+++ /dev/null
-/*
- * Use scissor to clear the four quadrants of the FBO to different
- * colors. Then draw a grey triangle in the middle.
- */
-
-
-#include <assert.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <math.h>
-#include <string.h>
-#include <GL/glew.h>
-#include <GL/glut.h>
-#include <GL/glu.h>
-
-
-static int Width = 512, Height = 512;
-static GLuint MyFB, MyRB;
-static GLboolean UseTex = GL_FALSE;
-static GLboolean UseCopyPix = GL_FALSE;
-
-
-#define CheckError() \
- do { \
- GLenum err = glGetError(); \
- if (err != GL_NO_ERROR) \
- printf("Error: %s\n", gluErrorString(err)); \
- assert(err == GL_NO_ERROR); \
- } while (0)
-
-
-static void
-Init(void)
-{
- GLenum status;
-
- fprintf(stderr, "GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
- fprintf(stderr, "GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
- fprintf(stderr, "GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR));
- fflush(stderr);
-
- if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
- printf("GL_EXT_framebuffer_object not found!\n");
- exit(0);
- }
-
- glGenFramebuffersEXT(1, &MyFB);
- glGenRenderbuffersEXT(1, &MyRB);
-
- glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
-
- if (UseTex) {
- GLuint tex;
- glGenTextures(1, &tex);
- glBindTexture(GL_TEXTURE_2D, tex);
- glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, Width, Height, 0,
- GL_RGBA, GL_UNSIGNED_BYTE, NULL);
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
- glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
- glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
- GL_COLOR_ATTACHMENT0_EXT,
- GL_TEXTURE_2D, tex, 0);
- }
- else {
- glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, MyRB);
-
- glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
- GL_COLOR_ATTACHMENT0_EXT,
- GL_RENDERBUFFER_EXT, MyRB);
-
- glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
- }
-
- status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
- if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
- fprintf(stderr, "Framebuffer object is incomplete (0x%x)!\n", status);
- }
-
- glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
-}
-
-
-static void
-Reshape(int width, int height)
-{
- glViewport(0, 0, width, height);
- glMatrixMode(GL_PROJECTION);
- glLoadIdentity();
- glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
- glMatrixMode(GL_MODELVIEW);
-
- Width = width;
- Height = height;
- if (!UseTex) {
- glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
- }
-}
-
-
-static void
-Key(unsigned char key, int x, int y)
-{
- if (key == 27) {
- exit(0);
- }
- glutPostRedisplay();
-}
-
-
-static void
-Draw(void)
-{
- GLboolean scissor = GL_TRUE;
-
- /* draw to user framebuffer */
- glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
- glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);
- glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
-
- glViewport(0, 0, Width, Height);
- CheckError();
-
- if (scissor) {
- glEnable(GL_SCISSOR_TEST);
-
- /* lower-left = red */
- glClearColor(1, 0, 0, 0);
- glScissor(0, 0, Width / 2, Height / 2);
- glClear(GL_COLOR_BUFFER_BIT);
-
- /* lower-right = green */
- glClearColor(0, 1, 0, 0);
- glScissor(Width / 2, 0, Width - Width / 2, Height / 2);
- glClear(GL_COLOR_BUFFER_BIT);
-
- /* upper-left = blue */
- glClearColor(0, 0, 1, 0);
- glScissor(0, Height / 2, Width / 2, Height - Height / 2);
- glClear(GL_COLOR_BUFFER_BIT);
-
- /* upper-right = white */
- glClearColor(1, 1, 1, 0);
- glScissor(Width / 2, Height / 2, Width - Width / 2, Height - Height / 2);
- glClear(GL_COLOR_BUFFER_BIT);
-
- glDisable(GL_SCISSOR_TEST);
- }
- else {
- glClearColor(0, 1, 0, 0);
- glClear(GL_COLOR_BUFFER_BIT);
- }
-
- CheckError();
-
- /* gray triangle in middle, pointing up */
- glColor3f(0.5, 0.5, 0.5);
- glBegin(GL_TRIANGLES);
- glVertex2f(Width/4, Height/4);
- glVertex2f(Width*3/4, Height/4);
- glVertex2f(Width/2, Height*3/4);
- glVertex2f(-0.5, -0.5);
- glVertex2f(+0.5, -0.5);
- glVertex2f( 0.0, 0.7);
- glEnd();
-
- CheckError();
-
- /* copy fbo to window */
- glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, MyFB);
- glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
- glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, 0);
- glDrawBuffer(GL_BACK);
-
- if (UseCopyPix) {
- glWindowPos2i(0, 0);
- glCopyPixels(0, 0, Width, Height, GL_COLOR);
- }
- else {
- GLubyte *buffer = malloc(Width * Height * 4);
-
- /* 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);
- }
-
- /* Bind normal framebuffer */
- glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
-
- glutSwapBuffers();
-
- CheckError();
-}
-
-
-int
-main(int argc, char *argv[])
-{
- int i;
-
- glutInit(&argc, argv);
- glutInitWindowPosition(100, 0);
- glutInitWindowSize(Width, Height);
- glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
-
- for (i = 1; i < argc; i++) {
- if (strcmp(argv[i], "-t") == 0)
- UseTex = GL_TRUE;
- else if (strcmp(argv[i], "-c") == 0)
- UseCopyPix = GL_TRUE;
- }
-
- if (UseTex)
- printf("Using render to texture\n");
- else
- printf("Using user-created render buffer\n");
-
- if (!glutCreateWindow(argv[0])) {
- exit(1);
- }
-
- glewInit();
- Init();
- glutReshapeFunc(Reshape);
- glutKeyboardFunc(Key);
- glutDisplayFunc(Draw);
- glutMainLoop();
- return 0;
-}
projects / mesa.git / blobdiff