capabilities_vk.cc

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "impeller/renderer/backend/vulkan/capabilities_vk.h"
 
#include <algorithm>
#include <array>
 
#include "impeller/base/validation.h"
#include "impeller/core/formats.h"
#include "impeller/renderer/backend/vulkan/vk.h"
#include "impeller/renderer/backend/vulkan/workarounds_vk.h"
 
namespace impeller {
 
static constexpr const char* kInstanceLayer = "ImpellerInstance";
 
CapabilitiesVK::CapabilitiesVK(bool enable_validations,
                               bool fatal_missing_validations,
                               bool use_embedder_extensions,
                               std::vector<std::string> instance_extensions,
                               std::vector<std::string> device_extensions)
    : use_embedder_extensions_(use_embedder_extensions),
      embedder_instance_extensions_(std::move(instance_extensions)),
      embedder_device_extensions_(std::move(device_extensions)) {
  if (!use_embedder_extensions_) {
    auto extensions = vk::enumerateInstanceExtensionProperties();
    auto layers = vk::enumerateInstanceLayerProperties();
 
    if (extensions.result != vk::Result::eSuccess ||
        layers.result != vk::Result::eSuccess) {
      return;
    }
 
    for (const auto& ext : extensions.value) {
      exts_[kInstanceLayer].insert(ext.extensionName);
    }
 
    for (const auto& layer : layers.value) {
      const std::string layer_name = layer.layerName;
      auto layer_exts = vk::enumerateInstanceExtensionProperties(layer_name);
      if (layer_exts.result != vk::Result::eSuccess) {
        return;
      }
      for (const auto& layer_ext : layer_exts.value) {
        exts_[layer_name].insert(layer_ext.extensionName);
      }
    }
  } else {
    for (const auto& ext : embedder_instance_extensions_) {
      exts_[kInstanceLayer].insert(ext);
    }
  }
 
  validations_enabled_ =
      enable_validations && HasLayer("VK_LAYER_KHRONOS_validation");
  if (enable_validations && !validations_enabled_) {
    FML_LOG(ERROR)
        << "Requested Impeller context creation with validations but the "
           "validation layers could not be found. Expect no Vulkan validation "
           "checks!";
    if (fatal_missing_validations) {
      FML_LOG(FATAL) << "Validation missing. Exiting.";
    }
  }
  if (validations_enabled_) {
    FML_LOG(INFO) << "Vulkan validations are enabled.";
  }
  is_valid_ = true;
}
 
CapabilitiesVK::~CapabilitiesVK() = default;
 
bool CapabilitiesVK::IsValid() const {
  return is_valid_;
}
 
bool CapabilitiesVK::AreValidationsEnabled() const {
  return validations_enabled_;
}
 
std::optional<std::vector<std::string>> CapabilitiesVK::GetEnabledLayers()
    const {
  std::vector<std::string> required;
 
  if (validations_enabled_) {
    // The presence of this layer is already checked in the ctor.
    required.push_back("VK_LAYER_KHRONOS_validation");
  }
 
  return required;
}
 
std::optional<std::vector<std::string>>
CapabilitiesVK::GetEnabledInstanceExtensions() const {
  std::vector<std::string> required;
 
  if (!HasExtension("VK_KHR_surface")) {
    // Swapchain support is required and this is a dependency of
    // VK_KHR_swapchain.
    VALIDATION_LOG << "Could not find the surface extension.";
    return std::nullopt;
  }
  required.push_back("VK_KHR_surface");
 
  auto has_wsi = false;
  if (HasExtension("VK_MVK_macos_surface")) {
    required.push_back("VK_MVK_macos_surface");
    has_wsi = true;
  }
 
  if (HasExtension("VK_EXT_metal_surface")) {
    required.push_back("VK_EXT_metal_surface");
    has_wsi = true;
  }
 
  if (HasExtension("VK_KHR_portability_enumeration")) {
    required.push_back("VK_KHR_portability_enumeration");
    has_wsi = true;
  }
 
