シャドウ uniform バッファを毎フレーム更新して影ズレを修正

src/Seed.Engine.App/Program.cs

@@ -1176,7 +1176,7 @@ private static void Main()
                 gBufferPipeline, lightingPipeline, lightingDescriptorSet,
                 resources,
                 imageAvailableSemaphore, renderFinishedSemaphore, inFlightFence,
-                shadowMap, shadowPipeline,
+                shadowMap, shadowPipeline, shadowBuffer,
                 pointLightPipeline, pointLightDescriptorSet, sphereMeshId,
                 spotLightPipeline, spotLightDescriptorSet, coneMeshId));
 

src/Seed.Engine.Tests/Platform/Xr/BoundarySystemTests.cs

@@ -454,6 +454,7 @@ public StubBuffer(BufferUsage usage, ulong size)
 
         public BufferUsage Usage { get; }
         public ulong SizeInBytes { get; }
+        public void Update(ReadOnlySpan<byte> data) { }
         public void Dispose() { }
     }
 

src/Seed.Engine.Tests/Rendering/PipelineSelectionTests.cs

@@ -1,3 +1,4 @@
+using System;
 using Xunit;
 
 using Seed.Engine.Ecs;
@@ -364,6 +365,7 @@ public StubBuffer(BufferUsage usage, ulong size)
 
         public BufferUsage Usage { get; }
         public ulong SizeInBytes { get; }
+        public void Update(ReadOnlySpan<byte> data) { }
         public void Dispose() { }
     }
 }

src/Seed.Engine.Tests/Rendering/StereoDeferredRenderSystemExecuteTests.cs

@@ -142,6 +142,8 @@ private static StereoDeferredRenderSystem CreateSystem(
             null,
             null,
             null,
+            null,
+            null,
             -1,
             null,
             null,
@@ -393,6 +395,7 @@ public StubBuffer(BufferUsage usage, ulong size)
 
         public BufferUsage Usage { get; }
         public ulong SizeInBytes { get; }
+        public void Update(ReadOnlySpan<byte> data) { }
         public void Dispose() { }
     }
 

src/Seed.Engine.Tests/Rendering/StereoForwardPlusRenderSystemTests.cs

@@ -550,6 +550,7 @@ public StubBuffer(BufferUsage usage, ulong size)
 
         public BufferUsage Usage { get; }
         public ulong SizeInBytes { get; }
+        public void Update(ReadOnlySpan<byte> data) { }
         public void Dispose() { }
     }
 

src/Seed.Engine/Graphics/IBuffer.cs

@@ -16,4 +16,10 @@ public interface IBuffer : IDisposable
     /// Gets the size in bytes of this buffer.
     /// </summary>
     ulong SizeInBytes { get; }
+
+    /// <summary>
+    /// Updates the buffer contents with new data.
+    /// The buffer must have been created with host-visible memory.
+    /// </summary>
+    void Update(ReadOnlySpan<byte> data);
 }

src/Seed.Engine/Graphics/Vulkan/VulkanBuffer.cs

@@ -125,6 +125,29 @@ private Result CreateBuffer(ReadOnlySpan<byte> data)
         }
     }
 
+    /// <inheritdoc />
+    public void Update(ReadOnlySpan<byte> data)
+    {
+        unsafe
+        {
+            void* mappedData;
+            VkResult result = VulkanNative.vkMapMemory(
+                _vulkanDevice.Device, _memory, 0, SizeInBytes, 0, &mappedData);
+            if (result != VkResult.VK_SUCCESS)
+            {
+                return;
+            }
+
+            fixed (byte* pData = data)
+            {
+                System.Runtime.InteropServices.NativeMemory.Copy(
+                    pData, mappedData, (nuint)data.Length);
+            }
+
+            VulkanNative.vkUnmapMemory(_vulkanDevice.Device, _memory);
+        }
+    }
+
     /// <inheritdoc />
     public void Dispose()
     {

src/Seed.Engine/Rendering/DeferredRenderSystem.cs

@@ -29,6 +29,7 @@ public sealed class DeferredRenderSystem : ISystem
 
     private readonly IRenderTarget? _shadowMap;
     private readonly IPipeline? _shadowPipeline;
+    private readonly IBuffer? _shadowBuffer;
 
