Shader "MyShader/VertexFragmentShader"
{
    Properties{
        _MainColor("MainColor",Color) = (1,1,1,1)
    }
        SubShader
    {
        Tags { "RenderType" = "Opaque" }
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            float4 _MainColor;
            float4 vert(float4 v:POSITION) :SV_POSITION
            {
                return UnityObjectToClipPos(v);
            }
            fixed4 frag () : SV_Target
            {        
                return _MainColor;
            }
            ENDCG
        }
    }
}

Shader "MyShader/SurfaceShader"
{
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        CGPROGRAM
        //表面著色器,使用Lambert光照
        #pragma surface surf Lambert 
           
        struct Input {
        float4 color :COLOR;
        };
        
        void surf(Input IN,inout SurfaceOutput o) {
            o.Albedo = 1;
        }
       
        ENDCG
    }
    Fallback "Diffuse"
}

v2f vert(a2v v) {
	v2f o;
	//頂點(diǎn)變換到裁剪空間
	o.pos = UnityObjectToClipPos(v.vertex); 
    
	//環(huán)境光
	fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
    
	//世界空間下法線
	fixed3 worldNormal = normalize(mul(v.normal,unity_WorldToObject));
    
	//世界空間下光照方向
	fixed3 worldLight = normalize(_WorldSpaceLightPos0.xyz);
    
	//點(diǎn)成光照和法線得出漫反射方向，satruate取區(qū)間0-1;
	fixed3 diffuse = _LightColor0.rgb * _Diffuse.rgb * saturate(dot(worldNormal, worldLight));
    
	//環(huán)境光+漫反射
	o.color = ambient + diffuse;
	return o;
}

v2f vert(a2v v) {
	v2f o;
	//頂點(diǎn)變換到裁剪空間
	o.pos = UnityObjectToClipPos(v.vertex);

	//傳遞世界坐標(biāo)法線到片元著色器
	o.worldNormal = mul(v.normal,unity_WorldToObject);
	
	return o;
}

fixed4 frag(v2f v) :SV_Target{
	//環(huán)境光
	fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
	
	//歸一化世界法線
	fixed3 worldNormal = normalize(v.worldNormal);

	//歸一化世界空間下光照方向
	fixed3 worldLight = normalize(_WorldSpaceLightPos0.xyz);
	
	//求漫反射
	fixed3 diffuse = _LightColor0.rgb * _Diffuse.rgb * saturate(dot(worldNormal, worldLight));
	
	//相加環(huán)境光和漫反射
	fixed3 color = ambient + diffuse;
	return fixed4(color,1.0);
}

//HalfLambertParma
fixed halfLambert = dot(worldNormal, worldLight) * 0.5 + 0.5;

//使用halfLambert計(jì)算漫反射
fixed3 diffuse = _LightColor0.rgb * _Diffuse.rgb * halfLambert;

//根據(jù)法線和光線方向用reflect方法計(jì)算反射方向
fixed3 reflectDir = normalize(reflect(-worldLight, worldNormal));

//計(jì)算觀察方向，攝像機(jī)位置-頂點(diǎn)位置（要求同在世界坐標(biāo)系下）
fixed3 viewDir = normalize(_WorldSpaceCameraPos.xyz - mul(unity_ObjectToWorld, v.vertex).xyz);

//Phong光照模型中高光計(jì)算公式，_Specular顏色，_Gloss粗糙度，_LightColor0系統(tǒng)參數(shù)光照顏色
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(saturate(dot(reflectDir, viewDir)), _Gloss);

o.color = ambient + diffuse + specular;

//世界光線方向和觀察方向中間方向;
fixed3 halfDir = normalize(worldLight + viewDir);

