ImageScanEffectShader.shader

Shader "Custom/Sprite"
{
    Properties
    {
        [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _Color ("Tint", Color) = (1,1,1,1)
        [MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
        [HideInInspector] _RendererColor ("RendererColor", Color) = (1,1,1,1)
        [HideInInspector] _Flip ("Flip", Vector) = (1,1,1,1)
        [PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
        [PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
        _LightTex ("Light Texture", 2D) = "white" {}
        _Duration ("Duration", Float) = 5
        _Speed ("Speed", Float) = 1
        _Rotate ("Rotate", Float) = 45
    }

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

        Cull Off
        Lighting Off
        ZWrite Off
        Blend One OneMinusSrcAlpha

        Pass
        {
        CGPROGRAM
            #pragma vertex SpriteVert
            #pragma fragment SpriteFrag
            #pragma target 2.0
            #pragma multi_compile_instancing
            #pragma multi_compile_local _ PIXELSNAP_ON
            #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
        
            #ifndef UNITY_SPRITES_INCLUDED
            #define UNITY_SPRITES_INCLUDED

            #include "UnityCG.cginc"

            #ifdef UNITY_INSTANCING_ENABLED

                UNITY_INSTANCING_BUFFER_START(PerDrawSprite)
                    // SpriteRenderer.Color while Non-Batched/Instanced.
                    UNITY_DEFINE_INSTANCED_PROP(fixed4, unity_SpriteRendererColorArray)
                    // this could be smaller but that's how bit each entry is regardless of type
                    UNITY_DEFINE_INSTANCED_PROP(fixed2, unity_SpriteFlipArray)
                UNITY_INSTANCING_BUFFER_END(PerDrawSprite)

                #define _RendererColor  UNITY_ACCESS_INSTANCED_PROP(PerDrawSprite, unity_SpriteRendererColorArray)
                #define _Flip           UNITY_ACCESS_INSTANCED_PROP(PerDrawSprite, unity_SpriteFlipArray)

            #endif // instancing

            CBUFFER_START(UnityPerDrawSprite)
            #ifndef UNITY_INSTANCING_ENABLED
                fixed4 _RendererColor;
                fixed2 _Flip;
            #endif
                float _EnableExternalAlpha;
            CBUFFER_END

            // Material Color.
            fixed4 _Color;

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

            struct v2f
            {
                float4 vertex   : SV_POSITION;
                fixed4 color    : COLOR;
                float2 texcoord : TEXCOORD0;
                UNITY_VERTEX_OUTPUT_STEREO
            };

            inline float4 UnityFlipSprite(in float3 pos, in fixed2 flip)
            {
                return float4(pos.xy * flip, pos.z, 1.0);
            }

            v2f SpriteVert(appdata_t IN)
            {
                v2f OUT;

                UNITY_SETUP_INSTANCE_ID (IN);
                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT);

                OUT.vertex = UnityFlipSprite(IN.vertex, _Flip);
                OUT.vertex = UnityObjectToClipPos(OUT.vertex);
                OUT.texcoord = IN.texcoord;
                OUT.color = IN.color * _Color * _RendererColor;

                #ifdef PIXELSNAP_ON
                OUT.vertex = UnityPixelSnap (OUT.vertex);
                #endif

                return OUT;
            }

            sampler2D _MainTex;
            sampler2D _AlphaTex;
            sampler2D _LightTex;
            float _Duration;
            float _Speed;
            float _Rotate;
        
            fixed4 SampleSpriteTexture (float2 uv)
            {
                fixed4 color = tex2D (_MainTex, uv);

                float r = radians(_Rotate);
                float2x2 rotate = float2x2(
                    cos(r), sin(r),
                    -sin(r), cos(r)
                );
                
                float2 offset = float2(1 - fmod(_Time.y * _Speed, _Duration * _Speed) * (2 / cos(r)), 0);
                offset = mul(rotate, offset);
                float2 lightUv = uv + offset;
                // 矩阵放在第一个参数要是行矩阵，乘的是列向量
                rotate[0][1] = -rotate[0][1];
                rotate[1][0] = -rotate[1][0];
                lightUv = mul(rotate, lightUv);
                
                fixed4 c = tex2D (_LightTex, lightUv);
                
                color.xyz *= c.xyz;

            #if ETC1_EXTERNAL_ALPHA
                fixed4 alpha = tex2D (_AlphaTex, uv);
                color.a = lerp (color.a, alpha.r, _EnableExternalAlpha);
            #endif

                return color;
            }

            fixed4 SpriteFrag(v2f IN) : SV_Target
            {
                fixed4 c = SampleSpriteTexture (IN.texcoord) * IN.color;
                c.rgb *= c.a;
                return c;
            }

            #endif // UNITY_SPRITES_INCLUDED
        ENDCG
        }
    }
}