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+/*
+ * OpenSCAD (www.openscad.at)
+ * Copyright (C) 2009 Clifford Wolf <clifford@clifford.at>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#define INCLUDE_ABSTRACT_NODE_DETAILS
+
+#include "openscad.h"
+
+struct tess_vdata {
+ GLdouble v[3];
+};
+
+struct tess_triangle {
+ GLdouble *p[3];
+ tess_triangle() { p[0] = NULL; p[1] = NULL; p[2] = NULL; }
+ tess_triangle(double *p1, double *p2, double *p3) { p[0] = p1; p[1] = p2; p[2] = p3; }
+};
+
+static GLenum tess_type;
+static int tess_count;
+static QVector<tess_triangle> tess_tri;
+static GLdouble *tess_p1, *tess_p2;
+
+static void tess_vertex(void *vertex_data)
+{
+ GLdouble *p = (double*)vertex_data;
+#if 0
+ printf(" %d: %f %f %f\n", tess_count, p[0], p[1], p[2]);
+#endif
+ if (tess_type == GL_TRIANGLE_FAN) {
+ if (tess_count == 0) {
+ tess_p1 = p;
+ }
+ if (tess_count == 1) {
+ tess_p2 = p;
+ }
+ if (tess_count > 1) {
+ tess_tri.append(tess_triangle(tess_p1, tess_p2, p));
+ tess_p2 = p;
+ }
+ }
+ if (tess_type == GL_TRIANGLE_STRIP) {
+ if (tess_count == 0) {
+ tess_p1 = p;
+ }
+ if (tess_count == 1) {
+ tess_p2 = p;
+ }
+ if (tess_count > 1) {
+ if (tess_count % 2 == 1) {
+ tess_tri.append(tess_triangle(tess_p2, tess_p1, p));
+ } else {
+ tess_tri.append(tess_triangle(tess_p1, tess_p2, p));
+ }
+ tess_p1 = tess_p2;
+ tess_p2 = p;
+ }
+ }
+ if (tess_type == GL_TRIANGLES) {
+ if (tess_count == 0) {
+ tess_p1 = p;
+ }
+ if (tess_count == 1) {
+ tess_p2 = p;
+ }
+ if (tess_count == 2) {
+ tess_tri.append(tess_triangle(tess_p1, tess_p2, p));
+ tess_count = -1;
+ }
+ }
+ tess_count++;
+}
+
+static void tess_begin(GLenum type)
+{
+#if 0
+ if (type == GL_TRIANGLE_FAN) {
+ printf("GL_TRIANGLE_FAN:\n");
+ }
+ if (type == GL_TRIANGLE_STRIP) {
+ printf("GL_TRIANGLE_STRIP:\n");
+ }
+ if (type == GL_TRIANGLES) {
+ printf("GL_TRIANGLES:\n");
+ }
+#endif
+ tess_count = 0;
+ tess_type = type;
+}
+
+static void tess_end(void)
+{
+ /* nothing to be done here */
+}
+
+static void tess_error(GLenum errno)
+{
+ PRINTF("GLU tesselation error %d!", errno);
+}
+
+static bool point_on_line(double *p1, double *p2, double *p3)
+{
+ if (fabs(p1[0] - p2[0]) < 0.0001 && fabs(p1[1] - p2[1]) < 0.0001)
+ return false;
+
+ if (fabs(p3[0] - p2[0]) < 0.0001 && fabs(p3[1] - p2[1]) < 0.0001)
+ return false;
+
+ double v1[2] = { p2[0] - p1[0], p2[1] - p1[1] };
+ double v2[2] = { p3[0] - p1[0], p3[1] - p1[1] };
+
+ if (fabs(atan2(v1[0], v1[1]) - atan2(v2[0], v2[1])) < 0.0001 &&
+ sqrt(v1[0]*v1[0] + v1[1]*v1[1]) < sqrt(v2[0]*v2[0] + v2[1]*v2[1])) {
+#if 0
+ printf("Point on line: %f/%f %f/%f %f/%f\n", p1[0], p1[1], p2[0], p2[1], p3[0], p3[1]);
+#endif
+ return true;
+ }
+
+ return false;
+}
+
+void dxf_tesselate(PolySet *ps, DxfData *dxf, bool up, double h)
+{
+ GLUtesselator *tobj = gluNewTess();
+
+ gluTessCallback(tobj, GLU_TESS_VERTEX, (GLvoid(*)())&tess_vertex);
+ gluTessCallback(tobj, GLU_TESS_BEGIN, (GLvoid(*)())&tess_begin);
+ gluTessCallback(tobj, GLU_TESS_END, (GLvoid(*)())&tess_end);
+ gluTessCallback(tobj, GLU_TESS_ERROR, (GLvoid(*)())&tess_error);
