shader_type spatial;
uniform bool is_target = false;
uniform bool is_focus = false;
uniform float target_position_y = 0;
uniform float target_level_top_y = 0;
uniform vec3 focus_min = vec3(0,0,0);
uniform vec3 focus_max = vec3(0,0,0);
uniform sampler2D tex_noise1 : source_color;
uniform sampler2D tex_noise2 : source_color;
uniform sampler2D tex_noise_sub : source_color;

uniform sampler2D tex_material : source_color;
uniform sampler2D tex_material_normal : source_color;
uniform sampler2D tex_material_sub : source_color;
uniform sampler2D tex_material_normal_sub : source_color;

varying vec3 world_position;
varying vec2 uv1;
varying vec2 uv2;
varying vec2 uv_sub;
varying vec2 uv_material;

void vertex()
{
	world_position = (MODEL_MATRIX * vec4(VERTEX, 1.0)).xyz;
    vec2 local_uv = vec2(world_position.x,world_position.y + world_position.z);
    uv1 = local_uv / 32.0;
    uv2 = local_uv / 32.0;
	uv_sub = local_uv / 4.0;
	uv_material = local_uv / 8.0;
}

bool is_in_focus(vec3 f_min,vec3 f_max){
    if(world_position.z>f_max.z){return false;}
    if(world_position.y>f_max.y){return false;}
    return true;
}

void fragment() {
	if (is_focus && !is_in_focus(focus_min,focus_max)){
        discard;
	}

    vec3 c = COLOR.rgb;
    if(c.r+c.g+c.b<0.1){
        ALBEDO = vec3(0.0);
    }else if(c.r+c.g+c.b>2.9){
        discard;
    }else{
        float brightness = 1.0;
        if(is_target){
            float offset_y = abs(floor((world_position.y-target_position_y) / 0.02) * 0.02);
            offset_y = max(0.0,offset_y-0.64);
            float rate = clamp(1.0-offset_y/4.48,0.0,1.0);
            brightness = rate;
        }else{
            brightness = 1.0;
        }
        vec3 world_normal = (INV_VIEW_MATRIX * vec4(NORMAL, 0.0)).xyz;
        bool is_light = c.r+c.g+c.b>2.8;
        if(!is_light && world_normal.y<0.1){
            brightness = brightness*0.6;
        }

		//通用网格纹理
		float noise_value1 = texture(tex_noise1,floor(uv1 /0.02) *0.02).r;
		float discrete_noise_value1 = floor(noise_value1 / 0.5) * 0.5;
		float noise_value2 = texture(tex_noise2,floor(uv2 /0.02) *0.02).r;
		float discrete_noise_value2 = floor(noise_value2 / 0.5) * 0.5;

		//材质纹理
		float noise_value_material = texture(tex_material,floor(uv_material /0.0025) *0.0025).r;
		float discrete_noise_value_material = floor(noise_value_material / 0.1) * 0.1;

		c -= discrete_noise_value1 * 0.2;
		c += discrete_noise_value2 * 0.2;
		c += discrete_noise_value_material * 0.2;

		//顶部侵蚀效果
        float offset_y = abs(world_position.y-target_level_top_y);
		float sub_rate = 1.0 - min(1.0,offset_y/0.2);
		float noise_value_material_sub = texture(tex_material_sub,floor(uv_material /0.0025) *0.0025).r;
		float discrete_noise_value_material_sub = floor(noise_value_material_sub / 0.1) * 0.1;
		float noise_value_sub = texture(tex_noise_sub,floor(uv_sub /0.02) *0.02).r;
		c.rgb = mix(c.rgb,vec3(0), noise_value_sub * sub_rate * sub_rate * 4.0);

		vec3 normal_map = texture(tex_material_normal, floor(uv_material /0.0025) *0.0025).rgb;
		normal_map.xy *= 0.2;
	    NORMAL = normalize(TANGENT * normal_map.x + BINORMAL * normal_map.y + NORMAL * normal_map.z);

		//应用亮度
		c = clamp(c,vec3(0.0),vec3(0.95));
        c.rgb = mix(vec3(0.0), c, brightness);

		//颜色像素化
		float div_rate = 0.02;
		c.r = floor(c.r /div_rate) *div_rate;
		c.g = floor(c.g /div_rate) *div_rate;
		c.b = floor(c.b /div_rate) *div_rate;

		ALBEDO = c.rgb;
        if(is_light){
            EMISSION = c.rgb * 2.0;
        }
    }
}

void light() {
    vec3 c = ALBEDO.rgb;
	float rgb_sum = c.r+c.g+c.b;
    if (!(rgb_sum<0.1 || rgb_sum>2.9)){
		DIFFUSE_LIGHT += clamp(dot(NORMAL, LIGHT), 0.0, 1.0) * ATTENUATION * LIGHT_COLOR;
	}
}