OpenGL 4 Shading Language Cookbook - Third Edition

How to do it...

Modify the code from the previous recipe in the following way.

Within the innermost loop, instead of calling glm::perlin, we'll instead call the overload that provides periodic Perlin noise. You will need to replace the following statement:

float val = glm::perlin(p) / scale; 

Replace it with the following:

float val = 0.0f; 
if( periodic ) { 
  val = glm::perlin(p, glm::vec2(freq)) / scale; 
} else { 
  val = glm::perlin(p) / scale; 
}