Merge pull request #4449 from stenzek/vulkan-pipeline-cache

Vulkan: Implement pipeline UID cache

7 files changed, 304 insertions, 53 deletions

diff --git a/Source/Core/VideoBackends/Vulkan/ObjectCache.cpp b/Source/Core/VideoBackends/Vulkan/ObjectCache.cpp
index 61e685874a..761402e478 100644
--- a/Source/Core/VideoBackends/Vulkan/ObjectCache.cpp
+++ b/Source/Core/VideoBackends/Vulkan/ObjectCache.cpp
@@ -159,12 +159,8 @@ GetVulkanColorBlendState(const BlendState& state,
   return vk_state;
 }
 
-VkPipeline ObjectCache::GetPipeline(const PipelineInfo& info)
+VkPipeline ObjectCache::CreatePipeline(const PipelineInfo& info)
 {
-  auto iter = m_pipeline_objects.find(info);
-  if (iter != m_pipeline_objects.end())
-    return iter->second;
-
   // Declare descriptors for empty vertex buffers/attributes
   static const VkPipelineVertexInputStateCreateInfo empty_vertex_input_state = {
       VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO,  // VkStructureType sType
@@ -278,16 +274,34 @@ VkPipeline ObjectCache::GetPipeline(const PipelineInfo& info)
       -1                     // int32_t                                          basePipelineIndex
   };
 
-  VkPipeline pipeline = VK_NULL_HANDLE;
+  VkPipeline pipeline;
   VkResult res = vkCreateGraphicsPipelines(g_vulkan_context->GetDevice(), m_pipeline_cache, 1,
                                            &pipeline_info, nullptr, &pipeline);
   if (res != VK_SUCCESS)
+  {
     LOG_VULKAN_ERROR(res, "vkCreateGraphicsPipelines failed: ");
+    return VK_NULL_HANDLE;
+  }
 
-  m_pipeline_objects.emplace(info, pipeline);
   return pipeline;
 }
 
+VkPipeline ObjectCache::GetPipeline(const PipelineInfo& info)
+{
+  return GetPipelineWithCacheResult(info).first;
+}
+
+std::pair<VkPipeline, bool> ObjectCache::GetPipelineWithCacheResult(const PipelineInfo& info)
+{
+  auto iter = m_pipeline_objects.find(info);
+  if (iter != m_pipeline_objects.end())
+    return {iter->second, true};
+
+  VkPipeline pipeline = CreatePipeline(info);
+  m_pipeline_objects.emplace(info, pipeline);
+  return {pipeline, false};
+}
+
 std::string ObjectCache::GetDiskCacheFileName(const char* type)
 {
   return StringFromFormat("%svulkan-%s-%s.cache", File::GetUserPath(D_SHADERCACHE_IDX).c_str(),
@@ -330,6 +344,13 @@ bool ObjectCache::CreatePipelineCache(bool load_from_disk)
       disk_data.clear();
   }
 
+  if (!disk_data.empty() && !ValidatePipelineCache(disk_data.data(), disk_data.size()))
+  {
+    // Don't use this data. In fact, we should delete it to prevent it from being used next time.
+    File::Delete(m_pipeline_cache_filename);
+    disk_data.clear();
+  }
+
   VkPipelineCacheCreateInfo info = {
       VK_STRUCTURE_TYPE_PIPELINE_CACHE_CREATE_INFO,  // VkStructureType            sType
       nullptr,                                       // const void*                pNext
@@ -355,6 +376,76 @@ bool ObjectCache::CreatePipelineCache(bool load_from_disk)
   return false;
 }
 
