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Merge pull request #10082 from FernandoS27/the-testers-really-love-chocolate

Refactor Accelerate DMA and do downloads through TC.
This commit is contained in:
bunnei 2023-04-29 11:46:01 -07:00 committed by GitHub
commit fe57f39676
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GPG Key ID: 4AEE18F83AFDEB23
9 changed files with 212 additions and 81 deletions

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@ -223,6 +223,9 @@ void Maxwell3D::ProcessMacro(u32 method, const u32* base_start, u32 amount, bool
}
void Maxwell3D::RefreshParametersImpl() {
if (!Settings::IsGPULevelHigh()) {
return;
}
size_t current_index = 0;
for (auto& segment : macro_segments) {
if (segment.first == 0) {

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@ -1287,8 +1287,7 @@ bool AccelerateDMA::DmaBufferImageCopy(const Tegra::DMA::ImageCopy& copy_info,
}
const u32 buffer_size = static_cast<u32>(buffer_operand.pitch * buffer_operand.height);
static constexpr auto sync_info = VideoCommon::ObtainBufferSynchronize::FullSynchronize;
const auto post_op = IS_IMAGE_UPLOAD ? VideoCommon::ObtainBufferOperation::DoNothing
: VideoCommon::ObtainBufferOperation::MarkAsWritten;
const auto post_op = VideoCommon::ObtainBufferOperation::DoNothing;
const auto [buffer, offset] =
buffer_cache.ObtainBuffer(buffer_operand.address, buffer_size, sync_info, post_op);
@ -1299,7 +1298,8 @@ bool AccelerateDMA::DmaBufferImageCopy(const Tegra::DMA::ImageCopy& copy_info,
if constexpr (IS_IMAGE_UPLOAD) {
image->UploadMemory(buffer->Handle(), offset, copy_span);
} else {
image->DownloadMemory(buffer->Handle(), offset, copy_span);
texture_cache.DownloadImageIntoBuffer(image, buffer->Handle(), offset, copy_span,
buffer_operand.address, buffer_size);
}
return true;
}

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@ -803,30 +803,40 @@ void Image::UploadMemory(const ImageBufferMap& map,
void Image::DownloadMemory(GLuint buffer_handle, size_t buffer_offset,
std::span<const VideoCommon::BufferImageCopy> copies) {
std::array buffer_handles{buffer_handle};
std::array buffer_offsets{buffer_offset};
DownloadMemory(buffer_handles, buffer_offsets, copies);
}
void Image::DownloadMemory(std::span<GLuint> buffer_handles, std::span<size_t> buffer_offsets,
std::span<const VideoCommon::BufferImageCopy> copies) {
const bool is_rescaled = True(flags & ImageFlagBits::Rescaled);
if (is_rescaled) {
ScaleDown();
}
glMemoryBarrier(GL_PIXEL_BUFFER_BARRIER_BIT); // TODO: Move this to its own API
glBindBuffer(GL_PIXEL_PACK_BUFFER, buffer_handle);
glPixelStorei(GL_PACK_ALIGNMENT, 1);
for (size_t i = 0; i < buffer_handles.size(); i++) {
auto& buffer_handle = buffer_handles[i];
glBindBuffer(GL_PIXEL_PACK_BUFFER, buffer_handle);
glPixelStorei(GL_PACK_ALIGNMENT, 1);
u32 current_row_length = std::numeric_limits<u32>::max();
u32 current_image_height = std::numeric_limits<u32>::max();
u32 current_row_length = std::numeric_limits<u32>::max();
u32 current_image_height = std::numeric_limits<u32>::max();
for (const VideoCommon::BufferImageCopy& copy : copies) {
if (copy.image_subresource.base_level >= gl_num_levels) {
continue;
for (const VideoCommon::BufferImageCopy& copy : copies) {
if (copy.image_subresource.base_level >= gl_num_levels) {
continue;
}
if (current_row_length != copy.buffer_row_length) {
current_row_length = copy.buffer_row_length;
glPixelStorei(GL_PACK_ROW_LENGTH, current_row_length);
}
if (current_image_height != copy.buffer_image_height) {
current_image_height = copy.buffer_image_height;
