cBloom.fx

/*
    Dual-filtering Bloom

    MIT License

    Copyright (c) 2022 brimson

    Permission is hereby granted, free of charge, to any person obtaining a copy
    of this software and associated documentation files (the "Software"), to deal
    in the Software without restriction, including without limitation the rights
    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    copies of the Software, and to permit persons to whom the Software is
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE.
*/

uniform float _Threshold <
    ui_type = "drag";
    ui_min = 0.0;
    ui_label = "Threshold";
> = 0.8;

uniform float _Smooth <
    ui_type = "drag";
    ui_min = 0.0;
    ui_label = "Smoothing";
    ui_max = 1.0;
> = 0.5;

uniform float _Saturation <
    ui_type = "drag";
    ui_min = 0.0;
    ui_label = "Saturation";
> = 1.0;

uniform float3 _ColorShift <
    ui_type = "color";
    ui_min = 0.0;
    ui_label = "Color Shift";
> = 1.0;

uniform float _Intensity <
    ui_type = "drag";
    ui_min = 0.0;
    ui_label = "Color Intensity";
> = 1.0;

texture2D _RenderColor : COLOR;

sampler2D _SampleColor
{
    Texture = _RenderColor;
    #if BUFFER_COLOR_BIT_DEPTH == 8
        SRGBTexture = TRUE;
    #endif
};

texture2D _RenderBloom1
{
    Width = BUFFER_WIDTH / 2;
    Height = BUFFER_HEIGHT / 2;
    Format = RGBA16F;
};

sampler2D _SampleBloom1
{
    Texture = _RenderBloom1;
};

texture2D _RenderBloom2
{
    Width = BUFFER_WIDTH / 4;
    Height = BUFFER_HEIGHT / 4;
    Format = RGBA16F;
};

sampler2D _SampleBloom2
{
    Texture = _RenderBloom2;
};

texture2D _RenderBloom3
{
    Width = BUFFER_WIDTH / 8;
    Height = BUFFER_HEIGHT / 8;
    Format = RGBA16F;
};

sampler2D _SampleBloom3
{
    Texture = _RenderBloom3;
};

texture2D _RenderBloom4
{
    Width = BUFFER_WIDTH / 16;
    Height = BUFFER_HEIGHT / 16;
    Format = RGBA16F;
};

sampler2D _SampleBloom4
{
    Texture = _RenderBloom4;
};

texture2D _RenderBloom5
{
    Width = BUFFER_WIDTH / 32;
    Height = BUFFER_HEIGHT / 32;
    Format = RGBA16F;
};

sampler2D _SampleBloom5
{
    Texture = _RenderBloom5;
};

texture2D _RenderBloom6
{
    Width = BUFFER_WIDTH / 64;
    Height = BUFFER_HEIGHT / 64;
    Format = RGBA16F;
};

sampler2D _SampleBloom6
{
    Texture = _RenderBloom6;
};

texture2D _RenderBloom7
{
    Width = BUFFER_WIDTH / 128;
    Height = BUFFER_HEIGHT / 128;
    Format = RGBA16F;
};

sampler2D _SampleBloom7
{
    Texture = _RenderBloom7;
};

texture2D _RenderBloom8
{
    Width = BUFFER_WIDTH / 256;
    Height = BUFFER_HEIGHT / 256;
    Format = RGBA16F;
};

sampler2D _SampleBloom8
{
    Texture = _RenderBloom8;
};

// Vertex shaders
// Sampling kernels: http://www.iryoku.com/next-generation-post-processing-in-call-of-duty-advanced-warfare

void PostProcessVS(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float2 TexCoord : TEXCOORD0)
{
    TexCoord.x = (ID == 2) ? 2.0 : 0.0;
    TexCoord.y = (ID == 1) ? 2.0 : 0.0;
    Position = float4(TexCoord * float2(2.0, -2.0) + float2(-1.0, 1.0), 0.0, 1.0);
}

void DownsampleVS(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[4] : TEXCOORD0, float Factor)
{
    float2 TexCoord0;
    PostProcessVS(ID, Position, TexCoord0);
    const float2 pSize = 1.0 / ldexp(float2(BUFFER_WIDTH, BUFFER_HEIGHT), -Factor);
    // Quadrant
    TexCoord[0] = TexCoord0.xyxy + float4(-1.0, -1.0, 1.0, 1.0) * pSize.xyxy;
    // Left column
    TexCoord[1] = TexCoord0.xyyy + float4(-2.0, 2.0, 0.0, -2.0) * pSize.xyyy;
    // Center column
    TexCoord[2] = TexCoord0.xyyy + float4(0.0, 2.0, 0.0, -2.0) * pSize.xyyy;
    // Right column
    TexCoord[3] = TexCoord0.xyyy + float4(2.0, 2.0, 0.0, -2.0) * pSize.xyyy;
}

