glFramebufferRenderbuffer example c c++ java objc

Name

glFramebufferRenderbuffer — attach a renderbuffer as a logical buffer to the currently bound framebuffer object

C Specification

GLsync glFramebufferRenderbuffer(	GLenum	target,
	GLenum	attachment,
	GLenum	renderbuffertarget,
	GLuint	renderbuffer);

Parameters

target

Specifies the framebuffer target. target must be GL_DRAW_FRAMEBUFFER, GL_READ_FRAMEBUFFER, or GL_FRAMEBUFFER. GL_FRAMEBUFFER is equivalent to GL_DRAW_FRAMEBUFFER.

attachment

Specifies the attachment point of the framebuffer.

renderbuffertarget

Specifies the renderbuffer target and must be GL_RENDERBUFFER.

renderbuffer

Specifies the name of an existing renderbuffer object of type renderbuffertarget to attach.

Description

glFramebufferRenderbuffer attaches a renderbuffer as one of the logical buffers of the currently bound framebuffer object. renderbuffer is the name of the renderbuffer object to attach and must be either zero, or the name of an existing renderbuffer object of type renderbuffertarget. If renderbuffer is not zero and if glFramebufferRenderbuffer is successful, then the renderbuffer name renderbufferwill be used as the logical buffer identified by attachment of the framebuffer currently bound to target.
The value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE for the specified attachment point is set to GL_RENDERBUFFER and the value of GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME is set torenderbuffer. All other state values of the attachment point specified by attachment are set to their default values. No change is made to the state of the renderbuuffer object and any previous attachment to theattachment logical buffer of the framebuffer target is broken.
Calling glFramebufferRenderbuffer with the renderbuffer name zero will detach the image, if any, identified by attachment, in the framebuffer currently bound to target. All state values of the attachment point specified by attachment in the object bound to target are set to their default values.
Setting attachment to the value GL_DEPTH_STENCIL_ATTACHMENT is a special case causing both the depth and stencil attachments of the framebuffer object to be set to renderbuffer, which should have the base internal format GL_DEPTH_STENCIL.

Errors

GL_INVALID_ENUM is generated if target is not one of the accepted tokens.
GL_INVALID_ENUM is generated if renderbuffertarget is not GL_RENDERBUFFER.
GL_INVALID_OPERATION is generated if zero is bound to target.

See Also

glGenFramebuffers, glBindFramebuffer, glGenRenderbuffers, glFramebufferTexture, glFramebufferTexture1D, glFramebufferTexture2D, glFramebufferTexture3D

Copyright

Copyright © 2010 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.

Example of glFramebufferRenderbuffer

// This function does any needed initialization on the rendering

// context. 

void SetupRC()

{

    fprintf(stdout, "FBO Draw Buffers Demo\n\n");

    // Make sure required functionality is available: cube maps, auto mip gen, etc.

    if (!GLEE_VERSION_1_4)

    {

        fprintf(stderr, "OpenGL 1.4 is not available!\n");

        Sleep(2000);

        exit(0);

    }

    if (GLEE_ARB_texture_non_power_of_two)

    {

        npotTexturesAvailable = GL_TRUE;

    }

    else

    {

        fprintf(stderr, "GL_ARB_texture_non_power_of_two extension is not available!\n");

        fprintf(stderr, "Framebuffer effects will be lower resolution (lower quality).\n\n");

    }

    if (!GLEE_EXT_framebuffer_object)

    {

        fprintf(stderr, "GL_EXT_framebuffer_object extension is unavailable!\n");

        Sleep(2000);

        exit(0);

    }

    // we'll use up to 4 render targets if they're available

    glGetIntegerv(GL_MAX_DRAW_BUFFERS, &maxDrawBuffers);

    glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS_EXT, &maxColorAttachments);

    glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &maxTexUnits);

    maxDrawBuffers = (maxDrawBuffers > maxColorAttachments) ? maxColorAttachments : maxDrawBuffers;

    maxDrawBuffers = (maxDrawBuffers > (maxTexUnits-1)) ? (maxTexUnits-1) : maxDrawBuffers;

    maxDrawBuffers = (maxDrawBuffers > 4) ? 4 : maxDrawBuffers;

    if (((!GLEE_ARB_draw_buffers || !GLEE_ARB_fragment_shader || !GLEE_ARB_shader_objects) 

        && !GLEE_VERSION_2_0) || (maxDrawBuffers != 4))

    {

        fprintf(stderr, "Support for at least 4 draw buffers is unavailable!\n");

        Sleep(2000);

        exit(0);

    }

    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTexSize);

    glGetIntegerv(GL_MAX_RENDERBUFFER_SIZE_EXT, &maxRenderbufferSize);

    maxTexSize = (maxRenderbufferSize > maxTexSize) ? maxTexSize : maxRenderbufferSize;

    fprintf(stdout, "Controls:\n");

    fprintf(stdout, "\tRight-click for menu\n\n");

    fprintf(stdout, "\tx/X\t\tMove +/- in x direction\n");

    fprintf(stdout, "\ty/Y\t\tMove +/- in y direction\n");

    fprintf(stdout, "\tz/Z\t\tMove +/- in z direction\n\n");

    fprintf(stdout, "\td/D\t\tToggle use of draw buffers\n\n");

    fprintf(stdout, "\tq\t\tExit demo\n\n");

    

    // Black background

    glClearColor(0.0f, 0.0f, 0.0f, 1.0f );

    // Hidden surface removal

    glEnable(GL_DEPTH_TEST);

    glDepthFunc(GL_LEQUAL);

    // Set up some lighting state that never changes

    glShadeModel(GL_SMOOTH);

    glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, 1);

    glLightfv(GL_LIGHT0, GL_AMBIENT, ambientLight);

    glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuseLight);

    glLightfv(GL_LIGHT0, GL_SPECULAR, specularLight);

    glLightfv(GL_LIGHT0, GL_POSITION, lightPos);

    glMaterialfv(GL_FRONT, GL_SPECULAR, specularLight);

    glMateriali(GL_FRONT, GL_SHININESS, 128);

    glEnable(GL_LIGHTING);

    glEnable(GL_COLOR_MATERIAL);

    glEnable(GL_NORMALIZE);

    glEnable(GL_LIGHT0);

    // Set up textures & shaders

    SetupTextures();

    SetupShaders();

    // Set up some renderbuffer state

    glGenRenderbuffersEXT(1, &renderbufferID);

    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, renderbufferID);

    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT32, fboWidth, fboHeight);

    glGenFramebuffersEXT(2, framebufferID);

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebufferID[0]);

    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, renderbufferID);

    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, renderTextureID[0], 0);

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebufferID[1]);

    for (int i = 0; i < maxDrawBuffers; i++)

    {

        glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT + i, GL_TEXTURE_2D, renderTextureID[i+1], 0);

    }

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

}