  if (HasExtension("VK_KHR_win32_surface")) {
    required.push_back("VK_KHR_win32_surface");
    has_wsi = true;
  }
 
  if (HasExtension("VK_KHR_android_surface")) {
    required.push_back("VK_KHR_android_surface");
    has_wsi = true;
  }
 
  if (HasExtension("VK_KHR_xcb_surface")) {
    required.push_back("VK_KHR_xcb_surface");
    has_wsi = true;
  }
 
  if (HasExtension("VK_KHR_xlib_surface")) {
    required.push_back("VK_KHR_xlib_surface");
    has_wsi = true;
  }
 
  if (HasExtension("VK_KHR_wayland_surface")) {
    required.push_back("VK_KHR_wayland_surface");
    has_wsi = true;
  }
 
  if (!has_wsi) {
    // Don't really care which WSI extension there is as long there is at least
    // one.
    VALIDATION_LOG << "Could not find a WSI extension.";
    return std::nullopt;
  }
 
  if (validations_enabled_) {
    if (!HasExtension("VK_EXT_debug_utils")) {
      VALIDATION_LOG << "Requested validations but could not find the "
                        "VK_EXT_debug_utils extension.";
      return std::nullopt;
    }
    required.push_back("VK_EXT_debug_utils");
 
    if (HasExtension("VK_EXT_validation_features")) {
      // It's valid to not have `VK_EXT_validation_features` available.  That's
      // the case when using AGI as a frame debugger.
      required.push_back("VK_EXT_validation_features");
    }
  }
 
  return required;
}
 
static const char* GetExtensionName(RequiredCommonDeviceExtensionVK ext) {
  switch (ext) {
    case RequiredCommonDeviceExtensionVK::kKHRSwapchain:
      return VK_KHR_SWAPCHAIN_EXTENSION_NAME;
    case RequiredCommonDeviceExtensionVK::kLast:
      return "Unknown";
  }
  FML_UNREACHABLE();
}
 
static const char* GetExtensionName(RequiredAndroidDeviceExtensionVK ext) {
  switch (ext) {
    case RequiredAndroidDeviceExtensionVK::
        kANDROIDExternalMemoryAndroidHardwareBuffer:
      return "VK_ANDROID_external_memory_android_hardware_buffer";
    case RequiredAndroidDeviceExtensionVK::kKHRSamplerYcbcrConversion:
      return VK_KHR_SAMPLER_YCBCR_CONVERSION_EXTENSION_NAME;
    case RequiredAndroidDeviceExtensionVK::kKHRExternalMemory:
      return VK_KHR_EXTERNAL_MEMORY_EXTENSION_NAME;
    case RequiredAndroidDeviceExtensionVK::kEXTQueueFamilyForeign:
      return VK_EXT_QUEUE_FAMILY_FOREIGN_EXTENSION_NAME;
    case RequiredAndroidDeviceExtensionVK::kKHRDedicatedAllocation:
      return VK_KHR_DEDICATED_ALLOCATION_EXTENSION_NAME;
    case RequiredAndroidDeviceExtensionVK::kKHRExternalFenceFd:
      return VK_KHR_EXTERNAL_FENCE_FD_EXTENSION_NAME;
    case RequiredAndroidDeviceExtensionVK::kKHRExternalFence:
      return VK_KHR_EXTERNAL_FENCE_EXTENSION_NAME;
    case RequiredAndroidDeviceExtensionVK::kKHRExternalSemaphoreFd:
      return VK_KHR_EXTERNAL_SEMAPHORE_FD_EXTENSION_NAME;
    case RequiredAndroidDeviceExtensionVK::kKHRExternalSemaphore:
      return VK_KHR_EXTERNAL_SEMAPHORE_EXTENSION_NAME;
    case RequiredAndroidDeviceExtensionVK::kLast:
      return "Unknown";
  }
  FML_UNREACHABLE();
}
 
