Book Image

OpenGL 4 Shading Language Cookbook - Third Edition

By : David Wolff
Book Image

OpenGL 4 Shading Language Cookbook - Third Edition

By: David Wolff

Overview of this book

OpenGL 4 Shading Language Cookbook, Third Edition provides easy-to-follow recipes that first walk you through the theory and background behind each technique, and then proceed to showcase and explain the GLSL and OpenGL code needed to implement them. The book begins by familiarizing you with beginner-level topics such as compiling and linking shader programs, saving and loading shader binaries (including SPIR-V), and using an OpenGL function loader library. We then proceed to cover basic lighting and shading effects. After that, you'll learn to use textures, produce shadows, and use geometry and tessellation shaders. Topics such as particle systems, screen-space ambient occlusion, deferred rendering, depth-based tessellation, and physically based rendering will help you tackle advanced topics. OpenGL 4 Shading Language Cookbook, Third Edition also covers advanced topics such as shadow techniques (including the two of the most common techniques: shadow maps and shadow volumes). You will learn how to use noise in shaders and how to use compute shaders. The book provides examples of modern shading techniques that can be used as a starting point for programmers to expand upon to produce modern, interactive, 3D computer-graphics applications.
Table of Contents (17 chapters)
Title Page
Packt Upsell

Using sampler objects

Sampler objects were introduced in OpenGL 3.3 and provide a convenient way to specify the sampling parameters for a GLSL sampler variable. The traditional way to specify the parameters for a texture is to specify them using glTexParameter, typically at the time that the texture is defined. The parameters define the sampling state (sampling mode, wrapping and clamping rules, and so on) for the associated texture. This essentially combines the texture and its sampling state into a single object. If we wanted to sample from a single texture in more than one way (with and without linear filtering for example), we'd have two choices. We would either need to modify the texture's sampling state, or use two copies of the same texture.



In addition, we might want to use the same set of texture sampling parameters for multiple textures. With what we've seen up until now, there's no easy way to do that. With sampler objects, we can specify the parameters once and share them among...