You're breathtaking!

Source/Engine/Renderer/Utils/MultiScaler.h

@@ -0,0 +1,110 @@
+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#include "../RendererPass.h"
+#include "Engine/Graphics/GPUPipelineStatePermutations.h"
+
+/// <summary>
+/// Scales an input texture to an output texture (down or up, depending on the relative size between input and output). Can perform image blurring.
+/// </summary>
+class MultiScaler : public RendererPass<MultiScaler>
+{
+private:
+
+    PACK_STRUCT(struct Data {
+        Vector2 TexelSize;
+        Vector2 Padding;
+    });
+
+    AssetReference<Shader> _shader;
+    GPUPipelineState* _psHalfDepth;
+    GPUPipelineStatePermutationsPs<2> _psBlur5;
+    GPUPipelineStatePermutationsPs<2> _psBlur9;
+    GPUPipelineStatePermutationsPs<2> _psBlur13;
+
+public:
+
+    /// <summary>
+    /// Init
+    /// </summary>
+    MultiScaler();
+
+public:
+
+    /// <summary>
+    /// Filter mode
+    /// </summary>
+    enum class FilterMode
+    {
+        /// <summary>
+        /// Optimized 5-tap gaussian blur with linear sampling (3 texture fetches).
+        /// </summary>
+        GaussianBlur5 = 1,
+
+        /// <summary>
+        /// Optimized 9-tap gaussian blur with linear sampling (5 texture fetches).
+        /// </summary>
+        GaussianBlur9 = 2,
+
+        /// <summary>
+        /// Optimized 13-tap gaussian blur with linear sampling (7 texture fetches).
+        /// </summary>
+        GaussianBlur13 = 3,
+    };
+
+    /// <summary>
+    /// Performs texture filtering.
+    /// </summary>
+    /// <param name="mode">The filter mode.</param>
+    /// <param name="context">The context.</param>
+    /// <param name="width">The output width.</param>
+    /// <param name="height">The output height.</param>
+    /// <param name="src">The source texture.</param>
+    /// <param name="dst">The destination texture.</param>
+    /// <param name="tmp">The temporary texture (should have the same size as destination texture).</param>
+    void Filter(const FilterMode mode, GPUContext* context, const int32 width, const int32 height, GPUTextureView* src, GPUTextureView* dst, GPUTextureView* tmp);
+
+    /// <summary>
+    /// Performs texture filtering.
+    /// </summary>
+    /// <param name="mode">The filter mode.</param>
+    /// <param name="context">The context.</param>
+    /// <param name="width">The output width.</param>
+    /// <param name="height">The output height.</param>
+    /// <param name="srcDst">The source and destination texture.</param>
+    /// <param name="tmp">The temporary texture (should have the same size as destination texture).</param>
+    void Filter(const FilterMode mode, GPUContext* context, const int32 width, const int32 height, GPUTextureView* srcDst, GPUTextureView* tmp);
+
+    /// <summary>
+    /// Downscales the depth buffer (to half resolution).
+    /// </summary>
+    /// <param name="context">The context.</param>
+    /// <param name="dstWidth">The width of the destination texture (in pixels).</param>
+    /// <param name="dstHeight">The height of the destination texture (in pixels).</param>
+    /// <param name="src">The source texture.</param>
+    /// <param name="dst">The destination texture.</param>
+    void DownscaleDepth(GPUContext* context, int32 dstWidth, int32 dstHeight, GPUTextureView* src, GPUTextureView* dst);
+
+public:
+
+    // [RendererPass]
+    String ToString() const override;
+    bool Init() override;
+    void Dispose() override;
+#if COMPILE_WITH_DEV_ENV
+    void OnShaderReloading(Asset* obj)
+    {
+        _psHalfDepth->ReleaseGPU();
+        _psBlur5.Release();
+        _psBlur9.Release();
+        _psBlur13.Release();
+        invalidateResources();
+    }
+#endif
+
+protected:
+
+    // [RendererPass]
+    bool setupResources() override;
+};