From 0c1b6439c4d96601580666c156bd26fd12959e86 Mon Sep 17 00:00:00 2001
From: dendron2000 <dendron2000@mail.ru>
Date: Tue, 26 Feb 2019 15:42:43 +0000
Subject: [PATCH] Fix reading back initial buffer/texture states in D3D12.

---
 renderdoc/driver/d3d12/d3d12_initstate.cpp | 37 ++++++++++++++++++++--
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/renderdoc/driver/d3d12/d3d12_initstate.cpp b/renderdoc/driver/d3d12/d3d12_initstate.cpp
index 6c3e4dcd2..0b0197c58 100644
--- a/renderdoc/driver/d3d12/d3d12_initstate.cpp
+++ b/renderdoc/driver/d3d12/d3d12_initstate.cpp
@@ -79,6 +79,10 @@ bool D3D12ResourceManager::Prepare_InitialState(ID3D12DeviceChild *res)
         SetInitialContents(GetResID(r), D3D12InitialContents(D3D12InitialContents::MapDirect));
         return true;
       }
+      else if(heapProps.Type == D3D12_HEAP_TYPE_UPLOAD)
+      {
+        return true;
+      }
 
       heapProps.Type = D3D12_HEAP_TYPE_READBACK;
       heapProps.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
@@ -96,10 +100,30 @@ bool D3D12ResourceManager::Prepare_InitialState(ID3D12DeviceChild *res)
       if(nonresident)
         m_Device->MakeResident(1, &pageable);
 
+      const vector<D3D12_RESOURCE_STATES> &states = m_Device->GetSubresourceStates(GetResID(res));
+      RDCASSERT(states.size() == 1);
+
+      D3D12_RESOURCE_BARRIER barrier;
+      const bool needsTransition = (states[0] & D3D12_RESOURCE_STATE_COPY_SOURCE) == 0;
+
+      if(needsTransition)
+      {
+        barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
+        barrier.Flags = D3D12_RESOURCE_BARRIER_FLAG_NONE;
+        barrier.Transition.pResource = r->GetReal();
+        barrier.Transition.Subresource = (UINT)0;
+        barrier.Transition.StateBefore = states[0];
+        barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_COPY_SOURCE;
+      }
+
+      ID3D12GraphicsCommandList *list = Unwrap(m_Device->GetInitialStateList());
+
+      // transition to copy source
+      if(needsTransition)
+        list->ResourceBarrier(1, &barrier);
+
       if(SUCCEEDED(hr))
       {
-        ID3D12GraphicsCommandList *list = Unwrap(m_Device->GetInitialStateList());
-
         list->CopyResource(copyDst, r->GetReal());
       }
       else
@@ -107,6 +131,13 @@ bool D3D12ResourceManager::Prepare_InitialState(ID3D12DeviceChild *res)
         RDCERR("Couldn't create readback buffer: HRESULT: %s", ToStr(hr).c_str());
       }
 
+      // transition back to whatever it was before
+      if(needsTransition)
+      {
+        std::swap(barrier.Transition.StateBefore, barrier.Transition.StateAfter);
+        list->ResourceBarrier(1, &barrier);
+      }
+
       if(nonresident)
       {
         m_Device->CloseInitialStateList();
@@ -172,7 +203,7 @@ bool D3D12ResourceManager::Prepare_InitialState(ID3D12DeviceChild *res)
 
         for(size_t i = 0; i < states.size(); i++)
         {
-          if(states[i] & D3D12_RESOURCE_STATE_COPY_SOURCE)
+          if(states[i] & destState)
             continue;
 
           D3D12_RESOURCE_BARRIER barrier;