[idd] capture: add direct full-copy workaround

doc/idd_configuration.rst

@@ -63,6 +63,14 @@ Disable no GPU warning
    processing. It does not enable GPU acceleration or change the active
    adapter.
 
+Force full direct frame copies
+   Works around GPU drivers that corrupt partial D3D12 copies into the shared
+   transport heap. When enabled, the GPU copies every direct frame in full;
+   readback/indirect transfers continue using partial damage copies. This can
+   substantially increase GPU and shared-memory bandwidth, so leave it
+   disabled unless you encounter corruption. Changing it requests a driver
+   reload.
+
 Unlike mode-list edits, preference checkboxes are saved when clicked.
 
 Software processing

doc/words.txt

@@ -82,6 +82,7 @@ quadraphonic
 Quadro
 queueing
 radeon
+readback
 realtime
 renderer
 repo

idd/LGIdd/capture/CHardwareFrameProcessor.cpp

@@ -19,6 +19,8 @@
  */
 
 #include "capture/CHardwareFrameProcessor.h"
+
+#include "config/CSettings.h"
 #include "capture/CFrameProcessorUtil.h"
 #include "transport/IFrameTransport.h"
 #include "CSRWLock.h"
@@ -76,11 +78,15 @@ CHardwareFrameProcessor::CHardwareFrameProcessor(
     CSRWLock * pipelineLock, HANDLE terminateEvent, bool useCadence) :
   CFrameProcessor(transport, std::move(dx12), postProcessors,
     pipelineLock, terminateEvent),
-  m_useCadence(useCadence)
+  m_useCadence(useCadence),
+  m_forceFullDirectCopy(CSettings::ShouldForceFullDirectCopy())
 {
   m_candidateAvailableEvent.Attach(
     CreateEvent(nullptr, FALSE, FALSE, nullptr));
   m_copySubmitEvent.Attach(CreateEvent(nullptr, TRUE, TRUE, nullptr));
+
+  if (m_forceFullDirectCopy)
+    DEBUG_INFO("Forcing full copies to direct transport memory");
 }
 
 bool CHardwareFrameProcessor::IsValid() const
@@ -668,7 +674,12 @@ bool CHardwareFrameProcessor::Publish(
 
     RECT copyDirtyRects[LG_MAX_DIRTY_RECTS * 2] = {};
     unsigned nbCopyDirtyRects = 0;
-    const bool fullCopy = CFrameProcessorUtil::BuildCopyDamage(
+    // Some GPUs corrupt fragmented writes to the external transport heap.
+    // An unmapped target is a direct D3D12 transport resource; readback
+    // targets remain mapped and continue using normal damage copies.
+    const bool fullCopy =
+      (m_forceFullDirectCopy && !fbRes->GetMap()) ||
+      CFrameProcessorUtil::BuildCopyDamage(
         postProcessor, prepared.targets[i].fullCopy,
         previousDirtyRects, nbPreviousDirtyRects,
         candidate.dirtyRects, candidate.nbDirtyRects,

idd/LGIdd/capture/CHardwareFrameProcessor.h

@@ -73,6 +73,7 @@ private:
   CSRWLock            m_copySubmitLock;
   bool                m_publishPending     = false;
   bool                m_useCadence         = true;
+  bool                m_forceFullDirectCopy = false;
   Wrappers::Event     m_candidateAvailableEvent;
   Wrappers::Event     m_copySubmitEvent;
 

idd/LGIdd/config/CSettings.h

@@ -96,6 +96,11 @@ class CSettings
       return ReadBoolValue(L"LogStatistics");
     }
 
+    static bool ShouldForceFullDirectCopy()
+    {
+      return ReadBoolValue(L"ForceFullDirectCopy");
+    }
+
   private:
     static const wchar_t * RegistryKey()
     {

idd/LGIddHelper/CConfigWindow.cpp

@@ -54,6 +54,7 @@ CConfigWindow::CConfigWindow() : m_scale(1)
     m_defaultRefresh = m_settings.getDefaultRefresh();
     m_noGPU = m_settings.getNoGPU();
     m_exclusive = m_settings.getExclusiveMonitor();
+    m_forceFullDirectCopy = m_settings.getForceFullDirectCopy();
   }
 
   if (!CreateWindowEx(0, MAKEINTATOM(s_atom), L"Looking Glass IDD Configuration",
@@ -94,6 +95,7 @@ void CConfigWindow::updateFont()
     *m_modeWidth, *m_modeHeight, *m_modeRefresh, *m_modeUpdate, *m_modeDelete, *m_modeReset,
     *m_defRefreshLabel, *m_defRefresh, *m_defRefreshHz, *m_modeSave, *m_modeRevert,
     *m_prefGroup, *m_prefNoGPU, *m_prefExclusive,
+    *m_prefForceFullDirectCopy,
   }))
     SendMessage(child, WM_SETFONT, (WPARAM)m_font.Get(), 1);
 }
@@ -187,6 +189,8 @@ LRESULT CConfigWindow::onCreate()
   m_prefGroup.reset(new CGroupBox(L"Preferences", 0, m_hwnd));
   m_prefNoGPU.reset(new CCheckbox(L"Disable no GPU warning", 0, m_hwnd));
   m_prefExclusive.reset(new CCheckbox(L"Make LG the only monitor", 0, m_hwnd));
+  m_prefForceFullDirectCopy.reset(new CCheckbox(
+    L"Force full direct frame copies", 0, m_hwnd));
 
   if (m_noGPU)
     m_prefNoGPU->setChecked(*m_noGPU);
@@ -194,6 +198,9 @@ LRESULT CConfigWindow::onCreate()
   if (m_exclusive)
     m_prefExclusive->setChecked(*m_exclusive);
 