+// Based on Vulkan 1.0 specification,
+// Table 9.1. Layout for pipeline cache header version VK_PIPELINE_CACHE_HEADER_VERSION_ONE
+// NOTE: This data is assumed to be in little-endian format.
+#pragma pack(push, 4)
+struct VK_PIPELINE_CACHE_HEADER
+{
+  u32 header_length;
+  u32 header_version;
+  u32 vendor_id;
+  u32 device_id;
+  u8 uuid[VK_UUID_SIZE];
+};
+#pragma pack(pop)
+// TODO: Remove the #if here when GCC 5 is a minimum build requirement.
+#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ < 5
+static_assert(std::has_trivial_copy_constructor<VK_PIPELINE_CACHE_HEADER>::value,
+              "VK_PIPELINE_CACHE_HEADER must be trivially copyable");
+#else
+static_assert(std::is_trivially_copyable<VK_PIPELINE_CACHE_HEADER>::value,
+              "VK_PIPELINE_CACHE_HEADER must be trivially copyable");
+#endif
+
+bool ObjectCache::ValidatePipelineCache(const u8* data, size_t data_length)
+{
+  if (data_length < sizeof(VK_PIPELINE_CACHE_HEADER))
+  {
+    ERROR_LOG(VIDEO, "Pipeline cache failed validation: Invalid header");
+    return false;
+  }
+
+  VK_PIPELINE_CACHE_HEADER header;
+  std::memcpy(&header, data, sizeof(header));
+  if (header.header_length < sizeof(VK_PIPELINE_CACHE_HEADER))
+  {
+    ERROR_LOG(VIDEO, "Pipeline cache failed validation: Invalid header length");
+    return false;
+  }
+
+  if (header.header_version != VK_PIPELINE_CACHE_HEADER_VERSION_ONE)
+  {
+    ERROR_LOG(VIDEO, "Pipeline cache failed validation: Invalid header version");
+    return false;
+  }
+
+  if (header.vendor_id != g_vulkan_context->GetDeviceProperties().vendorID)
+  {
+    ERROR_LOG(VIDEO,
+              "Pipeline cache failed validation: Incorrect vendor ID (file: 0x%X, device: 0x%X)",
+              header.vendor_id, g_vulkan_context->GetDeviceProperties().vendorID);
+    return false;
+  }
+
+  if (header.device_id != g_vulkan_context->GetDeviceProperties().deviceID)
+  {
+    ERROR_LOG(VIDEO,
+              "Pipeline cache failed validation: Incorrect device ID (file: 0x%X, device: 0x%X)",
+              header.device_id, g_vulkan_context->GetDeviceProperties().deviceID);
+    return false;
+  }
+
+  if (std::memcmp(header.uuid, g_vulkan_context->GetDeviceProperties().pipelineCacheUUID,
+                  VK_UUID_SIZE) != 0)
+  {
+    ERROR_LOG(VIDEO, "Pipeline cache failed validation: Incorrect UUID");
+    return false;
+  }
+
+  return true;
+}
+
 void ObjectCache::DestroyPipelineCache()
 {
   for (const auto& it : m_pipeline_objects)
@@ -368,15 +459,6 @@ void ObjectCache::DestroyPipelineCache()
   m_pipeline_cache = VK_NULL_HANDLE;
 }
 
-void ObjectCache::ClearPipelineCache()
-{
-  // Reallocate the pipeline cache object, so it starts fresh and we don't
-  // save old pipelines to disk. This is for major changes, e.g. MSAA mode change.
-  DestroyPipelineCache();
-  if (!CreatePipelineCache(false))
-    PanicAlert("Failed to re-create pipeline cache");
-}
-
 void ObjectCache::SavePipelineCache()
 {
   size_t data_size;
diff --git a/Source/Core/VideoBackends/Vulkan/ObjectCache.h b/Source/Core/VideoBackends/Vulkan/ObjectCache.h
index b991b8a3b8..26593d139d 100644
--- a/Source/Core/VideoBackends/Vulkan/ObjectCache.h
+++ b/Source/Core/VideoBackends/Vulkan/ObjectCache.h
@@ -111,12 +111,17 @@ public:
   // Perform at startup, create descriptor layouts, compiles all static shaders.
   bool Initialize();
 
-  // Find a pipeline by the specified description, if not found, attempts to create it
+  // Creates a pipeline for the specified description. The resulting pipeline, if successful
+  // is not stored anywhere, this is left up to the caller.
+  VkPipeline CreatePipeline(const PipelineInfo& info);
+
+  // Find a pipeline by the specified description, if not found, attempts to create it.
   VkPipeline GetPipeline(const PipelineInfo& info);
 
-  // Wipes out the pipeline cache, use when MSAA modes change, for example
-  // Also destroys the data that would be stored in the disk cache.
-  void ClearPipelineCache();
+  // Find a pipeline by the specified description, if not found, attempts to create it. If this
+  // resulted in a pipeline being created, the second field of the return value will be false,
+  // otherwise for a cache hit it will be true.
+  std::pair<VkPipeline, bool> GetPipelineWithCacheResult(const PipelineInfo& info);
 
