[host] d12: implement damage aware copy

host/platform/Windows/capture/D12/backend.h

@@ -25,6 +25,8 @@
 #include <d3d12.h>
 #include "interface/capture.h"
 
+#define D12_MAX_DIRTY_RECTS 256
+
 typedef struct D12Backend D12Backend;
 
 struct D12Backend
@@ -35,6 +37,9 @@ struct D12Backend
   // internal name
   const char * codeName;
 
+  // enable damage tracking
+  bool trackDamage;
+
   // creation/init/free
   bool (*create)(D12Backend ** instance, unsigned frameBuffers);
   bool (*init)(
@@ -54,7 +59,9 @@ struct D12Backend
     ID3D12CommandQueue * commandQueue);
 
   ID3D12Resource * (*fetch)(D12Backend * instance,
-    unsigned frameBufferIndex);
+    unsigned frameBufferIndex,
+    const RECT * dirtyRects[static D12_MAX_DIRTY_RECTS],
+    unsigned * nbDirtyRects);
 };
 
 static inline bool d12_backendCreate(const D12Backend * backend,
@@ -67,8 +74,12 @@ static inline bool d12_backendCreate(const D12Backend * backend,
 }
 
 static inline bool d12_backendInit(D12Backend * instance, bool debug,
-  ID3D12Device3 * device, IDXGIAdapter1 * adapter, IDXGIOutput * output)
+  ID3D12Device3 * device, IDXGIAdapter1 * adapter, IDXGIOutput * output,
-  { return instance->init(instance, debug, device, adapter, output); }
+  bool trackDamage)
+{
+  instance->trackDamage = trackDamage;
+  return instance->init(instance, debug, device, adapter, output);
+}
 
 static inline bool d12_backendDeinit(D12Backend * instance)
   { return instance->deinit(instance); }
@@ -85,8 +96,10 @@ static inline CaptureResult d12_backendSync(D12Backend * instance,
   { return instance->sync(instance, commandQueue); }
 
 static inline ID3D12Resource * d12_backendFetch(D12Backend * instance,
-  unsigned frameBufferIndex)
+  unsigned frameBufferIndex, const RECT * dirtyRects[static D12_MAX_DIRTY_RECTS],
-  { return instance->fetch(instance, frameBufferIndex); }
+  unsigned * nbDirtyRects)
+  { return instance->fetch(instance, frameBufferIndex, dirtyRects,
+      nbDirtyRects); }
 
 // Backend defines
 

host/platform/Windows/capture/D12/backend/dd.c

@@ -51,6 +51,9 @@ typedef struct DDCacheInfo
   ID3D12Fence       ** d12Fence;
   UINT64               fenceValue;
   bool                 ready;
+
+  RECT     dirtyRects[D12_MAX_DIRTY_RECTS];
+  unsigned nbDirtyRects;
 }
 DDCacheInfo;
 
@@ -416,13 +419,17 @@ static CaptureResult d12_dd_sync(D12Backend * instance,
 }
 
 static ID3D12Resource * d12_dd_fetch(D12Backend * instance,
-  unsigned frameBufferIndex)
+  unsigned frameBufferIndex, const RECT * dirtyRects[static D12_MAX_DIRTY_RECTS],
+  unsigned * nbDirtyRects)
 {
   DDInstance * this = UPCAST(DDInstance, instance);
 
   if (!this->current)
     return NULL;
 
+  *dirtyRects   = this->current->dirtyRects;
+  *nbDirtyRects = this->current->nbDirtyRects;
+
   ID3D12Resource_AddRef(*this->current->d12Res);
   return *this->current->d12Res;
 }
@@ -478,6 +485,75 @@ static bool d12_dd_handleFrameUpdate(DDInstance * this, IDXGIResource * res)
   ID3D11DeviceContext4_Signal(
     *this->context, *this->current->fence, this->current->fenceValue);
 
