/********************************************************************************* simpleCDT.C: a simple OpenGL test program for constructing CDTs.**** Copyright (C) 1995 by Dani Lischinski **** 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., 675 Mass Ave, Cambridge, MA 02139, USA.********************************************************************************/#include <unistd.h>#include <string.h>extern "C" {#include <GL/glut.h>}#include "quadedge.h"#include "cdt.h"char *program;void getArguments(int, char**, int&);void InsertPoints(Mesh&, int);void display(Mesh&, Real, Real, Real, Real);double points[100] = {0, 0,                      0.3, 0,                      0.8, 0,                      1, 0,                      1, 0.1,                      1, 0.7,                      1, 1,                      0.5, 1,                      0, 1};main(int argc, char** argv){	int num = 20;	getArguments(argc, argv, num);	Mesh mesh(9, points);	InsertPoints(mesh, num);	display(mesh, 0, 0, 1, 1);}static void usage(){	cerr << "usage: " << program << " [ options ]\n"	     << "options:\n"	     << " -n num     insert num initial points\n"	     << "an odd number will create a regular Delaunay triangulation\n"	     << "an even number will create a CDT (each pair defines a segment)\n";}static void errmsg(char *msg){	cerr << program << ": " << msg << endl;	usage();	exit(1);}void getArguments(int argc, char** argv, int& num){	program = argv[0];	if(argc == 2 && strcmp(argv[1], "-h") == 0) {		usage();		exit(0);	}	for (int i = 1; i < argc && argv[i][0] == '-'; i++)		if (strcmp(argv[i], "-n") == 0) {			if(++i < argc)				num = atoi(argv[i]);			else				errmsg("option ``-n'': missing parameter");		} else			errmsg("unknown option");		if(argc - i > 0)		errmsg("too many parameters");}extern "C" double drand48(void);void InsertPoints(Mesh& mesh, int num){	if (num % 2) {		for (int i = 0; i < num; i++) {			double u = drand48();			double v = drand48();			mesh.InsertSite(Point2d(u,v));		}	} else {		for (int i = 0; i < num/2; i += 2) {			mesh.InsertEdge(Point2d(drand48(),drand48()),			                Point2d(drand48(),drand48()));		}	}}/***************************************************************************/static Mesh *meshPtr;static Boolean outputPS = FALSE;void printEdge(char *str, Edge *e, Boolean c){	cerr << str << "from " << e->Org2d() << " to " << e->Dest2d();	cerr << ((c) ? " constrained" : " free") << endl;}void printVertex(char *str, Point2d *p){	cerr << str << *p << endl;}void setView(float cx, float cy, float xsize, float ysize){	float dx = 0.5 * xsize;	float dy = 0.5 * ysize;	glMatrixMode (GL_PROJECTION);	glLoadIdentity ();	glOrtho(cx - dx, cx + dx, cy - dy, cy + dy, -1.0, 1.0);	glMatrixMode (GL_MODELVIEW);	/*  back to modelview matrix	*/}void printHelp(){	cerr << "  <h>     print this message\n"	     << "  <a>     toggle anti-aliasing\n"	     << "  <d>     dump encapsulated PostScript to standrad output\n"	     << "  <p>     print out edges and vertices to standard error\n"	     << "  <q>     quit program\n"	     << "  <left>  insert a new point\n"	     << "  <right> insert a constrained edge\n";}static Point2d point(0.5, 0.5);void meshDraw(){	glClear(GL_COLOR_BUFFER_BIT);	glColor3f(1, 1, 1);	draw_mesh(meshPtr, outputPS);	glutSwapBuffers();}void toggleAntiAl(){	static Boolean antiAliased = FALSE;	antiAliased = !antiAliased;	if (antiAliased) {		glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);		glEnable(GL_LINE_SMOOTH);		glEnable(GL_BLEND);		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);		glLineWidth(1.5);	} else {		glDisable(GL_LINE_SMOOTH);		glDisable(GL_BLEND);		glLineWidth(1.0);	}		meshDraw();}Point2d window2uv(int x, int y){	GLdouble ox, oy, oz;	GLint viewport[4];	GLdouble modelM[16], projM[16];	glGetDoublev(GL_MODELVIEW_MATRIX, modelM);	glGetDoublev(GL_PROJECTION_MATRIX, projM);	glGetIntegerv(GL_VIEWPORT, viewport);	gluUnProject((GLdouble)x, (GLdouble)y, (GLdouble)0,	             modelM, projM, viewport, &ox, &oy, &oz);	ox = (ox < 0) ? 0 : (ox > 1) ? 1 : ox;	oy = (oy < 0) ? 1 : (oy > 1) ? 0 : 1 - oy;	return Point2d(ox, oy);}void addPoint(int x, int y){	point = window2uv(x, y);	meshPtr->InsertSite(point);	meshDraw();}void addEdge(int x, int y){	meshPtr->InsertEdge(point, window2uv(x, y));	point = window2uv(x, y);	meshDraw();}void processKey(unsigned char key, int, int){	switch (key) {	case 'h': printHelp();		break;	case 'a': toggleAntiAl();		break;	case 'd': outputPS = TRUE;		meshDraw();		outputPS = FALSE;		break;	case 'p': meshPtr->ApplyVertices(printVertex, "vertex: ");		meshPtr->ApplyEdges(printEdge, "edge: ");		cerr << "Total number of edges: " 		     << meshPtr->numEdges() << endl;		break;	case 'q': glutDestroyWindow(glutGetWindow());		exit(0);		break;	default:		break;	}}void processMouse(int btn, int state, int x, int y){	if (state != GLUT_DOWN)		return;	switch (btn) {	case GLUT_LEFT_BUTTON:		addPoint(x, y);		break;	case GLUT_RIGHT_BUTTON:		addEdge(x, y);		break;	}}void createWindow(char *title){	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);	glutInitWindowPosition(-1, -1);	glutInitWindowSize(500, 500);	glutCreateWindow(title);	glutDisplayFunc(meshDraw);	glutKeyboardFunc(processKey);	glutMouseFunc(processMouse);	glClearColor(0.0, 0.0, 0.0, 0.0);}void display(Mesh& mesh, Real left, Real bottom, Real right, Real top){	meshPtr = &mesh;	createWindow(program);	float cx = 0.5 * (left + right);	float cy = 0.5 * (bottom + top);	float xsize = 1.1 * (right - left);	float ysize = 1.1 * (top - bottom);	setView(cx, cy, xsize, ysize);	toggleAntiAl();	glutMainLoop();}