#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
#ifdef GLU_VERSION_1_2
#ifndef CALLBACK
#define CALLBACK
#endif
GLdouble currentWinding = GLU_TESS_WINDING_ODD;
int currentShape = 0;
GLUtesselator *tobj;
GLuint list;
void makeNewLists (void) {
int i;
static GLdouble rects[12][3] =
{{ 50.0, 50.0, 0.0}, {300.0, 50.0, 0.0},
{300.0, 300.0, 0.0}, { 50.0, 300.0, 0.0},
{100.0, 100.0, 0.0}, {250.0, 100.0, 0.0},
{250.0, 250.0, 0.0}, {100.0, 250.0, 0.0},
{150.0, 150.0, 0.0}, {200.0, 150.0, 0.0},
{200.0, 200.0, 0.0}, {150.0, 200.0, 0.0}};
static GLdouble spiral[16][3] =
{{400.0, 250.0, 0.0}, {400.0, 50.0, 0.0},
{ 50.0, 50.0, 0.0}, { 50.0, 400.0, 0.0},
{350.0, 400.0, 0.0}, {350.0, 100.0, 0.0},
{100.0, 100.0, 0.0}, {100.0, 350.0, 0.0},
{300.0, 350.0, 0.0}, {300.0, 150.0, 0.0},
{150.0, 150.0, 0.0}, {150.0, 300.0, 0.0},
{250.0, 300.0, 0.0}, {250.0, 200.0, 0.0},
{200.0, 200.0, 0.0}, {200.0, 250.0, 0.0}};
static GLdouble quad1[4][3] =
{{ 50.0, 150.0, 0.0}, {350.0, 150.0, 0.0},
{350.0, 200.0, 0.0}, { 50.0, 200.0, 0.0}};
static GLdouble quad2[4][3] =
{{100.0, 100.0, 0.0}, {300.0, 100.0, 0.0},
{300.0, 350.0, 0.0}, {100.0, 350.0, 0.0}};
static GLdouble tri[3][3] =
{{200.0, 50.0, 0.0}, {250.0, 300.0, 0.0},
{150.0, 300.0, 0.0}};
gluTessProperty(tobj, GLU_TESS_WINDING_RULE,
currentWinding);
glNewList(list, GL_COMPILE);
gluTessBeginPolygon(tobj, NULL);
gluTessBeginContour(tobj);
for (i = 0; i < 4; i++)
gluTessVertex(tobj, rects[i], rects[i]);
gluTessEndContour(tobj);
gluTessBeginContour(tobj);
for (i = 4; i < 8; i++)
gluTessVertex(tobj, rects[i], rects[i]);
gluTessEndContour(tobj);
gluTessBeginContour(tobj);
for (i = 8; i < 12; i++)
gluTessVertex(tobj, rects[i], rects[i]);
gluTessEndContour(tobj);
gluTessEndPolygon(tobj);
glEndList();
glNewList(list+1, GL_COMPILE);
gluTessBeginPolygon(tobj, NULL);
gluTessBeginContour(tobj);
for (i = 0; i < 4; i++)
gluTessVertex(tobj, rects[i], rects[i]);
gluTessEndContour(tobj);
gluTessBeginContour(tobj);
for (i = 7; i >= 4; i--)
gluTessVertex(tobj, rects[i], rects[i]);
gluTessEndContour(tobj);
gluTessBeginContour(tobj);
for (i = 11; i >= 8; i--)
gluTessVertex(tobj, rects[i], rects[i]);
gluTessEndContour(tobj);
gluTessEndPolygon(tobj);
glEndList();
glNewList(list+2, GL_COMPILE);
gluTessBeginPolygon(tobj, NULL);
gluTessBeginContour(tobj);
for (i = 0; i < 16; i++)
gluTessVertex(tobj, spiral[i], spiral[i]);
gluTessEndContour(tobj);
gluTessEndPolygon(tobj);
glEndList();
glNewList(list+3, GL_COMPILE);
gluTessBeginPolygon(tobj, NULL);
gluTessBeginContour(tobj);
for (i = 0; i < 4; i++)
gluTessVertex(tobj, quad1[i], quad1[i]);
gluTessEndContour(tobj);
gluTessBeginContour(tobj);
for (i = 0; i < 4; i++)
gluTessVertex(tobj, quad2[i], quad2[i]);
gluTessEndContour(tobj);
gluTessBeginContour(tobj);
