OpenGL Insights

Performance Tuning for

Tile-Based Architectures

Bruce Merry

23.1 Introduction

The OpenGL and OpenGL ES specifications describe a virtual pipeline in which

triangles are processed in order: the vertices of a triangle are transformed, the triangle

is set up and rasterized to produce fragments, the fragments are shaded and then

written to the framebuffer. Once this has been done, the next triangle is processed,

and so on. However, this is not the most efficient way for a GPU to work; GPUs will

usually reorder and parallelize things under the hood for better performance.

In this chapter, we will examine tile-based rendering, a par ticular way to arrange

a