glPixelStorei(GL_PACK_IMAGE_HEIGHT, current_image_height);
}
CopyImageToBuffer(copy, buffer_offsets[i]);
}
if (current_row_length != copy.buffer_row_length) {
current_row_length = copy.buffer_row_length;
glPixelStorei(GL_PACK_ROW_LENGTH, current_row_length);
}
if (current_image_height != copy.buffer_image_height) {
current_image_height = copy.buffer_image_height;
glPixelStorei(GL_PACK_IMAGE_HEIGHT, current_image_height);
}
CopyImageToBuffer(copy, buffer_offset);
}
if (is_rescaled) {
ScaleUp(true);

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@ -215,6 +215,9 @@ public:
void DownloadMemory(GLuint buffer_handle, size_t buffer_offset,
std::span<const VideoCommon::BufferImageCopy> copies);
void DownloadMemory(std::span<GLuint> buffer_handle, std::span<size_t> buffer_offset,
std::span<const VideoCommon::BufferImageCopy> copies);
void DownloadMemory(ImageBufferMap& map, std::span<const VideoCommon::BufferImageCopy> copies);
GLuint StorageHandle() noexcept;
@ -376,6 +379,7 @@ struct TextureCacheParams {
using Sampler = OpenGL::Sampler;
using Framebuffer = OpenGL::Framebuffer;
using AsyncBuffer = u32;
using BufferType = GLuint;
};
using TextureCache = VideoCommon::TextureCache<TextureCacheParams>;

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@ -781,8 +781,7 @@ bool AccelerateDMA::DmaBufferImageCopy(const Tegra::DMA::ImageCopy& copy_info,
}
const u32 buffer_size = static_cast<u32>(buffer_operand.pitch * buffer_operand.height);
static constexpr auto sync_info = VideoCommon::ObtainBufferSynchronize::FullSynchronize;
const auto post_op = IS_IMAGE_UPLOAD ? VideoCommon::ObtainBufferOperation::DoNothing
: VideoCommon::ObtainBufferOperation::MarkAsWritten;
const auto post_op = VideoCommon::ObtainBufferOperation::DoNothing;
const auto [buffer, offset] =
buffer_cache.ObtainBuffer(buffer_operand.address, buffer_size, sync_info, post_op);
@ -793,7 +792,8 @@ bool AccelerateDMA::DmaBufferImageCopy(const Tegra::DMA::ImageCopy& copy_info,
if constexpr (IS_IMAGE_UPLOAD) {
image->UploadMemory(buffer->Handle(), offset, copy_span);
} else {
image->DownloadMemory(buffer->Handle(), offset, copy_span);
texture_cache.DownloadImageIntoBuffer(image, buffer->Handle(), offset, copy_span,
buffer_operand.address, buffer_size);
}
return true;
}

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@ -1,10 +1,11 @@
// SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
// SPDX-License-Identifier: GPL-3.0-or-later
#include <algorithm>
#include <array>
#include <span>
#include <vector>
#include <boost/container/small_vector.hpp>
#include "common/bit_cast.h"
#include "common/bit_util.h"
@ -1343,14 +1344,31 @@ void Image::UploadMemory(const StagingBufferRef& map, std::span<const BufferImag
void Image::DownloadMemory(VkBuffer buffer, VkDeviceSize offset,
std::span<const VideoCommon::BufferImageCopy> copies) {
std::array buffer_handles{
buffer,
};
std::array buffer_offsets{
offset,
};
DownloadMemory(buffer_handles, buffer_offsets, copies);
}
void Image::DownloadMemory(std::span<VkBuffer> buffers_span, std::span<VkDeviceSize> offsets_span,
std::span<const VideoCommon::BufferImageCopy> copies) {
const bool is_rescaled = True(flags & ImageFlagBits::Rescaled);
if (is_rescaled) {
ScaleDown();
}
std::vector vk_copies = TransformBufferImageCopies(copies, offset, aspect_mask);
boost::container::small_vector<VkBuffer, 1> buffers_vector{};
boost::container::small_vector<std::vector<VkBufferImageCopy>, 1> vk_copies;
for (size_t index = 0; index < buffers_span.size(); index++) {
buffers_vector.emplace_back(buffers_span[index]);
vk_copies.emplace_back(