     private readonly IPipeline? _pointLightPipeline;
     private readonly IDescriptorSet? _pointLightDescriptorSet;
@@ -62,6 +63,7 @@ public DeferredRenderSystem(
         IntPtr inFlightFence,
         IRenderTarget? shadowMap = null,
         IPipeline? shadowPipeline = null,
+        IBuffer? shadowBuffer = null,
         IPipeline? pointLightPipeline = null,
         IDescriptorSet? pointLightDescriptorSet = null,
         int sphereMeshId = -1,
@@ -82,6 +84,7 @@ public DeferredRenderSystem(
         _inFlightFence = inFlightFence;
         _shadowMap = shadowMap;
         _shadowPipeline = shadowPipeline;
+        _shadowBuffer = shadowBuffer;
         _pointLightPipeline = pointLightPipeline;
         _pointLightDescriptorSet = pointLightDescriptorSet;
         _sphereMeshId = sphereMeshId;
@@ -154,6 +157,19 @@ public void Execute(World world)
             Matrix4x4 lightSpaceVP = ComputeLightSpaceVP(world);
             ExecuteShadowPass(world, lightSpaceVP);
             _commandBuffer.PipelineBarrier();
+
+            if (_shadowBuffer != null)
+            {
+                var invertResult = viewProjection.Invert();
+                Matrix4x4 inverseVP = invertResult.IsSuccess
+                    ? invertResult.Value
+                    : Matrix4x4.Identity;
+
+                Span<byte> shadowData = stackalloc byte[128];
+                MemoryMarshal.Write(shadowData, in lightSpaceVP);
+                MemoryMarshal.Write(shadowData.Slice(64), in inverseVP);
+                _shadowBuffer.Update(shadowData);
+            }
         }
 
         ExecuteGBufferPass(world, viewProjection);

src/Seed.Engine/Rendering/StereoDeferredRenderSystem.cs

@@ -33,6 +33,8 @@ public sealed class StereoDeferredRenderSystem : ISystem
 
     private readonly IRenderTarget? _shadowMap;
     private readonly IPipeline? _shadowPipeline;
+    private readonly IBuffer? _leftShadowBuffer;
+    private readonly IBuffer? _rightShadowBuffer;
 
     private readonly IPipeline? _pointLightPipeline;
     private readonly IDescriptorSet? _leftPointLightDescriptorSet;
@@ -76,6 +78,8 @@ public StereoDeferredRenderSystem(
         float farPlane,
         IRenderTarget? shadowMap,
         IPipeline? shadowPipeline,
+        IBuffer? leftShadowBuffer,
+        IBuffer? rightShadowBuffer,
         IPipeline? pointLightPipeline,
         IDescriptorSet? leftPointLightDescriptorSet,
         IDescriptorSet? rightPointLightDescriptorSet,
@@ -103,6 +107,8 @@ public StereoDeferredRenderSystem(
         _farPlane = farPlane;
         _shadowMap = shadowMap;
         _shadowPipeline = shadowPipeline;
+        _leftShadowBuffer = leftShadowBuffer;
+        _rightShadowBuffer = rightShadowBuffer;
         _pointLightPipeline = pointLightPipeline;
         _leftPointLightDescriptorSet = leftPointLightDescriptorSet;
         _rightPointLightDescriptorSet = rightPointLightDescriptorSet;
@@ -208,9 +214,10 @@ public void Execute(World world)
         }
 
         // Shadow pass is view-independent, execute once
+        Matrix4x4 lightSpaceVP = Matrix4x4.Identity;
         if (_shadowMap != null && _shadowPipeline != null)
         {
-            Matrix4x4 lightSpaceVP = ComputeLightSpaceVP(world);
+            lightSpaceVP = ComputeLightSpaceVP(world);
             ExecuteShadowPass(world, lightSpaceVP);
             _commandBuffer.PipelineBarrier();
         }
@@ -219,6 +226,7 @@ public void Execute(World world)
         var leftAcquire = _leftSwapChain.AcquireNextImage(IntPtr.Zero);
         if (leftAcquire.IsSuccess)
         {
+            UpdateShadowBuffer(_leftShadowBuffer, lightSpaceVP, leftVP);
             ExecuteGBufferPass(world, leftVP, _leftGBuffer);
             _commandBuffer.PipelineBarrier();
             ExecuteLightingPass(
@@ -232,6 +240,7 @@ public void Execute(World world)
         var rightAcquire = _rightSwapChain.AcquireNextImage(IntPtr.Zero);
         if (rightAcquire.IsSuccess)
         {
+            UpdateShadowBuffer(_rightShadowBuffer, lightSpaceVP, rightVP);
             ExecuteGBufferPass(world, rightVP, _rightGBuffer);
             _commandBuffer.PipelineBarrier();
             ExecuteLightingPass(
@@ -598,4 +607,23 @@ private Matrix4x4 ComputeLightSpaceVP(World world)
 
         return Matrix4x4.Identity;
     }
+
+    private static void UpdateShadowBuffer(
+        IBuffer? shadowBuffer, Matrix4x4 lightSpaceVP, Matrix4x4 viewProjection)
+    {
+        if (shadowBuffer == null)
+        {
+            return;
+        }
+
+        var invertResult = viewProjection.Invert();
+        Matrix4x4 inverseVP = invertResult.IsSuccess
+            ? invertResult.Value
+            : Matrix4x4.Identity;
+
+        Span<byte> data = stackalloc byte[128];
+        MemoryMarshal.Write(data, in lightSpaceVP);
+        MemoryMarshal.Write(data.Slice(64), in inverseVP);
+        shadowBuffer.Update(data);
+    }
 }