Shader example

Roughly speaking, a shader is a program that takes in coordinates pixel, time, cursor position, “screen” size, and returns a color, that the pixel should have. Since neighboring pixels don’t know about each other’s state, the shaders parallelize well.


Shaders are described in GLSL (OpenGL Script Language). For example, to fill the screen with red color you can write:

void main() {
  gl_FragColor=vec4(255, 0, 0, 1);

There are several services where you can “play around” with shaders and see the result in real time:

For those who want to dive deeper, I can recommend The Book Of Shaders (in progress) and Twitter accounts: