERIOR) {
- GLenum test;
-
- for (ptr = outer->next; ptr != NULL && ptr->type == GLU_INTERIOR;
- ptr = ptr->next) {
- test = is_contour_contained_in(ptr, contour);
- switch (test) {
- case GLU_INTERIOR:
- /* contour is contained in one of the interiors */
- /* check if possibly contained in other exteriors */
- /* move ptr to first EXTERIOR */
- for (; ptr != NULL && ptr->type == GLU_INTERIOR; ptr = ptr->next);
- if (ptr == NULL)
- /* another exterior */
- add_new_exterior(tobj, contour);
- else
- add_exterior_with_check(tobj, ptr, contour);
- return;
- case GLU_EXTERIOR:
- /* one of the interiors is contained in the contour */
- /* change it to EXTERIOR, and shift it away from the */
- /* interior sequence */
- shift_interior_to_exterior(tobj, ptr);
- break;
- case GLU_NO_ERROR:
- /* disjoint */
- break;
- default:
- abort();
- }
- }
- }
- /* add contour to the interior sequence */
- add_new_interior(tobj, outer, contour);
-}
-
-static void
-reverse_hierarchy_and_add_exterior(GLUtriangulatorObj * tobj,
- tess_contour * outer,
- tess_contour * contour)
-{
- tess_contour *ptr;
-
- /* reverse INTERIORS to EXTERIORS */
- /* any INTERIORS? */
- if (outer->next != NULL && outer->next->type == GLU_INTERIOR)
- for (ptr = outer->next; ptr != NULL && ptr->type == GLU_INTERIOR;
- ptr = ptr->next) ptr->type = GLU_EXTERIOR;
- /* the outer now becomes inner */
- outer->type = GLU_INTERIOR;
- /* contour is the EXTERIOR */
- contour->next = outer;
- if (tobj->contours == outer) {
- /* first contour beeing reversed */
- contour->previous = NULL;
- tobj->contours = contour;
- }
- else {
- outer->previous->next = contour;
- contour->previous = outer->previous;
- }
- outer->previous = contour;
-}
-
-static void
-shift_interior_to_exterior(GLUtriangulatorObj * tobj, tess_contour * contour)
-{
- contour->previous->next = contour->next;
- if (contour->next != NULL)
- contour->next->previous = contour->previous;
- else
- tobj->last_contour = contour->previous;
-}
-
-static void
-add_exterior_with_check(GLUtriangulatorObj * tobj,
- tess_contour * outer, tess_contour * contour)
-{
- GLenum test;
-
- /* this contour might be interior to further exteriors - check */
- /* if not, just add as a new exterior */
- for (; outer != NULL && outer->type == GLU_EXTERIOR; outer = outer->next) {
- test = is_contour_contained_in(outer, contour);
- switch (test) {
- case GLU_INTERIOR:
- /* now we have to check if contour is inside interiors */
- /* or not */
- /* any interiors? */
- if (outer->next != NULL && outer->next->type == GLU_INTERIOR) {
- /* for all interior, check if inside any of them */
- /* if not inside any of interiors, its another */
- /* interior */
- /* or it may contain some interiors, then change */
- /* the contained interiors to exterior ones */
- add_interior_with_hierarchy_check(tobj, outer, contour);
- }
- else {
- /* not in interior, add as new interior contour */
- add_new_interior(tobj, outer, contour);
- }
- return;
- case GLU_NO_ERROR:
- /* disjoint */
- break;
- default:
- abort();
- }
- }
- /* add contour to the exterior sequence */
- add_new_exterior(tobj, contour);
-}
-
-void
-tess_handle_holes(GLUtriangulatorObj * tobj)
-{
- tess_contour *contour, *hole;
- GLenum exterior_orientation;
-
- /* verify hole orientation */
- for (contour = tobj->contours; contour != NULL;) {
- exterior_orientation = contour->orientation;
- for (contour = contour->next;
- contour != NULL && contour->type == GLU_INTERIOR;
- contour = contour->next) {
- if (contour->orientation == exterior_orientation) {
- tess_call_user_error(tobj, GLU_TESS_ERROR5);
- return;
- }
- }
- }
- /* now cut-out holes */
- for (contour = tobj->contours; contour != NULL;) {
- hole = contour->next;
- while (hole != NULL && hole->type == GLU_INTERIOR) {
- if (cut_out_hole(tobj, contour, hole) == GLU_ERROR)
- return;
- hole = contour->next;
- }
- contour = contour->next;
- }
-}
-
-static GLenum
-cut_out_hole(GLUtriangulatorObj * tobj,
- tess_contour * contour, tess_contour * hole)
-{
- tess_contour *tmp_hole;
- tess_vertex *v1, *v2, *tmp_vertex;
- GLuint vertex1_cnt, vertex2_cnt, tmp_vertex_cnt;
- GLuint i, j, k;
- GLenum test = 0;
-
- /* find an edge connecting contour and hole not intersecting any other */
- /* edge belonging to either the contour or any of the other holes */
- for (v1 = contour->vertices, vertex1_cnt = contour->vertex_cnt, i = 0;
- i < vertex1_cnt; i++, v1 = v1->next) {
- for (v2 = hole->vertices, vertex2_cnt = hole->vertex_cnt, j = 0;
