Experiment to track coverage in a layer

Bug: skia:
Change-Id: I5ed334f63e64991944394dc8103092a2c6280546
Reviewed-on: https://skia-review.googlesource.com/122000
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/src/core/SkBitmapDevice.h b/src/core/SkBitmapDevice.h
index e040b6b0c6..f80cba6ee4 100644
--- a/src/core/SkBitmapDevice.h
+++ b/src/core/SkBitmapDevice.h
@@ -55,10 +55,19 @@ public:
      *  any drawing to this device will have no effect.
      */
     SkBitmapDevice(const SkBitmap& bitmap, const SkSurfaceProps& surfaceProps,
-                   void* externalHandle = nullptr);
+                   void* externalHandle, const SkBitmap* coverage);
 
     static SkBitmapDevice* Create(const SkImageInfo&, const SkSurfaceProps&,
-                                  SkRasterHandleAllocator* = nullptr);
+                                  bool trackCoverage,
+                                  SkRasterHandleAllocator*);
+
+    static SkBitmapDevice* Create(const SkImageInfo& info, const SkSurfaceProps& props) {
+        return Create(info, props, false, nullptr);
+    }
+
+    const SkPixmap* accessCoverage() const {
+        return fCoverage ? &fCoverage->pixmap() : nullptr;
+    }
 
 protected:
     void* getRasterHandle() const override { return fRasterHandle; }
@@ -165,6 +174,7 @@ private:
     SkBitmap    fBitmap;
     void*       fRasterHandle = nullptr;
     SkRasterClipStack  fRCStack;
+    std::unique_ptr<SkBitmap> fCoverage;    // if non-null, will have the same dimensions as fBitmap
 
     typedef SkBaseDevice INHERITED;
 };