#include <stdio.h> #include <string.h> #include <stdlib.h> #define GL_GLEXT_PROTOTYPES #include <GL/glut.h> static void Init(void) { static const char *modulate2D = "!!ARBfp1.0\n" "MUL result.depth.z, fragment.color.z, {.1}.x; \n" "MOV result.color, fragment.color.z; \n" "END" ; GLuint modulateProg; if (!glutExtensionSupported("GL_ARB_fragment_program")) { printf("Error: GL_ARB_fragment_program not supported!\n"); exit(1); } printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); /* Setup the fragment program */ glGenProgramsARB(1, &modulateProg); glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, modulateProg); glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB, strlen(modulate2D), (const GLubyte *)modulate2D); printf("glGetError = 0x%x\n", (int) glGetError()); printf("glError(GL_PROGRAM_ERROR_STRING_ARB) = %s\n", (char *) glGetString(GL_PROGRAM_ERROR_STRING_ARB)); glEnable(GL_FRAGMENT_PROGRAM_ARB); glClearColor(.3, .3, .3, 0); } static void Reshape(int width, int height) { glViewport(0, 0, (GLint)width, (GLint)height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0); glMatrixMode(GL_MODELVIEW); } static void Key(unsigned char key, int x, int y) { switch (key) { case 27: exit(1); default: return; } glutPostRedisplay(); } static void Draw(void) { glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); glEnable(GL_DEPTH_TEST); glBegin(GL_TRIANGLES); glColor4f(.8,0,.5,0); glVertex3f( 0.9, -0.9, -30.0); glVertex3f( 0.9, 0.9, -30.0); glVertex3f(-0.9, 0.0, -30.0); glColor4f(0,.8,.7,0); glVertex3f(-0.9, -0.9, -40.0); glColor4f(0,.8,.7,0); glVertex3f(-0.9, 0.9, -40.0); glColor4f(0,.8,.3,0); glVertex3f( 0.9, 0.0, -40.0); glEnd(); glFlush(); } int main(int argc, char **argv) { glutInit(&argc, argv); glutInitWindowPosition(0, 0); glutInitWindowSize( 300, 300); glutInitDisplayMode(GLUT_DEPTH | GLUT_RGB | GLUT_SINGLE); if (glutCreateWindow("Depth Test") == GL_FALSE) { exit(1); } Init(); glutReshapeFunc(Reshape); glutKeyboardFunc(Key); glutDisplayFunc(Draw); glutMainLoop(); return 0; }