GLRENDERBUFFERREDSIZE

GLRENDERBUFFERREDSIZE is a queryable parameter in OpenGL that returns the number of color samples in a renderbuffer object. Renderbuffers are a type of OpenGL object used for offscreen rendering. They store pixel data that can be used as a source for rendering operations or as a destination for rendering. Renderbuffers are often used in conjunction with framebuffers for tasks such as shadow mapping, post-processing effects, and multisample anti-aliasing (MSAA).

When a renderbuffer is created with multisampling enabled, it is configured to store multiple samples per pixel. These samples are used to improve image quality, particularly by reducing aliasing artifacts. The GLRENDERBUFFERREDSIZE query allows an application to determine how many samples are being stored by a specific renderbuffer. This information can be useful for various purposes, such as optimizing rendering pipelines or ensuring compatibility between different rendering operations.

To query the number of color samples, an application first binds the renderbuffer object of interest using glBindRenderbuffer. Subsequently, glGetRenderbufferParameteriv is called with the target set to GL_RENDERBUFFER_BINDING and the pname set to GL_RENDERBUFFER_RED_SIZE. The returned value will indicate the number of color samples. For renderbuffers that do not use multisampling, or where multisampling is not enabled, this value will typically be 1. The maximum number of samples supported by a renderbuffer can be queried using GL_MAX_SAMPLES.

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