# copyRenderedTexture(forCGLContext:pixelFormat:bounds:isFlipped:) Returns the name of an OpenGL texture of type `GL_TEXTURE_RECTANGLE_EXT` that contains a subregion of the image in a given pixel format. ``` optional func copyRenderedTexture(forCGLContext cgl_ctx: CGLContextObj!, pixelFormat format: String!, bounds: NSRect, isFlipped flipped: UnsafeMutablePointer!) -> GLuint ``` ## Parameters `cgl_ctx` The CGL context to render to. `format` A string that represents the pixel format of the texture. `bounds` The bounds of the subregion of the image. `flipped` Set to on output if the contents of the returned texture are vertically flipped. ## Return Value The name of an OpenGL texture of type `GL_TEXTURE_RECTANGLE_EXT` that contains a subregion of the image in a given pixel format or `0` if the texture can’t be provided. ## Discussion Implement this method if you want to create the texture yourself or use framebuffer objects (FBO). Use `` to send commands to the OpenGL context. Make sure to preserve all the OpenGL states except the ones defined by `GL_CURRENT_BIT`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)