- j < vertex2_cnt; j++, v2 = v2->next) {
- /* does edge (v1,v2) intersect any edge of contour */
- for (tmp_vertex = contour->vertices, tmp_vertex_cnt =
- contour->vertex_cnt, k = 0; k < tmp_vertex_cnt;
- tmp_vertex = tmp_vertex->next, k++) {
- /* skip edge tests for edges directly connected */
- if (v1 == tmp_vertex || v1 == tmp_vertex->next)
- continue;
- test = edge_edge_intersect(v1, v2, tmp_vertex, tmp_vertex->next);
- if (test != GLU_NO_ERROR)
- break;
- }
- if (test == GLU_NO_ERROR) {
- /* does edge (v1,v2) intersect any edge of hole */
- for (tmp_vertex = hole->vertices,
- tmp_vertex_cnt = hole->vertex_cnt, k = 0;
- k < tmp_vertex_cnt; tmp_vertex = tmp_vertex->next, k++) {
- /* skip edge tests for edges directly connected */
- if (v2 == tmp_vertex || v2 == tmp_vertex->next)
- continue;
- test =
- edge_edge_intersect(v1, v2, tmp_vertex, tmp_vertex->next);
- if (test != GLU_NO_ERROR)
- break;
- }
- if (test == GLU_NO_ERROR) {
- /* does edge (v1,v2) intersect any other hole? */
- for (tmp_hole = hole->next;
- tmp_hole != NULL && tmp_hole->type == GLU_INTERIOR;
- tmp_hole = tmp_hole->next) {
- /* does edge (v1,v2) intersect any edge of hole */
- for (tmp_vertex = tmp_hole->vertices,
- tmp_vertex_cnt = tmp_hole->vertex_cnt, k = 0;
- k < tmp_vertex_cnt; tmp_vertex = tmp_vertex->next, k++) {
- test = edge_edge_intersect(v1, v2, tmp_vertex,
- tmp_vertex->next);
- if (test != GLU_NO_ERROR)
- break;
- }
- if (test != GLU_NO_ERROR)
- break;
- }
- }
- }
- if (test == GLU_NO_ERROR) {
- /* edge (v1,v2) is good for eliminating the hole */
- if (merge_hole_with_contour(tobj, contour, hole, v1, v2)
- == GLU_NO_ERROR)
- return GLU_NO_ERROR;
- else
- return GLU_ERROR;
- }
- }
- }
- /* other holes are blocking all possible connections of hole */
- /* with contour, we shift this hole as the last hole and retry */
- for (tmp_hole = hole;
- tmp_hole != NULL && tmp_hole->type == GLU_INTERIOR;
- tmp_hole = tmp_hole->next);
- contour->next = hole->next;
- hole->next->previous = contour;
- if (tmp_hole == NULL) {
- /* last EXTERIOR contour, shift hole as last contour */
- hole->next = NULL;
- hole->previous = tobj->last_contour;
- tobj->last_contour->next = hole;
- tobj->last_contour = hole;
- }
- else {
- tmp_hole->previous->next = hole;
- hole->previous = tmp_hole->previous;
- tmp_hole->previous = hole;
- hole->next = tmp_hole;
- }
- hole = contour->next;
- /* try once again - recurse */
- return cut_out_hole(tobj, contour, hole);
-}
-
-static GLenum
-merge_hole_with_contour(GLUtriangulatorObj * tobj,
- tess_contour * contour,
- tess_contour * hole,
- tess_vertex * v1, tess_vertex * v2)
-{
- tess_vertex *v1_new, *v2_new;
-
- /* make copies of v1 and v2, place them respectively after their originals */
- if ((v1_new = (tess_vertex *) malloc(sizeof(tess_vertex))) == NULL) {
- tess_call_user_error(tobj, GLU_OUT_OF_MEMORY);
- return GLU_ERROR;
- }
- if ((v2_new = (tess_vertex *) malloc(sizeof(tess_vertex))) == NULL) {
- tess_call_user_error(tobj, GLU_OUT_OF_MEMORY);
- return GLU_ERROR;
- }
- v1_new->edge_flag = GL_TRUE;
- v1_new->data = v1->data;
- v1_new->location[0] = v1->location[0];
- v1_new->location[1] = v1->location[1];
- v1_new->location[2] = v1->location[2];
- v1_new->x = v1->x;
- v1_new->y = v1->y;
- v1_new->shadow_vertex = v1;
- v1->shadow_vertex = v1_new;
- v1_new->next = v1->next;
- v1_new->previous = v1;
- v1->next->previous = v1_new;
- v1->next = v1_new;
- v2_new->edge_flag = GL_TRUE;
- v2_new->data = v2->data;
- v2_new->location[0] = v2->location[0];
- v2_new->location[1] = v2->location[1];
- v2_new->location[2] = v2->location[2];
- v2_new->x = v2->x;
- v2_new->y = v2->y;
- v2_new->shadow_vertex = v2;
- v2->shadow_vertex = v2_new;
- v2_new->next = v2->next;
- v2_new->previous = v2;
- v2->next->previous = v2_new;
- v2->next = v2_new;
- /* link together the two lists */
- v1->next = v2_new;
- v2_new->previous = v1;
- v2->next = v1_new;
- v1_new->previous = v2;
- /* update the vertex count of the contour */
- contour->vertex_cnt += hole->vertex_cnt + 2;
- /* remove the INTERIOR contour */
- contour->next = hole->next;
- if (hole->next != NULL)
- hole->next->previous = contour;
- free(hole);
- /* update tobj structure */
- --(tobj->contour_cnt);
- if (contour->last_vertex == v1)
- contour->last_vertex = v1_new;
- /* mark two vertices with edge_flag */
- v2->edge_flag = GL_FALSE;
- v1->edge_flag = GL_FALSE;
- return GLU_NO_ERROR;
-}
projects / mesa.git / blobdiff