summaryrefslogtreecommitdiffstats
path: root/src/glu/mesa/tesselat.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/glu/mesa/tesselat.c')
-rw-r--r--src/glu/mesa/tesselat.c406
1 files changed, 0 insertions, 406 deletions
diff --git a/src/glu/mesa/tesselat.c b/src/glu/mesa/tesselat.c
deleted file mode 100644
index 47d2300..0000000
--- a/src/glu/mesa/tesselat.c
+++ /dev/null
@@ -1,406 +0,0 @@
-
-/*
- * 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 <stdlib.h>
-#include <math.h>
-#include "tess.h"
-#endif
-
-
-
-static GLboolean edge_flag;
-
-static void emit_triangle(GLUtriangulatorObj *, tess_vertex *,
- tess_vertex *, tess_vertex *);
-
-static void emit_triangle_with_edge_flag(GLUtriangulatorObj *,
- tess_vertex *, GLboolean,
- tess_vertex *, GLboolean,
- tess_vertex *, GLboolean);
-
-static GLdouble
-twice_the_triangle_area(tess_vertex * va, tess_vertex * vb, tess_vertex * vc)
-{
- return (vb->x - va->x) * (vc->y - va->y) - (vb->y - va->y) * (vc->x -
- va->x);
-}
-
-static GLboolean
-left(GLdouble A, GLdouble B, GLdouble C, GLdouble x, GLdouble y)
-{
- if (A * x + B * y + C > -EPSILON)
- return GL_TRUE;
- else
- return GL_FALSE;
-}
-
-static GLboolean
-right(GLdouble A, GLdouble B, GLdouble C, GLdouble x, GLdouble y)
-{
- if (A * x + B * y + C < EPSILON)
- return GL_TRUE;
- else
- return GL_FALSE;
-}
-
-static GLint
-convex_ccw(tess_vertex * va,
- tess_vertex * vb, tess_vertex * vc, GLUtriangulatorObj * tobj)
-{
- GLdouble d;
-
- d = twice_the_triangle_area(va, vb, vc);
-
- if (d > EPSILON) {
- return 1;
- }
- else if (d < -EPSILON) {
- return 0;
- }
- else {
- return -1;
- }
-}
-
-static GLint
-convex_cw(tess_vertex * va,
- tess_vertex * vb, tess_vertex * vc, GLUtriangulatorObj * tobj)
-{
- GLdouble d;
-
- d = twice_the_triangle_area(va, vb, vc);
-
- if (d < -EPSILON) {
- return 1;
- }
- else if (d > EPSILON) {
- return 0;
- }
- else {
- return -1;
- }
-}
-
-static GLboolean
-diagonal_ccw(tess_vertex * va,
- tess_vertex * vb,
- GLUtriangulatorObj * tobj, tess_contour * contour)
-{
- tess_vertex *vc = va->next, *vertex, *shadow_vertex;
- struct
- {
- GLdouble A, B, C;
- }
- ac, cb, ba;
- GLdouble x, y;
-
- GLint res = convex_ccw(va, vc, vb, tobj);
- if (res == 0)
- return GL_FALSE;
- if (res == -1)
- return GL_TRUE;
-
- ba.A = vb->y - va->y;
- ba.B = va->x - vb->x;
- ba.C = -ba.A * va->x - ba.B * va->y;
- ac.A = va->y - vc->y;
- ac.B = vc->x - va->x;
- ac.C = -ac.A * vc->x - ac.B * vc->y;
- cb.A = vc->y - vb->y;
- cb.B = vb->x - vc->x;
- cb.C = -cb.A * vb->x - cb.B * vb->y;
- for (vertex = vb->next; vertex != va; vertex = vertex->next) {
- shadow_vertex = vertex->shadow_vertex;
- if (shadow_vertex != NULL &&
- (shadow_vertex == va || shadow_vertex == vb || shadow_vertex == vc))
- continue;
- x = vertex->x;
- y = vertex->y;
- if (left(ba.A, ba.B, ba.C, x, y) &&
- left(ac.A, ac.B, ac.C, x, y) && left(cb.A, cb.B, cb.C, x, y))
- return GL_FALSE;
- }
- return GL_TRUE;
-}
-
-static GLboolean
-diagonal_cw(tess_vertex * va,
- tess_vertex * vb,
- GLUtriangulatorObj * tobj, tess_contour * contour)
-{
- tess_vertex *vc = va->next, *vertex, *shadow_vertex;
- struct
- {
- GLdouble A, B, C;
- }
- ac, cb, ba;
- GLdouble x, y;
-
