Revert "Vulkan: readPixels improvement - use DynamicBuffer"

This reverts commit 82a420bb9af221e659b9510aed6791a87ac97b25.

Reason for revert: breaks readPixels on Android, probably because memory there is not host coherent by default.

Original change's description:
> Vulkan: readPixels improvement - use DynamicBuffer
> 
> - Instead of using a new Staging image everytime, we now
> just use a DynamicBuffer that should be bit less wasteful.
> 
> Bug: angleproject:2480
> 
> Change-Id: I09edfb16f6ec49a0ca320d9e5dd9ce34e9dbf99e
> Reviewed-on: https://chromium-review.googlesource.com/1059452
> Commit-Queue: Luc Ferron <lucferron@chromium.org>
> Reviewed-by: Jamie Madill <jmadill@chromium.org>
> Reviewed-by: Geoff Lang <geofflang@chromium.org>

TBR=geofflang@chromium.org,jmadill@chromium.org,lucferron@chromium.org

Change-Id: Id7c493915ec7131f5202a7224267a79cd53007d2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: angleproject:2480
Reviewed-on: https://chromium-review.googlesource.com/1064770
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/FramebufferVk.cpp b/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
index e5cb11a..c1151a0 100644
--- a/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
+++ b/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
@@ -31,8 +31,6 @@
 
 namespace
 {
-constexpr size_t kMinReadPixelsBufferSize = 128000;
-
 const gl::InternalFormat &GetReadAttachmentInfo(const gl::Context *context,
                                                 RenderTargetVk *renderTarget)
 {
@@ -61,10 +59,8 @@
       mRenderPassDesc(),
       mFramebuffer(),
       mActiveColorComponents(0),
-      mMaskedClearDescriptorSet(VK_NULL_HANDLE),
-      mReadPixelsBuffer(VK_BUFFER_USAGE_TRANSFER_DST_BIT, kMinReadPixelsBufferSize)
+      mMaskedClearDescriptorSet(VK_NULL_HANDLE)
 {
-    mReadPixelsBuffer.init(1);
 }
 
 FramebufferVk::FramebufferVk(const gl::FramebufferState &state, WindowSurfaceVk *backbuffer)
@@ -73,10 +69,8 @@
       mRenderPassDesc(),
       mFramebuffer(),
       mActiveColorComponents(0),
-      mMaskedClearDescriptorSet(VK_NULL_HANDLE),
-      mReadPixelsBuffer(VK_BUFFER_USAGE_TRANSFER_DST_BIT, kMinReadPixelsBufferSize)
+      mMaskedClearDescriptorSet(VK_NULL_HANDLE)
 {
-    mReadPixelsBuffer.init(1);
 }
 
 FramebufferVk::~FramebufferVk()
@@ -85,13 +79,10 @@
 
 void FramebufferVk::destroy(const gl::Context *context)
 {
-    ContextVk *contextVk = vk::GetImpl(context);
-    RendererVk *renderer = contextVk->getRenderer();
+    RendererVk *renderer = vk::GetImpl(context)->getRenderer();
     renderer->releaseResource(*this, &mFramebuffer);
     renderer->releaseResource(*this, &mMaskedClearUniformBuffer.buffer);
     renderer->releaseResource(*this, &mMaskedClearUniformBuffer.memory);
-
-    mReadPixelsBuffer.destroy(contextVk->getDevice());
 }
 
 gl::Error FramebufferVk::discard(const gl::Context *context,
@@ -296,10 +287,8 @@
     }
 
     const gl::State &glState = context->getGLState();
-    RendererVk *renderer     = vk::GetImpl(context)->getRenderer();
-
-    vk::CommandBuffer *commandBuffer = nullptr;
-    ANGLE_TRY(beginWriteResource(renderer, &commandBuffer));
+    RenderTargetVk *renderTarget = getColorReadRenderTarget();
+    ASSERT(renderTarget);
 
     const gl::PixelPackState &packState       = context->getGLState().getPackState();
     const gl::InternalFormat &sizedFormatInfo = gl::GetInternalFormatInfo(format, type);
@@ -316,18 +305,17 @@
                        (clippedArea.y - area.y) * outputPitch;
 
     PackPixelsParams params;
-    params.area        = clippedArea;
+    params.area        = area;
     params.format      = format;
     params.type        = type;
     params.outputPitch = outputPitch;
     params.packBuffer  = glState.getTargetBuffer(gl::BufferBinding::PixelPack);
     params.pack        = glState.getPackState();
 
-    ANGLE_TRY(ReadPixelsFromRenderTarget(context, clippedArea, params, mReadPixelsBuffer,
-                                         getColorReadRenderTarget(), commandBuffer,
-                                         reinterpret_cast<uint8_t *>(pixels) + outputSkipBytes));
-    mReadPixelsBuffer.releaseRetainedBuffers(renderer);
-    return gl::NoError();
+    vk::CommandBuffer *commandBuffer = nullptr;
+    ANGLE_TRY(beginWriteResource(vk::GetImpl(context)->getRenderer(), &commandBuffer));
+    return ReadPixelsFromRenderTarget(context, clippedArea, params, renderTarget, commandBuffer,
+                                      reinterpret_cast<uint8_t *>(pixels) + outputSkipBytes);
 }
 