//使用halfDir來(lái)計(jì)算高光
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0, dot(worldNormal, halfDir)), _Gloss);

fixed3 color = ambient + diffuse + specular;

v2f vert(a2v v){
	//uv傳遞給片元著色器,可以使用宏命令TRANSFORM_TEX
	o.uv = v.texcoord.xy * _MainTexture_ST.xy + _MainTexture_ST.zw;
	//o.uv = TRANSFORM_TEX(v.texcoord,_Maintexture);
}
fixed4 farg(v2f v) :SV_Target{
    //紋理取樣,表面顏色-紋素
	fixed3 albedo = tex2D(_MainTexture, v.uv).rgb * _Color.rgb;
	//環(huán)境光*表面顏色
	fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz *albedo;
					
	fixed halfLambert = dot(worldNormal, worldLight) * 0.5 + 0.5;
	//漫反射*表面顏色
	fixed3 diffuse = _LightColor0.rgb * albedo.rgb * halfLambert;
}

v2f vert(a2v v) {
	v2f o;
	o.pos = UnityObjectToClipPos(v.vertex);

	o.uv.xy = v.texcoord.xy * _MainTexture_ST.xy + _MainTexture_ST.zw;
	//o.uv = TRANSFORM_TEX(v.texcoord,_Maintexture);
	o.uv.zw = TRANSFORM_TEX(v.texcoord,_BumpMap);

	//宏定義,求世界空間——切線空間變換矩陣rotation
	TANGENT_SPACE_ROTATION;
	
	o.lightDir = mul(rotation,ObjSpaceLightDir(v.vertex)).xyz;
	o.viewDir = mul(rotation,ObjSpaceViewDir(v.vertex)).xyz;

	return o;
}

fixed4 frag(v2f v) :SV_Target{
	//切線空間-光線方向
	fixed3 tangentLightDir = normalize(v.lightDir);
   
	//切線空間-觀察方向
    fixed3 tangentViewDir = normalize(v.viewDir);
		
	//法線貼圖格式為NormalMap,使用UnpackNormal解壓,取樣得到切線空間下法線
	fixed3 tangentNormal = UnpackNormal(tex2D(_BumpMap,v.uv.zw));
	//法線縮放
	tangentNormal.xy *= _BumpScale;
	//法線貼圖壓縮方法,z值可以計(jì)算得出,勾股定理,以下是簡(jiǎn)化后公式
	tangentNormal.z = sqrt(1.0-saturate(dot(tangentNormal.xy,tangentNormal.xy)));
	
    ...//漫反射高光計(jì)算都使用tangentNormal
}

v2f vert(a2v v) {
	v2f o;
	o.pos = UnityObjectToClipPos(v.vertex);
	//減少寄存器使用,xy記錄主紋理uv,zw記錄法線uv
	o.uv.xy = v.texcoord.xy * _MainTexture_ST.xy + _MainTexture_ST.zw;
	o.uv.zw = TRANSFORM_TEX(v.texcoord,_BumpMap);
	//求世界空間下法線、切線、副切線
	float3 worldPos = mul(unity_ObjectToWorld,v.vertex).xyz;
	fixed3 worldNormal = UnityObjectToWorldNormal(v.normal);
	fixed3 worldTangent = UnityObjectToWorldDir(v.tangent.xyz);
	fixed3 worldBinnormal = cross(worldNormal,worldTangent)*v.tangent.w;
	
	//法線、切線、副切線構(gòu)成切線空間變換矩陣,w值trick利用存儲(chǔ)世界坐標(biāo)系頂點(diǎn)坐標(biāo)
	o.Ttow0 = float4(worldTangent.x,worldBinnormal.x,worldNormal.x,worldPos.x);	
	o.Ttow1 = float4(worldTangent.y,worldBinnormal.y,worldNormal.y,worldPos.y);	
	o.Ttow2 = float4(worldTangent.z,worldBinnormal.z,worldNormal.z,worldPos.z);	
	return o;
}
fixed4 frag(v2f v) :SV_Target{
    ...
        
    //法線貼圖格式為NormalMap,使用UnpackNormal解壓,取樣得到切線空間法線
	fixed3 tangentNormal = UnpackNormal( tex2D(_BumpMap,v.uv.zw));
	
    //法線縮放
	tangentNormal.xy *= _BumpScale;
	
    //法線貼圖壓縮方法,z值可以計(jì)算得出,勾股定理,以下是簡(jiǎn)化后公式
	tangentNormal.z = sqrt(1.0-saturate(dot(tangentNormal.xy,tangentNormal.xy)));
	
    //矩陣變換求出世界空間法線
	tangentNormal = normalize(half3(dot(v.Ttow0.xyz,tangentNormal),dot(v.Ttow1.xyz,tangentNormal),dot(v.Ttow2.xyz,tangentNormal)));
	
