post-process

Deprecated: you may find this useful as a reference, but it's otherwise more worthwhile writing your own implementation :)

A generic GLSL post-processing module for applying super-speedy GPU effects to any <img>, <canvas> or <video> element. If you're already working with a 3D scene you're better off using an FBO, but this is useful for cases where you've already got a 2D canvas/video thing and just want to add some niceties.

Usage

post = pp(gl, element, frag[, vert])

Takes the following and returns a new post-processing object:

• gl is a WebGL canvas context.
• element is a canvas element, video or image.
• frag is a fragment shader, which may either be specified as a string or
  as a gl-shader.
• vert is a vertex shader, and optional - you'll only need to specify this
  in special cases.

Your shader is supplied the following uniforms:

• float width: the width of the element in pixels.
• float height: the height of the element in pixels.
• sampler2D map: the element you specified as a texture.

post.render([width, height])

Renders element to gl, using the shader specified above. You can optionally pass a width and height value to override the defaults, which are the dimensions of element.