iOS OpenGL 函数renderbufferStorage:fromDrawable:

Create a color renderbuffer. Allocate its storage by calling the context’srenderbufferStorage:fromDrawable: method, passing the layer object as the parameter. The width,height and pixel format are taken from the layer and used to allocate storage for the renderbuffer.

myEAGLLayer = (CAEAGLLayer*)self.layer;

GLuint colorRenderbuffer;

glGenRenderbuffers(1, &colorRenderbuffer);glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);

[myContext renderbufferStorage:GL_RENDERBUFFER fromDrawable:myEAGLLayer];

glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,GL_RENDERBUFFER, colorRenderbuffer);

NoteWhentheCoreAnimationlayer’sboundsorpropertieschange,yourapplicationshouldreallocate the renderbuffer’s storage. If you do not reallocate the renderbuffers, the renderbuffersize won’t match the size of the view; in this case, Core Animation may scale the image’s contentsto fit in the view. To prevent this, the Xcode template reallocates the framebuffer and renderbufferwhenever the view layout changes.