OpenGL 4 Shading Language Cookbook - Third Edition

How it works...

Phew! This seems like a lot of work! However, the real advantage comes when using multiple programs where the same buffer object can be used for each program. Let's take a look at each step individually.

First, we get the index of the uniform block by calling glGetUniformBlockIndex, then we query for the size of the block by calling glGetActiveUniformBlockiv. After getting the size, we allocate a temporary buffer named blockBuffer to hold the data for our block.

The layout of data within a uniform block is implementation-dependent, and implementations may use different padding and/or byte alignment. So in order to accurately lay out our data, we need to query for the offset of each variable within the block. This is done in ...