Update uniform sub-buffers to the latest data before using

maplibre · Dec 16, 2024 · fd10156 · fd10156
1 parent c6f08c6
commit fd10156
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Showing 3 changed files with 83 additions and 19 deletions.
diff --git a/include/mbgl/vulkan/buffer_resource.hpp b/include/mbgl/vulkan/buffer_resource.hpp
@@ -51,14 +51,18 @@ class BufferResource {
     void update(const void* data, std::size_t size, std::size_t offset) noexcept;
 
     std::size_t getSizeInBytes() const noexcept { return size; }
-    const void* contents() const noexcept { return (raw.empty() ? nullptr : raw.data()); }
+    const void* contents() const noexcept;
+    const void* contents(uint8_t resourceIndex) const noexcept;
 
     Context& getContext() const noexcept { return context; }
     const vk::Buffer& getVulkanBuffer() const noexcept { return bufferAllocation->buffer; }
     std::size_t getVulkanBufferOffset() const noexcept;
-    std::size_t getVulkanBufferSize() const noexcept;
+    std::size_t getVulkanBufferOffset(uint8_t resourceIndex) const noexcept;
+    // update the current sub-buffer with the latest data
+    void updateVulkanBuffer();
+    void updateVulkanBuffer(const int8_t destination, const uint8_t source);
 
-    bool isValid() const noexcept { return !raw.empty(); }
+    bool isValid() const noexcept { return !!bufferAllocation; }
     operator bool() const noexcept { return isValid(); }
     bool operator!() const noexcept { return !isValid(); }
 
@@ -69,14 +73,14 @@ class BufferResource {
 
 protected:
     Context& context;
-    std::vector<std::uint8_t> raw;
     std::size_t size;
     std::uint32_t usage;
-    std::uint16_t version = 0;
+    VersionType version = 0;
     bool persistent;
 
     SharedBufferAllocation bufferAllocation;
     size_t bufferWindowSize = 0;
+    std::vector<VersionType> bufferWindowVersions;
 };
 
 } // namespace vulkan

diff --git a/src/mbgl/vulkan/buffer_resource.cpp b/src/mbgl/vulkan/buffer_resource.cpp
@@ -64,7 +64,10 @@ BufferResource::BufferResource(
 
         assert(bufferWindowSize != 0);
 
-        totalSize = bufferWindowSize * backend.getMaxFrames();
+        const auto frameCount = backend.getMaxFrames();
+        totalSize = bufferWindowSize * frameCount;
+
+        bufferWindowVersions = std::vector<std::uint16_t>(frameCount, 0);
     }
 
     const auto bufferInfo = vk::BufferCreateInfo()
@@ -87,9 +90,7 @@ BufferResource::BufferResource(
     vmaMapMemory(allocator, bufferAllocation->allocation, &bufferAllocation->mappedBuffer);
 
     if (data) {
-        raw.resize(size);
-        std::memcpy(raw.data(), data, size);
-        std::memcpy(static_cast<uint8_t*>(bufferAllocation->mappedBuffer) + getVulkanBufferOffset(), data, size);
+        update(data, size, 0);
     }
 
     if (isValid()) {
@@ -104,12 +105,13 @@ BufferResource::BufferResource(
 
 BufferResource::BufferResource(BufferResource&& other) noexcept
     : context(other.context),
-      raw(std::move(other.raw)),
       size(other.size),
       usage(other.usage),
       persistent(other.persistent),
       bufferAllocation(std::move(other.bufferAllocation)),
-      bufferWindowSize(other.bufferWindowSize) {
+      bufferWindowSize(other.bufferWindowSize),
+      version(other.version),
+      bufferWindowVersions(std::move(other.bufferWindowVersions)) {
     other.bufferAllocation = nullptr;
 }
 
@@ -134,7 +136,7 @@ BufferResource& BufferResource::operator=(BufferResource&& other) noexcept {
         context.renderingStats().numBuffers--;
         context.renderingStats().memBuffers -= size;
     };
-    raw = std::move(other.raw);
+
     size = other.size;
     usage = other.usage;
     persistent = other.persistent;
@@ -152,21 +154,63 @@ void BufferResource::update(const void* newData, std::size_t updateSize, std::si
         return;
     }
 
