sine_dance.glsl

// Doodle based on Sound Visualizer https://www.shadertoy.com/view/Xds3Rr
// and http://vimeo.com/51993089 @ the 0min 44s mark
// For Shadertone, tap into Overtone's volume...
uniform float iOvertoneVolume;
void main(void)
{
    vec2 uv = 2*(gl_FragCoord.xy/iResolution.xy) - 1.0;
    // equvalent to the video's spec.y, I think
    float spec_y = 0.01 + 1.0*iOvertoneVolume;
    float col = 0;
    float i = 2;
    uv.x += sin(iGlobalTime * i * 1.0 + uv.y*2.5)* 10 * spec_y;
    uv.x -= sin(iGlobalTime * i * 2.0 + uv.y*2)* 10.5 * spec_y;
    col += abs(1.5/uv.x) * spec_y;
    col =  col;

    gl_FragColor = vec4(-20 * iOvertoneVolume,col,2 * col,1.0);

}