OpenGL ES 3.0 Programming Guide, Second Edition

Appendix A. GL_HALF_FLOAT

GL_HALF_FLOAT is a vertex and texture data type supported by OpenGL ES 3.0. The GL_HALF_FLOAT data type is used to specify 16-bit floating-point values. This can be useful, for example, in specifying vertex attributes such as texture coordinates,normals,binormals, and tangent vectors. Using GL_HALF_FLOAT rather than GL_FLOAT provides a two times reduction in memory bandwidth required to read vertex or texture data by the GPU.

One might argue that we can use GL_SHORT or GL_UNSIGNED_SHORT instead of a 16-bit floating-point data type and get the same memory footprint and bandwidth savings. However, with that approach, you will need to scale the data or matrices appropriately and apply a transform in the vertexshader. For ...