GL_IMG_multisampled_render_to_texture

Supported Hardware

Series5XT, Series6, Series6XE, Series6XT

Valid APIs

OpenGL ES 1.x, 2.0, 3.x

Description

This extension adds multisampled rendering capabilities to OpenGLES, allowing a user to create multisampled render buffers, and attach textures to a framebuffer in a way that they can be used for multisampled renders. By enabling textures to be attached as multisampled but without using actual multisample textures, a significant amount of bandwidth can be saved. This mode of operation enables multisampled anti-aliasing to smooth lines at the edges of polygons and reduce the appearance of jagged lines. This is functionally equivalent to GL_EXT_multisampled_render_to_texture on PowerVR hardware.

Note

Part of this functionality is core to OpenGL ES 3.0. The renderbuffer functionality is present in core, however, the multisampled texture attachment is not.

Registry Link

http://www.khronos.org/registry/gles/extensions/IMG/IMG_multisampled_render_to_texture.txt

Example

// Create a multisampled depth renderbuffer 
GLint depthBuffer = glRenderbufferStorageMultisampleIMG(GL_RENDERBUFFER, 4, GL_DEPTH_COMPONENT16, 1024, 1024); 
// Attach the renderbuffer to the framebuffer as per usual. Note: If one attachment is 
// multi-sampled, all attachments need to be. If there is a mix, the framebuffer will be 
// incomplete. 
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthBuffer); 
// Create a regular colour buffer (texture). This extension doesn't introduce multi-sample 
// textures, instead attaching regular textures that multi-sampling will resolve to before 
// writing out. 
GLint colourBuffer = glTexStorage(GL_TEXTURE_2D, 1, GL_RGBA8, 1024, 1024); 
// Attach it to a framebuffer as multisampled, so that OpenGL ES knows that it should resolve 
// a multisampled render to this texture. 
glFramebufferTexture2DMultisampleIMG(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colourBuffer, 0);