径向渐变着色器

Question

我需要径向渐变着色器，任何人都可以指导一些有用的资源，我有一个，但是它只使用两种颜色和它们之间的lerp，我想要像CSS中的一般着色器一样。我们对CSS的颜色停止了。 目前我所拥有的是。

 Shader "Sprites/RadialGradient"
{
    Properties
    {
//      [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _Color ("Tint", Color) = (1,1,1,1)

         _ColorA ("Color A", Color) = (1, 1, 1, 1)
         _ColorB ("Color B", Color) = (0, 0, 0, 1)
         _Slide ("Slide", Range(0, 1)) = 0.5

//        _Color ("Color Tint", Color) = (1,1,1,1)
       _MainTex ("Base (RGB), Alpha (A)", 2D) = "white" {}


    }

    SubShader
    {
        Tags
        { 
            "Queue"="Transparent" 
            "IgnoreProjector"="True" 
            "RenderType"="Transparent" 
            "PreviewType"="Plane"
            "CanUseSpriteAtlas"="True"
        }
          LOD 100
            Cull Off
            Lighting Off
            ZWrite Off

            Fog { Mode Off }
            ColorMask RGB
            Blend SrcAlpha OneMinusSrcAlpha

        Pass
        {
        CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma target 2.0
            #pragma multi_compile _ PIXELSNAP_ON
            #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
            #include "UnityCG.cginc"
              struct appdata_t {
                 float4 vertex : POSITION;
                 float2 texcoord : TEXCOORD0;
                 float4 color    : COLOR;
             };

             struct v2f {
                 float4 vertex : SV_POSITION;
                 half2 texcoord : TEXCOORD0;
                   half4 color : COLOR;
             };

            fixed4 _Color;
             v2f vert (appdata_t v)
             {
                 v2f o;
                 o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
                 o.texcoord = v.texcoord;
                   o.color = _Color;
                 return o;
             }


             fixed4 _ColorA, _ColorB;
             float _Slide;




            sampler2D _MainTex;
            sampler2D _AlphaTex;



            fixed4 SampleSpriteTexture (float2 uv)
            {
                fixed4 color = tex2D (_MainTex, uv);

#if ETC1_EXTERNAL_ALPHA
                // get the color from an external texture (usecase: Alpha support for ETC1 on android)
                color.a = tex2D (_AlphaTex, uv).r;
#endif //ETC1_EXTERNAL_ALPHA

                return color;
            }



                 fixed4 frag (v2f i) : SV_Target
             {
                 float t = length(i.texcoord - float2(0.5, 0.5)) * 1.41421356237; // 1.141... = sqrt(2)
                 fixed4 c = SampleSpriteTexture (i.texcoord) * i.color;
                 c.rgb *=lerp(_ColorA, _ColorB, t + (_Slide - 0.5) * 2);
                c.rgb *= c.a;

                return c;

             }

        ENDCG
        }
    }
}

谢谢。