TransformBufferImageCopies(copies, offsets_span[index], aspect_mask));
}
scheduler->RequestOutsideRenderPassOperationContext();
scheduler->Record([buffer, image = *original_image, aspect_mask = aspect_mask,
vk_copies](vk::CommandBuffer cmdbuf) {
scheduler->Record([buffers = std::move(buffers_vector), image = *original_image,
aspect_mask = aspect_mask, vk_copies](vk::CommandBuffer cmdbuf) {
const VkImageMemoryBarrier read_barrier{
.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER,
.pNext = nullptr,
@ -1369,6 +1387,20 @@ void Image::DownloadMemory(VkBuffer buffer, VkDeviceSize offset,
.layerCount = VK_REMAINING_ARRAY_LAYERS,
},
};
cmdbuf.PipelineBarrier(VK_PIPELINE_STAGE_ALL_COMMANDS_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT,
0, read_barrier);
for (size_t index = 0; index < buffers.size(); index++) {
cmdbuf.CopyImageToBuffer(image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL, buffers[index],
vk_copies[index]);
}
const VkMemoryBarrier memory_write_barrier{
.sType = VK_STRUCTURE_TYPE_MEMORY_BARRIER,
.pNext = nullptr,
.srcAccessMask = VK_ACCESS_MEMORY_WRITE_BIT,
.dstAccessMask = VK_ACCESS_MEMORY_READ_BIT | VK_ACCESS_MEMORY_WRITE_BIT,
};
const VkImageMemoryBarrier image_write_barrier{
.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER,
.pNext = nullptr,
@ -1387,15 +1419,6 @@ void Image::DownloadMemory(VkBuffer buffer, VkDeviceSize offset,
.layerCount = VK_REMAINING_ARRAY_LAYERS,
},
};
const VkMemoryBarrier memory_write_barrier{
.sType = VK_STRUCTURE_TYPE_MEMORY_BARRIER,
.pNext = nullptr,
.srcAccessMask = VK_ACCESS_MEMORY_WRITE_BIT,
.dstAccessMask = VK_ACCESS_MEMORY_READ_BIT | VK_ACCESS_MEMORY_WRITE_BIT,
};
cmdbuf.PipelineBarrier(VK_PIPELINE_STAGE_ALL_COMMANDS_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT,
0, read_barrier);
cmdbuf.CopyImageToBuffer(image, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL, buffer, vk_copies);
cmdbuf.PipelineBarrier(VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
0, memory_write_barrier, nullptr, image_write_barrier);
});
@ -1405,7 +1428,13 @@ void Image::DownloadMemory(VkBuffer buffer, VkDeviceSize offset,
}
void Image::DownloadMemory(const StagingBufferRef& map, std::span<const BufferImageCopy> copies) {
DownloadMemory(map.buffer, map.offset, copies);
std::array buffers{
map.buffer,
};
std::array offsets{
map.offset,
};
DownloadMemory(buffers, offsets, copies);
}
bool Image::IsRescaled() const noexcept {

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@ -1,5 +1,5 @@
// SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
// SPDX-License-Identifier: GPL-3.0-or-later
#pragma once
@ -141,6 +141,9 @@ public:
void DownloadMemory(VkBuffer buffer, VkDeviceSize offset,
std::span<const VideoCommon::BufferImageCopy> copies);
void DownloadMemory(std::span<VkBuffer> buffers, std::span<VkDeviceSize> offsets,
std::span<const VideoCommon::BufferImageCopy> copies);
void DownloadMemory(const StagingBufferRef& map,
std::span<const VideoCommon::BufferImageCopy> copies);
@ -371,6 +374,7 @@ struct TextureCacheParams {
using Sampler = Vulkan::Sampler;
using Framebuffer = Vulkan::Framebuffer;
using AsyncBuffer = Vulkan::StagingBufferRef;
using BufferType = VkBuffer;
};
using TextureCache = VideoCommon::TextureCache<TextureCacheParams>;

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@ -1,9 +1,10 @@
// SPDX-FileCopyrightText: 2021 yuzu Emulator Project
// SPDX-FileCopyrightText: 2023 yuzu Emulator Project
// SPDX-License-Identifier: GPL-3.0-or-later
#pragma once
#include <unordered_set>
#include <boost/container/small_vector.hpp>
#include "common/alignment.h"