static const char* GetExtensionName(OptionalDeviceExtensionVK ext) {
  switch (ext) {
    case OptionalDeviceExtensionVK::kEXTPipelineCreationFeedback:
      return VK_EXT_PIPELINE_CREATION_FEEDBACK_EXTENSION_NAME;
    case OptionalDeviceExtensionVK::kVKKHRPortabilitySubset:
      return "VK_KHR_portability_subset";
    case OptionalDeviceExtensionVK::kEXTImageCompressionControl:
      return VK_EXT_IMAGE_COMPRESSION_CONTROL_EXTENSION_NAME;
    case OptionalDeviceExtensionVK::kLast:
      return "Unknown";
  }
  FML_UNREACHABLE();
}
 
template <class T>
static bool IterateExtensions(const std::function<bool(T)>& it) {
  if (!it) {
    return false;
  }
  for (size_t i = 0; i < static_cast<uint32_t>(T::kLast); i++) {
    if (!it(static_cast<T>(i))) {
      return false;
    }
  }
  return true;
}
 
static std::optional<std::set<std::string>> GetSupportedDeviceExtensions(
    const vk::PhysicalDevice& physical_device) {
  auto device_extensions = physical_device.enumerateDeviceExtensionProperties();
  if (device_extensions.result != vk::Result::eSuccess) {
    return std::nullopt;
  }
 
  std::set<std::string> exts;
  for (const auto& device_extension : device_extensions.value) {
    exts.insert(device_extension.extensionName);
  };
 
  return exts;
}
 
std::optional<std::vector<std::string>>
CapabilitiesVK::GetEnabledDeviceExtensions(
    const vk::PhysicalDevice& physical_device) const {
  std::set<std::string> exts;
 
  if (!use_embedder_extensions_) {
    auto maybe_exts = GetSupportedDeviceExtensions(physical_device);
 
    if (!maybe_exts.has_value()) {
      return std::nullopt;
    }
    exts = maybe_exts.value();
  } else {
    exts = std::set(embedder_device_extensions_.begin(),
                    embedder_device_extensions_.end());
  }
 
  std::vector<std::string> enabled;
 
  auto for_each_common_extension = [&](RequiredCommonDeviceExtensionVK ext) {
    auto name = GetExtensionName(ext);
    if (exts.find(name) == exts.end()) {
      VALIDATION_LOG << "Device does not support required extension: " << name;
      return false;
    }
    enabled.push_back(name);
    return true;
  };
 
  auto for_each_android_extension = [&](RequiredAndroidDeviceExtensionVK ext) {
#ifdef FML_OS_ANDROID
    auto name = GetExtensionName(ext);
    if (exts.find(name) == exts.end()) {
      VALIDATION_LOG << "Device does not support required Android extension: "
                     << name;
      return false;
    }
    enabled.push_back(name);
#endif  //  FML_OS_ANDROID
    return true;
  };
 
  auto for_each_optional_extension = [&](OptionalDeviceExtensionVK ext) {
    auto name = GetExtensionName(ext);
    if (exts.find(name) != exts.end()) {
      enabled.push_back(name);
    }
    return true;
  };
 
  const auto iterate_extensions =
      IterateExtensions<RequiredCommonDeviceExtensionVK>(
          for_each_common_extension) &&
      IterateExtensions<RequiredAndroidDeviceExtensionVK>(
          for_each_android_extension) &&
      IterateExtensions<OptionalDeviceExtensionVK>(for_each_optional_extension);
 
  if (!iterate_extensions) {
    VALIDATION_LOG << "Device not suitable since required extensions are not "
                      "supported.";
    return std::nullopt;
  }
 
  return enabled;
}
 
static bool HasSuitableColorFormat(const vk::PhysicalDevice& device,
                                   vk::Format format) {
  const auto props = device.getFormatProperties(format);
  // This needs to be more comprehensive.
  return !!(props.optimalTilingFeatures &
            vk::FormatFeatureFlagBits::eColorAttachment);
}
 