   // Saves the pipeline cache to disk. Call when shutting down.
   void SavePipelineCache();
@@ -133,8 +138,12 @@ public:
   VkShaderModule GetPassthroughVertexShader() const { return m_passthrough_vertex_shader; }
   VkShaderModule GetScreenQuadGeometryShader() const { return m_screen_quad_geometry_shader; }
   VkShaderModule GetPassthroughGeometryShader() const { return m_passthrough_geometry_shader; }
+  // Gets the filename of the specified type of cache object (e.g. vertex shader, pipeline).
+  std::string GetDiskCacheFileName(const char* type);
+
 private:
   bool CreatePipelineCache(bool load_from_disk);
+  bool ValidatePipelineCache(const u8* data, size_t data_length);
   void DestroyPipelineCache();
   void LoadShaderCaches();
   void DestroyShaderCaches();
@@ -148,8 +157,6 @@ private:
   void DestroySharedShaders();
   void DestroySamplers();
 
-  std::string GetDiskCacheFileName(const char* type);
-
   std::array<VkDescriptorSetLayout, NUM_DESCRIPTOR_SETS> m_descriptor_set_layouts = {};
 
   VkPipelineLayout m_standard_pipeline_layout = VK_NULL_HANDLE;
diff --git a/Source/Core/VideoBackends/Vulkan/Renderer.cpp b/Source/Core/VideoBackends/Vulkan/Renderer.cpp
index 5348d6beec..1a82184fc4 100644
--- a/Source/Core/VideoBackends/Vulkan/Renderer.cpp
+++ b/Source/Core/VideoBackends/Vulkan/Renderer.cpp
@@ -116,6 +116,9 @@ bool Renderer::Initialize()
                                                m_bounding_box->GetGPUBufferSize());
   }
 
+  // Ensure all pipelines previously used by the game have been created.
+  StateTracker::GetInstance()->LoadPipelineUIDCache();
+
   // Various initialization routines will have executed commands on the command buffer.
   // Execute what we have done before beginning the first frame.
   g_command_buffer_mgr->PrepareToSubmitCommandBuffer();
@@ -1134,8 +1137,8 @@ void Renderer::CheckForConfigChanges()
     g_command_buffer_mgr->WaitForGPUIdle();
     RecompileShaders();
     FramebufferManager::GetInstance()->RecompileShaders();
-    g_object_cache->ClearPipelineCache();
     g_object_cache->RecompileSharedShaders();
+    StateTracker::GetInstance()->LoadPipelineUIDCache();
   }
 
   // For vsync, we need to change the present mode, which means recreating the swap chain.
diff --git a/Source/Core/VideoBackends/Vulkan/StateTracker.cpp b/Source/Core/VideoBackends/Vulkan/StateTracker.cpp
index bfd198886b..c7c4c77c54 100644
--- a/Source/Core/VideoBackends/Vulkan/StateTracker.cpp
+++ b/Source/Core/VideoBackends/Vulkan/StateTracker.cpp
@@ -14,6 +14,7 @@
 #include "VideoBackends/Vulkan/ObjectCache.h"
 #include "VideoBackends/Vulkan/StreamBuffer.h"
 #include "VideoBackends/Vulkan/Util.h"
+#include "VideoBackends/Vulkan/VertexFormat.h"
 #include "VideoBackends/Vulkan/VulkanContext.h"
 
 #include "VideoCommon/GeometryShaderManager.h"
@@ -116,6 +117,93 @@ bool StateTracker::Initialize()
   return true;
 }
 