#include "common/settings.h"
@ -17,15 +18,10 @@
namespace VideoCommon {
using Tegra::Texture::SwizzleSource;
using Tegra::Texture::TextureType;
using Tegra::Texture::TICEntry;
using Tegra::Texture::TSCEntry;
using VideoCore::Surface::GetFormatType;
using VideoCore::Surface::IsCopyCompatible;
using VideoCore::Surface::PixelFormat;
using VideoCore::Surface::PixelFormatFromDepthFormat;
using VideoCore::Surface::PixelFormatFromRenderTargetFormat;
using VideoCore::Surface::SurfaceType;
using namespace Common::Literals;
@ -143,6 +139,13 @@ void TextureCache<P>::TickFrame() {
runtime.TickFrame();
critical_gc = 0;
++frame_tick;
if constexpr (IMPLEMENTS_ASYNC_DOWNLOADS) {
for (auto& buffer : async_buffers_death_ring) {
runtime.FreeDeferredStagingBuffer(buffer);
}
async_buffers_death_ring.clear();
}
}
template <class P>
@ -661,25 +664,39 @@ template <class P>
void TextureCache<P>::CommitAsyncFlushes() {
// This is intentionally passing the value by copy
if constexpr (IMPLEMENTS_ASYNC_DOWNLOADS) {
const std::span<const ImageId> download_ids = uncommitted_downloads;
auto& download_ids = uncommitted_downloads;
if (download_ids.empty()) {
committed_downloads.emplace_back(std::move(uncommitted_downloads));
uncommitted_downloads.clear();
async_buffers.emplace_back(std::optional<AsyncBuffer>{});
async_buffers.emplace_back(std::move(uncommitted_async_buffers));
uncommitted_async_buffers.clear();
return;
}
size_t total_size_bytes = 0;
for (const ImageId image_id : download_ids) {
total_size_bytes += slot_images[image_id].unswizzled_size_bytes;
size_t last_async_buffer_id = uncommitted_async_buffers.size();
bool any_none_dma = false;
for (PendingDownload& download_info : download_ids) {
if (download_info.is_swizzle) {
total_size_bytes +=
Common::AlignUp(slot_images[download_info.object_id].unswizzled_size_bytes, 64);
any_none_dma = true;
download_info.async_buffer_id = last_async_buffer_id;
}
}
auto download_map = runtime.DownloadStagingBuffer(total_size_bytes, true);
for (const ImageId image_id : download_ids) {
Image& image = slot_images[image_id];
const auto copies = FullDownloadCopies(image.info);
image.DownloadMemory(download_map, copies);
download_map.offset += Common::AlignUp(image.unswizzled_size_bytes, 64);
if (any_none_dma) {
auto download_map = runtime.DownloadStagingBuffer(total_size_bytes, true);
for (const PendingDownload& download_info : download_ids) {
if (download_info.is_swizzle) {
Image& image = slot_images[download_info.object_id];
const auto copies = FullDownloadCopies(image.info);
image.DownloadMemory(download_map, copies);
download_map.offset += Common::AlignUp(image.unswizzled_size_bytes, 64);
}
}
uncommitted_async_buffers.emplace_back(download_map);
}
async_buffers.emplace_back(download_map);
async_buffers.emplace_back(std::move(uncommitted_async_buffers));
uncommitted_async_buffers.clear();
}
committed_downloads.emplace_back(std::move(uncommitted_downloads));
uncommitted_downloads.clear();
@ -691,39 +708,57 @@ void TextureCache<P>::PopAsyncFlushes() {
return;
}
if constexpr (IMPLEMENTS_ASYNC_DOWNLOADS) {
const std::span<const ImageId> download_ids = committed_downloads.front();
const auto& download_ids = committed_downloads.front();
if (download_ids.empty()) {
committed_downloads.pop_front();
async_buffers.pop_front();
return;
}
auto download_map = *async_buffers.front();
std::span<u8> download_span = download_map.mapped_span;
auto download_map = std::move(async_buffers.front());
for (size_t i = download_ids.size(); i > 0; i--) {
const ImageBase& image = slot_images[download_ids[i - 1]];
