---

/*{
	"IMPORTED": [],
	"CATEGORIES": [
		"procedural",
		"mondrian",
		"short",
		"quadtree",
		"Automatically Converted",
		"Shadertoy"
	],
	"DESCRIPTION": "Automatically converted from https://www.shadertoy.com/view/MlsXDf by FabriceNeyret2.  translate and move with mouse.\n#define tunes the probabilty of subdividing.",
	"INPUTS": [
		{
			"NAME": "iMouse",
			"TYPE": "point2D"
		}
	]
}
*/


#define P_SUBDIV .2+.2*sin(TIME)
//#define P_SUBDIV .2

float rnd(vec3 v) { return fract(4e4*sin(dot(v,vec3(13.46,41.74,-73.36))+17.34)); }
    
void main() {

vec4 fragCoordPos = gl_FragCoord;
	

    vec2 u, R=RENDERSIZE.xy, m=iMouse.xy;
    if (m.x+m.y<1e-2*R.x) m = R*(.5+.5*sin(.1*TIME+vec2(0,1.6)));
    fragCoordPos.x -= 8.*(m.x-R.x/2.);
    fragCoordPos.xy /= (1.-m.y/R.y)*4.;
    
	float z = R.y;
    for (int i=0; i<128; i++) {
        u = floor(fragCoordPos.xy/z)+.5;
        if (rnd(vec3(z*u, z)) < P_SUBDIV) break;
        z /= 2.;
    }
    fragCoordPos.xy = z/2.-abs(fragCoordPos.xy-z*u);
    gl_FragColor = min(fragCoordPos.x,fragCoordPos.y)<1. ? vec4(0) :
    			// vec4(1); // vec4(z/R.y);
				.6+.4*cos(6.28*rnd(vec3(z*u+1.,z))+vec4(0,2.1,-2.1,0));
}