static bool HasSuitableDepthStencilFormat(const vk::PhysicalDevice& device,
                                          vk::Format format) {
  const auto props = device.getFormatProperties(format);
  return !!(props.optimalTilingFeatures &
            vk::FormatFeatureFlagBits::eDepthStencilAttachment);
}
 
static bool PhysicalDeviceSupportsRequiredFormats(
    const vk::PhysicalDevice& device) {
  const auto has_color_format =
      HasSuitableColorFormat(device, vk::Format::eR8G8B8A8Unorm);
  const auto has_stencil_format =
      HasSuitableDepthStencilFormat(device, vk::Format::eD32SfloatS8Uint) ||
      HasSuitableDepthStencilFormat(device, vk::Format::eD24UnormS8Uint);
  return has_color_format && has_stencil_format;
}
 
static bool HasRequiredProperties(const vk::PhysicalDevice& physical_device) {
  auto properties = physical_device.getProperties();
  if (!(properties.limits.framebufferColorSampleCounts &
        (vk::SampleCountFlagBits::e1 | vk::SampleCountFlagBits::e4))) {
    return false;
  }
  return true;
}
 
static bool HasRequiredQueues(const vk::PhysicalDevice& physical_device) {
  auto queue_flags = vk::QueueFlags{};
  for (const auto& queue : physical_device.getQueueFamilyProperties()) {
    if (queue.queueCount == 0) {
      continue;
    }
    queue_flags |= queue.queueFlags;
  }
  return static_cast<VkQueueFlags>(queue_flags &
                                   (vk::QueueFlagBits::eGraphics |
                                    vk::QueueFlagBits::eCompute |
                                    vk::QueueFlagBits::eTransfer));
}
 
template <class ExtensionEnum>
static bool IsExtensionInList(const std::vector<std::string>& list,
                              ExtensionEnum ext) {
  const std::string name = GetExtensionName(ext);
  return std::find(list.begin(), list.end(), name) != list.end();
}
 
std::optional<CapabilitiesVK::PhysicalDeviceFeatures>
CapabilitiesVK::GetEnabledDeviceFeatures(
    const vk::PhysicalDevice& device) const {
  if (!PhysicalDeviceSupportsRequiredFormats(device)) {
    VALIDATION_LOG << "Device doesn't support the required formats.";
    return std::nullopt;
  }
 
  if (!HasRequiredProperties(device)) {
    VALIDATION_LOG << "Device doesn't support the required properties.";
    return std::nullopt;
  }
 
  if (!HasRequiredQueues(device)) {
    VALIDATION_LOG << "Device doesn't support the required queues.";
    return std::nullopt;
  }
 
  const auto enabled_extensions = GetEnabledDeviceExtensions(device);
  if (!enabled_extensions.has_value()) {
    VALIDATION_LOG << "Device doesn't support the required queues.";
    return std::nullopt;
  }
 
  PhysicalDeviceFeatures supported_chain;
 
  // Swiftshader seems to be fussy about just this structure even being in the
  // chain. Just unlink it if its not supported. We already perform an
  // extensions check on the other side when reading.
  if (!IsExtensionInList(
          enabled_extensions.value(),
          OptionalDeviceExtensionVK::kEXTImageCompressionControl)) {
    supported_chain
        .unlink<vk::PhysicalDeviceImageCompressionControlFeaturesEXT>();
  }
 
  device.getFeatures2(&supported_chain.get());
 
  PhysicalDeviceFeatures required_chain;
 
  // Base features.
  {
    auto& required = required_chain.get().features;
    const auto& supported = supported_chain.get().features;
 