const auto copies = FullDownloadCopies(image.info);
download_map.offset -= Common::AlignUp(image.unswizzled_size_bytes, 64);
std::span<u8> download_span_alt = download_span.subspan(download_map.offset);
SwizzleImage(*gpu_memory, image.gpu_addr, image.info, copies, download_span_alt,
swizzle_data_buffer);
auto& download_info = download_ids[i - 1];
auto& download_buffer = download_map[download_info.async_buffer_id];
if (download_info.is_swizzle) {
const ImageBase& image = slot_images[download_info.object_id];
const auto copies = FullDownloadCopies(image.info);
download_buffer.offset -= Common::AlignUp(image.unswizzled_size_bytes, 64);
std::span<u8> download_span =
download_buffer.mapped_span.subspan(download_buffer.offset);
SwizzleImage(*gpu_memory, image.gpu_addr, image.info, copies, download_span,
swizzle_data_buffer);
} else {
const BufferDownload& buffer_info = slot_buffer_downloads[download_info.object_id];
std::span<u8> download_span =
download_buffer.mapped_span.subspan(download_buffer.offset);
gpu_memory->WriteBlockUnsafe(buffer_info.address, download_span.data(),
buffer_info.size);
slot_buffer_downloads.erase(download_info.object_id);
}
}
for (auto& download_buffer : download_map) {
async_buffers_death_ring.emplace_back(download_buffer);
}
runtime.FreeDeferredStagingBuffer(download_map);
committed_downloads.pop_front();
async_buffers.pop_front();
} else {
const std::span<const ImageId> download_ids = committed_downloads.front();
const auto& download_ids = committed_downloads.front();
if (download_ids.empty()) {
committed_downloads.pop_front();
return;
}
size_t total_size_bytes = 0;
for (const ImageId image_id : download_ids) {
total_size_bytes += slot_images[image_id].unswizzled_size_bytes;
for (const PendingDownload& download_info : download_ids) {
if (download_info.is_swizzle) {
total_size_bytes += slot_images[download_info.object_id].unswizzled_size_bytes;
}
}
auto download_map = runtime.DownloadStagingBuffer(total_size_bytes);
const size_t original_offset = download_map.offset;
for (const ImageId image_id : download_ids) {
Image& image = slot_images[image_id];
for (const PendingDownload& download_info : download_ids) {
if (!download_info.is_swizzle) {
continue;
}
Image& image = slot_images[download_info.object_id];
const auto copies = FullDownloadCopies(image.info);
image.DownloadMemory(download_map, copies);
download_map.offset += image.unswizzled_size_bytes;
@ -732,8 +767,11 @@ void TextureCache<P>::PopAsyncFlushes() {
runtime.Finish();
download_map.offset = original_offset;
std::span<u8> download_span = download_map.mapped_span;
for (const ImageId image_id : download_ids) {
const ImageBase& image = slot_images[image_id];
for (const PendingDownload& download_info : download_ids) {
if (!download_info.is_swizzle) {
continue;
}
const ImageBase& image = slot_images[download_info.object_id];
const auto copies = FullDownloadCopies(image.info);
SwizzleImage(*gpu_memory, image.gpu_addr, image.info, copies, download_span,
swizzle_data_buffer);
@ -833,6 +871,33 @@ std::pair<typename TextureCache<P>::Image*, BufferImageCopy> TextureCache<P>::Dm
return {image, copy};
}
template <class P>
void TextureCache<P>::DownloadImageIntoBuffer(typename TextureCache<P>::Image* image,
typename TextureCache<P>::BufferType buffer,
size_t buffer_offset,
std::span<const VideoCommon::BufferImageCopy> copies,
GPUVAddr address, size_t size) {
if constexpr (IMPLEMENTS_ASYNC_DOWNLOADS) {
const BufferDownload new_buffer_download{address, size};
auto slot = slot_buffer_downloads.insert(new_buffer_download);
