[idd] hdr: complete HDR display and cursor metadata

Publish BT.2020 chromaticities in the virtual monitor EDID so
Windows receives a valid HDR colour volume.

Extend cursor messages with their IddCx SDR white level and an
explicit visibility-valid flag. Consumers can then calibrate cursors
without treating colour-transform-only messages as cursor hides.

common/include/common/KVMFR.h

@@ -28,7 +28,7 @@
 #include "types.h"
 
 #define KVMFR_MAGIC   "KVMFR---"
-#define KVMFR_VERSION 22
+#define KVMFR_VERSION 23
 
 // Fallback used by producers that cannot report the source display's SDR
 // white level. IDD frames override this with IDDCX_METADATA2::SdrWhiteLevel.
@@ -54,7 +54,10 @@ enum
   CURSOR_FLAG_POSITION        = 0x1,
   CURSOR_FLAG_VISIBLE         = 0x2,
   CURSOR_FLAG_SHAPE           = 0x4,
-  CURSOR_FLAG_COLOR_TRANSFORM = 0x8
+  CURSOR_FLAG_COLOR_TRANSFORM = 0x8,
+  // CURSOR_FLAG_VISIBLE contains a new visibility state. This distinguishes
+  // an invisible cursor update from messages carrying unrelated cursor data.
+  CURSOR_FLAG_VISIBLE_VALID   = 0x10
 };
 
 typedef uint32_t KVMFRCursorFlags;
@@ -135,6 +138,7 @@ typedef struct KVMFRCursor
   uint32_t   width;       // width of the shape
   uint32_t   height;      // height of the shape
   uint32_t   pitch;       // row length in bytes of the shape
+  uint32_t   sdrWhiteLevel; // cursor white level in nits for HDR composition
 }
 KVMFRCursor;
 

host/src/app.c

@@ -515,8 +515,9 @@ static void sendPointer(bool newClient)
     KVMFRCursor *cursor = lgmpHostMemPtr(mem);
     cursor->x = app.pointerInfo.x;
     cursor->y = app.pointerInfo.y;
+    cursor->sdrWhiteLevel = KVMFR_SDR_WHITE_LEVEL_DEFAULT;
 
-    const uint32_t flags = CURSOR_FLAG_POSITION |
+    const uint32_t flags = CURSOR_FLAG_POSITION | CURSOR_FLAG_VISIBLE_VALID |
       (app.pointerShapeValid   ? CURSOR_FLAG_SHAPE   : 0) |
       (app.pointerInfo.visible ? CURSOR_FLAG_VISIBLE : 0);
 
@@ -524,7 +525,7 @@ static void sendPointer(bool newClient)
     return;
   }
 
-  uint32_t flags = 0;
+  uint32_t flags = CURSOR_FLAG_VISIBLE_VALID;
   PLGMPMemory mem;
   if (app.pointerInfo.shapeUpdate)
   {
@@ -539,6 +540,7 @@ static void sendPointer(bool newClient)
       app.pointerIndex = 0;
   }
   KVMFRCursor *cursor = lgmpHostMemPtr(mem);
+  cursor->sdrWhiteLevel = KVMFR_SDR_WHITE_LEVEL_DEFAULT;
 
   if (app.pointerInfo.positionUpdate || newClient)
   {

idd/LGIdd/CEdid.cpp

@@ -309,6 +309,41 @@ static EdidStandardTiming MakeUnusedStandardTiming()
   return timing;
 }
 
