[gd_resource type="ShaderMaterial" load_steps=4 format=2]

[ext_resource path="res://resources/graphics/GUI/SelectLanguage/noise.webp" type="Texture" id=1]
[ext_resource path="res://resources/graphics/GUI/SelectLanguage/FirstRunBack.webp" type="Texture" id=2]

[sub_resource type="Shader" id=9]
code = "shader_type canvas_item;

uniform sampler2D origin;
uniform sampler2D noise;

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, 2.5);
    
    // Loop through the different inverse sizes of drops
    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) * 2.);
        
        // d.r -> only x% of drops are kept on, with x depending on the size of drops
        if (d.r < (5.-r)*.08 && t > .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(origin, u - v.xy * .3);
			
			if(f.r == 1.0 && f.g == 1.0 && f.b == 1.0){
				f.a = 0.0
			}
        }
		COLOR = f;
    }
}"

[resource]
resource_local_to_scene = true
shader = SubResource( 9 )
shader_param/origin = ExtResource( 2 )
shader_param/noise = ExtResource( 1 )