GodotComponentTest/materials/shader/IslandColorRampShader.gdshader

shader_type canvas_item;
render_mode skip_vertex_transform;

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

vec3 color_ramp(float h) {
	if (h < 0.4f) {
		return vec3(0, 0, 0.6);
	} else if (h < 0.45f) {
		return vec3(0, 0, 0.7);
	} else if (h < 0.5f) {
		return vec3(0, 0, 1);
	} else if (h < 0.55){
		return vec3(0.8, 0.8, 0.1);
	} else if (h < 0.6){
		return vec3(0, 0.6, 0);
	} else if (h < 0.78){
		return vec3(0, 0.4, 0);
	} else if (h < 1.0){
		return vec3(0.5, 0.5, 0.4);
	}
	
	return vec3(1.0);
}

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);
}