-    auto& stats = context.renderingStats();
+    uint8_t* data = static_cast<uint8_t*>(bufferAllocation->mappedBuffer) + getVulkanBufferOffset() + offset;
+    std::memcpy(data, newData, updateSize);
 
-    std::memcpy(raw.data() + offset, newData, updateSize);
-    std::memcpy(
-        static_cast<uint8_t*>(bufferAllocation->mappedBuffer) + getVulkanBufferOffset() + offset, newData, updateSize);
+    auto& stats = context.renderingStats();
     stats.bufferUpdateBytes += updateSize;
-
     stats.bufferUpdates++;
     version++;
+
+    if (bufferWindowSize) {
+        const auto frameIndex = context.getCurrentFrameResourceIndex();
+        bufferWindowVersions[frameIndex] = version;
+    }
+}
+
+const void* BufferResource::contents() const noexcept {
+    return contents(context.getCurrentFrameResourceIndex());
+}
+
+const void* BufferResource::contents(uint8_t resourceIndex) const noexcept {
+    if (!isValid()) {
+        return nullptr;
+    }
+
+    return static_cast<uint8_t*>(bufferAllocation->mappedBuffer) + getVulkanBufferOffset(resourceIndex);
 }
 
 std::size_t BufferResource::getVulkanBufferOffset() const noexcept {
-    if (bufferWindowSize > 0) return 0;
+    return getVulkanBufferOffset(context.getCurrentFrameResourceIndex());
+}
+
+std::size_t BufferResource::getVulkanBufferOffset(std::uint8_t resourceIndex) const noexcept {
+    assert(context.getBackend().getMaxFrames() >= resourceIndex);
+    return bufferWindowSize ? resourceIndex * bufferWindowSize : 0;
+}
+
+void BufferResource::updateVulkanBuffer() {
+    const auto frameCount = context.getBackend().getMaxFrames();
+
+    const int8_t currentIndex = context.getCurrentFrameResourceIndex();
+    const int8_t prevIndex = currentIndex == 0 ? frameCount - 1 : currentIndex - 1;
+
+    updateVulkanBuffer(currentIndex, prevIndex);
+}
+
+void BufferResource::updateVulkanBuffer(const int8_t destination, const uint8_t source) {
+    if (!bufferWindowSize) {
+        return;
+    }
+
+    if (bufferWindowVersions[destination] < bufferWindowVersions[source]) {
+        uint8_t* dstData = static_cast<uint8_t*>(bufferAllocation->mappedBuffer) + bufferWindowSize * destination;
+        uint8_t* srcData = static_cast<uint8_t*>(bufferAllocation->mappedBuffer) + bufferWindowSize * source;
+
+        std::memcpy(dstData, srcData, size);
 
-    return context.getCurrentFrameResourceIndex() * bufferWindowSize;
+        bufferWindowVersions[destination] = bufferWindowVersions[source];
+    }
 }
 
 } // namespace vulkan

diff --git a/src/mbgl/vulkan/uniform_buffer.cpp b/src/mbgl/vulkan/uniform_buffer.cpp
@@ -74,6 +74,22 @@ void UniformBufferArray::bindDescriptorSets(CommandEncoder& encoder) {
     }
 
     descriptorSet->update(*this, descriptorStartIndex, descriptorBindingCount);
+
+    const auto frameCount = encoder.getContext().getBackend().getMaxFrames();
+    const int32_t currentIndex = encoder.getContext().getCurrentFrameResourceIndex();
+    const int32_t prevIndex = currentIndex == 0 ? frameCount - 1 : currentIndex - 1;
+
+    for (uint32_t i = 0; i < descriptorBindingCount; ++i) {
+        const uint32_t index = descriptorStartIndex + i;
+
+        if (!uniformBufferVector[index]) {
+            continue;
+        }
+
+        auto& buff = static_cast<UniformBuffer*>(uniformBufferVector[index].get())->mutableBufferResource();
+        buff.updateVulkanBuffer(currentIndex, prevIndex);
+    }
+
     descriptorSet->bind(encoder);
 }