Shader "BlendModes/Extra/UIOverlay"
{
    Properties
    {
        [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _OverlayTex1("Overlay Texture 1", 2D) = "white" {}
        _OverlayTex2("Overlay Texture 2", 2D) = "white" {}
        _OverlayTex3("Overlay Texture 3", 2D) = "white" {}
        _OverlayTex4("Overlay Texture 4", 2D) = "white" {}
        _OverlayTex5("Overlay Texture 5", 2D) = "white" {}
        _OverlayColor1("Overlay Color 1", Color) = (1,1,1,0)
        _OverlayColor2("Overlay Color 2", Color) = (1,1,1,0)
        _OverlayColor3("Overlay Color 3", Color) = (1,1,1,0)
        _OverlayColor4("Overlay Color 4", Color) = (1,1,1,0)
        _OverlayColor5("Overlay Color 5", Color) = (1,1,1,0)
        _Color ("Tint", Color) = (1,1,1,1)
    }

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

        Cull Off
        Lighting Off
        ZWrite Off
        ZTest [unity_GUIZTestMode]
        Fog { Mode Off }
        Blend SrcAlpha OneMinusSrcAlpha

        Pass
        {
            CGPROGRAM

            #include "UnityCG.cginc"
            #include "../BlendModes.cginc"

            #pragma target 3.0
            #pragma multi_compile BmDarken BmMultiply BmColorBurn BmLinearBurn BmDarkerColor BmLighten BmScreen BmColorDodge BmLinearDodge BmLighterColor BmOverlay BmSoftLight BmHardLight BmVividLight BmLinearLight BmPinLight BmHardMix BmDifference BmExclusion BmSubtract BmDivide BmHue BmSaturation BmColor BmLuminosity
            #pragma vertex ComputeVertex
            #pragma fragment ComputeFragment

            sampler2D _MainTex;
            sampler2D _MainTex_ST;
            fixed4 _Color;
            sampler2D _OverlayTex1, _OverlayTex2, _OverlayTex3, _OverlayTex4, _OverlayTex5;
            fixed4 _OverlayColor1, _OverlayColor2, _OverlayColor3, _OverlayColor4, _OverlayColor5;

            struct VertexInput
            {
                float4 Vertex : POSITION;
                fixed4 Color : COLOR;
                float2 TexCoord : TEXCOORD;
            };

            struct VertexOutput
            {
                float4 Vertex : SV_POSITION;
                fixed4 Color : COLOR;
                float2 TexCoord : TEXCOORD;
            };

            VertexOutput ComputeVertex (VertexInput vertexInput)
            {
                VertexOutput vertexOutput;

                vertexOutput.Vertex = ObjectToClipPos(vertexInput.Vertex);
                vertexOutput.TexCoord = vertexInput.TexCoord;
                #ifdef UNITY_HALF_TEXEL_OFFSET
                vertexOutput.Vertex.xy += (_ScreenParams.zw - 1.0) * float2(-1.0, 1.0);
                #endif
                vertexOutput.Color = vertexInput.Color * _Color;

                return vertexOutput;
            }

            fixed4 ComputeFragment (VertexOutput vertexOutput) : SV_Target
            {
                fixed4 texColor = tex2D(_MainTex, vertexOutput.TexCoord) * vertexOutput.Color;
                clip(texColor.a - .01);

                fixed4 grabColor;
                fixed4 blendResult;

                grabColor = tex2D(_OverlayTex1, vertexOutput.TexCoord) * _OverlayColor1;
                blendResult = ColorDodge(grabColor, texColor);
                texColor = lerp(texColor, blendResult, grabColor.a);
                texColor = saturate(texColor);

                grabColor = tex2D(_OverlayTex2, vertexOutput.TexCoord) * _OverlayColor2;
                blendResult = ColorDodge(grabColor, texColor);
                texColor = lerp(texColor, blendResult, grabColor.a);
                texColor = saturate(texColor);

                grabColor = tex2D(_OverlayTex3, vertexOutput.TexCoord) * _OverlayColor3;
                blendResult = LinearBurn(grabColor, texColor);
                texColor = lerp(texColor, blendResult, grabColor.a);

                //grabColor = tex2D(_OverlayTex4, vertexOutput.TexCoord) * _OverlayColor4;
                //blendResult = ColorDodge(grabColor, texColor);
                //texColor = lerp(texColor, blendResult, grabColor.a);

                //grabColor = tex2D(_OverlayTex5, vertexOutput.TexCoord) * _OverlayColor5;
                //blendResult = ColorDodge(grabColor, texColor);
                //texColor = lerp(texColor, blendResult, grabColor.a);

                return texColor;
            }

            ENDCG
        }
    }

    Fallback "UI/Default"
}