Unity2D Sprite灰白图（Unity3D开发之十一）

Shader "Sprites/Gray"
{
Properties
{
[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
_Color ("Tint", Color) = (1,1,1,1)
[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
}

SubShader
{
Tags
{
"Queue"="Transparent"
"IgnoreProjector"="True"
"RenderType"="Transparent"
"PreviewType"="Plane"
"CanUseSpriteAtlas"="True"
}

Cull Off
Lighting Off
ZWrite Off
Fog { Mode Off }
Blend One OneMinusSrcAlpha

Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile DUMMY PIXELSNAP_ON
#include "UnityCG.cginc"

struct appdata_t
{
float4 vertex   : POSITION;
float4 color    : COLOR;
float2 texcoord : TEXCOORD0;
};

struct v2f
{
float4 vertex   : SV_POSITION;
fixed4 color    : COLOR;
half2 texcoord  : TEXCOORD0;
};

fixed4 _Color;

v2f vert(appdata_t IN)
{
v2f OUT;
OUT.vertex = mul(UNITY_MATRIX_MVP, IN.vertex);
OUT.texcoord = IN.texcoord;
OUT.color = IN.color * _Color;
#ifdef PIXELSNAP_ON
OUT.vertex = UnityPixelSnap (OUT.vertex);
#endif

return OUT;
}

sampler2D _MainTex;

fixed4 frag(v2f IN) : SV_Target
{
fixed4 c = tex2D(_MainTex, IN.texcoord) * IN.color;
c.rgb *= c.a;
float gray = dot(c.xyz, float3(0.299, 0.587, 0.114));
c.xyz = float3(gray, gray, gray);
return c;
}
ENDCG
}
}
}

// Use this for initialization
void Start () {
SpriteRenderer render = this.GetComponent<SpriteRenderer> ();
render.material.shader = Shader.Find ("Sprites/Gray");
}