dude

gistfile1.glsl

void main(void) 
{ 
    float x,y;
	float ratio = iResolution.y / iResolution.x;
     
	x = gl_FragCoord.x / iResolution.x - 0.5;
	y = gl_FragCoord.y / iResolution.y * ratio - 0.25;
	
	float PI = 3.14159265358979323846264;

		vec2 position = vec2(x, y);
    
	float angle = 0.0;
	float radius = length(position);
	
	angle = degrees(atan(x, y));
	
	float amod = mod(angle + 30.0 * fract(iGlobalTime * 1.0) - 120.0 * log(radius), 30.0);

    gl_FragColor = vec4(amod / 30.0, amod * cos(iGlobalTime * 3.0), sin(iGlobalTime) * 2.0, 1); 
	/*
	if (amod < 15.0)
	gl_FragColor = vec4(1,1,1,1);
else
	
	gl_FragColor = vec4(1,0,0,1);
*/
	
	/*
	vec2 tc = vec2(tx, ty);	
	vec2 norm = (1.0 - tc) * 2.0 - 1.0;
	
	float theta = PI + atan(norm.x, norm.y);
	float r = length(norm);
	
	vec2 polar = 1.0 - vec2(theta / (2.0 * PI), r);	
	
	float xxx = r * cos(PI);
	
	vec4 color = vec4(xxx, polar.y, 0, 1.0);
	
	gl_FragColor = color;
	*/
	//tx = tx * 2.0 * PI - PI;	
	//ty = ty * 2.0 * PI - PI;
	
	//tx = log(sqrt(tx * tx + ty * ty));
	//ty = atan(ty, tx);
	
	// tx = exp(tx) * 1000.0;
/*	
	if ((tx > 0.5 && ty > 0.5) || (tx < 0.5 && ty < 0.5)) {
		gl_FragColor = vec4(0.3, 0.4, 0.5, 1);
	} else {
		gl_FragColor = vec4(0, 0, 0, 1);
	}
*/
}