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/** Test Z-axis clipping of a triangle */
#include <stdio.h>
#include <stdlib.h>
#include "glut_wrap.h"
static GLboolean ztest = GL_FALSE;
static void
Reshape(int width, int height)
{
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-1.0, 1.0, -1.0, 1.0, 2.0, 10.0);
glMatrixMode(GL_MODELVIEW);
glTranslatef(0, 0, -6.0);
}
static void
Key(unsigned char key, int x, int y)
{
if (key == 'z') {
ztest = !ztest;
printf("ztest = %d\n", ztest);
fflush(stdout);
}
else if (key == 27) {
exit(1);
}
glutPostRedisplay();
}
static void
Draw(void)
{
glClearColor(0.5, 0.5, 0.5, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
if (ztest)
glEnable(GL_DEPTH_TEST);
else
glDisable(GL_DEPTH_TEST);
glBegin(GL_TRIANGLES);
glColor3f(0, 0, 1);
glVertex3f(-0.5, 0.7, -10.0);
glColor3f(1, 0, 0);
glVertex3f(-0.5, -0.7, -10.0);
glColor3f(0, 1, 0);
glVertex3f(1.0, 0.0, 12.0);
glEnd();
glutSwapBuffers();
}
int
main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitWindowPosition(0, 0);
glutInitWindowSize(250, 250);
glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
glutCreateWindow(*argv);
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutDisplayFunc(Draw);
glutMainLoop();
return 0;
}
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