+#include <algorithm> // Ensure this header is included for std::min and std::max
+
+static WORD EdidChromaticity(double value)
+{
+ return (WORD)min(1023.0, max(0.0, value * 1024.0 + 0.5));
+}
+
+static void SetChromaticityCoordinates(BYTE coordinates[10])
+{
+  // The virtual display transports HDR in the BT.2020 container. Describe
+  // that full container gamut and its D65 white point rather than leaving an
+  // invalid all-zero base-block colour volume.
+  const WORD rx = EdidChromaticity(0.7080);
+  const WORD ry = EdidChromaticity(0.2920);
+  const WORD gx = EdidChromaticity(0.1700);
+  const WORD gy = EdidChromaticity(0.7970);
+  const WORD bx = EdidChromaticity(0.1310);
+  const WORD by = EdidChromaticity(0.0460);
+  const WORD wx = EdidChromaticity(0.3127);
+  const WORD wy = EdidChromaticity(0.3290);
+
+  coordinates[0] = (BYTE)(((rx & 3) << 6) | ((ry & 3) << 4) |
+      ((gx & 3) << 2) | (gy & 3));
+  coordinates[1] = (BYTE)(((bx & 3) << 6) | ((by & 3) << 4) |
+      ((wx & 3) << 2) | (wy & 3));
+  coordinates[2] = (BYTE)(rx >> 2);
+  coordinates[3] = (BYTE)(ry >> 2);
+  coordinates[4] = (BYTE)(gx >> 2);
+  coordinates[5] = (BYTE)(gy >> 2);
+  coordinates[6] = (BYTE)(bx >> 2);
+  coordinates[7] = (BYTE)(by >> 2);
+  coordinates[8] = (BYTE)(wx >> 2);
+  coordinates[9] = (BYTE)(wy >> 2);
+}
+
 static void InitEdidBaseBlock(EdidBaseBlock& base)
 {
   memcpy(base.header, EDID_HEADER, sizeof(base.header));
@@ -328,6 +363,7 @@ static void InitEdidBaseBlock(EdidBaseBlock& base)
   base.verticalSizeCm       = EDID_VERTICAL_SIZE_CM;
   base.displayGamma         = EDID_DISPLAY_GAMMA_2_2;
   base.supportedFeatures    = EDID_FEATURES_PREFERRED_TIMING_RGB;
+  SetChromaticityCoordinates(base.chromaticityCoordinates);
 
   for (UINT i = 0; i < EDID_STANDARD_TIMING_COUNT; ++i)
     base.standardTimings[i] = MakeUnusedStandardTiming();
@@ -612,4 +648,4 @@ void CEdid::Build(const CSettings::DisplayModes& modes)
 
   SetChecksum(cta);
   memcpy(m_data.data() + sizeof(baseBlock), &ctaBlock, sizeof(ctaBlock));
-}
+}

idd/LGIdd/CIndirectDeviceContext.cpp

@@ -1222,7 +1222,8 @@ void CIndirectDeviceContext::FinalizeFrameBuffer(unsigned frameIndex) const
   fb->wp = m_height * m_pitch;
 }
 
-void CIndirectDeviceContext::SendCursor(const IDARG_OUT_QUERY_HWCURSOR& info, const BYTE * data)
+void CIndirectDeviceContext::SendCursor(const IDARG_OUT_QUERY_HWCURSOR& info,
+  const BYTE * data, UINT sdrWhiteLevel)
 {
   PLGMPMemory mem;
   if (info.CursorShapeInfo.CursorType == IDDCX_CURSOR_SHAPE_TYPE_UNINITIALIZED)
@@ -1239,9 +1240,11 @@ void CIndirectDeviceContext::SendCursor(const IDARG_OUT_QUERY_HWCURSOR& info, co
   }
 
   KVMFRCursor * cursor = (KVMFRCursor *)lgmpHostMemPtr(mem);
+  cursor->sdrWhiteLevel = sdrWhiteLevel ?
+    sdrWhiteLevel : KVMFR_SDR_WHITE_LEVEL_DEFAULT;
 
   m_cursorVisible = info.IsCursorVisible;
-  uint32_t flags  = 0;
+  uint32_t flags  = CURSOR_FLAG_VISIBLE_VALID;
 
   if (info.IsCursorVisible)
   {
@@ -1416,7 +1419,7 @@ void CIndirectDeviceContext::ResendCursor()
   cursor->y = (int16_t)m_cursorY;
 
   const uint32_t flags =
-    CURSOR_FLAG_POSITION | CURSOR_FLAG_SHAPE |
+    CURSOR_FLAG_POSITION | CURSOR_FLAG_SHAPE | CURSOR_FLAG_VISIBLE_VALID |
     (m_cursorVisible ? CURSOR_FLAG_VISIBLE : 0);
 