 RenderTargetVk *FramebufferVk::getColorReadRenderTarget()
@@ -814,52 +802,48 @@
 gl::Error ReadPixelsFromRenderTarget(const gl::Context *context,
                                      const gl::Rectangle &area,
                                      const PackPixelsParams &packPixelsParams,
-                                     vk::DynamicBuffer &dynamicBuffer,
                                      RenderTargetVk *renderTarget,
                                      vk::CommandBuffer *commandBuffer,
                                      void *pixels)
 {
-    RendererVk *renderer = vk::GetImpl(context)->getRenderer();
+    ContextVk *contextVk = vk::GetImpl(context);
+    RendererVk *renderer = contextVk->getRenderer();
+    VkDevice device      = renderer->getDevice();
 
-    vk::ImageHelper *renderTargetImage = renderTarget->image;
-    const angle::Format &angleFormat   = renderTargetImage->getFormat().textureFormat();
-    VkBuffer bufferHandle              = VK_NULL_HANDLE;
-    uint8_t *readPixelBuffer           = nullptr;
-    bool newBufferAllocated            = false;
-    uint32_t stagingOffset             = 0;
-    size_t allocationSize              = area.width * angleFormat.pixelBytes * area.height;
+    vk::ImageHelper stagingImage;
+    ANGLE_TRY(stagingImage.init2DStaging(
+        device, renderer->getMemoryProperties(), renderTarget->image->getFormat(),
+        gl::Extents(area.width, area.height, 1), vk::StagingUsage::Read));
 
-    dynamicBuffer.allocate(renderer, allocationSize, &readPixelBuffer, &bufferHandle,
-                           &stagingOffset, &newBufferAllocated);
+    stagingImage.changeLayoutWithStages(VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_GENERAL,
+                                        VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
+                                        VK_PIPELINE_STAGE_ALL_COMMANDS_BIT, commandBuffer);
 
-    VkBufferImageCopy region;
-    region.bufferImageHeight               = area.height;
-    region.bufferOffset                    = static_cast<VkDeviceSize>(stagingOffset);
-    region.bufferRowLength                 = area.width;
-    region.imageExtent.width               = area.width;
-    region.imageExtent.height              = area.height;
-    region.imageExtent.depth               = 1;
-    region.imageOffset.x                   = area.x;
-    region.imageOffset.y                   = area.y;
-    region.imageOffset.z                   = 0;
-    region.imageSubresource.aspectMask     = VK_IMAGE_ASPECT_COLOR_BIT;
-    region.imageSubresource.baseArrayLayer = 0;
-    region.imageSubresource.layerCount     = 1;
-    region.imageSubresource.mipLevel       = 0;
+    vk::ImageHelper::Copy(renderTarget->image, &stagingImage, gl::Offset(area.x, area.y, 0),
+                          gl::Offset(), gl::Extents(area.width, area.height, 1),
+                          VK_IMAGE_ASPECT_COLOR_BIT, commandBuffer);
 
-    renderTargetImage->changeLayoutWithStages(
-        VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
-        VK_PIPELINE_STAGE_ALL_COMMANDS_BIT, VK_PIPELINE_STAGE_ALL_COMMANDS_BIT, commandBuffer);
-
-    commandBuffer->copyImageToBuffer(renderTargetImage->getImage(),
-                                     renderTargetImage->getCurrentLayout(), bufferHandle, 1,
-                                     &region);
     // Triggers a full finish.
     // TODO(jmadill): Don't block on asynchronous readback.
     ANGLE_TRY(renderer->finish(context));
 
-    PackPixels(packPixelsParams, angleFormat, area.width * angleFormat.pixelBytes, readPixelBuffer,
-               reinterpret_cast<uint8_t *>(pixels));
+    // TODO(jmadill): parameters
+    uint8_t *mapPointer = nullptr;
+    ANGLE_TRY(stagingImage.getDeviceMemory().map(device, 0, stagingImage.getAllocatedMemorySize(),
+                                                 0, &mapPointer));
+
+    const angle::Format &angleFormat = renderTarget->image->getFormat().textureFormat();
+
+    // Get the staging image pitch and use it to pack the pixels later.
+    VkSubresourceLayout subresourceLayout;
+    stagingImage.getImage().getSubresourceLayout(device, VK_IMAGE_ASPECT_COLOR_BIT, 0, 0,
+                                                 &subresourceLayout);
+
+    PackPixels(packPixelsParams, angleFormat, static_cast<int>(subresourceLayout.rowPitch),
+               mapPointer, reinterpret_cast<uint8_t *>(pixels));
+
+    stagingImage.getDeviceMemory().unmap(device);
+    renderer->releaseObject(renderer->getCurrentQueueSerial(), &stagingImage);
 
     return vk::NoError();
 }