/* * Test GL_EXT_framebuffer_object * * Brian Paul * 19 Mar 2006 */ #define GL_GLEXT_PROTOTYPES #include <assert.h> #include <stdio.h> #include <stdlib.h> #include <math.h> #include <GL/glut.h> static int Win = 0; static int Width = 400, Height = 400; static GLuint MyFB, ColorRb, DepthRb; static GLboolean Animate = GL_TRUE; static GLfloat Rotation = 0.0; static void CheckError(int line) { GLenum err = glGetError(); if (err) { printf("fbotest2: GL Error 0x%x at line %d\n", (int) err, line); } } static void Display( void ) { GLubyte *buffer = malloc(Width * Height * 4); GLenum status; CheckError(__LINE__); /* 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("fbotest2: Error: Framebuffer is incomplete!!!\n"); } CheckError(__LINE__); glClearColor(0.5, 0.5, 1.0, 0.0); glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); glEnable(GL_DEPTH_TEST); glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); glPushMatrix(); glRotatef(30.0, 1, 0, 0); glRotatef(Rotation, 0, 1, 0); glutSolidTeapot(2.0); glPopMatrix(); /* read from user framebuffer */ glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer); /* draw to window */ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); glDisable(GL_DEPTH_TEST); /* in case window has depth buffer */ glWindowPos2iARB(0, 0); glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer); free(buffer); glutSwapBuffers(); CheckError(__LINE__); } static void Reshape( int width, int height ) { float ar = (float) width / (float) height; glViewport( 0, 0, width, height ); glMatrixMode( GL_PROJECTION ); glLoadIdentity(); glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 ); glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); glTranslatef( 0.0, 0.0, -15.0 ); glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb); glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, width, height); glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb); glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, width, height); Width = width; Height = height; } static void CleanUp(void) { glDeleteFramebuffersEXT(1, &MyFB); glDeleteRenderbuffersEXT(1, &ColorRb); glDeleteRenderbuffersEXT(1, &DepthRb); assert(!glIsFramebufferEXT(MyFB)); assert(!glIsRenderbufferEXT(ColorRb)); assert(!glIsRenderbufferEXT(DepthRb)); glutDestroyWindow(Win); exit(0); } static void Idle(void) { Rotation = glutGet(GLUT_ELAPSED_TIME) * 0.1; glutPostRedisplay(); } static void Key( unsigned char key, int x, int y ) { (void) x; (void) y; switch (key) { case 'a': Animate = !Animate; if (Animate) glutIdleFunc(Idle); else glutIdleFunc(NULL); break; case 27: CleanUp(); break; } glutPostRedisplay(); } static void Init( void ) { if (!glutExtensionSupported("GL_EXT_framebuffer_object")) { printf("fbotest2: GL_EXT_framebuffer_object not found!\n"); exit(0); } printf("fbotest2: GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); glGenFramebuffersEXT(1, &MyFB); glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB); assert(glIsFramebufferEXT(MyFB)); /* set color buffer */ glGenRenderbuffersEXT(1, &ColorRb); glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb); assert(glIsRenderbufferEXT(ColorRb)); glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT, GL_RENDERBUFFER_EXT, ColorRb); glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height); /* setup depth buffer */ glGenRenderbuffersEXT(1, &DepthRb); glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb); assert(glIsRenderbufferEXT(DepthRb)); glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, DepthRb); glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, Width, Height); CheckError(__LINE__); /* restore to default */ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); CheckError(__LINE__); } int main( int argc, char *argv[] ) { glutInit( &argc, argv ); glutInitWindowPosition( 0, 0 ); glutInitWindowSize(Width, Height); glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE ); Win = glutCreateWindow(argv[0]); glutReshapeFunc( Reshape ); glutKeyboardFunc( Key ); glutDisplayFunc( Display ); if (Animate) glutIdleFunc(Idle); Init(); glutMainLoop(); return 0; }