+void StateTracker::LoadPipelineUIDCache()
+{
+  class PipelineInserter final : public LinearDiskCacheReader<SerializedPipelineUID, u32>
+  {
+  public:
+    explicit PipelineInserter(StateTracker* this_ptr_) : this_ptr(this_ptr_) {}
+    void Read(const SerializedPipelineUID& key, const u32* value, u32 value_size)
+    {
+      this_ptr->PrecachePipelineUID(key);
+    }
+
+  private:
+    StateTracker* this_ptr;
+  };
+
+  std::string filename = g_object_cache->GetDiskCacheFileName("pipeline-uid");
+  PipelineInserter inserter(this);
+
+  // OpenAndRead calls Close() first, which will flush all data to disk when reloading.
+  // This assertion must hold true, otherwise data corruption will result.
+  m_uid_cache.OpenAndRead(filename, inserter);
+}
+
+void StateTracker::AppendToPipelineUIDCache(const PipelineInfo& info)
+{
+  SerializedPipelineUID sinfo;
+  sinfo.blend_state_bits = info.blend_state.bits;
+  sinfo.rasterizer_state_bits = info.rasterization_state.bits;
+  sinfo.depth_stencil_state_bits = info.depth_stencil_state.bits;
+  sinfo.vertex_decl = m_pipeline_state.vertex_format->GetVertexDeclaration();
+  sinfo.vs_uid = m_vs_uid;
+  sinfo.gs_uid = m_gs_uid;
+  sinfo.ps_uid = m_ps_uid;
+  sinfo.primitive_topology = info.primitive_topology;
+
+  u32 dummy_value = 0;
+  m_uid_cache.Append(sinfo, &dummy_value, 1);
+}
+
+bool StateTracker::PrecachePipelineUID(const SerializedPipelineUID& uid)
+{
+  PipelineInfo pinfo = {};
+
+  // Need to create the vertex declaration first, rather than deferring to when a game creates a
+  // vertex loader that uses this format, since we need it to create a pipeline.
+  pinfo.vertex_format = VertexFormat::GetOrCreateMatchingFormat(uid.vertex_decl);
+  pinfo.pipeline_layout = uid.ps_uid.GetUidData()->bounding_box ?
+                              g_object_cache->GetBBoxPipelineLayout() :
+                              g_object_cache->GetStandardPipelineLayout();
+  pinfo.vs = g_object_cache->GetVertexShaderForUid(uid.vs_uid);
+  if (pinfo.vs == VK_NULL_HANDLE)
+  {
+    WARN_LOG(VIDEO, "Failed to get vertex shader from cached UID.");
+    return false;
+  }
+  if (!uid.gs_uid.GetUidData()->IsPassthrough())
+  {
+    pinfo.gs = g_object_cache->GetGeometryShaderForUid(uid.gs_uid);
+    if (pinfo.gs == VK_NULL_HANDLE)
+    {
+      WARN_LOG(VIDEO, "Failed to get geometry shader from cached UID.");
+      return false;
+    }
+  }
+  pinfo.ps = g_object_cache->GetPixelShaderForUid(uid.ps_uid);
+  if (pinfo.ps == VK_NULL_HANDLE)
+  {
+    WARN_LOG(VIDEO, "Failed to get pixel shader from cached UID.");
+    return false;
+  }
+  pinfo.render_pass = m_load_render_pass;
+  pinfo.blend_state.bits = uid.blend_state_bits;
+  pinfo.rasterization_state.bits = uid.rasterizer_state_bits;
+  pinfo.depth_stencil_state.bits = uid.depth_stencil_state_bits;
+  pinfo.primitive_topology = uid.primitive_topology;
+
+  VkPipeline pipeline = g_object_cache->GetPipeline(pinfo);
+  if (pipeline == VK_NULL_HANDLE)
+  {
+    WARN_LOG(VIDEO, "Failed to get pipeline from cached UID.");
+    return false;
+  }
+
+  // We don't need to do anything with this pipeline, just make sure it exists.
+  return true;
+}
+
 void StateTracker::SetVertexBuffer(VkBuffer buffer, VkDeviceSize offset)
 {
   if (m_vertex_buffer == buffer && m_vertex_buffer_offset == offset)
@@ -793,41 +881,54 @@ void StateTracker::EndClearRenderPass()
   EndRenderPass();
 }
 
+PipelineInfo StateTracker::GetAlphaPassPipelineConfig(const PipelineInfo& info) const
+{
+  PipelineInfo temp_info = info;
+
+  // Skip depth writes for this pass. The results will be the same, so no
+  // point in overwriting depth values with the same value.
+  temp_info.depth_stencil_state.write_enable = VK_FALSE;
+
+  // Only allow alpha writes, and disable blending.
+  temp_info.blend_state.blend_enable = VK_FALSE;
+  temp_info.blend_state.logic_op_enable = VK_FALSE;
+  temp_info.blend_state.write_mask = VK_COLOR_COMPONENT_A_BIT;
+
+  return temp_info;
+}
+
+VkPipeline StateTracker::GetPipelineAndCacheUID(const PipelineInfo& info)
+{
+  auto result = g_object_cache->GetPipelineWithCacheResult(info);
+
+  // Add to the UID cache if it is a new pipeline.
+  if (!result.second)
+    AppendToPipelineUIDCache(info);
+
+  return result.first;
+}
+
 bool StateTracker::UpdatePipeline()
 {
   // We need at least a vertex and fragment shader
   if (m_pipeline_state.vs == VK_NULL_HANDLE || m_pipeline_state.ps == VK_NULL_HANDLE)
     return false;
 