+  if (m_forceFullDirectCopy)
+    m_prefForceFullDirectCopy->setChecked(*m_forceFullDirectCopy);
+
   LONG width, height;
   getMinimumSize(width, height);
   SetWindowPos(m_hwnd, NULL, 0, 0, width, height, SWP_NOMOVE | SWP_NOZORDER);
@@ -233,9 +240,10 @@ LRESULT CConfigWindow::onResize(DWORD width, DWORD height)
   pos.pinBottomLeft(*m_modeSave, 20, 20, 132, 24);
   pos.pinBottomLeft(*m_modeRevert, 154, 20, 50, 24);
 
-  pos.pinTopLeft(*m_prefGroup, 224, 40, 200, 72);
+  pos.pinTopLeft(*m_prefGroup, 224, 40, 200, 92);
   pos.pinTopLeft(*m_prefNoGPU, 236, 64, 176, 20);
   pos.pinTopLeft(*m_prefExclusive, 236, 84, 176, 20);
+  pos.pinTopLeft(*m_prefForceFullDirectCopy, 236, 104, 188, 20);
   return 0;
 }
 
@@ -344,6 +352,22 @@ LRESULT CConfigWindow::onCommand(WORD id, WORD code, HWND hwnd)
     m_settings.setExclusiveMonitor(*m_exclusive);
     m_prefExclusive->setChecked(*m_exclusive);
   }
+  else if (m_prefForceFullDirectCopy &&
+           hwnd == *m_prefForceFullDirectCopy && code == BN_CLICKED &&
+           m_forceFullDirectCopy)
+  {
+    const bool value = !*m_forceFullDirectCopy;
+    const LSTATUS result = m_settings.setForceFullDirectCopy(value);
+    if (result != ERROR_SUCCESS)
+    {
+      DEBUG_ERROR_HR(result, "Failed to save ForceFullDirectCopy");
+      return 0;
+    }
+
+    *m_forceFullDirectCopy = value;
+    m_prefForceFullDirectCopy->setChecked(value);
+    sendSettingChange();
+  }
   else if (m_modeSave && hwnd == *m_modeSave && code == BN_CLICKED)
   {
     bool updated = false;

idd/LGIddHelper/CConfigWindow.h

@@ -64,6 +64,7 @@ class CConfigWindow : public CWindow
   std::unique_ptr<CGroupBox> m_prefGroup;
   std::unique_ptr<CCheckbox> m_prefNoGPU;
   std::unique_ptr<CCheckbox> m_prefExclusive;
+  std::unique_ptr<CCheckbox> m_prefForceFullDirectCopy;
 
   std::function<void()> m_onDestroy;
   std::function<void()> m_onSettingChange;
@@ -75,6 +76,7 @@ class CConfigWindow : public CWindow
   std::optional<DWORD> m_defaultRefresh;
   std::optional<bool> m_noGPU;
   std::optional<bool> m_exclusive;
+  std::optional<bool> m_forceFullDirectCopy;
 
   void getMinimumSize(LONG &width, LONG &height);
   void updateFont();

idd/LGIddHelper/CRegistrySettings.cpp

@@ -265,3 +265,28 @@ LSTATUS CRegistrySettings::setExclusiveMonitor(bool exclusive)
   DWORD dwValue = exclusive;
   return RegSetValueEx(hKey, L"ExclusiveMonitor", 0, REG_DWORD, (LPBYTE)&dwValue, sizeof(DWORD));
 }
+
+std::optional<bool> CRegistrySettings::getForceFullDirectCopy()
+{
+  DWORD result, cbData = sizeof result;
+
+  LSTATUS status = RegGetValue(hKey, nullptr, L"ForceFullDirectCopy",
+    RRF_RT_REG_DWORD, nullptr, &result, &cbData);
+  switch (status)
+  {
+  case ERROR_SUCCESS:
+    return !!result;
+  case ERROR_FILE_NOT_FOUND:
+    return false;
+  default:
+    DEBUG_ERROR_HR(status, "RegGetValue(ForceFullDirectCopy)");
+    return {};
+  }
+}
+
+LSTATUS CRegistrySettings::setForceFullDirectCopy(bool forceFullCopy)
+{
+  DWORD dwValue = forceFullCopy;
+  return RegSetValueEx(hKey, L"ForceFullDirectCopy", 0, REG_DWORD,
+    (LPBYTE)&dwValue, sizeof(DWORD));
+}

idd/LGIddHelper/CRegistrySettings.h

@@ -56,4 +56,7 @@ public:
 
   std::optional<bool> getExclusiveMonitor();
   LSTATUS setExclusiveMonitor(bool exclusive);
+
+  std::optional<bool> getForceFullDirectCopy();
+  LSTATUS setForceFullDirectCopy(bool forceFullCopy);
 };