- GLint res = convex_cw(va, vc, vb, tobj);
- if (res == 0)
- return GL_FALSE;
- if (res == -1)
- return GL_TRUE;
-
- ba.A = vb->y - va->y;
- ba.B = va->x - vb->x;
- ba.C = -ba.A * va->x - ba.B * va->y;
- ac.A = va->y - vc->y;
- ac.B = vc->x - va->x;
- ac.C = -ac.A * vc->x - ac.B * vc->y;
- cb.A = vc->y - vb->y;
- cb.B = vb->x - vc->x;
- cb.C = -cb.A * vb->x - cb.B * vb->y;
- for (vertex = vb->next; vertex != va; vertex = vertex->next) {
- shadow_vertex = vertex->shadow_vertex;
- if (shadow_vertex != NULL &&
- (shadow_vertex == va || shadow_vertex == vb || shadow_vertex == vc))
- continue;
- x = vertex->x;
- y = vertex->y;
- if (right(ba.A, ba.B, ba.C, x, y) &&
- right(ac.A, ac.B, ac.C, x, y) && right(cb.A, cb.B, cb.C, x, y))
- return GL_FALSE;
- }
- return GL_TRUE;
-}
-
-static void
-clip_ear(GLUtriangulatorObj * tobj, tess_vertex * v, tess_contour * contour)
-{
- emit_triangle(tobj, v->previous, v, v->next);
- /* the first in the list */
- if (contour->vertices == v) {
- contour->vertices = v->next;
- contour->last_vertex->next = v->next;
- v->next->previous = contour->last_vertex;
- }
- else
- /* the last ? */
- if (contour->last_vertex == v) {
- contour->vertices->previous = v->previous;
- v->previous->next = v->next;
- contour->last_vertex = v->previous;
- }
- else {
- v->next->previous = v->previous;
- v->previous->next = v->next;
- }
- free(v);
- --(contour->vertex_cnt);
-}
-
-static void
-clip_ear_with_edge_flag(GLUtriangulatorObj * tobj,
- tess_vertex * v, tess_contour * contour)
-{
- emit_triangle_with_edge_flag(tobj, v->previous, v->previous->edge_flag,
- v, v->edge_flag, v->next, GL_FALSE);
- v->previous->edge_flag = GL_FALSE;
- /* the first in the list */
- if (contour->vertices == v) {
- contour->vertices = v->next;
- contour->last_vertex->next = v->next;
- v->next->previous = contour->last_vertex;
- }
- else
- /* the last ? */
- if (contour->last_vertex == v) {
- contour->vertices->previous = v->previous;
- v->previous->next = v->next;
- contour->last_vertex = v->previous;
- }
- else {
- v->next->previous = v->previous;
- v->previous->next = v->next;
- }
- free(v);
- --(contour->vertex_cnt);
-}
-
-static void
-triangulate_ccw(GLUtriangulatorObj * tobj, tess_contour * contour)
-{
- tess_vertex *vertex;
- GLuint vertex_cnt = contour->vertex_cnt;
-
- while (vertex_cnt > 3) {
- vertex = contour->vertices;
- while (diagonal_ccw(vertex, vertex->next->next, tobj, contour) ==
- GL_FALSE && tobj->error == GLU_NO_ERROR)
- vertex = vertex->next;
- if (tobj->error != GLU_NO_ERROR)
- return;
- clip_ear(tobj, vertex->next, contour);
- --vertex_cnt;
- }
-}
-
-static void
-triangulate_cw(GLUtriangulatorObj * tobj, tess_contour * contour)
-{
- tess_vertex *vertex;
- GLuint vertex_cnt = contour->vertex_cnt;
-
- while (vertex_cnt > 3) {
- vertex = contour->vertices;
- while (diagonal_cw(vertex, vertex->next->next, tobj, contour) ==
- GL_FALSE && tobj->error == GLU_NO_ERROR)
- vertex = vertex->next;
- if (tobj->error != GLU_NO_ERROR)
- return;
- clip_ear(tobj, vertex->next, contour);
- --vertex_cnt;
- }
-}
-
-static void
-triangulate_ccw_with_edge_flag(GLUtriangulatorObj * tobj,
- tess_contour * contour)
-{
- tess_vertex *vertex;
- GLuint vertex_cnt = contour->vertex_cnt;
