Unity自用2D像素图描边Shader

Shader 学习中,基于 Sprite-Default。

效果

img

代码

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Shader "Custom/NewSurfaceShader"
{
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 //关闭背面剔除
Lighting Off //关闭灯光
ZWrite Off //关闭Z缓冲
Blend One OneMinusSrcAlpha //混合源系数one(1) 目标系数OneMinusSrcAlpha(1-one=0)
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile _ PIXELSNAP_ON //告诉Unity编译不同版本的Shader,这里和后面vert中的PIXELSNAP_ON对应
#include "UnityCG.cginc"
sampler2D _MainTex;
float4 _MainTex_TexelSize;
fixed4 _Color;
struct appdata_t //vert输入
{
float4 vertex : POSITION;
float4 color : COLOR;
float2 texcoord : TEXCOORD0;
};
struct v2f //vert输出数据结构
{
float4 vertex : SV_POSITION;
fixed4 color : COLOR;
float2 texcoord : TEXCOORD0;
};
v2f vert(appdata_t IN)
{
v2f OUT;
OUT.vertex = UnityObjectToClipPos(IN.vertex);
OUT.texcoord = IN.texcoord;
OUT.color = IN.color * _Color;
#ifdef PIXELSNAP_ON
OUT.vertex = UnityPixelSnap (OUT.vertex);
#endif
return OUT;
}
fixed4 SampleSpriteTexture (float2 uv)
{
fixed4 color = tex2D (_MainTex, uv);
return color;
}
fixed4 frag(v2f IN) : SV_Target
{
float _CheckRange = 1;
float _CheckAccuracy = 0.5;
fixed4 _OutlineColor = fixed4(1,1,1,1);
float _LineWidth = 2;
fixed4 c = SampleSpriteTexture (IN.texcoord) * IN.color;
c.rgb *= c.a;
float isOut = step(abs(1/_LineWidth),c.a);
if(isOut != 0)
{
fixed4 pixelUp = tex2D(_MainTex, IN.texcoord + fixed2(0, _MainTex_TexelSize.y*_CheckRange));
fixed4 pixelDown = tex2D(_MainTex, IN.texcoord - fixed2(0, _MainTex_TexelSize.y*_CheckRange));
fixed4 pixelRight = tex2D(_MainTex, IN.texcoord + fixed2(_MainTex_TexelSize.x*_CheckRange, 0));
fixed4 pixelLeft = tex2D(_MainTex, IN.texcoord - fixed2(_MainTex_TexelSize.x*_CheckRange, 0));
float bOut = step((1-_CheckAccuracy),pixelUp.a*pixelDown.a*pixelRight.a*pixelLeft.a);
c = lerp(_OutlineColor,c,bOut);
return c;
}
return c;
}
ENDCG
}
}
}