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-rw-r--r--progs/demos/fbotexture.c621
1 files changed, 621 insertions, 0 deletions
diff --git a/progs/demos/fbotexture.c b/progs/demos/fbotexture.c
new file mode 100644
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+++ b/progs/demos/fbotexture.c
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+/*
+ * 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 */
+#define DEPTH 1
+#define STENCIL 1
+#define DRAW 1
+
+
+static int Win = 0;
+static int Width = 400, Height = 400;
+
+#if 1
+static GLenum TexTarget = GL_TEXTURE_2D;
+static int TexWidth = 512, TexHeight = 512;
+static GLenum TexIntFormat = GL_RGB; /* either GL_RGB or GL_RGBA */
+#else
+static GLenum TexTarget = GL_TEXTURE_RECTANGLE_ARB;
+static int TexWidth = 200, TexHeight = 200;
+static GLenum TexIntFormat = GL_RGB5; /* either GL_RGB or GL_RGBA */
+#endif
+static GLuint TextureLevel = 0; /* which texture level to render to */
+
+static GLuint MyFB;
+static GLuint TexObj;
+static GLuint DepthRB = 0, StencilRB = 0;
+static GLboolean Anim = GL_FALSE;
+static GLfloat Rot = 0.0;
+static GLboolean UsePackedDepthStencil = GL_FALSE;
+static GLboolean UsePackedDepthStencilBoth = GL_FALSE;
+static GLboolean Use_ARB_fbo = GL_FALSE;
+static GLboolean Cull = GL_FALSE;
+static GLboolean Wireframe = GL_FALSE;
+
+
+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);
+
+ /* 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, TexHeight);
+
+ glClearColor(0.5, 0.5, 1.0, 0.0);
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+ CheckError(__LINE__);
+
+#if DEPTH
+ glEnable(GL_DEPTH_TEST);
+#endif
+
+#if STENCIL
+ glEnable(GL_STENCIL_TEST);
+ glStencilFunc(GL_NEVER, 1, ~0);
+ glStencilOp(GL_REPLACE, GL_KEEP, GL_REPLACE);
+#endif
+
+ CheckError(__LINE__);
+
+#if DEPTH || STENCIL
+ /* draw diamond-shaped stencil pattern */
+ glColor3f(0, 1, 0);
+ glBegin(GL_POLYGON);
+ glVertex2f(-0.2, 0.0);
+ glVertex2f( 0.0, -0.2);
+ glVertex2f( 0.2, 0.0);
+ glVertex2f( 0.0, 0.2);
+ glEnd();
+#endif
+
+ /* draw teapot where stencil != 1 */
+#if STENCIL
+ glStencilFunc(GL_NOTEQUAL, 1, ~0);
+ glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
+#endif
+
+ CheckError(__LINE__);
+
+ if (Wireframe) {
+ glPolygonMode(GL_FRONT, GL_LINE);
+ }
+ else {
+ glPolygonMode(GL_FRONT, GL_FILL);
+ }
+
+ if (Cull) {
+ /* cull back */
+ glCullFace(GL_BACK);
+ glEnable(GL_CULL_FACE);
+ }
+ else {
+ glDisable(GL_CULL_FACE);
+ }
+
+#if 0
+ 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();
+#else
+ glEnable(GL_LIGHTING);
+ glEnable(GL_LIGHT0);
+ glPushMatrix();
+ glRotatef(0.5 * Rot, 1.0, 0.0, 0.0);
+ glFrontFace(GL_CW); /* Teapot patches backward */
+ glutSolidTeapot(0.5);
+ glFrontFace(GL_CCW);
+ glPopMatrix();
+ glDisable(GL_LIGHTING);
+ /*
+ PrintStencilHistogram(TexWidth, TexHeight);
+ */
+#endif
+
+ glDisable(GL_DEPTH_TEST);
+ glDisable(GL_STENCIL_TEST);
+ glDisable(GL_CULL_FACE);
+ glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+
+#if DRAW
+ /* Bind normal framebuffer */
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+#endif
+
+ CheckError(__LINE__);
+}
+
+
+
+static void
+Display(void)
+{
+ float ar = (float) Width / (float) Height;
+
+ RenderTexture();
+
+ /* draw textured quad in the window */
+#if DRAW
+ 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);
+ if (TexTarget == GL_TEXTURE_2D) {
+ 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);
+ }
+ else {
+ assert(TexTarget == GL_TEXTURE_RECTANGLE_ARB);
+ glTexCoord2f(0, 0);
+ glVertex2f(-1, -1);
+ glTexCoord2f(TexWidth, 0);
+ glVertex2f(1, -1);
+ glColor3f(1.0, 1.0, 1.0);
+ glTexCoord2f(TexWidth, TexHeight);
+ glVertex2f(1, 1);
+ glTexCoord2f(0, TexHeight);
+ glVertex2f(-1, 1);
+ }
+ glEnd();
+ glPopMatrix();
+ glDisable(TexTarget);
+#endif
+
+ glutSwapBuffers();
+ CheckError(__LINE__);
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ glViewport(0, 0, width, height);
+ Width = width;
+ Height = height;
+}
+
+
+static void
+CleanUp(void)
+{
+#if DEPTH
+ glDeleteRenderbuffersEXT(1, &DepthRB);
+#endif
+#if STENCIL
+ glDeleteRenderbuffersEXT(1, &StencilRB);
+#endif
+ 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 'c':
+ Cull = !Cull;
+ break;
+ case 'w':
+ Wireframe = !Wireframe;
+ break;
+ case 's':
+ Rot += 2.0;
+ break;
+ case 'S':
+ Rot -= 2.0;
+ break;
+ case 27:
+ CleanUp();
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+/**
+ * Attach depth and stencil renderbuffer(s) to the given framebuffer object.
