Vulkan: Create buffer view for BufferHelper

Bug: angleproject:2958
Change-Id: Ifa40537bc6003486b37d5d2ac9a2b7f1f5c3d1c2
Reviewed-on: https://chromium-review.googlesource.com/c/1351115
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>

Author: ShabbyX

src/libANGLE/renderer/vulkan/vk_helpers.cpp

@@ -897,25 +897,30 @@ void LineLoopHelper::Draw(uint32_t count, CommandBuffer *commandBuffer)
 BufferHelper::BufferHelper()
     : RecordableGraphResource(CommandGraphResourceType::Buffer),
       mMemoryPropertyFlags{},
+      mSize(0),
       mCurrentWriteAccess(0),
       mCurrentReadAccess(0)
 {
 }
 
 BufferHelper::~BufferHelper() = default;
 
-angle::Result BufferHelper::init(ContextVk *contextVk,
+angle::Result BufferHelper::init(Context *context,
                                  const VkBufferCreateInfo &createInfo,
                                  VkMemoryPropertyFlags memoryPropertyFlags)
 {
-    ANGLE_VK_TRY(contextVk, mBuffer.init(contextVk->getDevice(), createInfo));
-    return vk::AllocateBufferMemory(contextVk, memoryPropertyFlags, &mMemoryPropertyFlags, &mBuffer,
+    mSize = createInfo.size;
+    ANGLE_VK_TRY(context, mBuffer.init(context->getDevice(), createInfo));
+    return vk::AllocateBufferMemory(context, memoryPropertyFlags, &mMemoryPropertyFlags, &mBuffer,
                                     &mDeviceMemory);
 }
 
 void BufferHelper::release(RendererVk *renderer)
 {
+    mSize = 0;
+
     renderer->releaseObject(getStoredQueueSerial(), &mBuffer);
+    renderer->releaseObject(getStoredQueueSerial(), &mBufferView);
     renderer->releaseObject(getStoredQueueSerial(), &mDeviceMemory);
 }
 
@@ -930,13 +935,13 @@ void BufferHelper::onFramebufferRead(FramebufferHelper *framebuffer, VkAccessFla
     }
 }
 
-angle::Result BufferHelper::copyFromBuffer(ContextVk *contextVk,
+angle::Result BufferHelper::copyFromBuffer(Context *context,
                                            const Buffer &buffer,
                                            const VkBufferCopy &copyRegion)
 {
     // 'recordCommands' will implicitly stop any reads from using the old buffer data.
     vk::CommandBuffer *commandBuffer = nullptr;
-    ANGLE_TRY(recordCommands(contextVk, &commandBuffer));
+    ANGLE_TRY(recordCommands(context, &commandBuffer));
 
     if (mCurrentReadAccess != 0 || mCurrentWriteAccess != 0)
     {
@@ -960,6 +965,23 @@ angle::Result BufferHelper::copyFromBuffer(ContextVk *contextVk,
     return angle::Result::Continue();
 }
 
+angle::Result BufferHelper::initBufferView(Context *context, const Format &format)
+{
+    ASSERT(!mBufferView.valid());
+    ASSERT(format.valid());
+
+    VkBufferViewCreateInfo viewCreateInfo = {};
+    viewCreateInfo.sType                  = VK_STRUCTURE_TYPE_BUFFER_VIEW_CREATE_INFO;
+    viewCreateInfo.buffer                 = mBuffer.getHandle();
+    viewCreateInfo.format                 = format.vkBufferFormat;
+    viewCreateInfo.offset                 = 0;
+    viewCreateInfo.range                  = mSize;
+
+    ANGLE_VK_TRY(context, mBufferView.init(context->getDevice(), viewCreateInfo));
+
+    return angle::Result::Continue();
+}
+
 // ImageHelper implementation.
 ImageHelper::ImageHelper()
     : RecordableGraphResource(CommandGraphResourceType::Image),

src/libANGLE/renderer/vulkan/vk_helpers.h

@@ -378,7 +378,7 @@ class BufferHelper final : public RecordableGraphResource
     BufferHelper();
     ~BufferHelper();
 
-    angle::Result init(ContextVk *contextVk,
+    angle::Result init(Context *context,
                        const VkBufferCreateInfo &createInfo,
                        VkMemoryPropertyFlags memoryPropertyFlags);
     void release(RendererVk *renderer);
@@ -391,17 +391,34 @@ class BufferHelper final : public RecordableGraphResource
     void onFramebufferRead(FramebufferHelper *framebuffer, VkAccessFlagBits accessType);
 
     // Also implicitly sets up the correct barriers.
-    angle::Result copyFromBuffer(ContextVk *contextVk,
+    angle::Result copyFromBuffer(Context *context,
                                  const Buffer &buffer,
                                  const VkBufferCopy &copyRegion);
 
+    angle::Result getBufferView(Context *context, const Format &format, BufferView **bufferViewOut)
+    {
+        // Note: currently only one view is allowed.  If needs be, multiple views can be created
+        // based on format.
+        if (!mBufferView.valid())
+        {
+            ANGLE_TRY(initBufferView(context, format));
+        }
+
+        *bufferViewOut = &mBufferView;
+        return angle::Result::Continue();
+    }
+
   private:
+    angle::Result initBufferView(Context *context, const Format &format);
+
     // Vulkan objects.
     Buffer mBuffer;
+    BufferView mBufferView;
     DeviceMemory mDeviceMemory;
 
     // Cached properties.
     VkMemoryPropertyFlags mMemoryPropertyFlags;
+    VkDeviceSize mSize;
 
     // For memory barriers.
     VkFlags mCurrentWriteAccess;