    // We require this for enabling wireframes in the playground. But its not
    // necessarily a big deal if we don't have this feature.
    required.fillModeNonSolid = supported.fillModeNonSolid;
  }
  // VK_KHR_sampler_ycbcr_conversion features.
  if (IsExtensionInList(
          enabled_extensions.value(),
          RequiredAndroidDeviceExtensionVK::kKHRSamplerYcbcrConversion)) {
    auto& required =
        required_chain
            .get<vk::PhysicalDeviceSamplerYcbcrConversionFeaturesKHR>();
    const auto& supported =
        supported_chain
            .get<vk::PhysicalDeviceSamplerYcbcrConversionFeaturesKHR>();
 
    required.samplerYcbcrConversion = supported.samplerYcbcrConversion;
  }
 
  // VK_EXT_image_compression_control
  if (IsExtensionInList(
          enabled_extensions.value(),
          OptionalDeviceExtensionVK::kEXTImageCompressionControl)) {
    auto& required =
        required_chain
            .get<vk::PhysicalDeviceImageCompressionControlFeaturesEXT>();
    const auto& supported =
        supported_chain
            .get<vk::PhysicalDeviceImageCompressionControlFeaturesEXT>();
 
    required.imageCompressionControl = supported.imageCompressionControl;
  } else {
    required_chain
        .unlink<vk::PhysicalDeviceImageCompressionControlFeaturesEXT>();
  }
 
  // Vulkan 1.1
  {
    auto& required =
        required_chain.get<vk::PhysicalDevice16BitStorageFeatures>();
    const auto& supported =
        supported_chain.get<vk::PhysicalDevice16BitStorageFeatures>();
 
    required.uniformAndStorageBuffer16BitAccess =
        supported.uniformAndStorageBuffer16BitAccess;
  }
 
  return required_chain;
}
 
bool CapabilitiesVK::HasLayer(const std::string& layer) const {
  for (const auto& [found_layer, exts] : exts_) {
    if (found_layer == layer) {
      return true;
    }
  }
  return false;
}
 
bool CapabilitiesVK::HasExtension(const std::string& ext) const {
  for (const auto& [layer, exts] : exts_) {
    if (exts.find(ext) != exts.end()) {
      return true;
    }
  }
  return false;
}
 
bool CapabilitiesVK::SupportsPrimitiveRestart() const {
  return has_primitive_restart_;
}
 
void CapabilitiesVK::SetOffscreenFormat(PixelFormat pixel_format) const {
  default_color_format_ = pixel_format;
}
 
bool CapabilitiesVK::SetPhysicalDevice(
    const vk::PhysicalDevice& device,
    const PhysicalDeviceFeatures& enabled_features) {
  if (HasSuitableColorFormat(device, vk::Format::eR8G8B8A8Unorm)) {
    default_color_format_ = PixelFormat::kR8G8B8A8UNormInt;
  } else {
    default_color_format_ = PixelFormat::kUnknown;
  }
 
  if (HasSuitableDepthStencilFormat(device, vk::Format::eD32SfloatS8Uint)) {
    default_depth_stencil_format_ = PixelFormat::kD32FloatS8UInt;
  } else if (HasSuitableDepthStencilFormat(device,
                                           vk::Format::eD24UnormS8Uint)) {
    default_depth_stencil_format_ = PixelFormat::kD24UnormS8Uint;
  } else {
    default_depth_stencil_format_ = PixelFormat::kUnknown;
  }
 
  if (HasSuitableDepthStencilFormat(device, vk::Format::eS8Uint)) {
    default_stencil_format_ = PixelFormat::kS8UInt;
  } else if (default_depth_stencil_format_ != PixelFormat::kUnknown) {
    default_stencil_format_ = default_depth_stencil_format_;
  }
 
  physical_device_ = device;
  device_properties_ = device.getProperties();
 
  auto physical_properties_2 =
      device.getProperties2<vk::PhysicalDeviceProperties2,
                            vk::PhysicalDeviceSubgroupProperties>();
 
  // Currently shaders only want access to arithmetic subgroup features.
  // If that changes this needs to get updated, and so does Metal (which right
  // now assumes it from compile time flags based on the MSL target version).
 
