// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Tut/Shader/Toon/toon" {
	Properties {
		//_Color("Main Color",2d)="white" {}//物体的颜色
		_Color("Main Color",color)=(1,1,1,1)//物体的颜色
		_Outline("Thick of Outline",range(0,0.1))=0.02//挤出描边的粗细
		_Factor("Factor",range(0,1))=0.5//挤出多远
		_ToonEffect("Toon Effect",range(0,1))=0.5//卡通化程度（二次元与三次元的交界线）
		_Steps("Steps of toon",range(0,9))=3//色阶层数
		//_diff("diff",2d)="white"{}
		_MainTex ("Base (RGB)", 2D) = "white" {}
	}
	SubShader {
		pass{//处理光照前的pass渲染
		Tags{"LightMode"="Always"}
		Cull Front
		ZWrite On
		CGPROGRAM
		#pragma vertex vert
		#pragma fragment frag
		#include "UnityCG.cginc"
		float _Outline;
		float _Factor;
		struct v2f {
		float4 pos:SV_POSITION;
		//sampler2D _Color;
		//float4 _Color_ST;
			//float4 vertex : POSITION;
			//float3 normal : NORMAL;
			//float4 texcoord : TEXTOORD0;
		};

		v2f vert (appdata_full v) {
			v2f o;
			//o.texcoord = TRANSFORM_TEX(v.texcoord, _color);
			float3 dir=normalize(v.vertex.xyz);
			float3 dir2=v.normal;
			float D=dot(dir,dir2);
			dir=dir*sign(D);
			dir=dir*_Factor+dir2*(1-_Factor);
			v.vertex.xyz+=dir*_Outline;
			o.pos=UnityObjectToClipPos(v.vertex);
			return o;
		}
		float4 frag(v2f i):COLOR
		{
			float4 c=0;
			return c;
		}
		ENDCG
		}//end of pass
		pass{//平行光的的pass渲染
		Tags{"LightMode"="ForwardBase"}
		Cull Back
		CGPROGRAM
		#pragma vertex vert
		#pragma fragment frag
		#include "UnityCG.cginc"

		float4 _LightColor0;
		float4 _Color;
		float _Steps;
		float _ToonEffect;
		sampler2D _MainTex;
		//sampler2D _Color;
		//float4 _Color_ST;

		struct v2f {
			float4 pos:SV_POSITION;
			float3 lightDir:TEXCOORD0;
			float3 viewDir:TEXCOORD1;
			float3 normal:TEXCOORD2;
			float2 texcoord:TEXCOORD3;
		};

		v2f vert (appdata_full v) {
			v2f o;
			o.pos=UnityObjectToClipPos(v.vertex);//切换到世界坐标
			o.normal=v.normal;
			o.lightDir=ObjSpaceLightDir(v.vertex);
			o.viewDir=ObjSpaceViewDir(v.vertex);
			o.texcoord = v.texcoord;
			return o;
		}
		float4 frag(v2f i):COLOR
		{
			float4 c=1;
			float3 N=normalize(i.normal);
			float3 viewDir=normalize(i.viewDir);
			float3 lightDir=normalize(i.lightDir);
			float diff=max(0,dot(N,i.lightDir));//求出正常的漫反射颜色
			diff=(diff+1)/2;//做亮化处理
			diff=smoothstep(0,1,diff);//使颜色平滑的在[0,1]范围之内
			float toon=floor(diff*_Steps)/_Steps;//把颜色做离散化处理，把diffuse颜色限制在_Steps种（_Steps阶颜色），简化颜色，这样的处理使色阶间能平滑的显示
			diff=lerp(diff,toon,_ToonEffect);//根据外部我们可控的卡通化程度值_ToonEffect，调节卡通与现实的比重


			float4 col = tex2D(_MainTex, i.texcoord);
			c=_Color*_LightColor0*(diff)*col;//把最终颜色混合
			return c;
		}
		ENDCG
		}//
		pass{//附加点光源的pass渲染
		Tags{"LightMode"="ForwardAdd"}
		Blend One One
		Cull Back
		ZWrite Off
		CGPROGRAM
		#pragma vertex vert
		#pragma fragment frag
		#include "UnityCG.cginc"

		float4 _LightColor0;
		float4 _Color;
		float _Steps;
		float _ToonEffect;

		struct v2f {
			float4 pos:SV_POSITION;
			float3 lightDir:TEXCOORD0;
			float3 viewDir:TEXCOORD1;
			float3 normal:TEXCOORD2;
		};

		v2f vert (appdata_full v) {
			v2f o;
			//o.texcoord = TRANSFORM_TEX(v.texcoord, _color);
			o.pos=UnityObjectToClipPos(v.vertex);
			o.normal=v.normal;
			o.viewDir=ObjSpaceViewDir(v.vertex);
			o.lightDir=_WorldSpaceLightPos0-v.vertex;

			return o;
		}
		float4 frag(v2f i):COLOR
		{
			float4 c=1;
			//float4 _diff_var = tex2D(_diff,TRANSFORM_TEX(i.uv0, diff));
			float3 N=normalize(i.normal);
			float3 viewDir=normalize(i.viewDir);
			float dist=length(i.lightDir);//求出距离光源的距离
			float3 lightDir=normalize(i.lightDir);
			float diff=max(0,dot(N,i.lightDir));
			diff=(diff+1)/2;
			diff=smoothstep(0,1,diff);
			float atten=1/(dist);//根据距光源的距离求出衰减
			float toon=floor(diff*atten*_Steps)/_Steps;
			diff=lerp(diff,toon,_ToonEffect);

			half3 h = normalize (lightDir + viewDir);//求出半角向量
			float nh = max (0, dot (N, h));
			float spec = pow (nh, 32.0);//求出高光强度
			float toonSpec=floor(spec*atten*2)/ 2;//把高光也离散化
			spec=lerp(spec,toonSpec,_ToonEffect);//调节卡通与现实高光的比重

			
			c=_Color*_LightColor0*(diff+spec);//求出最终颜色
			return c;
		}
		ENDCG
		}
	} 
}