artCenter2-webcam-shader.glsl

// to see this function graphed out go to: https://www.desmos.com/calculator/rz7abjujdj
vec3 cosPalette( float t )
{
    // please play around with these numbers to get a better palette
    vec3 brightness = vec3(0.3);
    vec3 contrast = vec3(0.5);
    vec3 osc = vec3(0.5,1.0,0.0);
    vec3 phase = vec3(0.4,0.9,0.2);
    return brightness + contrast*cos( 6.28318*(osc*t+phase) );
}

void main () {
    vec2 pos = uvN();
    vec4 webcam = texture2D(channel0, pos );
    vec4 bb = texture2D(backbuffer, pos* vec2(1.01));
    
    vec3 cosPal = cosPalette(webcam.r);
    
    vec4 color = mix(bb,vec4(cosPal,1.), 1.-webcam);
    
	gl_FragColor = color;
}