  supports_compute_subgroups_ =
      !!(physical_properties_2.get<vk::PhysicalDeviceSubgroupProperties>()
             .supportedOperations &
         vk::SubgroupFeatureFlagBits::eArithmetic);
 
  {
    // Query texture support.
    // TODO(129784): Add a capability check for expected memory types.
    vk::PhysicalDeviceMemoryProperties memory_properties;
    device.getMemoryProperties(&memory_properties);
 
    for (auto i = 0u; i < memory_properties.memoryTypeCount; i++) {
      if (memory_properties.memoryTypes[i].propertyFlags &
          vk::MemoryPropertyFlagBits::eLazilyAllocated) {
        supports_device_transient_textures_ = true;
      }
    }
  }
 
  // Determine the optional device extensions this physical device supports.
  {
    required_common_device_extensions_.clear();
    required_android_device_extensions_.clear();
    optional_device_extensions_.clear();
 
    std::set<std::string> exts;
    if (!use_embedder_extensions_) {
      auto maybe_exts = GetSupportedDeviceExtensions(device);
      if (!maybe_exts.has_value()) {
        return false;
      }
      exts = maybe_exts.value();
    } else {
      exts = std::set(embedder_device_extensions_.begin(),
                      embedder_device_extensions_.end());
    }
 
    IterateExtensions<RequiredCommonDeviceExtensionVK>([&](auto ext) -> bool {
      auto ext_name = GetExtensionName(ext);
      if (exts.find(ext_name) != exts.end()) {
        required_common_device_extensions_.insert(ext);
      }
      return true;
    });
    IterateExtensions<RequiredAndroidDeviceExtensionVK>([&](auto ext) -> bool {
      auto ext_name = GetExtensionName(ext);
      if (exts.find(ext_name) != exts.end()) {
        required_android_device_extensions_.insert(ext);
      }
      return true;
    });
    IterateExtensions<OptionalDeviceExtensionVK>([&](auto ext) -> bool {
      auto ext_name = GetExtensionName(ext);
      if (exts.find(ext_name) != exts.end()) {
        optional_device_extensions_.insert(ext);
      }
      return true;
    });
  }
 
  supports_texture_fixed_rate_compression_ =
      enabled_features
          .isLinked<vk::PhysicalDeviceImageCompressionControlFeaturesEXT>() &&
      enabled_features
          .get<vk::PhysicalDeviceImageCompressionControlFeaturesEXT>()
          .imageCompressionControl;
 
  max_render_pass_attachment_size_ =
      ISize{device_properties_.limits.maxFramebufferWidth,
            device_properties_.limits.maxFramebufferHeight};
 
  // Molten, Vulkan on Metal, cannot support triangle fans because Metal doesn't
  // support triangle fans.
  // See VUID-VkPipelineInputAssemblyStateCreateInfo-triangleFans-04452.
  has_triangle_fans_ =
      !HasExtension(OptionalDeviceExtensionVK::kVKKHRPortabilitySubset);
 
  return true;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsOffscreenMSAA() const {
  return true;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsImplicitResolvingMSAA() const {
  return false;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsSSBO() const {
  return true;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsTextureToTextureBlits() const {
  return true;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsFramebufferFetch() const {
  return has_framebuffer_fetch_;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsCompute() const {
  // Vulkan 1.1 requires support for compute.
  return true;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsComputeSubgroups() const {
  // Set by |SetPhysicalDevice|.
  return supports_compute_subgroups_;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsReadFromResolve() const {
  return false;
}
 
bool CapabilitiesVK::SupportsDecalSamplerAddressMode() const {
  return true;
}
 
// |Capabilities|
bool CapabilitiesVK::SupportsDeviceTransientTextures() const {
  return supports_device_transient_textures_;
}
 
// |Capabilities|
PixelFormat CapabilitiesVK::GetDefaultColorFormat() const {
  return default_color_format_;
}
 
// |Capabilities|
PixelFormat CapabilitiesVK::GetDefaultStencilFormat() const {
  return default_stencil_format_;
}
 
