--- /dev/null
+/*
+ * Test GL_EXT_framebuffer_object render-to-texture
+ *
+ * Draw a teapot into a texture image with stenciling.
+ * Then draw a textured quad using that texture.
+ *
+ * Brian Paul
+ * 18 Apr 2005
+ */
+
+
+#include <GL/glew.h>
+#include <GL/glut.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+/* For debug */
+
+
+static int Win = 0;
+static int Width = 512, Height = 512;
+
+static GLenum TexTarget = GL_TEXTURE_2D;
+static int TexWidth = 512, TexHeight = 512;
+
+static GLuint MyFB;
+static GLuint TexObj;
+static GLboolean Anim = GL_FALSE;
+static GLfloat Rot = 0.0;
+static GLuint TextureLevel = 4; /* which texture level to render to */
+static GLenum TexIntFormat = GL_RGB; /* either GL_RGB or GL_RGBA */
+
+
+static void
+CheckError(int line)
+{
+ GLenum err = glGetError();
+ if (err) {
+ printf("GL Error 0x%x at line %d\n", (int) err, line);
+ }
+}
+
+
+static void
+Idle(void)
+{
+ Rot = glutGet(GLUT_ELAPSED_TIME) * 0.1;
+ glutPostRedisplay();
+}
+
+
+static void
+RenderTexture(void)
+{
+ GLenum status;
+
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+ glTranslatef(0.0, 0.0, -15.0);
+
+ if (1) {
+ /* draw to texture image */
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+
+ status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+ if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+ printf("Framebuffer incomplete!!!\n");
+ }
+
+ glViewport(0, 0,
+ TexWidth / (1 << TextureLevel),
+ TexHeight / (1 << TextureLevel));
+ glClearColor(0.5, 0.5, 1.0, 0.0);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ CheckError(__LINE__);
+
+ 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();
+
+ /* Bind normal framebuffer */
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+ }
+ else {
+ }
+
+ CheckError(__LINE__);
+}
+
+
+
+static void
+Display(void)
+{
+ float ar = (float) Width / (float) Height;
+
+ RenderTexture();
+
+ /* draw textured quad in the window */
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glFrustum(-ar, ar, -1.0, 1.0, 5.0, 25.0);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+ glTranslatef(0.0, 0.0, -7.0);
+
+ glViewport(0, 0, Width, Height);
+
+ glClearColor(0.25, 0.25, 0.25, 0);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ glPushMatrix();
+ glRotatef(Rot, 0, 1, 0);
+ glEnable(TexTarget);
+ glBindTexture(TexTarget, TexObj);
+
+ {
+ glBegin(GL_POLYGON);
+ glColor3f(0.25, 0.25, 0.25);
+ glTexCoord2f(0, 0);
+ glVertex2f(-1, -1);
+ glTexCoord2f(1, 0);
+ glVertex2f(1, -1);
+ glColor3f(1.0, 1.0, 1.0);
+ glTexCoord2f(1, 1);
+ glVertex2f(1, 1);
+ glTexCoord2f(0, 1);
+ glVertex2f(-1, 1);
+ glEnd();
+ }
+
+ glPopMatrix();
+ glDisable(TexTarget);
+
+ glutSwapBuffers();
+ CheckError(__LINE__);
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ glViewport(0, 0, width, height);
+ Width = width;
+ Height = height;
+}
+
+
+static void
+CleanUp(void)
+{
+ glDeleteFramebuffersEXT(1, &MyFB);
+
+ glDeleteTextures(1, &TexObj);
+
+ glutDestroyWindow(Win);
+
+ exit(0);
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+ (void) x;
+ (void) y;
+ switch (key) {
+ case 'a':
+ Anim = !Anim;
+ if (Anim)
+ glutIdleFunc(Idle);
+ else
+ glutIdleFunc(NULL);
+ break;
+ case 's':
+ Rot += 2.0;
+ break;
+ case 27:
+ CleanUp();
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+Init(int argc, char *argv[])
+{
+ 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));
+
+
+ /* Make texture object/image */
+ glGenTextures(1, &TexObj);
+ glBindTexture(TexTarget, TexObj);
+ glTexParameteri(TexTarget, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+ glTexParameteri(TexTarget, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glTexParameteri(TexTarget, GL_TEXTURE_BASE_LEVEL, TextureLevel);
+ glTexParameteri(TexTarget, GL_TEXTURE_MAX_LEVEL, TextureLevel);
+
+ glTexImage2D(TexTarget, 0, TexIntFormat, TexWidth, TexHeight, 0,
+ GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+ glTexImage2D(TexTarget, TextureLevel, TexIntFormat,
+ TexWidth / (1 << TextureLevel), TexHeight / (1 << TextureLevel), 0,
+ GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+
+
+ glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+
+
+
+
+ /* gen framebuffer id, delete it, do some assertions, just for testing */
+ glGenFramebuffersEXT(1, &MyFB);
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
+ assert(glIsFramebufferEXT(MyFB));
+
+
+ CheckError(__LINE__);
+
+ /* Render color to texture */
+ glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
+ TexTarget, TexObj, TextureLevel);
+
+
+
+ CheckError(__LINE__);
+
+ /* bind regular framebuffer */
+ 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);
+ Win = glutCreateWindow(argv[0]);
+ glewInit();
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Display);
+ if (Anim)
+ glutIdleFunc(Idle);
+ Init(argc, argv);
+ glutMainLoop();
+ return 0;
+}
projects / mesa.git / commitdiff