-
- while (vertex_cnt > 3) {
- vertex = contour->vertices;
- while (diagonal_ccw(vertex, vertex->next->next, tobj, contour) ==
- GL_FALSE && tobj->error == GLU_NO_ERROR)
- vertex = vertex->next;
- if (tobj->error != GLU_NO_ERROR)
- return;
- clip_ear_with_edge_flag(tobj, vertex->next, contour);
- --vertex_cnt;
- }
-}
-
-static void
-triangulate_cw_with_edge_flag(GLUtriangulatorObj * tobj,
- tess_contour * contour)
-{
- tess_vertex *vertex;
- GLuint vertex_cnt = contour->vertex_cnt;
-
- while (vertex_cnt > 3) {
- vertex = contour->vertices;
- while (diagonal_cw(vertex, vertex->next->next, tobj, contour) ==
- GL_FALSE && tobj->error == GLU_NO_ERROR)
- vertex = vertex->next;
- if (tobj->error != GLU_NO_ERROR)
- return;
- clip_ear_with_edge_flag(tobj, vertex->next, contour);
- --vertex_cnt;
- }
-}
-
-void
-tess_tesselate(GLUtriangulatorObj * tobj)
-{
- tess_contour *contour;
-
- for (contour = tobj->contours; contour != NULL; contour = contour->next) {
- if (contour->orientation == GLU_CCW) {
- triangulate_ccw(tobj, contour);
- }
- else {
- triangulate_cw(tobj, contour);
- }
- if (tobj->error != GLU_NO_ERROR)
- return;
-
- /* emit the last triangle */
- emit_triangle(tobj, contour->vertices, contour->vertices->next,
- contour->vertices->next->next);
- }
-}
-
-void
-tess_tesselate_with_edge_flag(GLUtriangulatorObj * tobj)
-{
- tess_contour *contour;
-
- edge_flag = GL_TRUE;
- /* first callback with edgeFlag set to GL_TRUE */
- (tobj->callbacks.edgeFlag) (GL_TRUE);
-
- for (contour = tobj->contours; contour != NULL; contour = contour->next) {
- if (contour->orientation == GLU_CCW)
- triangulate_ccw_with_edge_flag(tobj, contour);
- else
- triangulate_cw_with_edge_flag(tobj, contour);
- if (tobj->error != GLU_NO_ERROR)
- return;
- /* emit the last triangle */
- emit_triangle_with_edge_flag(tobj, contour->vertices,
- contour->vertices->edge_flag,
- contour->vertices->next,
- contour->vertices->next->edge_flag,
- contour->vertices->next->next,
- contour->vertices->next->next->edge_flag);
- }
-}
-
-static void
-emit_triangle(GLUtriangulatorObj * tobj,
- tess_vertex * v1, tess_vertex * v2, tess_vertex * v3)
-{
- (tobj->callbacks.begin) (GL_TRIANGLES);
- (tobj->callbacks.vertex) (v1->data);
- (tobj->callbacks.vertex) (v2->data);
- (tobj->callbacks.vertex) (v3->data);
- (tobj->callbacks.end) ();
-}
-
-static void
-emit_triangle_with_edge_flag(GLUtriangulatorObj * tobj,
- tess_vertex * v1,
- GLboolean edge_flag1,
- tess_vertex * v2,
- GLboolean edge_flag2,
- tess_vertex * v3, GLboolean edge_flag3)
-{
- (tobj->callbacks.begin) (GL_TRIANGLES);
- if (edge_flag1 != edge_flag) {
- edge_flag = (edge_flag == GL_TRUE ? GL_FALSE : GL_TRUE);
- (tobj->callbacks.edgeFlag) (edge_flag);
- }
- (tobj->callbacks.vertex) (v1->data);
- if (edge_flag2 != edge_flag) {
- edge_flag = (edge_flag == GL_TRUE ? GL_FALSE : GL_TRUE);
- (tobj->callbacks.edgeFlag) (edge_flag);
- }
- (tobj->callbacks.vertex) (v2->data);
- if (edge_flag3 != edge_flag) {
- edge_flag = (edge_flag == GL_TRUE ? GL_FALSE : GL_TRUE);
- (tobj->callbacks.edgeFlag) (edge_flag);
- }
- (tobj->callbacks.vertex) (v3->data);
- (tobj->callbacks.end) ();
-}
generated by cgit v1.1 at 2024-11-16 17:12:27 +0000