// |Capabilities|
PixelFormat CapabilitiesVK::GetDefaultDepthStencilFormat() const {
  return default_depth_stencil_format_;
}
 
const vk::PhysicalDeviceProperties&
CapabilitiesVK::GetPhysicalDeviceProperties() const {
  return device_properties_;
}
 
PixelFormat CapabilitiesVK::GetDefaultGlyphAtlasFormat() const {
  return PixelFormat::kR8UNormInt;
}
 
bool CapabilitiesVK::HasExtension(RequiredCommonDeviceExtensionVK ext) const {
  return required_common_device_extensions_.find(ext) !=
         required_common_device_extensions_.end();
}
 
bool CapabilitiesVK::HasExtension(RequiredAndroidDeviceExtensionVK ext) const {
  return required_android_device_extensions_.find(ext) !=
         required_android_device_extensions_.end();
}
 
bool CapabilitiesVK::HasExtension(OptionalDeviceExtensionVK ext) const {
  return optional_device_extensions_.find(ext) !=
         optional_device_extensions_.end();
}
 
bool CapabilitiesVK::SupportsTextureFixedRateCompression() const {
  return supports_texture_fixed_rate_compression_;
}
 
std::optional<vk::ImageCompressionFixedRateFlagBitsEXT>
CapabilitiesVK::GetSupportedFRCRate(CompressionType compression_type,
                                    const FRCFormatDescriptor& desc) const {
  if (compression_type != CompressionType::kLossy) {
    return std::nullopt;
  }
  if (!supports_texture_fixed_rate_compression_) {
    return std::nullopt;
  }
  // There are opportunities to hash and cache the FRCFormatDescriptor if
  // needed.
  vk::StructureChain<vk::PhysicalDeviceImageFormatInfo2,
                     vk::ImageCompressionControlEXT>
      format_chain;
 
  auto& format_info = format_chain.get();
 
  format_info.format = desc.format;
  format_info.type = desc.type;
  format_info.tiling = desc.tiling;
  format_info.usage = desc.usage;
  format_info.flags = desc.flags;
 
  const auto kIdealFRCRate = vk::ImageCompressionFixedRateFlagBitsEXT::e4Bpc;
 
  std::array<vk::ImageCompressionFixedRateFlagsEXT, 1u> rates = {kIdealFRCRate};
 
  auto& compression = format_chain.get<vk::ImageCompressionControlEXT>();
  compression.flags = vk::ImageCompressionFlagBitsEXT::eFixedRateExplicit;
  compression.compressionControlPlaneCount = rates.size();
  compression.pFixedRateFlags = rates.data();
 
  const auto [result, supported] = physical_device_.getImageFormatProperties2<
      vk::ImageFormatProperties2, vk::ImageCompressionPropertiesEXT>(
      format_chain.get());
 
  if (result != vk::Result::eSuccess ||
      !supported.isLinked<vk::ImageCompressionPropertiesEXT>()) {
    return std::nullopt;
  }
 
  const auto& compression_props =
      supported.get<vk::ImageCompressionPropertiesEXT>();
 
  if ((compression_props.imageCompressionFlags &
       vk::ImageCompressionFlagBitsEXT::eFixedRateExplicit) &&
      (compression_props.imageCompressionFixedRateFlags & kIdealFRCRate)) {
    return kIdealFRCRate;
  }
 
  return std::nullopt;
}
 
bool CapabilitiesVK::SupportsTriangleFan() const {
  return has_triangle_fans_;
}
 
ISize CapabilitiesVK::GetMaximumRenderPassAttachmentSize() const {
  return max_render_pass_attachment_size_;
}
 
void CapabilitiesVK::ApplyWorkarounds(const WorkaroundsVK& workarounds) {
  has_primitive_restart_ = !workarounds.slow_primitive_restart_performance;
  has_framebuffer_fetch_ = !workarounds.input_attachment_self_dependency_broken;
}
 
}  // namespace impeller