| /* |
| * Test GL_EXT_framebuffer_object |
| * |
| * Brian Paul |
| * 7 Feb 2005 |
| */ |
| |
| |
| #define GL_GLEXT_PROTOTYPES |
| #include <assert.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <math.h> |
| #include <GL/glut.h> |
| |
| static int Width = 400, Height = 400; |
| static GLuint MyFB; |
| |
| |
| static void |
| CheckError(int line) |
| { |
| GLenum err = glGetError(); |
| if (err) { |
| printf("GL Error 0x%x at line %d\n", (int) err, line); |
| } |
| } |
| |
| |
| static void |
| Display( void ) |
| { |
| GLubyte *buffer = malloc(Width * Height * 4); |
| GLenum status; |
| |
| /* draw to user framebuffer */ |
| glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB); |
| glDrawBuffer(GL_COLOR_ATTACHMENT1_EXT); |
| glReadBuffer(GL_COLOR_ATTACHMENT1_EXT); |
| |
| status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT); |
| if (status != GL_FRAMEBUFFER_COMPLETE_EXT) { |
| printf("Framebuffer incomplete!!!\n"); |
| } |
| |
| glClearColor(0.5, 0.5, 1.0, 0.0); |
| glClear( GL_COLOR_BUFFER_BIT ); |
| |
| glBegin(GL_POLYGON); |
| glColor3f(1, 0, 0); |
| glVertex2f(-1, -1); |
| glColor3f(0, 1, 0); |
| glVertex2f(1, -1); |
| glColor3f(0, 0, 1); |
| glVertex2f(0, 1); |
| glEnd(); |
| |
| /* read from user framebuffer */ |
| glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer); |
| |
| /* draw to window */ |
| glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); |
| glWindowPos2iARB(0, 0); |
| glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer); |
| |
| free(buffer); |
| glutSwapBuffers(); |
| } |
| |
| |
| static void |
| Reshape( int width, int height ) |
| { |
| float ar = (float) width / (float) height; |
| glViewport( 0, 0, width, height ); |
| glMatrixMode( GL_PROJECTION ); |
| glLoadIdentity(); |
| #if 0 |
| glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 ); |
| #else |
| glOrtho(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0 ); |
| #endif |
| glMatrixMode( GL_MODELVIEW ); |
| glLoadIdentity(); |
| glTranslatef( 0.0, 0.0, -15.0 ); |
| Width = width; |
| Height = height; |
| glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height); |
| } |
| |
| |
| static void |
| Key( unsigned char key, int x, int y ) |
| { |
| (void) x; |
| (void) y; |
| switch (key) { |
| case 27: |
| exit(0); |
| break; |
| } |
| glutPostRedisplay(); |
| } |
| |
| |
| static void |
| Init( void ) |
| { |
| GLuint rb; |
| GLint i; |
| |
| if (!glutExtensionSupported("GL_EXT_framebuffer_object")) { |
| printf("GL_EXT_framebuffer_object not found!\n"); |
| /*exit(0);*/ |
| } |
| printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); |
| |
| glGenFramebuffersEXT(1, &MyFB); |
| assert(MyFB); |
| assert(glIsFramebufferEXT(MyFB)); |
| glDeleteFramebuffersEXT(1, &MyFB); |
| assert(!glIsFramebufferEXT(MyFB)); |
| /* Note, continue to use MyFB below */ |
| |
| glGenRenderbuffersEXT(1, &rb); |
| assert(rb); |
| assert(glIsRenderbufferEXT(rb)); |
| glDeleteRenderbuffersEXT(1, &rb); |
| assert(!glIsRenderbufferEXT(rb)); |
| rb = 42; /* an arbitrary ID */ |
| |
| glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB); |
| assert(glIsFramebufferEXT(MyFB)); |
| glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, rb); |
| assert(glIsRenderbufferEXT(rb)); |
| |
| glGetIntegerv(GL_RENDERBUFFER_BINDING_EXT, &i); |
| assert(i == rb); |
| |
| glGetIntegerv(GL_FRAMEBUFFER_BINDING_EXT, &i); |
| assert(i == MyFB); |
| |
| glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT, |
| GL_RENDERBUFFER_EXT, rb); |
| |
| glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height); |
| |
| CheckError(__LINE__); |
| |
| /* restore to default */ |
| glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); |
| } |
| |
| |
| int |
| main( int argc, char *argv[] ) |
| { |
| glutInit( &argc, argv ); |
| glutInitWindowPosition( 0, 0 ); |
| glutInitWindowSize(Width, Height); |
| glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE ); |
| glutCreateWindow(argv[0]); |
| glutReshapeFunc( Reshape ); |
| glutKeyboardFunc( Key ); |
| glutDisplayFunc( Display ); |
| Init(); |
| glutMainLoop(); |
| return 0; |
| } |