#include <GL/openglut.h>
#include <stdlib.h>
GLfloat ctrlpoints[4][4][3] =
{
{
{-1.5, -1.5, 4.0},
{-0.5, -1.5, 2.0},
{0.5, -1.5, -1.0},
{1.5, -1.5, 2.0}},
{
{-1.5, -0.5, 1.0},
{-0.5, -0.5, 3.0},
{0.5, -0.5, 0.0},
{1.5, -0.5, -1.0}},
{
{-1.5, 0.5, 4.0},
{-0.5, 0.5, 0.0},
{0.5, 0.5, 3.0},
{1.5, 0.5, 4.0}},
{
{-1.5, 1.5, -2.0},
{-0.5, 1.5, -2.0},
{0.5, 1.5, 0.0},
{1.5, 1.5, -1.0}}
};
void
initlights(void)
{
GLfloat ambient[] =
{0.2, 0.2, 0.2, 1.0};
GLfloat position[] =
{0.0, 0.0, 2.0, 1.0};
GLfloat mat_diffuse[] =
{0.6, 0.6, 0.6, 1.0};
GLfloat mat_specular[] =
{1.0, 1.0, 1.0, 1.0};
GLfloat mat_shininess[] =
{50.0};
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
glLightfv(GL_LIGHT0, GL_POSITION, position);
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
}
void
display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(85.0, 1.0, 1.0, 1.0);
glEvalMesh2(GL_FILL, 0, 20, 0, 20);
glPopMatrix();
glFlush();
}
void
myinit(void)
{
glClearColor(0.0, 0.0, 0.0, 1.0);
glEnable(GL_DEPTH_TEST);
glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4,
0, 1, 12, 4, &ctrlpoints[0][0][0]);
glEnable(GL_MAP2_VERTEX_3);
glEnable(GL_AUTO_NORMAL);
glEnable(GL_NORMALIZE);
glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0);
initlights();
}
void
myReshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
glOrtho(-4.0, 4.0, -4.0 * (GLfloat) h / (GLfloat) w,
4.0 * (GLfloat) h / (GLfloat) w, -4.0, 4.0);
else
glOrtho(-4.0 * (GLfloat) w / (GLfloat) h,
4.0 * (GLfloat) w / (GLfloat) h, -4.0, 4.0, -4.0, 4.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
static void
key(unsigned char k, int x, int y)
{
switch (k) {
case 27:
exit(0);
break;
default:
return;
}
glutPostRedisplay();
}
int
main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
glutCreateWindow(argv[0]);
myinit();
glutReshapeFunc(myReshape);
glutDisplayFunc(display);
glutKeyboardFunc(key);
glutMainLoop();
return 0;
}