-  // Grab a new pipeline object, this can fail
-  if (m_dstalpha_mode != DSTALPHA_ALPHA_PASS)
+  // Grab a new pipeline object, this can fail.
+  // We have to use a different blend state for the alpha pass of the dstalpha fallback.
+  if (m_dstalpha_mode == DSTALPHA_ALPHA_PASS)
   {
-    m_pipeline_object = g_object_cache->GetPipeline(m_pipeline_state);
-    if (m_pipeline_object == VK_NULL_HANDLE)
-      return false;
+    // We need to retain the existing state, since we don't want to break the next draw.
+    PipelineInfo temp_info = GetAlphaPassPipelineConfig(m_pipeline_state);
+    m_pipeline_object = GetPipelineAndCacheUID(temp_info);
   }
   else
   {
-    // We need to make a few modifications to the pipeline object, but retain
-    // the existing state, since we don't want to break the next draw.
-    PipelineInfo temp_info = m_pipeline_state;
-
-    // Skip depth writes for this pass. The results will be the same, so no
-    // point in overwriting depth values with the same value.
-    temp_info.depth_stencil_state.write_enable = VK_FALSE;
-
-    // Only allow alpha writes, and disable blending.
-    temp_info.blend_state.blend_enable = VK_FALSE;
-    temp_info.blend_state.logic_op_enable = VK_FALSE;
-    temp_info.blend_state.write_mask = VK_COLOR_COMPONENT_A_BIT;
-
-    m_pipeline_object = g_object_cache->GetPipeline(temp_info);
-    if (m_pipeline_object == VK_NULL_HANDLE)
-      return false;
+    m_pipeline_object = GetPipelineAndCacheUID(m_pipeline_state);
   }
 
   m_dirty_flags |= DIRTY_FLAG_PIPELINE_BINDING;
-  return true;
+  return m_pipeline_object != VK_NULL_HANDLE;
 }
 
 bool StateTracker::UpdateDescriptorSet()
diff --git a/Source/Core/VideoBackends/Vulkan/StateTracker.h b/Source/Core/VideoBackends/Vulkan/StateTracker.h
index b31adec6b5..a42a9dc72d 100644
--- a/Source/Core/VideoBackends/Vulkan/StateTracker.h
+++ b/Source/Core/VideoBackends/Vulkan/StateTracker.h
@@ -9,6 +9,7 @@
 #include <memory>
 
 #include "Common/CommonTypes.h"
+#include "Common/LinearDiskCache.h"
 #include "VideoBackends/Vulkan/Constants.h"
 #include "VideoBackends/Vulkan/ObjectCache.h"
 #include "VideoCommon/GeometryShaderGen.h"
@@ -111,15 +112,22 @@ public:
 
   bool IsWithinRenderArea(s32 x, s32 y, u32 width, u32 height) const;
 
-private:
-  bool Initialize();
+  // Reloads the UID cache, ensuring all pipelines used by the game so far have been created.
+  void LoadPipelineUIDCache();
 
-  // Check that the specified viewport is within the render area.
-  // If not, ends the render pass if it is a clear render pass.
-  bool IsViewportWithinRenderArea() const;
-  bool UpdatePipeline();
-  bool UpdateDescriptorSet();
-  void UploadAllConstants();
+private:
+  // Serialized version of PipelineInfo, used when loading/saving the pipeline UID cache.
+  struct SerializedPipelineUID
+  {
+    u64 blend_state_bits;
+    u32 rasterizer_state_bits;
+    u32 depth_stencil_state_bits;
+    PortableVertexDeclaration vertex_decl;
+    VertexShaderUid vs_uid;
+    GeometryShaderUid gs_uid;
+    PixelShaderUid ps_uid;
+    VkPrimitiveTopology primitive_topology;
+  };
 
