main.noasm

vec4 quatMult(vec4 q1, vec4 q2) {
	vec4 r;
	r.x = q1.x * q2.x - dot(q1.yzw,q2.yzw);
	r.yzw = q2.yzw * q1.x + q1.yzw * q2.x + cross( q1.yzw, q2.yzw );
	return r;
}
vec4 quatSq(vec4 q) {
	vec4 r;
	r.x = q.x * q.x - dot(q.yzw,q.yzw);
	r.yzw = q.yzw * 2.0 * q.x;
	return r;
}
void main(){
	float f=dot(gl_Color.xyz,vec3(1,256,256*256))*0.3;
	float f = time;
	mat3 rotation = mat3(
        vec3(  cos(f), 0.0, sin(f) ),
        vec3(         0.0, 1.0, 0.0        ),
        vec3( -sin(f), 0.0, cos(f) )
    );
	vec3 r=normalize(vec3(3.0-0.005*gl_FragCoord.x,1.5-0.005*gl_FragCoord.y,1.0))*rotation;
	vec3 p=vec3(0,0,-2)*rotation;
	float u=300;
	int c=0;
	int jt = 0;
	vec4 j = vec4( sin(time/2.0)/2.0, sin(time)/2.0, sin(time/4.0)/2.0, sin(time/8.0)/2.0 );
	while(u>0.01&&c<255){
		vec4 q = vec4(p,0);
		vec4 qp = vec4(1,0,0,0);
		for( int i = 0; i < 8; i++ ) {
			qp = quatMult(q,qp) * 2.0;
			q = quatSq(q) + j;
			jt++;
			if( dot(q,q) > 1000.0 ) {
				break;
			}
		}
		float l = length( q );
		u = 0.5 *  l * log( l ) / length( qp );
		p=p+r*u;
		c++;
	}
	gl_FragColor.rgb=vec3(c/(100.0),0,jt/400.0);
}