+  // handle damage tracking
+  this->current->nbDirtyRects = 0;
+  if (this->base.trackDamage)
+  {
+    /* Get the frame damage, if there is too many damage rects, we disable
+     * damage tracking for the frame and assume full frame damage */
+
+    UINT requiredSize;
+    hr = IDXGIOutputDuplication_GetFrameDirtyRects(*this->dup,
+      sizeof(this->current->dirtyRects),
+      this->current->dirtyRects,
+      &requiredSize);
+    if (FAILED(hr))
+    {
+      if (hr != DXGI_ERROR_MORE_DATA)
+      {
+        DEBUG_WINERROR("GetFrameDirtyRects failed", hr);
+        goto exit;
+      }
+    }
+    else
+      this->current->nbDirtyRects =
+        requiredSize / sizeof(*this->current->dirtyRects);
+
+    DXGI_OUTDUPL_MOVE_RECT moveRects[
+      (ARRAY_LENGTH(this->current->dirtyRects) - this->current->nbDirtyRects) / 2
+    ];
+    hr = IDXGIOutputDuplication_GetFrameMoveRects(*this->dup,
+      sizeof(moveRects), moveRects, &requiredSize);
+    if (FAILED(hr))
+    {
+      this->current->nbDirtyRects = 0;
+      if (hr != DXGI_ERROR_MORE_DATA)
+      {
+        DEBUG_WINERROR("GetFrameMoveRects failed", hr);
+        goto exit;
+      }
+    }
+
+    /* Move rects are seemingly not generated on Windows 10, but incase it
+     * becomes a thing in the future we still need to implement this */
+    const unsigned moveRectCount = requiredSize / sizeof(*moveRects);
+    for(DXGI_OUTDUPL_MOVE_RECT *moveRect = moveRects; moveRect < moveRects +
+      moveRectCount; ++moveRect)
+    {
+      /* According to WebRTC source comments, the DirectX capture API may
+       * randomly return unmoved rects, which should be skipped to avoid
+       * unnecessary work */
+      if (moveRect->SourcePoint.x == moveRect->DestinationRect.left &&
+          moveRect->SourcePoint.y == moveRect->DestinationRect.top)
+        continue;
+
+      /* Add the source rect to the dirty array */
+      this->current->dirtyRects[this->current->nbDirtyRects++] = (RECT)
+      {
+        .left  = moveRect->SourcePoint.x,
+        .top   = moveRect->SourcePoint.y,
+        .right = moveRect->SourcePoint.x +
+          (moveRect->DestinationRect.right - moveRect->DestinationRect.left),
+        .bottom = moveRect->SourcePoint.y +
+          (moveRect->DestinationRect.bottom - moveRect->DestinationRect.top)
+      };
+
+      /* Add the destination rect to the dirty array */
+      this->current->dirtyRects[this->current->nbDirtyRects++] =
+        moveRect->DestinationRect;
+    }
+  }
+
   result = true;
 
 exit:

host/platform/Windows/capture/D12/d12.c

@@ -65,8 +65,13 @@ struct D12Interface
   // output format tracking
   D3D12_RESOURCE_DESC dstFormat;
 
+  // prior frame dirty rects
+  RECT      dirtyRects[D12_MAX_DIRTY_RECTS];
+  unsigned  nbDirtyRects;
+
   // options
   bool debug;
+  bool trackDamage;
   bool allowRGB24;
 
   unsigned frameBufferCount;
@@ -131,6 +136,13 @@ static void d12_initOptions(void)
       .type           = OPTION_TYPE_STRING,
       .value.x_string = NULL
     },
+    {
+      .module         = "d12",
+      .name           = "trackDamage",
+      .description    = "Perform damage-aware copies (saves bandwidth)",
+      .type           = OPTION_TYPE_BOOL,
+      .value.x_bool   = true
+    },
     {
       .module       = "d12",
       .name         = "allowRGB24",
@@ -139,6 +151,13 @@ static void d12_initOptions(void)
       .type         = OPTION_TYPE_BOOL,
       .value.x_bool = false
     },
+    {
+      .module         = "d12",
+      .name           = "debug",
+      .description    = "Enable DirectX12 debugging and validation (SLOW!)",
+      .type           = OPTION_TYPE_BOOL,
+      .value.x_bool   = false
+    },
     {0}
   };
 
@@ -158,7 +177,16 @@ static bool d12_create(
     return false;
   }
 
-  this->debug = false;
+  this->debug       = option_get_bool("d12", "debug"      );
+  this->trackDamage = option_get_bool("d12", "trackDamage");
+  this->allowRGB24  = option_get_bool("d12", "allowRGB24" );
+
+  DEBUG_INFO(
+    "debug:%d trackDamage:%d allowRGB24:%d",
+    this->debug,
+    this->trackDamage,
+    this->allowRGB24);
+
   this->d3d12 = LoadLibrary("d3d12.dll");
   if (!this->d3d12)
   {
@@ -190,8 +218,6 @@ static bool d12_create(
 
   this->frameBufferCount = frameBuffers;
 
-  this->allowRGB24 = option_get_bool("d12", "allowRGB24");
-
   return true;
 }
 
@@ -318,7 +344,8 @@ retryCreateCommandQueue:
   *alignSize = heapDesc.Alignment;
 
   // initialize the backend
-  if (!d12_backendInit(this->backend, this->debug, *device, *adapter, *output))
+  if (!d12_backendInit(this->backend, this->debug, *device, *adapter, *output,
+    this->trackDamage))
     goto exit;
 
   if (this->allowRGB24)
@@ -396,8 +423,12 @@ static CaptureResult d12_waitFrame(unsigned frameBufferIndex,
   CaptureResult result = CAPTURE_RESULT_ERROR;
   comRef_scopePush(1);
 