   enum DITRY_FLAG : u32
   {
@@ -140,6 +148,32 @@ private:
     DIRTY_FLAG_ALL_DESCRIPTOR_SETS =
         DIRTY_FLAG_VS_UBO | DIRTY_FLAG_GS_UBO | DIRTY_FLAG_PS_SAMPLERS | DIRTY_FLAG_PS_SSBO
   };
+
+  bool Initialize();
+
+  // Appends the specified pipeline info, combined with the UIDs stored in the class.
+  // The info is here so that we can store variations of a UID, e.g. blend state.
+  void AppendToPipelineUIDCache(const PipelineInfo& info);
+
+  // Precaches a pipeline based on the UID information.
+  bool PrecachePipelineUID(const SerializedPipelineUID& uid);
+
+  // Check that the specified viewport is within the render area.
+  // If not, ends the render pass if it is a clear render pass.
+  bool IsViewportWithinRenderArea() const;
+
+  // Gets a pipeline state that can be used to draw the alpha pass with constant alpha enabled.
+  PipelineInfo GetAlphaPassPipelineConfig(const PipelineInfo& info) const;
+
+  // Obtains a Vulkan pipeline object for the specified pipeline configuration.
+  // Also adds this pipeline configuration to the UID cache if it is not present already.
+  VkPipeline GetPipelineAndCacheUID(const PipelineInfo& info);
+
+  bool UpdatePipeline();
+  bool UpdateDescriptorSet();
+  void UploadAllConstants();
+
+  // Which bindings/state has to be updated before the next draw.
   u32 m_dirty_flags = 0;
 
   // input assembly
@@ -194,5 +228,11 @@ private:
   std::vector<u32> m_cpu_accesses_this_frame;
   std::vector<u32> m_scheduled_command_buffer_kicks;
   bool m_allow_background_execution = true;
+
+  // Draw state cache on disk
+  // We don't actually use the value field here, instead we generate the shaders from the uid
+  // on-demand. If all goes well, it should hit the shader and Vulkan pipeline cache, therefore
+  // loading should be reasonably efficient.
+  LinearDiskCache<SerializedPipelineUID, u32> m_uid_cache;
 };
 }
diff --git a/Source/Core/VideoBackends/Vulkan/VertexFormat.cpp b/Source/Core/VideoBackends/Vulkan/VertexFormat.cpp
index 27c1d06199..ba67472394 100644
--- a/Source/Core/VideoBackends/Vulkan/VertexFormat.cpp
+++ b/Source/Core/VideoBackends/Vulkan/VertexFormat.cpp
@@ -53,6 +53,19 @@ VertexFormat::VertexFormat(const PortableVertexDeclaration& in_vtx_decl)
   SetupInputState();
 }
 
+VertexFormat* VertexFormat::GetOrCreateMatchingFormat(const PortableVertexDeclaration& decl)
+{
+  auto vertex_format_map = VertexLoaderManager::GetNativeVertexFormatMap();
+  auto iter = vertex_format_map->find(decl);
+  if (iter == vertex_format_map->end())
+  {
+    auto ipair = vertex_format_map->emplace(decl, std::make_unique<VertexFormat>(decl));
+    iter = ipair.first;
+  }
+
+  return static_cast<VertexFormat*>(iter->second.get());
+}
+
 void VertexFormat::MapAttributes()
 {
   m_num_attributes = 0;
diff --git a/Source/Core/VideoBackends/Vulkan/VertexFormat.h b/Source/Core/VideoBackends/Vulkan/VertexFormat.h
index 3614366e2f..ef2d31d748 100644
--- a/Source/Core/VideoBackends/Vulkan/VertexFormat.h
+++ b/Source/Core/VideoBackends/Vulkan/VertexFormat.h
@@ -16,6 +16,11 @@ class VertexFormat : public ::NativeVertexFormat
 public:
   VertexFormat(const PortableVertexDeclaration& in_vtx_decl);
 
+  // Creates or obtains a pointer to a VertexFormat representing decl.
+  // If this results in a VertexFormat being created, if the game later uses a matching vertex
+  // declaration, the one that was previously created will be used.
+  static VertexFormat* GetOrCreateMatchingFormat(const PortableVertexDeclaration& decl);
+
   // Passed to pipeline state creation
   const VkPipelineVertexInputStateCreateInfo& GetVertexInputStateInfo() const
   {