Framebuffer Objects - Praise for OpenGL ES 30 Programming Guide - page 349

Example 12-2 Render to Texture (continued)

glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR);

// bind renderbuffer and create a 16-bit depth buffer
// width and height of renderbuffer = width and height of
// the texture
glBindRenderbuffer ( GL_RENDERBUFFER, depthRenderbuffer );
glRenderbufferStorage ( GL_RENDERBUFFER, GL_DEPTH_COMPONENT16,
texWidth, texHeight );

// bind the framebuffer
glBindFramebuffer ( GL_FRAMEBUFFER, framebuffer );

// specify texture as color attachment
glFramebufferTexture2D ( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_TEXTURE_2D, texture, 0 );

// specify depth_renderbuffer as depth attachment
glFramebufferRenderbuffer ( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
GL_RENDERBUFFER, depthRenderbuffer);

// check for framebuffer complete
status = glCheckFramebufferStatus ( GL_FRAMEBUFFER );
if ( status == GL_FRAMEBUFFER_COMPLETE )
{
// render to texture using FBO
// clear color and depth buffer
glClearColor ( 0.0f, 0.0f, 0.0f, 1.0f );
glClear ( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

// Load uniforms for vertex and fragment shaders
// used to render to FBO. The vertex shader is the
// ES 1.1 vertex shader described in Example 8-8 in
// Chapter 8. The fragment shader outputs the color
// computed by the vertex shader as fragment color and
// is described in Example 1-2 in Chapter 1.
set_fbo_texture_shader_and_uniforms( );

// drawing commands to the framebuffer object draw_teapot();

// render to window system-provided framebuffer
glBindFramebuffer ( GL_FRAMEBUFFER, 0 );
// Use texture to draw to window system-provided framebuffer.
// We draw a quad that is the size of the viewport.
//
// The vertex shader outputs the vertex position and texture
// coordinates passed as inputs.

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