How do I grab an image from my EAGLLayer ?

Question

I\'m looking for way to grab the content of my opengl (as UIImage) and then save it into a file. I\'m now giving glReadPixels a try though I\'m not sure I\'m doing the right

Answer 1

All OpenGL|ES complient GL-implementations have to support GL_RGBA as a parameter to glReadPixels.

If your OpenGL|Es supports the

GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES 

extension you can also query the native format. glReadPixels will understand this format as a parameter to glReadPixels and allows you to directly get the pixel-data in native format. This is usually a bit faster than GL_RGBA.

Take a look at the header-file or query the extension-support via glGetString.