for (i = 0; i < 3; i++)
gluTessVertex(tobj, tri[i], tri[i]);
gluTessEndContour(tobj);
gluTessEndPolygon(tobj);
glEndList();
}
void display (void) {
glClear(GL_COLOR_BUFFER_BIT);
glColor3f(1.0, 1.0, 1.0);
glPushMatrix();
glCallList(list);
glTranslatef(0.0, 500.0, 0.0);
glCallList(list+1);
glTranslatef(500.0, -500.0, 0.0);
glCallList(list+2);
glTranslatef(0.0, 500.0, 0.0);
glCallList(list+3);
glPopMatrix();
glFlush();
}
void CALLBACK beginCallback(GLenum which)
{
glBegin(which);
}
void CALLBACK errorCallback(GLenum errorCode)
{
const GLubyte *estring;
estring = gluErrorString(errorCode);
fprintf(stderr, "Tessellation Error: %s\n", (char *) estring);
exit(0);
}
void CALLBACK endCallback(void)
{
glEnd();
}
void CALLBACK combineCallback(GLdouble coords[3], GLdouble *data[4],
GLfloat weight[4], GLdouble **dataOut )
{
GLdouble *vertex;
vertex = (GLdouble *) malloc(3 * sizeof(GLdouble));
vertex[0] = coords[0];
vertex[1] = coords[1];
vertex[2] = coords[2];
*dataOut = vertex;
}
void init(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
glShadeModel(GL_FLAT);
tobj = gluNewTess();
gluTessCallback(tobj, GLU_TESS_VERTEX,
(GLvoid (CALLBACK*) ()) &glVertex3dv);
gluTessCallback(tobj, GLU_TESS_BEGIN,
(GLvoid (CALLBACK*) ()) &beginCallback);
gluTessCallback(tobj, GLU_TESS_END,
(GLvoid (CALLBACK*) ()) &endCallback);
gluTessCallback(tobj, GLU_TESS_ERROR,
(GLvoid (CALLBACK*) ()) &errorCallback);
gluTessCallback(tobj, GLU_TESS_COMBINE,
(GLvoid (CALLBACK*) ()) &combineCallback);
list = glGenLists(4);
makeNewLists();
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
gluOrtho2D(0.0, 1000.0, 0.0, 1000.0 * (GLdouble)h/(GLdouble)w);
else
gluOrtho2D(0.0, 1000.0 * (GLdouble)w/(GLdouble)h, 0.0, 1000.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 'w':
case 'W':
if (currentWinding == GLU_TESS_WINDING_ODD)
currentWinding = GLU_TESS_WINDING_NONZERO;
else if (currentWinding == GLU_TESS_WINDING_NONZERO)
currentWinding = GLU_TESS_WINDING_POSITIVE;
else if (currentWinding == GLU_TESS_WINDING_POSITIVE)
currentWinding = GLU_TESS_WINDING_NEGATIVE;
else if (currentWinding == GLU_TESS_WINDING_NEGATIVE)
currentWinding = GLU_TESS_WINDING_ABS_GEQ_TWO;
else if (currentWinding == GLU_TESS_WINDING_ABS_GEQ_TWO)
currentWinding = GLU_TESS_WINDING_ODD;
makeNewLists();
glutPostRedisplay();
break;
case 27:
exit(0);
break;
default:
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
glutInitWindowSize(500, 500);
glutCreateWindow(argv[0]);
init();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
glutMainLoop();
return 0;
}
#else
int main(int argc, char** argv)
{
fprintf (stderr, "This program demonstrates the new tesselator API in GLU 1.2.\n");
fprintf (stderr, "Your GLU library does not support this new interface, sorry.\n");
return 0;
}
#endif