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/*
* 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;
}
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