shader"practice/12.14"
{
properties
{
_MainTex("MainTex",2D) = ""{}
}
Subshader
{
pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
sampler2D _MainTex;
float4 _MainTex_ST;

        struct v2f  
        {  
            float4 pos : POSITION;  
            fixed2 uv: TEXCOORD0;  
            fixed2 uv2 : TEXCOORD1;  
            float z : TEXCOORD2;  
        };  
        v2f vert(appdata\_full a)  
        {  
            v2f v;  
            v.pos = UnityObjectToClipPos(a.vertex);  
            v.uv = TRANSFORM\_TEX(a.texcoord,\_MainTex);  
            v.z = mul(unity\_ObjectToWorld,a.vertex).z;  
            return v;  
        }  
        float4 frag(v2f f):COLOR  
        {  
            float data = 0.01;  
            fixed4 color;  
            /\*  // 1.顶点偏移多次采样  
            float2 uv = f.uv;  
            color = tex2D(\_MainTex,f.uv);  
            uv.x = f.uv.x + data;  
            color += tex2D(\_MainTex,uv);  
            uv.x = f.uv.x - data;  
            color += tex2D(\_MainTex,uv);  
            uv.y = f.uv.y + data;  
            color += tex2D(\_MainTex,uv);  
            uv.y = f.uv.y - data;  
            color += tex2D(\_MainTex,uv);  
            color/=5;  

　　　　　　　　　　*/

            // 2.  内置函数实现  
            //color = tex2D(\_MainTex,f.uv,float2(0.01,0.01),float2(0.01,0.01));

            //   3.偏导数计算方案    旋转物体动态改变模糊度  正面清晰，其他面都模糊，可以试试  
            float2 dsdx = ddx(f.z) \* 5;  
            float2 dsdy = ddy(f.z) \* 5;  
            color = tex2D(\_MainTex,f.uv,dsdx,dsdy);

            return  color;        
        }

        ENDCG  
    }  
}  

}