boilerPlate.glsl

#version 150
uniform float time;
uniform vec2 resolution;
uniform vec2 mouse;
uniform vec3 spectrum;

uniform sampler2D texture0;
uniform sampler2D texture1;
uniform sampler2D texture2;
uniform sampler2D texture3;
uniform sampler2D prevFrame;
uniform sampler2D prevPass;

in VertexData
{
    vec4 v_position;
    vec3 v_normal;
    vec2 v_texcoord;
} inData;

out vec4 fragColor;


float circ(vec2 p){
    return length(p) - 0.5;
}

// http://www.iquilezles.org/www/articles/palettes/palettes.htm
// As t runs from 0 to 1 (our normalized palette index or domain), 
//the cosine oscilates c times with a phase of d. 
//The result is scaled and biased by a and b to meet the desired constrast and brightness.
vec3 cosPalette( float t, vec3 a, vec3 b, vec3 c, vec3 d )
{
    return a + b*cos( 6.28318*(c*t+d) );
}


void main(void)
{
    vec2 fragCoord = inData.v_texcoord * resolution.xy;
 
    vec2 p = (-resolution.xy + 2.0*fragCoord)/resolution.y;
    
    // distance metric
    float shape = circ(p+vec2(spectrum.x * 20));
    
    vec3 col = cosPalette(0.5,vec3(0.5),vec3(0.5),vec3(1),vec3(time*0.01,time*0.1,time*.2));
    
    // lighting: darken at the center    
    col = vec3(shape) * col;
    
    // output: pixel color
    fragColor = vec4( col.bgr, 1.0 );
}