/* * Measure glCopyPixels speed * * Brian Paul * 26 Jan 2006 */ #define GL_GLEXT_PROTOTYPES #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include <GL/glut.h> static GLint WinWidth = 1000, WinHeight = 800; static GLint ImgWidth, ImgHeight; static GLenum Buffer = GL_FRONT; static GLenum AlphaTest = GL_FALSE; static GLboolean UseBlit = GL_FALSE; static PFNGLBLITFRAMEBUFFEREXTPROC glBlitFramebufferEXT_func = NULL; /** * draw teapot in lower-left corner of window */ static void DrawTestImage(void) { GLfloat ar; ImgWidth = WinWidth / 3; ImgHeight = WinHeight / 3; glViewport(0, 0, ImgWidth, ImgHeight); glScissor(0, 0, ImgWidth, ImgHeight); glEnable(GL_SCISSOR_TEST); glClearColor(0.5, 0.5, 0.5, 0.0); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); ar = (float) WinWidth / WinHeight; glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustum(-ar, ar, -1.0, 1.0, 5.0, 25.0); glMatrixMode(GL_MODELVIEW); glEnable(GL_LIGHTING); glEnable(GL_LIGHT0); glEnable(GL_DEPTH_TEST); glFrontFace(GL_CW); glPushMatrix(); glRotatef(45, 1, 0, 0); glutSolidTeapot(2.0); glPopMatrix(); glFrontFace(GL_CCW); glDisable(GL_DEPTH_TEST); glDisable(GL_LIGHTING); glDisable(GL_SCISSOR_TEST); glViewport(0, 0, WinWidth, WinHeight); glFinish(); } static int Rand(int max) { return ((int) random()) % max; } /** * Measure glCopyPixels rate */ static void RunTest(void) { double t1, t0 = glutGet(GLUT_ELAPSED_TIME) / 1000.0; int iters = 0; float copyRate, mbRate; int r, g, b, a, bpp; if (AlphaTest) { glEnable(GL_ALPHA_TEST); glAlphaFunc(GL_GREATER, 0.0); } glGetIntegerv(GL_RED_BITS, &r); glGetIntegerv(GL_GREEN_BITS, &g); glGetIntegerv(GL_BLUE_BITS, &b); glGetIntegerv(GL_ALPHA_BITS, &a); bpp = (r + g + b + a) / 8; do { int x, y; x = Rand(WinWidth); y = Rand(WinHeight); if (x > ImgWidth || y > ImgHeight) { #ifdef GL_EXT_framebuffer_blit if (UseBlit) { glBlitFramebufferEXT_func(0, 0, ImgWidth, ImgHeight, x, y, x + ImgWidth, y + ImgHeight, GL_COLOR_BUFFER_BIT, GL_LINEAR); } else #endif { glWindowPos2iARB(x, y); glCopyPixels(0, 0, ImgWidth, ImgHeight, GL_COLOR); } glFinish(); /* XXX OK? */ iters++; t1 = glutGet(GLUT_ELAPSED_TIME) / 1000.0; } } while (t1 - t0 < 5.0); glDisable(GL_ALPHA_TEST); copyRate = iters / (t1 - t0); mbRate = ImgWidth * ImgHeight * bpp * copyRate / (1024 * 1024); printf("Image size: %d x %d, %d Bpp\n", ImgWidth, ImgHeight, bpp); printf("%d copies in %.2f = %.2f copies/sec, %.2f MB/s\n", iters, t1-t0, copyRate, mbRate); } static void Draw(void) { glClearColor(0.0, 0.0, 0.0, 0.0); glClearColor(0.2, 0.2, 0.8, 0); glReadBuffer(Buffer); glDrawBuffer(Buffer); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); DrawTestImage(); RunTest(); if (Buffer == GL_FRONT) glFinish(); else glutSwapBuffers(); printf("exiting\n"); exit(0); } static void Reshape(int width, int height) { glViewport(0, 0, width, height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0, 0.0, -15.0); } static void Key(unsigned char key, int x, int y) { (void) x; (void) y; switch (key) { case 27: exit(0); break; } glutPostRedisplay(); } static void SpecialKey(int key, int x, int y) { (void) x; (void) y; switch (key) { case GLUT_KEY_UP: break; case GLUT_KEY_DOWN: break; case GLUT_KEY_LEFT: break; case GLUT_KEY_RIGHT: break; } glutPostRedisplay(); } static void ParseArgs(int argc, char *argv[]) { int i; for (i = 1; i < argc; i++) { if (strcmp(argv[i], "-back") == 0) Buffer = GL_BACK; else if (strcmp(argv[i], "-alpha") == 0) AlphaTest = GL_TRUE; else if (strcmp(argv[i], "-blit") == 0) UseBlit = GL_TRUE; } } static void Init(void) { if (glutExtensionSupported("GL_EXT_framebuffer_blit")) { glBlitFramebufferEXT_func = (PFNGLBLITFRAMEBUFFEREXTPROC) glutGetProcAddress("glBlitFramebufferEXT"); } else if (UseBlit) { printf("Warning: GL_EXT_framebuffer_blit not supported.\n"); UseBlit = GL_FALSE; } } int main(int argc, char *argv[]) { GLint mode = GLUT_RGB | GLUT_ALPHA | GLUT_DOUBLE | GLUT_DEPTH; glutInit(&argc, argv); ParseArgs(argc, argv); if (AlphaTest) mode |= GLUT_ALPHA; glutInitWindowPosition(0, 0); glutInitWindowSize(WinWidth, WinHeight); glutInitDisplayMode(mode); glutCreateWindow(argv[0]); glutReshapeFunc(Reshape); glutKeyboardFunc(Key); glutSpecialFunc(SpecialKey); glutDisplayFunc(Draw); printf("GL_RENDERER: %s\n", (char *) glGetString(GL_RENDERER)); printf("Draw Buffer: %s\n", (Buffer == GL_BACK) ? "Back" : "Front"); Init(); glutMainLoop(); return 0; }