Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Why would I use OpenGL’s matrix stack (as opposed to wrapping my own matrix class and just using that)? I’m not really sure why it is so complicated for such a simple task. Is there’s some special use case for it?
If it isn’t necessary, what’s a good replacement for it?
OpenGL’s matrix stacks (there are multiples–one for each matrix mode) are intended for use with hierarchical models. That is, you can define the rigging of a child object (say, a wheel) with respect to its parent body (say, a car), without regard to the location/orientation of the parent when the child is drawn. That is, it allows you to compose transforms easily and intuitively.
The matix stacks (and GL matrix operations in general) are no substitute for a general purpose matrix math library. They simply exist to allow composed transforms to be efficiently applied to vertex data. As others have said, this functionality has been removed from OpenGL with the demise of the fixed-function pipeline, because the needs of shader programs are less uniform than the needs of the old pipeline.