Logo闪白边效果

Shader "Custom/LogoShader" {
    Properties {
        _MainTex ("Texture", 2D) = "white" {}
    }
    SubShader {
        Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Opaque" }
        Blend SrcAlpha OneMinusSrcAlpha
            pass{
        CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            sampler2D _MainTex;
            float4 _MainTex_ST;

            struct v2f{
                float4 pos:SV_POSITION;
                float2 uv:TEXCOORD0;
            };

            v2f vert(appdata_base v){
                v2f o;
                o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
                o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
                return o;
            }

            float inFlash(float angle, float2 uv, float xLength, int interval, int beginTime, float offX, float loopTime){
                float brightness = 0;
                float angleInRad = 0.017444 * angle;
                float currentTime = _Time.y;
                int currentTimeInt = _Time.y/interval;
                currentTimeInt *= interval;
                float currentTimePassed = currentTime - currentTimeInt;

                if(currentTimePassed > beginTime){
                    float xBottomLeftBound;
                    float xBottomRightBound;
                    float xPointLeftBound;
                    float xPointRightBound;
                    float x0 = currentTimePassed - beginTime;
                    x0 /= loopTime;
                    xBottomRightBound = x0;
                    xBottomLeftBound = x0 - xLength;

                    float xProjL;
                    xProjL = (uv.y)/tan(angleInRad);

                    xPointLeftBound = xBottomLeftBound - xProjL;
                    xPointRightBound = xBottomRightBound - xProjL;
                    xPointLeftBound += offX;
                    xPointRightBound += offX;
                    if(uv.x > xPointLeftBound && uv.x<xPointRightBound){
                        float midness = (xPointLeftBound+xPointRightBound)/2;
                        float rate = (xLength - 2*abs(uv.x-midness))/(xLength);
                        brightness = rate;
                    }
                }
                brightness = max(brightness, 0);
                float col = float4(1,1,1,1) * brightness;

                return brightness;
            }

            float4 frag(v2f i):COLOR{
                float4 outp;
                float4 texCol = tex2D(_MainTex, i.uv);

                float tmpBrightness;
                tmpBrightness = inFlash(75, i.uv, 0.15f, 2.5f, 0.5f, 0.15, 1.2f);
                if(texCol.w>0.5)
                    outp = texCol + float4(1,1,1,1)*tmpBrightness;
                else
                    outp = float4(0,0,0,0);

                return outp;
            }

        ENDCG
        }
    }
    FallBack "Diffuse"
}