[Feat] (MG_Backend/DirectVulkan): Buffer arena, buffer slice

2026-09-11 05:38:31 +09:00 · 2026-03-19 17:23:52 +08:00
parent 5e9f0f0c70
commit b6ac6c182e
8 changed files with 356 additions and 125 deletions
@@ -0,0 +1,138 @@
+// MobileGL - MobileGL/MG_Backend/DirectVulkan/Renderer/BufferArena.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#include "BufferArena.h"
+
+namespace MobileGL::MG_Backend::DirectVulkan {
+    Bool BufferArena::Initialize(const BufferArenaDesc& desc) {
+        Shutdown();
+
+        MOBILEGL_ASSERT(desc.allocator != nullptr, "BufferArena::Initialize requires valid allocator");
+        MOBILEGL_ASSERT(desc.frameCount > 0, "BufferArena::Initialize requires non-zero frame count");
+        MOBILEGL_ASSERT(desc.usage != 0, "BufferArena::Initialize requires non-zero buffer usage");
+
+        m_desc = desc;
+        m_frames.clear();
+        m_frames.resize(desc.frameCount);
+        m_deferredReleases.resize(desc.frameCount);
+        return true;
+    }
+
+    void BufferArena::Shutdown() {
+        for (auto& frame : m_frames) {
+            frame.buffer.Destroy();
+            frame.writeCursor = 0;
+        }
+        m_frames.clear();
+        m_deferredReleases.clear();
+        m_desc = {};
+    }
+
+    void BufferArena::BeginFrame(Uint32 frameIndex) {
+        CollectDeferredReleases(frameIndex);
+        ResetFrame(frameIndex);
+    }
+
+    void BufferArena::ResetFrame(Uint32 frameIndex) {
+        AssertValidFrameIndex(frameIndex);
+        m_frames[frameIndex].writeCursor = 0;
+    }
+
+    void BufferArena::CollectDeferredReleases(Uint32 frameIndex) {
+        AssertValidFrameIndex(frameIndex);
+        m_deferredReleases[frameIndex].clear();
+    }
+
+    Bool BufferArena::Allocate(Uint32 frameIndex, VkDeviceSize size, VkDeviceSize alignment, BufferSlice& outSlice) {
+        AssertValidFrameIndex(frameIndex);
+        MOBILEGL_ASSERT(size > 0, "BufferArena::Allocate requires non-zero size");
+
+        auto& frame = m_frames[frameIndex];
+        const VkDeviceSize resolvedAlignment = alignment > 0 ? alignment : 1;
+        const VkDeviceSize offset = (frame.writeCursor + resolvedAlignment - 1) & ~(resolvedAlignment - 1);
+        const VkDeviceSize endOffset = offset + size;
+
+        if (!EnsureCapacity(frameIndex, endOffset)) {
+            return false;
+        }
+
+        frame.writeCursor = endOffset;
+        outSlice = frame.buffer.GetSlice(offset, size);
+        return outSlice.IsValid();
+    }
+
+    Bool BufferArena::Upload(Uint32 frameIndex, const void* data, VkDeviceSize size, VkDeviceSize alignment,
+                             BufferSlice& outSlice) {
+        MOBILEGL_ASSERT(data != nullptr || size == 0, "BufferArena::Upload data pointer is null");
+        if (!Allocate(frameIndex, size, alignment, outSlice)) {
+            return false;
+        }
+
+        if (outSlice.mapped != nullptr) {
+            Memcpy(outSlice.mapped, data, static_cast<SizeT>(size));
+            return true;
+        }
+
+        return m_frames[frameIndex].buffer.Upload(data, size, outSlice.offset);
+    }
+
+    VkDeviceSize BufferArena::GetWriteCursor(Uint32 frameIndex) const {
+        AssertValidFrameIndex(frameIndex);
+        return m_frames[frameIndex].writeCursor;
+    }
+
+    Uint32 BufferArena::GetFrameCount() const {
+        return static_cast<Uint32>(m_frames.size());
+    }
+
+    Bool BufferArena::EnsureCapacity(Uint32 frameIndex, VkDeviceSize requiredEndOffset) {
+        AssertValidFrameIndex(frameIndex);
+        auto& frame = m_frames[frameIndex];
+        auto& buffer = frame.buffer;
+
+        if (buffer.IsValid() && buffer.GetSize() >= requiredEndOffset) {
+            return true;
+        }
+
+        VkDeviceSize newCapacity = buffer.IsValid() ? buffer.GetSize() : 0;
+        if (newCapacity < m_desc.minBufferSize) {
+            newCapacity = m_desc.minBufferSize;
+        }
+        if (newCapacity == 0) {
+            newCapacity = requiredEndOffset;
+        }
+        while (newCapacity < requiredEndOffset) {
+            newCapacity *= 2;
+        }
+
+        if (buffer.IsValid()) {
+            m_deferredReleases[frameIndex].push_back(std::move(buffer));
+        }
+
+        VkBufferObjectDesc bufferDesc{};
+        bufferDesc.allocator = m_desc.allocator;
+        bufferDesc.size = newCapacity;
+        bufferDesc.usage = m_desc.usage;
+        bufferDesc.memoryUsage = m_desc.memoryUsage;
+        bufferDesc.allocationFlags = m_desc.allocationFlags;
+        if (!buffer.Create(bufferDesc)) {
+            return false;
+        }
+        if (m_desc.persistentlyMapped && buffer.Map() == nullptr) {
+            buffer.Destroy();
+            return false;
+        }
+
+        frame.writeCursor = 0;
+        return true;
+    }
+
+    void BufferArena::AssertValidFrameIndex(Uint32 frameIndex) const {
+        MOBILEGL_ASSERT(frameIndex < m_frames.size(), "BufferArena frame index out of range");
+    }
+} // namespace MobileGL::MG_Backend::DirectVulkan