void UpsampleVS(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[3] : TEXCOORD0, float Factor)
{
    float2 TexCoord0;
    PostProcessVS(ID, Position, TexCoord0);
    const float2 pSize = 1.0 / ldexp(float2(BUFFER_WIDTH, BUFFER_HEIGHT), -Factor);
    // Left column
    TexCoord[0] = TexCoord0.xyyy + float4(-1.0, 1.0, 0.0, -1.0) * pSize.xyyy;
    // Center column
    TexCoord[1] = TexCoord0.xyyy + float4(0.0, 1.0, 0.0, -1.0) * pSize.xyyy;
    // Right column
    TexCoord[2] = TexCoord0.xyyy + float4(1.0, 1.0, 0.0, -1.0) * pSize.xyyy;
}

void DownsampleVS1(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[4] : TEXCOORD0)
{
    DownsampleVS(ID, Position, TexCoord, 1.0);
}

void DownsampleVS2(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[4] : TEXCOORD0)
{
    DownsampleVS(ID, Position, TexCoord, 2.0);
}

void DownsampleVS3(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[4] : TEXCOORD0)
{
    DownsampleVS(ID, Position, TexCoord, 3.0);
}

void DownsampleVS4(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[4] : TEXCOORD0)
{
    DownsampleVS(ID, Position, TexCoord, 4.0);
}

void DownsampleVS5(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[4] : TEXCOORD0)
{
    DownsampleVS(ID, Position, TexCoord, 5.0);
}

void DownsampleVS6(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[4] : TEXCOORD0)
{
    DownsampleVS(ID, Position, TexCoord, 6.0);
}

void DownsampleVS7(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[4] : TEXCOORD0)
{
    DownsampleVS(ID, Position, TexCoord, 7.0);
}

void UpsampleVS8(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[3] : TEXCOORD0)
{
    UpsampleVS(ID, Position, TexCoord, 8.0);
}

void UpsampleVS7(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[3] : TEXCOORD0)
{
    UpsampleVS(ID, Position, TexCoord, 7.0);
}

void UpsampleVS6(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[3] : TEXCOORD0)
{
    UpsampleVS(ID, Position, TexCoord, 6.0);
}

void UpsampleVS5(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[3] : TEXCOORD0)
{
    UpsampleVS(ID, Position, TexCoord, 5.0);
}

void UpsampleVS4(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[3] : TEXCOORD0)
{
    UpsampleVS(ID, Position, TexCoord, 4.0);
}

void UpsampleVS3(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[3] : TEXCOORD0)
{
    UpsampleVS(ID, Position, TexCoord, 3.0);
}

void UpsampleVS2(in uint ID : SV_VertexID, out float4 Position : SV_Position, out float4 TexCoord[3] : TEXCOORD0)
{
    UpsampleVS(ID, Position, TexCoord, 2.0);
}

// Pixel shaders
// Thresholding: https://github.com/keijiro/Kino [MIT]
// Tonemapping: https://github.com/TheRealMJP/BakingLab [MIT]

float4 DownsamplePS(sampler2D Source, float4 TexCoord[4])
{
    // A0    B0    C0
    //    D0    D1
    // A1    B1    C1
    //    D2    D3
    // A2    B2    C2

    float4 D0 = tex2D(Source, TexCoord[0].xw);
    float4 D1 = tex2D(Source, TexCoord[0].zw);
    float4 D2 = tex2D(Source, TexCoord[0].xy);
    float4 D3 = tex2D(Source, TexCoord[0].zy);

    float4 A0 = tex2D(Source, TexCoord[1].xy);
    float4 A1 = tex2D(Source, TexCoord[1].xz);
    float4 A2 = tex2D(Source, TexCoord[1].xw);

    float4 B0 = tex2D(Source, TexCoord[2].xy);
    float4 B1 = tex2D(Source, TexCoord[2].xz);
    float4 B2 = tex2D(Source, TexCoord[2].xw);

    float4 C0 = tex2D(Source, TexCoord[3].xy);
    float4 C1 = tex2D(Source, TexCoord[3].xz);
    float4 C2 = tex2D(Source, TexCoord[3].xw);

    float4 Output;
    const float2 Weights = float2(0.5, 0.125) / 4.0;
    Output += (D0 + D1 + D2 + D3) * Weights.x;
    Output += (A0 + B0 + A1 + B1) * Weights.y;
    Output += (B0 + C0 + B1 + C1) * Weights.y;
    Output += (A1 + B1 + A2 + B2) * Weights.y;
    Output += (B1 + C1 + B2 + C2) * Weights.y;
    return Output;
}

float4 UpsamplePS(sampler2D Source, float4 TexCoord[3])
{
    // A0 B0 C0
    // A1 B1 C1
    // A2 B2 C2

