shader_type canvas_item;

//uniform sampler2D origin;
uniform sampler2D noise;
uniform vec2 tiling;
uniform vec2 extraoffset;
uniform bool isON=true;

void fragment()
{
	vec2 c = vec2(FRAGCOORD.x, FRAGCOORD.y);
	vec2 res = vec2(1.0 / SCREEN_PIXEL_SIZE.x,1.0 / SCREEN_PIXEL_SIZE.y);
	
	vec2 u = c / res.xy,
         n = texture(noise, u * .1).rg;  // Displacement
    
    //vec4 f = textureLod(origin, u*tiling+extraoffset, 2.5);
	vec4 f=texture(SCREEN_TEXTURE,SCREEN_UV*tiling+extraoffset);
    
    // Loop through the different inverse sizes of drops
	if (isON) {
	    for (float r = 4. ; r > 0. ; r--) {
	        vec2 x = res.xy * r * .015,  // Number of potential drops (in a grid)
	             p = 6.28 * u * x + (n - .5) * 2.,
	             s = sin(p);
	        
	        // Current drop properties. Coordinates are rounded to ensure a
	        // consistent value among the fragment of a given drop.
	        vec4 d = texture(noise, round(u * x - 0.25) / x);
	        
	        // Drop shape and fading
	        float t = (s.x+s.y) * max(0., 1. - fract(TIME * (d.b + .1) + d.g) * 1.7);
	        
	        // d.r -> only x% of drops are kept on, with x depending on the size of drops
	        if (d.r < (3.-r)*.02 && t > 0.5) {
	            // Drop normal
	            vec3 v = normalize(-vec3(cos(p), mix(.2, 2., t-.5)));
	            // fragColor = vec4(v * 0.5 + 0.5, 1.0);  // show normals
	            
	            // Poor man's refraction (no visual need to do more)
	            f = texture(SCREEN_TEXTURE, (u - v.xy * .1)*tiling+extraoffset);
				
				if(f.r == 1.0 && f.g == 1.0 && f.b == 1.0){
					f.a = 0.0
				}
	        }
		}
    } else {
		f=texture(SCREEN_TEXTURE,SCREEN_UV);
	}
	COLOR = f;
}