Fragment Operations - Praise for OpenGL ES 30 Programming Guide - page 324

Example 11-2 Fragment Shader with Multiple Render Targets

#version 300 es
precision mediump float;
layout(location = 0) out vec4 fragData0;
layout(location = 1) out vec4 fragData1;
layout(location = 2) out vec4 fragData2;
layout(location = 3) out vec4 fragData3;
void main()
{
// first buffer will contain red color
fragData0 = vec4 ( 1, 0, 0, 1 );

// second buffer will contain green color
fragData1 = vec4 ( 0, 1, 0, 1 );

// third buffer will contain blue color
fragData2 = vec4 ( 0, 0, 1, 1 );

// fourth buffer will contain gray color
fragData3 = vec4 ( 0.5, 0.5, 0.5, 1 );
}

Summary

In this chapter, you learned about tests and operations (scissor box testing,
stencil buffer testing, depth buffer testing, multisampling, blending and
dithering) that happen after the fragment shader. This is the final phase
in the OpenGL ES 3.0 pipeline. In the next chapter, you will learn an
efficient method for rendering to a texture or an off-screen surface using
framebuffer objects.