    float4 A0 = tex2D(Source, TexCoord[0].xy);
    float4 A1 = tex2D(Source, TexCoord[0].xz);
    float4 A2 = tex2D(Source, TexCoord[0].xw);

    float4 B0 = tex2D(Source, TexCoord[1].xy);
    float4 B1 = tex2D(Source, TexCoord[1].xz);
    float4 B2 = tex2D(Source, TexCoord[1].xw);

    float4 C0 = tex2D(Source, TexCoord[2].xy);
    float4 C1 = tex2D(Source, TexCoord[2].xz);
    float4 C2 = tex2D(Source, TexCoord[2].xw);

    float4 Output;
    Output  = (A0 + C0 + A2 + C2) * 1.0;
    Output += (A1 + B0 + C1 + B2) * 2.0;
    Output += B1 * 4.0;
    return Output / 16.0;
}

float Med3(float x, float y, float z)
{
    return max(min(x, y), min(max(x, y), z));
}

void PrefilterPS(in float4 Position : SV_Position, in float2 TexCoord : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    const float Knee = mad(_Threshold, _Smooth, 1e-5f);
    const float3 Curve = float3(_Threshold - Knee, Knee * 2.0, 0.25 / Knee);
    float4 Color = tex2D(_SampleColor, TexCoord);

    // Under-threshold
    float Brightness = Med3(Color.r, Color.g, Color.b);
    float ResponseCurve = clamp(Brightness - Curve.x, 0.0, Curve.y);
    ResponseCurve = Curve.z * ResponseCurve * ResponseCurve;

    // Combine and apply the brightness response curve
    Color = Color * max(ResponseCurve, Brightness - _Threshold) / max(Brightness, 1e-10);
    Brightness = Med3(Color.r, Color.g, Color.b);
    OutputColor0 = saturate(lerp(Brightness, Color.rgb, _Saturation)) * _ColorShift;

    // Set alpha to 1.0 so we can see the complete results in ReShade's statistics
    OutputColor0.a = 1.0;
}

// sRGB => XYZ => D65_2_D60 => AP1 => RRT_SAT
static const float3x3 ACESInputMat = float3x3(
    0.59719, 0.35458, 0.04823,
    0.07600, 0.90834, 0.01566,
    0.02840, 0.13383, 0.83777
);

// ODT_SAT => XYZ => D60_2_D65 => sRGB
static const float3x3 ACESOutputMat = float3x3(
     1.60475, -0.53108, -0.07367,
    -0.10208,  1.10813, -0.00605,
    -0.00327, -0.07276,  1.07602
);

float3 RRTAndODTFit(float3 v)
{
    float3 a = v * (v + 0.0245786f) - 0.000090537f;
    float3 b = v * (0.983729f * v + 0.4329510f) + 0.238081f;
    return a / b;
}

void DownsamplePS1(in float4 Position : SV_Position, in float4 TexCoord[4] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = DownsamplePS(_SampleBloom1, TexCoord);
}

void DownsamplePS2(in float4 Position : SV_Position, in float4 TexCoord[4] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = DownsamplePS(_SampleBloom2, TexCoord);
}

void DownsamplePS3(in float4 Position : SV_Position, in float4 TexCoord[4] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = DownsamplePS(_SampleBloom3, TexCoord);
}

void DownsamplePS4(in float4 Position : SV_Position, in float4 TexCoord[4] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = DownsamplePS(_SampleBloom4, TexCoord);
}

void DownsamplePS5(in float4 Position : SV_Position, in float4 TexCoord[4] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = DownsamplePS(_SampleBloom5, TexCoord);
}

void DownsamplePS6(in float4 Position : SV_Position, in float4 TexCoord[4] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = DownsamplePS(_SampleBloom6, TexCoord);
}

void DownsamplePS7(in float4 Position : SV_Position, in float4 TexCoord[4] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = DownsamplePS(_SampleBloom7, TexCoord);
}

void UpsamplePS8(in float4 Position : SV_Position, in float4 TexCoord[3] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = UpsamplePS(_SampleBloom8, TexCoord);
}

void UpsamplePS7(in float4 Position : SV_Position, in float4 TexCoord[3] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = UpsamplePS(_SampleBloom7, TexCoord);
}

void UpsamplePS6(in float4 Position : SV_Position, in float4 TexCoord[3] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = UpsamplePS(_SampleBloom6, TexCoord);
}

void UpsamplePS5(in float4 Position : SV_Position, in float4 TexCoord[3] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = UpsamplePS(_SampleBloom5, TexCoord);
}

void UpsamplePS4(in float4 Position : SV_Position, in float4 TexCoord[3] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = UpsamplePS(_SampleBloom4, TexCoord);
}