    ...//漫反射高光計(jì)算都使用tangentNormal
}

//頂點(diǎn)著色器轉(zhuǎn)化RampTex的uv
 fixed4 frag (v2f i) : SV_Target{
    fixed halfLambert = 0.5 * dot(worldNormal,worldLightDir)+0.5;
    
     //根據(jù)halfLambert反射方向取樣RampTex紋素
	fixed3 diffuseColor = tex2D(_RampTex, fixed2(halfLambert, 			halfLambert)).rgb*_Color.rgb;

	fixed3 diffuse = _LightColor0.rgb * diffuseColor;
 }

//反射方向
fixed3 halfDir = normalize(tangentLightDir + tangentViewDir);

//uv取樣高光遮罩紋理*高光范圍
fixed3 specularMask = tex2D(_SpecularMask,i.uv).r *_SpecularScale;

//高光結(jié)果混合遮罩紋理
fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0,dot(tangentNormal,halfDir)),_Gloss) * specularMask;

//渲染隊(duì)列,忽略投影器,渲染類型
Tags { "Queue"="AlphaTest" "IgnoreProjector"="True" "RenderType"="Transparent"}
        
//關(guān)閉裁剪
Cull Off

Pass{
	...
	  fixed4 frag (v2f i) : SV_Target{
	  		...
	  		//alpha值小于_Cutoff的都不畫(huà)
            clip(texColor.a - _Cutoff);
	  		...
	  }
	...
}

//三套件
Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
      
Pass{
	//關(guān)閉深度吸入,打開(kāi)深度測(cè)試,選擇顏色混合模式
	Tags{"LightMode"="ForwardBase"}
    ZWrite Off
    Blend SrcAlpha OneMinusSrcAlpha 
    
    ...
    
    fixed4 frag (v2f i) : SV_Target{
    	...
     	//返回著色是,加上透明度
        return fixed4(ambient +diffuse,texColor.a*_AlphaScale);
    }    
}

Pass{
    ZWrite On
    ColorMask 0     //RGBA任意|,選擇需要寫(xiě)入的通道,只做深度緩沖,0不輸出顏色
}

Tags{"LightMode" = "ForwardAdd"}
#pragma multi_compile_fwdadd

#include "Lighting.cginc"
#include "AutoLight.cginc"

fixed4 frag (v2f i) : SV_Target
{            
    fixed3 worldNormal = normalize(i.worldNormal);              
    
    //deal with different light,get worldLightDir;
    #ifdef USING_DIRECTIONAL_LIGHT
        fixed3 worldLightDir = normalize(_WorldSpaceLightPos0.xyz);
        fixed atten = 1.0;
    #else
        fixed3 worldLightDir = normalize(_WorldSpaceLightPos0.xyz - i.worldPos.xyz);  
        
    	//Get light attenuation
        #if defined (POINT)
	        float3 lightCoord = mul(unity_WorldToLight, float4(i.worldPos, 1)).xyz;
	        fixed atten = tex2D(_LightTexture0, dot(lightCoord, lightCoord).rr).UNITY_ATTEN_CHANNEL;
	    #elif defined (SPOT)
	        float4 lightCoord = mul(unity_WorldToLight, float4(i.worldPos, 1));
	        fixed atten = (lightCoord.z > 0) * tex2D(_LightTexture0, lightCoord.xy / lightCoord.w + 0.5).w * tex2D(_LightTextureB0, dot(lightCoord, lightCoord).rr).UNITY_ATTEN_CHANNEL;
	    #else
	        fixed atten = 1.0;
	    #endif
    #endif
	
    ...
	
    return fixed4((diffuse+specular)*atten,1.0);
}

Tags { "LightMode"="ForwardBase" }

CGPROGRAM
#pragma multi_compile_fwdbase

#include "Lighting.cginc"
#include "AutoLight.cginc"

struct v2f
{
    float4 pos : SV_POSITION;
    SHADOW_COORDS(2)
};

v2f vert (appdata v)
{
    v2f o;
    o.pos = UnityObjectToClipPos(v.vertex);

    TRANSFER_SHADOW(o);
    return o;
}


fixed4 frag (v2f i) : SV_Target
{
	fixed atten = 1.0;
	fixed shadow = SHADOW_ATTENUATION(i);
	return fixed4((ambient+ diffuse + specular)*atten*shadow,1.0);
}