+ * \param tryDepthStencil if true, try to use a combined depth+stencil buffer
+ * \param bindDepthStencil if true, and tryDepthStencil is true, bind with
+ * the GL_DEPTH_STENCIL_ATTACHMENT target.
+ * \return GL_TRUE for success, GL_FALSE for failure
+ */
+static GLboolean
+AttachDepthAndStencilBuffers(GLuint fbo,
+ GLsizei width, GLsizei height,
+ GLboolean tryDepthStencil,
+ GLboolean bindDepthStencil,
+ GLuint *depthRbOut, GLuint *stencilRbOut)
+{
+ GLenum status;
+
+ *depthRbOut = *stencilRbOut = 0;
+
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo);
+
+ if (tryDepthStencil) {
+ GLuint rb;
+
+ glGenRenderbuffersEXT(1, &rb);
+ glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, rb);
+ glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT,
+ GL_DEPTH24_STENCIL8_EXT,
+ width, height);
+ if (glGetError())
+ return GL_FALSE;
+
+ if (bindDepthStencil) {
+ /* attach to both depth and stencil at once */
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
+ GL_DEPTH_STENCIL_ATTACHMENT,
+ GL_RENDERBUFFER_EXT, rb);
+ if (glGetError())
+ return GL_FALSE;
+ }
+ else {
+ /* attach to depth attachment point */
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
+ GL_DEPTH_ATTACHMENT_EXT,
+ GL_RENDERBUFFER_EXT, rb);
+ if (glGetError())
+ return GL_FALSE;
+
+ /* and attach to stencil attachment point */
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
+ GL_STENCIL_ATTACHMENT_EXT,
+ GL_RENDERBUFFER_EXT, rb);
+ if (glGetError())
+ return GL_FALSE;
+ }
+
+ status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+ if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
+ return GL_FALSE;
+
+ *depthRbOut = *stencilRbOut = rb;
+ return GL_TRUE;
+ }
+
+ /* just depth renderbuffer */
+ {
+ GLuint rb;
+
+ glGenRenderbuffersEXT(1, &rb);
+ glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, rb);
+ glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT,
+ GL_DEPTH_COMPONENT,
+ width, height);
+ if (glGetError())
+ return GL_FALSE;
+
+ /* attach to depth attachment point */
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
+ GL_DEPTH_ATTACHMENT_EXT,
+ GL_RENDERBUFFER_EXT, rb);
+ if (glGetError())
+ return GL_FALSE;
+
+ status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+ if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
+ return GL_FALSE;
+
+ *depthRbOut = rb;
+ }
+
+ /* just stencil renderbuffer */
+ {
+ GLuint rb;
+
+ glGenRenderbuffersEXT(1, &rb);
+ glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, rb);
+ glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT,
+ GL_STENCIL_INDEX,
+ width, height);
+ if (glGetError())
+ return GL_FALSE;
+
+ /* attach to depth attachment point */
+ glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
+ GL_STENCIL_ATTACHMENT_EXT,
+ GL_RENDERBUFFER_EXT, rb);
+ if (glGetError())
+ return GL_FALSE;
+
+ status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
+ if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+ glDeleteRenderbuffersEXT(1, depthRbOut);
+ *depthRbOut = 0;
+ glDeleteRenderbuffersEXT(1, &rb);
+ return GL_FALSE;
+ }
+
+ *stencilRbOut = rb;
+ }
+
+ return GL_TRUE;
+}
+
+
+static void
+ParseArgs(int argc, char *argv[])
+{
+ GLint i;
+ for (i = 1; i < argc; i++) {
+ if (strcmp(argv[i], "-ds") == 0) {
+ if (!glutExtensionSupported("GL_EXT_packed_depth_stencil")) {
+ printf("GL_EXT_packed_depth_stencil not found!\n");
+ exit(0);
+ }
+ UsePackedDepthStencil = GL_TRUE;
+ printf("Using GL_EXT_packed_depth_stencil\n");
+ }
+ else if (strcmp(argv[i], "-ds2") == 0) {
+ if (!glutExtensionSupported("GL_EXT_packed_depth_stencil")) {
+ printf("GL_EXT_packed_depth_stencil not found!\n");
+ exit(0);
+ }
+ if (!glutExtensionSupported("GL_ARB_framebuffer_object")) {
+ printf("GL_ARB_framebuffer_object not found!\n");
+ exit(0);
+ }
+ UsePackedDepthStencilBoth = GL_TRUE;
+ printf("Using GL_EXT_packed_depth_stencil and GL_DEPTH_STENCIL attachment point\n");
+ }
+ else if (strcmp(argv[i], "-arb") == 0) {
+ if (!glutExtensionSupported("GL_ARB_framebuffer_object")) {
+ printf("Sorry, GL_ARB_framebuffer object not supported!\n");
+ }
+ else {
+ Use_ARB_fbo = GL_TRUE;
+ }
+ }
+ else {
+ printf("Unknown option: %s\n", argv[i]);
+ }
+ }
+}
+
+
+/*
+ * Make FBO to render into given texture.
