shader_type canvas_item;

uniform vec4 DeepWaterColor : hint_color = vec4(0, 0, 0.6, 1);
uniform vec4 WaterColor : hint_color = vec4(0, 0, 0.7, 1);
uniform vec4 LightWaterColor : hint_color = vec4(0, 0, 1, 1);
uniform vec4 SandColor : hint_color = vec4(0.8, 0.8, 0.1, 1);
uniform vec4 GrassColor : hint_color = vec4(0, 0.6, 0, 1);
uniform vec4 ForestColor : hint_color = vec4(0, 0.4, 0, 1);
uniform vec4 RockColor : hint_color = vec4(0.5, 0.5, 0.4, 1);
uniform vec4 SnowColor : hint_color = vec4(1);

vec2 rand2d(vec2 uv) {
	return vec2(fract(sin(dot(uv.xy,
		vec2(12.9898,78.233))) * 43758.5453123));
}

float rand1d(vec2 uv){
    return fract(sin(dot(uv, vec2(12.9898, 78.233))) * 43758.5453);
}

vec2 voronoi_segment(vec2 uv, float columns, float rows) {
	vec2 index_uv = floor(vec2(uv.x * columns, uv.y * rows));
	vec2 fract_uv = fract(vec2(uv.x * columns, uv.y * rows));
	
	float minimum_dist = 1.0;
	vec2 minimum_point;
	vec2 minimum_neighbour;
	
	for (int y = -1; y <= 1; y++) {
		for (int x = -1; x <= 1; x++) {
			vec2 neighbour = vec2(float(x), float(y));
			vec2 point = rand2d(index_uv + neighbour);
			
			vec2 diff = neighbour + point - fract_uv;
			float dist = length(diff);
			
			if (dist < minimum_dist) {
				minimum_dist = dist;
				minimum_point = point;
				minimum_neighbour = neighbour;
			}
		}
	}
	
	return minimum_point;
}

ivec2 voronoiCellId(vec2 uv, vec2 grid_size) {
	vec2 index_uv = floor(uv * grid_size);
	vec2 fract_uv = fract(uv * grid_size);
	
		float minimum_dist = 1.0;
	vec2 minimum_point;
	vec2 minimum_neighbour;
	
	for (int y = -1; y <= 1; y++) {
		for (int x = -1; x <= 1; x++) {
			vec2 neighbour = vec2(float(x), float(y));
			vec2 point = rand2d(index_uv + neighbour);
			
			vec2 diff = neighbour + point - fract_uv;
			float dist = length(diff);
			
			if (dist < minimum_dist) {
				minimum_dist = dist;
				minimum_point = point;
				minimum_neighbour = index_uv + neighbour;
			}
		}
	}
	
	return ivec2(minimum_neighbour);
}

void fragment() {
	// float worley = worley(UV, 6.0, 6.0);
	
	int biome_count = 4;
	float big_columns = 0.2;
	float big_rows = 0.2;
	
	float columns = 0.1;
	float rows = 0.1;
	vec2 uv = UV / 0.01;
	vec2 offset = vec2(sin(TIME * 0.1), cos(TIME * 0.1));
	
	uv += offset;
	vec2 index_uv = floor(vec2(uv.x * columns, uv.y * rows));
	vec2 segment_big = voronoi_segment(uv + offset + vec2(1.0, 3.0), big_columns, big_rows);
	
	int biome_big = int(floor(rand1d(segment_big) * float(5)));
	vec2 segment = voronoi_segment(uv + offset, columns, rows);

	// segment = index_uv;
	int biome_id = int(ceil(rand1d(segment) * float(biome_count)));
	if (biome_big < 4) {
		biome_id = 0;
	}
	
	int cell_rows = 6;
	int cell_cols = 6;
	ivec2 cellId = voronoiCellId(uv + offset, vec2(0.125, 0.125));
	vec4 water_land_value = rand1d(vec2(cellId)) < 0.66 ? GrassColor : DeepWaterColor;
	
	COLOR = water_land_value;
	
	// COLOR = vec4(float((cellId.x)) * 0.01, 0.0, 0.0, 1.0);
	
//	if (biome_id == 0) {
//		COLOR = DeepWaterColor;
//	} else if (biome_id == 1) {
//		COLOR = GrassColor;
//	} else if (biome_id == 2) {
//		COLOR = SandColor;
//	} else if (biome_id == 3) {
//		COLOR = RockColor;
//	} else if (biome_id == 4) {
//		COLOR = SnowColor;
//	} else {
//		COLOR = vec4(float(biome_id) / float(biome_count), 0.0, 0.0, 1.0);
//	}
}