+  const RECT * dirtyRects;
+  unsigned nbDirtyRects;
+
   comRef_defineLocal(ID3D12Resource, src);
-  *src = d12_backendFetch(this->backend, frameBufferIndex);
+  *src = d12_backendFetch(this->backend, frameBufferIndex,
+    &dirtyRects, &nbDirtyRects);
   if (!*src)
   {
     DEBUG_ERROR("D12 backend failed to produce an expected frame: %u",
@@ -457,7 +488,23 @@ static CaptureResult d12_waitFrame(unsigned frameBufferIndex,
   frame->hdr              = false;
   frame->hdrPQ            = false;
   frame->rotation         = CAPTURE_ROT_0;
-  frame->damageRectsCount = 0;
+
+  // if there are too many rects
+  if (unlikely(nbDirtyRects > ARRAY_LENGTH(frame->damageRects)))
+    frame->damageRectsCount = 0;
+  else
+  {
+    // send the list of dirty rects for this frame
+    frame->damageRectsCount = nbDirtyRects;
+    for(unsigned i = 0; i < nbDirtyRects; ++i)
+      frame->damageRects[i] = (FrameDamageRect)
+      {
+        .x      = dirtyRects[i].left,
+        .y      = dirtyRects[i].top,
+        .width  = dirtyRects[i].right  - dirtyRects[i].left,
+        .height = dirtyRects[i].bottom - dirtyRects[i].top
+      };
+  }
 
   result = CAPTURE_RESULT_OK;
 
@@ -472,8 +519,12 @@ static CaptureResult d12_getFrame(unsigned frameBufferIndex,
   CaptureResult result = CAPTURE_RESULT_ERROR;
   comRef_scopePush(3);
 
+  const RECT * dirtyRects;
+  unsigned nbDirtyRects;
+
   comRef_defineLocal(ID3D12Resource, src);
-  *src = d12_backendFetch(this->backend, frameBufferIndex);
+  *src = d12_backendFetch(this->backend, frameBufferIndex,
+    &dirtyRects, &nbDirtyRects);
   if (!*src)
   {
     DEBUG_ERROR("D12 backend failed to produce an expected frame: %u",
@@ -526,8 +577,62 @@ static CaptureResult d12_getFrame(unsigned frameBufferIndex,
     }
   };
 
-  ID3D12GraphicsCommandList_CopyTextureRegion(
+  // if full frame damage
-    *this->copyCommand.gfxList, &dstLoc, 0, 0, 0, &srcLoc, NULL);
+  if (nbDirtyRects == 0)
+  {
+    this->nbDirtyRects = 0;
+    ID3D12GraphicsCommandList_CopyTextureRegion(
+      *this->copyCommand.gfxList, &dstLoc, 0, 0, 0, &srcLoc, NULL);
+  }
+  else
+  {
+    /* we must update the rects that were dirty in the prior frame also,
+     * otherwise the frame in memory will not be consistent when areas need to
+     * be redrawn by the client, such as under the cursor */
+    if (this->nbDirtyRects > 0)
+    {
+      for(const RECT * rect = this->dirtyRects;
+        rect < this->dirtyRects + this->nbDirtyRects; ++rect)
+      {
+        D3D12_BOX box =
+        {
+          .left   = rect->left,
+          .top    = rect->top,
+          .front  = 0,
+          .back   = 1,
+          .right  = rect->right,
+          .bottom = rect->bottom
+        };
+
+        ID3D12GraphicsCommandList_CopyTextureRegion(
+          *this->copyCommand.gfxList, &dstLoc,
+          box.left, box.top, 0, &srcLoc, &box);
+      }
+    }
+
+    /* update the frame with the new dirty areas */
+    for(const RECT * rect = dirtyRects; rect < dirtyRects + nbDirtyRects; ++rect)
+    {
+      D3D12_BOX box =
+      {
+        .left   = rect->left,
+        .top    = rect->top,
+        .front  = 0,
+        .back   = 1,
+        .right  = rect->right,
+        .bottom = rect->bottom
+      };
+
+      ID3D12GraphicsCommandList_CopyTextureRegion(
+        *this->copyCommand.gfxList, &dstLoc,
+        box.left, box.top, 0, &srcLoc, &box);
+    }
+
+    /* store the dirty rects for the next frame */
+    memcpy(this->dirtyRects, dirtyRects,
+      nbDirtyRects * sizeof(*this->dirtyRects));
+    this->nbDirtyRects = nbDirtyRects;
+  }
 
   // execute the compute commands
   if (this->allowRGB24)