/* * 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 #include #include #include #include #include #include /* 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 Tye 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; }