const PendingDownload new_download{false, uncommitted_async_buffers.size(), slot};
uncommitted_downloads.emplace_back(new_download);
auto download_map = runtime.DownloadStagingBuffer(size, true);
uncommitted_async_buffers.emplace_back(download_map);
std::array buffers{
buffer,
download_map.buffer,
};
std::array buffer_offsets{
buffer_offset,
download_map.offset,
};
image->DownloadMemory(buffers, buffer_offsets, copies);
} else {
image->DownloadMemory(buffer, buffer_offset, copies);
}
}
template <class P>
void TextureCache<P>::RefreshContents(Image& image, ImageId image_id) {
if (False(image.flags & ImageFlagBits::CpuModified)) {
@ -2209,7 +2274,8 @@ void TextureCache<P>::BindRenderTarget(ImageViewId* old_id, ImageViewId new_id)
if (new_id) {
const ImageViewBase& old_view = slot_image_views[new_id];
if (True(old_view.flags & ImageViewFlagBits::PreemtiveDownload)) {
uncommitted_downloads.push_back(old_view.image_id);
const PendingDownload new_download{true, 0, old_view.image_id};
uncommitted_downloads.emplace_back(new_download);
}
}
*old_id = new_id;

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@ -1,4 +1,4 @@
// SPDX-FileCopyrightText: 2021 yuzu Emulator Project
// SPDX-FileCopyrightText: 2023 yuzu Emulator Project
// SPDX-License-Identifier: GPL-3.0-or-later
#pragma once
@ -40,14 +40,9 @@ struct ChannelState;
namespace VideoCommon {
using Tegra::Texture::SwizzleSource;
using Tegra::Texture::TICEntry;
using Tegra::Texture::TSCEntry;
using VideoCore::Surface::GetFormatType;
using VideoCore::Surface::IsCopyCompatible;
using VideoCore::Surface::PixelFormat;
using VideoCore::Surface::PixelFormatFromDepthFormat;
using VideoCore::Surface::PixelFormatFromRenderTargetFormat;
using namespace Common::Literals;
struct ImageViewInOut {
@ -119,6 +114,7 @@ class TextureCache : public VideoCommon::ChannelSetupCaches<TextureCacheChannelI
using Sampler = typename P::Sampler;
using Framebuffer = typename P::Framebuffer;
using AsyncBuffer = typename P::AsyncBuffer;
using BufferType = typename P::BufferType;
struct BlitImages {
ImageId dst_id;
@ -215,6 +211,10 @@ public:
const Tegra::DMA::ImageCopy& copy_info, const Tegra::DMA::BufferOperand& buffer_operand,
const Tegra::DMA::ImageOperand& image_operand, ImageId image_id, bool modifies_image);
void DownloadImageIntoBuffer(Image* image, BufferType buffer, size_t buffer_offset,
std::span<const VideoCommon::BufferImageCopy> copies,
GPUVAddr address = 0, size_t size = 0);
/// Return true when a CPU region is modified from the GPU
[[nodiscard]] bool IsRegionGpuModified(VAddr addr, size_t size);
@ -424,17 +424,32 @@ private:
u64 critical_memory;
size_t critical_gc;
struct BufferDownload {
GPUVAddr address;
size_t size;
};
struct PendingDownload {
bool is_swizzle;
size_t async_buffer_id;
SlotId object_id;
};
SlotVector<Image> slot_images;
SlotVector<ImageMapView> slot_map_views;
SlotVector<ImageView> slot_image_views;
SlotVector<ImageAlloc> slot_image_allocs;
SlotVector<Sampler> slot_samplers;
SlotVector<Framebuffer> slot_framebuffers;
SlotVector<BufferDownload> slot_buffer_downloads;
// TODO: This data structure is not optimal and it should be reworked
std::vector<ImageId> uncommitted_downloads;
std::deque<std::vector<ImageId>> committed_downloads;
std::deque<std::optional<AsyncBuffer>> async_buffers;
std::vector<PendingDownload> uncommitted_downloads;
std::deque<std::vector<PendingDownload>> committed_downloads;
std::vector<AsyncBuffer> uncommitted_async_buffers;
std::deque<std::vector<AsyncBuffer>> async_buffers;
std::deque<AsyncBuffer> async_buffers_death_ring;
struct LRUItemParams {
using ObjectType = ImageId;