#include <GL/glut.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef GL_VERSION_1_1
GLuint list;
GLint fill = 1;
GLfloat spinx = 0;
GLfloat spiny = 0;
GLfloat tdist = 0.0;
GLfloat polyfactor = 1.0;
GLfloat polyunits = 1.0;
GLboolean doubleBuffer;
void display (void)
{
GLfloat gray[] = { 0.8, 0.8, 0.8, 1.0 };
GLfloat black[] = { 0.0, 0.0, 0.0, 1.0 };
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix ();
glTranslatef (0.0, 0.0, tdist);
glRotatef ((GLfloat) spinx, 1.0, 0.0, 0.0);
glRotatef ((GLfloat) spiny, 0.0, 1.0, 0.0);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, gray);
glMaterialfv(GL_FRONT, GL_SPECULAR, black);
glMaterialf(GL_FRONT, GL_SHININESS, 0.0);
if (fill) {
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_POLYGON_OFFSET_FILL);
glPolygonOffset(polyfactor, polyunits);
glCallList (list);
glDisable(GL_POLYGON_OFFSET_FILL);
}
glDisable(GL_LIGHTING);
glDisable(GL_LIGHT0);
glColor3f (1.0, 1.0, 1.0);
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glPolygonOffset(-polyfactor, -polyunits);
if (!fill) glEnable(GL_POLYGON_OFFSET_LINE);
glCallList (list);
glDisable(GL_POLYGON_OFFSET_LINE);
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
if (!fill) {
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glCallList (list);
}
glPopMatrix ();
glFlush ();
if (doubleBuffer) glutSwapBuffers();
}
void gfxinit (void)
{
GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
GLfloat global_ambient[] = { 0.2, 0.2, 0.2, 1.0 };
glClearColor (0.0, 0.0, 0.0, 1.0);
list = glGenLists(1);
glNewList (list, GL_COMPILE);
glutSolidSphere(1.0, 20, 12);
glEndList ();
glEnable(GL_DEPTH_TEST);
glLightfv (GL_LIGHT0, GL_AMBIENT, light_ambient);
glLightfv (GL_LIGHT0, GL_DIFFUSE, light_diffuse);
glLightfv (GL_LIGHT0, GL_SPECULAR, light_specular);
glLightfv (GL_LIGHT0, GL_POSITION, light_position);
glLightModelfv (GL_LIGHT_MODEL_AMBIENT, global_ambient);
}
void reshape(int width, int height)
{
glViewport (0, 0, width, height);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
gluPerspective(45.0, (GLdouble)width/(GLdouble)height,
1.0, 10.0);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
gluLookAt (0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
}
static void Benchmark( float xdiff, float ydiff )
{
int startTime, endTime;
int draws;
double seconds, fps;
printf("Benchmarking...\n");
draws = 0;
startTime = glutGet(GLUT_ELAPSED_TIME);
spinx = spiny = 0.0;
do {
spinx += xdiff;
spiny += ydiff;
display();
draws++;
endTime = glutGet(GLUT_ELAPSED_TIME);
} while (endTime - startTime < 5000);
seconds = (double) (endTime - startTime) / 1000.0;
fps = draws / seconds;
printf("Result: fps: %g\n", fps);
}
void mouse(int button, int state, int x, int y) {
switch (button) {
case GLUT_LEFT_BUTTON:
switch (state) {
case GLUT_DOWN:
spinx += 5;
glutPostRedisplay();
break;
default:
break;
}
break;
case GLUT_MIDDLE_BUTTON:
switch (state) {
case GLUT_DOWN:
spiny += 5;
glutPostRedisplay();
break;
default:
break;
}
break;
case GLUT_RIGHT_BUTTON:
switch (state) {
case GLUT_UP:
exit(0);
break;
default:
break;
}
break;
default:
break;
}
}
void keyboard (unsigned char key, int x, int y)
{
switch (key) {
case 't':
if (tdist < 4.0) {
tdist = (tdist + 0.5);
glutPostRedisplay();
}
break;
case 'T':
if (tdist > -5.0) {
tdist = (tdist - 0.5);
glutPostRedisplay();
}
break;
case 'F':
polyfactor = polyfactor + 0.1;
printf ("polyfactor is %f\n", polyfactor);
glutPostRedisplay();
break;
case 'f':
polyfactor = polyfactor - 0.1;
printf ("polyfactor is %f\n", polyfactor);
glutPostRedisplay();
break;
case 'U':
polyunits = polyunits + 1.0;
printf ("polyunits is %f\n", polyunits);
glutPostRedisplay();
break;
case 'u':
polyunits = polyunits - 1.0;
printf ("polyunits is %f\n", polyunits);
glutPostRedisplay();
break;
case 'b':
Benchmark(5.0, 0);
break;
case 'B':
Benchmark(0, 5.0);
break;
case ' ':
fill = !fill;
printf ("fill/line: %d\n", fill);
glutPostRedisplay();
break;
case 27:
exit(0);
break;
default:
break;
}
}
static void
key(unsigned char k, int x, int y)
{
switch (k) {
case 27:
exit(0);
break;
default:
return;
}
glutPostRedisplay();
}
GLenum Args(int argc, char **argv)
{
GLint i;
doubleBuffer = GL_FALSE;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-sb") == 0) {
doubleBuffer = GL_FALSE;
} else if (strcmp(argv[i], "-db") == 0) {
doubleBuffer = GL_TRUE;
} else {
printf("%s (Bad option).\n", argv[i]);
return GL_FALSE;
}
}
return GL_TRUE;
}
int main(int argc, char** argv)
{
GLuint type;
glutInit(&argc, argv);
Args(argc, argv);
type = GLUT_DEPTH | GLUT_RGB;
type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
glutInitDisplayMode(type);
glutCreateWindow("polyoff");
glutReshapeFunc(reshape);
glutDisplayFunc(display);
glutMouseFunc(mouse);
glutKeyboardFunc(keyboard);
gfxinit();
glutMainLoop();
return 0;
}
#else
int main(int argc, char** argv)
{
fprintf (stderr, "This program demonstrates a feature which is not in OpenGL Version 1.0.\n");
fprintf (stderr, "If your implementation of OpenGL Version 1.0 has the right extensions,\n");
fprintf (stderr, "you may be able to modify this program to make it run.\n");
return 0;
}
#endif