   LGMP_STATUS status;

idd/LGIdd/CIndirectDeviceContext.h

@@ -225,7 +225,8 @@ public:
   void WriteFrameBuffer(unsigned frameIndex, void* src, size_t offset, size_t len, bool setWritePos) const;
   void FinalizeFrameBuffer(unsigned frameIndex) const;
 
-  void SendCursor(const IDARG_OUT_QUERY_HWCURSOR & info, const BYTE * data);
+  void SendCursor(const IDARG_OUT_QUERY_HWCURSOR & info, const BYTE * data,
+    UINT sdrWhiteLevel);
 
   // Tracks HDR state from EvtIddCxMonitorSetDefaultHdrMetadata
   void SetHDRActive(const struct IDDCX_HDR10_METADATA * hdrMeta);

idd/LGIdd/CSwapChainProcessor.cpp

@@ -206,6 +206,7 @@ bool CSwapChainProcessor::SwapChainThreadCore()
         surface        = buffer.MetaData.pSurface;
         colorSpace     = buffer.MetaData.SurfaceColorSpace;
         sdrWhiteLevel  = buffer.MetaData.SdrWhiteLevel;
+        m_sdrWhiteLevel.store(sdrWhiteLevel, std::memory_order_relaxed);
         UpdateHDRMetadata(buffer.MetaData);
       }
     }
@@ -776,6 +777,7 @@ bool CSwapChainProcessor::QueryHWCursor()
   in.ShapeBufferSizeInBytes = 512 * 512 * 4;
 
   IDARG_OUT_QUERY_HWCURSOR out = {};
+  UINT cursorWhiteLevel = m_sdrWhiteLevel.load(std::memory_order_relaxed);
   NTSTATUS status;
 #ifdef HAS_IDDCX_110
   if (m_devContext->CanProcessFP16())
@@ -787,6 +789,8 @@ bool CSwapChainProcessor::QueryHWCursor()
     out.Y                    = out3.Y;
     out.IsCursorShapeUpdated = out3.IsCursorShapeUpdated;
     out.CursorShapeInfo      = out3.CursorShapeInfo;
+    if (out3.SdrWhiteLevel)
+      cursorWhiteLevel = out3.SdrWhiteLevel;
   }
   else
 #endif
@@ -810,7 +814,7 @@ bool CSwapChainProcessor::QueryHWCursor()
   if (out.IsCursorShapeUpdated)
     m_lastShapeId = out.CursorShapeInfo.ShapeId;
 
-  m_devContext->SendCursor(out, m_shapeBuffer);
+  m_devContext->SendCursor(out, m_shapeBuffer, cursorWhiteLevel);
   return true;
 }
 

idd/LGIdd/CSwapChainProcessor.h

@@ -30,6 +30,7 @@
 #include <Windows.h>
 #include <wrl.h>
 #include <IddCx.h>
+#include <atomic>
 #include <memory>
 
 using namespace Microsoft::WRL;
@@ -60,6 +61,7 @@ private:
   Wrappers::Event m_cursorDataEvent;
   BYTE*           m_shapeBuffer;
   DWORD           m_lastShapeId = 0;
+  std::atomic<UINT> m_sdrWhiteLevel { KVMFR_SDR_WHITE_LEVEL_DEFAULT };
 
   // Output-space damage from the previous published frame. The shared-memory
   // frame buffers alternate, so this must be copied along with the current