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Matrinix

OpenGL OpenGL Deprecation

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I am currently writing some graphics code for a game I want to make. My goal for would be for the game to work with OpenGL 1.4 (as the base implementation, and then visual addons to make it a higher version of OpenGL; the purpose is I want to try to support computers that use the lower-end Intel graphics such as the older Intel Macs). However, I was looking at the OpenGL 3.1 specifications and it shows that many features are removed (glRotate, glTransform, glScale, glFrustum, glLight, etc.) and I was wondering if I should actually go through the effort of writing my own code to handle the functionality of those functions or if I should just stick with using the deprecated functions and use the compatibility extension if running in OpenGL 3.1. Also, I was planning on using shaders to cel shade my game using Cg and compile them into OpenGL 1.4-compatible assembly shaders, is there any immediate concerns with doing this? Lastly, would using glLight be a good way to do lighting or should I try to do shader-based lighting (per-pixel lighting)... I am probably wanting to have shadows as well if that affects what I should do. Thanks for your help, Matrinix

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I would in general try to use not too much deprecated stuff. Although I cannot advice on many of the requested topics, I can definitely say the following:

Even if going back to OpenGL 1.1, it is IMHO not a good idea to use OpenGL's transformations at all (besides the easiest use cases). Most often you have to deal with matrices anyway because you'll need access to e.g. world matrices of models for collision detection or the like. So you will probably be able to compute the transformations by your own (you should at least). Whether you use glMultMatrix for feeding the MODELVIEW or transfer the matrix directly to a shader is then hiden in a thin layer that adapts to the respective OpenGL version.

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To actually remove the deprecated features, you need to create a forward compatible OpenGL context. If you create a normal OpenGL context (you most likely doing so), all deprecated functions will be still there. So, don't worry.

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