Shadertoy wrapper

erb_template.rb

require 'erb'

shadertoy = File.read(ARGV[0])

def shader_template
  %(
#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

\/\/ ----------------------
\/\/ SHADERTOY UNIFORMS  -
\/\/ ----------------------

uniform vec3      iResolution;           \/\/ viewport resolution (in pixels)
uniform float     iTime;                 \/\/ shader playback time (in seconds)
uniform float     iTimeDelta;            \/\/ render time (in seconds)
uniform int       iFrame;                \/\/ shader playback frame

uniform vec4      iMouse;                \/\/ mouse pixel coords. xy: current (if MLB down), zw: click
uniform vec4      iDate;                 \/\/ (year, month, day, time in seconds)

\/\/uniform float     iChannelTime[2];
\/\/uniform vec3      iChannelResolution[2];


\/\/ Channels can be either 2D maps or Cubemaps.
\/\/ Pick the ones you need and uncomment them.


\/\/ uniform float     iChannelTime[1..4];       \/\/ channel playback time (in seconds)
\/\/ uniform vec3      iChannelResolution[1..4]; \/\/ channel resolution (in pixels)

/*
uniform sampler2D iChannel0;
uniform sampler2D iChannel1;
uniform sampler2D iChannel2;
uniform sampler2D iChannel3;

uniform samplerCube iChannel0;
uniform samplerCube iChannel1;
uniform samplerCube iChannel2;
uniform samplerCube iChannel3;

uniform vec3  iChannelResolution[4]; \/\/ channel resolution (in pixels)

uniform float iChannelTime[4]; \/\/ Channel playback time (in seconds)
*/

void mainImage( out vec4 fragColor, in vec2 fragCoord );

void main() {
    mainImage(gl_FragColor,gl_FragCoord.xy);
}
\/\/ Shadertoy code
<%= shadertoy %>
\/\/ End of Shadertoy code
  )
end

renderer = ERB.new(shader_template)
output = renderer.result

File.write('wrapper.glsl', output)