+ */
+static GLuint
+MakeFBO_RenderTexture(GLuint TexObj)
+{
+ GLuint fb;
+ GLint sizeFudge = 0;
+
+ glGenFramebuffersEXT(1, &fb);
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
+ /* Render color to texture */
+ glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
+ TexTarget, TexObj, TextureLevel);
+
+ if (Use_ARB_fbo) {
+ /* use a smaller depth buffer to see what happens */
+ sizeFudge = 90;
+ }
+
+ /* Setup depth and stencil buffers */
+ {
+ GLboolean b;
+ b = AttachDepthAndStencilBuffers(fb,
+ TexWidth - sizeFudge,
+ TexHeight - sizeFudge,
+ UsePackedDepthStencil,
+ UsePackedDepthStencilBoth,
+ &DepthRB, &StencilRB);
+ if (!b) {
+ /* try !UsePackedDepthStencil */
+ b = AttachDepthAndStencilBuffers(fb,
+ TexWidth - sizeFudge,
+ TexHeight - sizeFudge,
+ !UsePackedDepthStencil,
+ UsePackedDepthStencilBoth,
+ &DepthRB, &StencilRB);
+ }
+ if (!b) {
+ printf("Unable to create/attach depth and stencil renderbuffers "
+ " to FBO!\n");
+ exit(1);
+ }
+ }
+
+ /* queries */
+ {
+ GLint bits, w, h;
+
+ glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRB);
+ glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
+ GL_RENDERBUFFER_WIDTH_EXT, &w);
+ glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
+ GL_RENDERBUFFER_HEIGHT_EXT, &h);
+ printf("Color/Texture size: %d x %d\n", TexWidth, TexHeight);
+ printf("Depth buffer size: %d x %d\n", w, h);
+
+ glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
+ GL_RENDERBUFFER_DEPTH_SIZE_EXT, &bits);
+ printf("Depth renderbuffer size = %d bits\n", bits);
+
+ glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, StencilRB);
+ glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
+ GL_RENDERBUFFER_STENCIL_SIZE_EXT, &bits);
+ printf("Stencil renderbuffer size = %d bits\n", bits);
+ }
+
+ /* bind the regular framebuffer */
+ glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+
+ return fb;
+}
+
+
+static void
+Init(void)
+{
+ 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));
+
+ /* lighting */
+ {
+ static const GLfloat mat[4] = { 1.0, 0.5, 0.5, 1.0 };
+ glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, mat);
+ }
+
+ /*
+ * Make texture object/image (we'll render into this texture)
+ */
+ {
+ glGenTextures(1, &TexObj);
+ glBindTexture(TexTarget, TexObj);
+
+ /* make two image levels */
+ glTexImage2D(TexTarget, 0, TexIntFormat, TexWidth, TexHeight, 0,
+ GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+ if (TexTarget == GL_TEXTURE_2D) {
+ glTexImage2D(TexTarget, 1, TexIntFormat, TexWidth/2, TexHeight/2, 0,
+ GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+ TexWidth = TexWidth >> TextureLevel;
+ TexHeight = TexHeight >> TextureLevel;
+ glTexParameteri(TexTarget, GL_TEXTURE_MAX_LEVEL, TextureLevel);
+ }
+
+ glTexParameteri(TexTarget, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+ glTexParameteri(TexTarget, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glTexParameteri(TexTarget, GL_TEXTURE_BASE_LEVEL, TextureLevel);
+ glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+ }
+
+ MyFB = MakeFBO_RenderTexture(TexObj);
+}
+
+
+static void
+Usage(void)
+{
+ printf("Usage:\n");
+ printf(" -ds Use combined depth/stencil renderbuffer\n");
+ printf(" -arb Try GL_ARB_framebuffer_object's mismatched buffer sizes\n");
+ printf(" -ds2 Try GL_ARB_framebuffer_object's GL_DEPTH_STENCIL_ATTACHMENT\n");
+ printf("Keys:\n");
+ printf(" a Toggle animation\n");
+ printf(" s/s Step/rotate\n");
+ printf(" c Toggle back-face culling\n");
+ printf(" w Toggle wireframe mode (front-face only)\n");
+ printf(" Esc Exit\n");
+}
+
+
+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);
+
+ ParseArgs(argc, argv);
+ Init();
+ Usage();
+
+ glutMainLoop();
+ return 0;
+}
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