void UpsamplePS3(in float4 Position : SV_Position, in float4 TexCoord[3] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = UpsamplePS(_SampleBloom3, TexCoord);
}

void UpsamplePS2(in float4 Position : SV_Position, in float4 TexCoord[3] : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    OutputColor0 = UpsamplePS(_SampleBloom2, TexCoord);
}

void CompositePS(in float4 Position : SV_Position, in float2 TexCoord : TEXCOORD0, out float4 OutputColor0 : SV_Target0)
{
    float4 Src = tex2D(_SampleBloom1, TexCoord);
    Src *= _Intensity;
    Src = mul(ACESInputMat, Src.rgb);
    Src = RRTAndODTFit(Src.rgb);
    Src = saturate(mul(ACESOutputMat, Src.rgb));
    OutputColor0 = Src;
}

/* [ TECHNIQUE ] */

technique cBloom
{
    pass
    {
        VertexShader = PostProcessVS;
        PixelShader = PrefilterPS;
        RenderTarget0 = _RenderBloom1;
    }

    pass
    {
        VertexShader = DownsampleVS1;
        PixelShader = DownsamplePS1;
        RenderTarget0 = _RenderBloom2;
    }

    pass
    {
        VertexShader = DownsampleVS2;
        PixelShader = DownsamplePS2;
        RenderTarget0 = _RenderBloom3;
    }

    pass
    {
        VertexShader = DownsampleVS3;
        PixelShader = DownsamplePS3;
        RenderTarget0 = _RenderBloom4;
    }

    pass
    {
        VertexShader = DownsampleVS4;
        PixelShader = DownsamplePS4;
        RenderTarget0 = _RenderBloom5;
    }

    pass
    {
        VertexShader = DownsampleVS5;
        PixelShader = DownsamplePS5;
        RenderTarget0 = _RenderBloom6;
    }

    pass
    {
        VertexShader = DownsampleVS6;
        PixelShader = DownsamplePS6;
        RenderTarget0 = _RenderBloom7;
    }

    pass
    {
        VertexShader = DownsampleVS7;
        PixelShader = DownsamplePS7;
        RenderTarget0 = _RenderBloom8;
    }

    pass
    {
        VertexShader = UpsampleVS8;
        PixelShader = UpsamplePS8;
        RenderTarget0 = _RenderBloom7;
        ClearRenderTargets = FALSE;
        BlendEnable = TRUE;
        BlendOp = ADD;
        SrcBlend = ONE;
        DestBlend = ONE;
    }

    pass
    {
        VertexShader = UpsampleVS7;
        PixelShader = UpsamplePS7;
        RenderTarget0 = _RenderBloom6;
        ClearRenderTargets = FALSE;
        BlendEnable = TRUE;
        BlendOp = ADD;
        SrcBlend = ONE;
        DestBlend = ONE;
    }

    pass
    {
        VertexShader = UpsampleVS6;
        PixelShader = UpsamplePS6;
        RenderTarget0 = _RenderBloom5;
        ClearRenderTargets = FALSE;
        BlendEnable = TRUE;
        BlendOp = ADD;
        SrcBlend = ONE;
        DestBlend = ONE;
    }

    pass
    {
        VertexShader = UpsampleVS5;
        PixelShader = UpsamplePS5;
        RenderTarget0 = _RenderBloom4;
        ClearRenderTargets = FALSE;
        BlendEnable = TRUE;
        BlendOp = ADD;
        SrcBlend = ONE;
        DestBlend = ONE;
    }

    pass
    {
        VertexShader = UpsampleVS4;
        PixelShader = UpsamplePS4;
        RenderTarget0 = _RenderBloom3;
        ClearRenderTargets = FALSE;
        BlendEnable = TRUE;
        BlendOp = ADD;
        SrcBlend = ONE;
        DestBlend = ONE;
    }

    pass
    {
        VertexShader = UpsampleVS3;
        PixelShader = UpsamplePS3;
        RenderTarget0 = _RenderBloom2;
        ClearRenderTargets = FALSE;
        BlendEnable = TRUE;
        BlendOp = ADD;
        SrcBlend = ONE;
        DestBlend = ONE;
    }

    pass
    {
        VertexShader = UpsampleVS2;
        PixelShader = UpsamplePS2;
        RenderTarget0 = _RenderBloom1;
        ClearRenderTargets = FALSE;
        BlendEnable = FALSE;
    }

    pass
    {
        VertexShader = PostProcessVS;
        PixelShader = CompositePS;
        ClearRenderTargets = FALSE;
        BlendEnable = TRUE;
        BlendOp = ADD;
        SrcBlend = ONE;
        DestBlend = INVSRCCOLOR;
        #if BUFFER_COLOR_BIT_DEPTH == 8
            SRGBWriteEnable = TRUE;
        #endif
    }
}