I want to draw onto a single channel frame buffer object. I’ve found this is not supported by default, but I can use the GL_ARB_texture_rg extension.
For that I need to allocate a frame buffer to GL_RED, which is not possible with ofFbo, I get the errors:
[ error ] ofGLUtils: ofGetGlTypeFromInternal(): unknown internal format 6403, returning GL_UNSIGNED_BYTE [ error ] ofGLUtils: ofGetGLFormatFromInternal(): unknown internal format 6403, returning GL_RGBA
I can use GL_LUMINANCE, but that may not work, because openGL handles it differently.
Has anyone succesfully rendered onto a single channel FBO?