shader_type canvas_item;
render_mode skip_vertex_transform;

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);
uniform sampler2D TextureMask : hint_albedo;

void vertex() {
    VERTEX = (WORLD_MATRIX * (EXTRA_MATRIX * vec4(VERTEX, 0.0, 1.0))).xy;
}

vec3 color_ramp(float h) {
	if (h < 0.1f) {
		return DeepWaterColor.rgb;
	} else if (h < 0.12f) {
		return WaterColor.rgb;
	} else if (h < 0.45f) {
		return LightWaterColor.rgb;
//	} else if (h < 0.25){
//		return SandColor.rgb;
	} else if (h < 0.75){
		return GrassColor.rgb;
//	} else if (h < 0.78){
//		return ForestColor.rgb;
	} else if (h < 1.0){
		return RockColor.rgb;
	}
	
	return SnowColor.rgb;
}

vec3 rgbToGrayscale(vec3 color) {
	return vec3(dot(color.rgb, vec3(0.299, 0.587, 0.144)));
}

float borderFalloff(vec2 uv) {
	return min(
		(0.5 - abs(-uv.x + 0.5)) * 2.0,
		(0.5 - abs(-uv.y + 0.5)) * 2.0);
}

float borderFalloffCircle(vec2 uv) {
	return (0.5 - length(vec2(uv - vec2(0.5, 0.5)))) * 2.0;
}

void fragment() {
	vec4 texture_color = texture(TEXTURE, UV);

	COLOR.rgb = vec3(abs(UV.x - 0.5) * 2.0);
	
	// COLOR.rgb = color_ramp(texture_color.r * borderFalloffCircle(UV) * 1.8);
	COLOR.rgb = color_ramp(texture_color.r * texture(TextureMask, UV).r);
	COLOR.a = 1.0;
	// COLOR.rgb = vec3(1, 0, 0);
}