Snap the bitmap as it may be changed later

Bug: skia:
Change-Id: If06510f6fd3b64cce3440a543973c9c83913da10
Reviewed-on: https://skia-review.googlesource.com/120141
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Yuqian Li <liyuqian@google.com>

2 files changed, 15 insertions, 2 deletions

diff --git a/src/core/SkThreadedBMPDevice.cpp b/src/core/SkThreadedBMPDevice.cpp
index 0cff9681c3..0c302370b0 100644
--- a/src/core/SkThreadedBMPDevice.cpp
+++ b/src/core/SkThreadedBMPDevice.cpp
@@ -161,6 +161,15 @@ void SkThreadedBMPDevice::drawPath(const SkPath& path, const SkPaint& paint,
     }
 }
 
+SkBitmap SkThreadedBMPDevice::snapBitmap(const SkBitmap& bitmap) {
+    // We can't use bitmap.isImmutable() because it could be temporarily immutable
+    // TODO(liyuqian): use genID to reduce the copy frequency
+    SkBitmap snap;
+    snap.allocPixels(bitmap.info());
+    bitmap.readPixels(snap.pixmap());
+    return snap;
+}
+
 void SkThreadedBMPDevice::drawBitmap(const SkBitmap& bitmap, const SkMatrix& matrix,
                                      const SkRect* dstOrNull, const SkPaint& paint) {
     SkRect drawBounds;
@@ -173,16 +182,18 @@ void SkThreadedBMPDevice::drawBitmap(const SkBitmap& bitmap, const SkMatrix& mat
         clonedDstOrNull = fAlloc.make<SkRect>(*dstOrNull);
     }
 
+    SkBitmap snap = this->snapBitmap(bitmap);
     fQueue.push(drawBounds, [=](SkArenaAlloc*, const DrawState& ds, const SkIRect& tileBounds){
-        TileDraw(ds, tileBounds).drawBitmap(bitmap, matrix, clonedDstOrNull, paint);
+        TileDraw(ds, tileBounds).drawBitmap(snap, matrix, clonedDstOrNull, paint);
     });
 }
 
 void SkThreadedBMPDevice::drawSprite(const SkBitmap& bitmap, int x, int y, const SkPaint& paint) {
     SkRect drawBounds = SkRect::MakeXYWH(x, y, bitmap.width(), bitmap.height());
+    SkBitmap snap = this->snapBitmap(bitmap);
     fQueue.push<false>(drawBounds, [=](SkArenaAlloc*, const DrawState& ds,
                                        const SkIRect& tileBounds){
-        TileDraw(ds, tileBounds).drawSprite(bitmap, x, y, paint);
+        TileDraw(ds, tileBounds).drawSprite(snap, x, y, paint);
     });
 }
 
diff --git a/src/core/SkThreadedBMPDevice.h b/src/core/SkThreadedBMPDevice.h
index b539a5609e..a901470255 100644
--- a/src/core/SkThreadedBMPDevice.h
+++ b/src/core/SkThreadedBMPDevice.h
@@ -183,6 +183,8 @@ private:
        return clone;
     }
 
+    SkBitmap snapBitmap(const SkBitmap& bitmap);
+
     const int fTileCnt;
     const int fThreadCnt;
     SkTArray<SkIRect> fTileBounds;