+
+ tess_tri.clear();
+ QList<tess_vdata> vl;
+
+ gluTessBeginPolygon(tobj, NULL);
+
+ for (int i = 0; i < dxf->paths.count(); i++) {
+ if (!dxf->paths[i].is_closed)
+ continue;
+ gluTessBeginContour(tobj);
+ if (up != dxf->paths[i].is_inner) {
+ for (int j = 1; j < dxf->paths[i].points.count(); j++) {
+ vl.append(tess_vdata());
+ vl.last().v[0] = dxf->paths[i].points[j]->x;
+ vl.last().v[1] = dxf->paths[i].points[j]->y;
+ vl.last().v[2] = h;
+ gluTessVertex(tobj, vl.last().v, vl.last().v);
+ }
+ } else {
+ for (int j = dxf->paths[i].points.count() - 1; j > 0; j--) {
+ vl.append(tess_vdata());
+ vl.last().v[0] = dxf->paths[i].points[j]->x;
+ vl.last().v[1] = dxf->paths[i].points[j]->y;
+ vl.last().v[2] = h;
+ gluTessVertex(tobj, vl.last().v, vl.last().v);
+ }
+ }
+ gluTessEndContour(tobj);
+ }
+
+ gluTessEndPolygon(tobj);
+ gluDeleteTess(tobj);
+
+#if 0
+ for (int i = 0; i < tess_tri.count(); i++) {
+ printf("~~~\n");
+ printf(" %f %f %f\n", tess_tri[i].p[0][0], tess_tri[i].p[0][1], tess_tri[i].p[0][2]);
+ printf(" %f %f %f\n", tess_tri[i].p[1][0], tess_tri[i].p[1][1], tess_tri[i].p[1][2]);
+ printf(" %f %f %f\n", tess_tri[i].p[2][0], tess_tri[i].p[2][1], tess_tri[i].p[2][2]);
+ }
+#endif
+
+ // GLU tessing sometimes generates degenerated triangles. We must find and remove
+ // them so we can use the triangle array with CGAL..
+ for (int i = 0; i < tess_tri.count(); i++) {
+ if (point_on_line(tess_tri[i].p[0], tess_tri[i].p[1], tess_tri[i].p[2]) ||
+ point_on_line(tess_tri[i].p[1], tess_tri[i].p[2], tess_tri[i].p[0]) ||
+ point_on_line(tess_tri[i].p[2], tess_tri[i].p[0], tess_tri[i].p[1])) {
+ tess_tri.remove(i--);
+ }
+ }
+
+ // GLU tessing might merge points into edges. This is ok for GL displaying but
+ // creates invalid polyeders for CGAL. So we split this tirangles up again in order
+ // to create polyeders that are also accepted by CGAL..
+ bool added_triangles = true;
+ while (added_triangles)
+ {
+ added_triangles = false;
+ for (int i = 0; i < tess_tri.count(); i++)
+ for (int j = 0; j < tess_tri.count(); j++)
+ for (int k = 0; k < 3; k++)
+ for (int l = 0; l < 3; l++) {
+ if (point_on_line(tess_tri[i].p[k], tess_tri[j].p[l], tess_tri[i].p[(k+1)%3])) {
+ tess_tri.append(tess_triangle(tess_tri[j].p[l],
+ tess_tri[i].p[(k+1)%3], tess_tri[i].p[(k+2)%3]));
+ tess_tri[i].p[(k+1)%3] = tess_tri[j].p[l];
+ added_triangles = true;
+ }
+ }
+ }
+
+ for (int i = 0; i < tess_tri.count(); i++) {
+#if 0
+ printf("---\n");
+ printf(" %f %f %f\n", tess_tri[i].p[0][0], tess_tri[i].p[0][1], tess_tri[i].p[0][2]);
+ printf(" %f %f %f\n", tess_tri[i].p[1][0], tess_tri[i].p[1][1], tess_tri[i].p[1][2]);
+ printf(" %f %f %f\n", tess_tri[i].p[2][0], tess_tri[i].p[2][1], tess_tri[i].p[2][2]);
+#endif
+ ps->append_poly();
+ ps->insert_vertex(tess_tri[i].p[0][0], tess_tri[i].p[0][1], tess_tri[i].p[0][2]);
+ ps->insert_vertex(tess_tri[i].p[1][0], tess_tri[i].p[1][1], tess_tri[i].p[1][2]);
+ ps->insert_vertex(tess_tri[i].p[2][0], tess_tri[i].p[2][1], tess_tri[i].p[2][2]);
+ }
+
+ tess_tri.clear();
+}
+
contact: Jan Huwald // Impressum