Book Image

GLSL Essentials

By : Jacobo Rodriguez
Book Image

GLSL Essentials

By: Jacobo Rodriguez

Overview of this book

Shader programming has been the largest revolution in graphics programming. OpenGL Shading Language (abbreviated: GLSL or GLslang), is a high-level shading language based on the syntax of the C programming language.With GLSL you can execute code on your GPU (aka graphics card). More sophisticated effects can be achieved with this technique.Therefore, knowing how OpenGL works and how each shader type interacts with each other, as well as how they are integrated into the system, is imperative for graphic programmers. This knowledge is crucial in order to be familiar with the mechanisms for rendering 3D objects. GLSL Essentials is the only book on the market that teaches you about shaders from the very beginning. It shows you how graphics programming has evolved, in order to understand why you need each stage in the Graphics Rendering Pipeline, and how to manage it in a simple but concise way. This book explains how shaders work in a step-by-step manner, with an explanation of how they interact with the application assets at each stage. This book will take you through the graphics pipeline and will describe each section in an interactive and clear way. You will learn how the OpenGL state machine works and all its relevant stages. Vertex shaders, fragment shaders, and geometry shaders will be covered, as well some use cases and an introduction to the math needed for lighting algorithms or transforms. Generic GPU programming (GPGPU) will also be covered. After reading GLSL Essentials you will be ready to generate any rendering effect you need.
Table of Contents (13 chapters)

Summary


In this chapter, we have learnt how to use the GPU to offload the CPU in some rendering tasks. The butterflies example taught us how, parting from a plain array of 3D points, we can create on the fly more elaborated (in terms of mesh complexity) structures using only the GPU. A good exercise for you would be to give life to the butterflies by animating their wings (easy to achieve, changing the wings' aperture angle according to the time), coloring each butterfly instance differently based on gl_PrimitiveID, or calculating the strips' normal vectors to include lighting calculations.

In the next chapter, we will increase the flexibility of our renders with the usage of the compute shaders, which will allow us to perform other GPU calculations without being constrained by the pipeline's execution order.