make an image from a mutable bitmap

src/image/SkImage_Raster.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImage_Base.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 76 matching lines @@
     sk_sp<SkImage> onMakeSubset(const SkIRect&) const override;
 
     // exposed for SkSurface_Raster via SkNewImageFromPixelRef
     SkImage_Raster(const SkImageInfo&, SkPixelRef*, const SkIPoint& origin, size_t rowBytes);
 
     SkPixelRef* getPixelRef() const { return fBitmap.pixelRef(); }
 
     bool isOpaque() const override;
     bool onAsLegacyBitmap(SkBitmap*, LegacyBitmapMode) const override;
 
-    SkImage_Raster(const SkBitmap& bm)
+    SkImage_Raster(const SkBitmap& bm, bool bitmapMayBeMutable = false)
         : INHERITED(bm.width(), bm.height(),
                     is_not_subset(bm) ? bm.getGenerationID()
                                       : (uint32_t)kNeedNewImageUniqueID)
         , fBitmap(bm)
     {
         if (bm.pixelRef()->isPreLocked()) {
             // we only preemptively lock if there is no chance of triggering something expensive
             // like a lazy decode or imagegenerator. PreLocked means it is flat pixels already.
             fBitmap.lockPixels();
         }
-        SkASSERT(fBitmap.isImmutable());
+        SkASSERT(bitmapMayBeMutable || fBitmap.isImmutable());
     }
 
     bool onIsLazyGenerated() const override {
         return fBitmap.pixelRef() && fBitmap.pixelRef()->isLazyGenerated();
     }
 
 private:
     SkBitmap fBitmap;
 
     typedef SkImage_Base INHERITED;
@@ skipping 138 matching lines @@
     if (kIndex_8_SkColorType == bm.colorType()) {
         SkAutoLockPixels autoLockPixels(bm);
         hasColorTable = bm.getColorTable() != nullptr;
     }
 
     if (!SkImage_Raster::ValidArgs(bm.info(), bm.rowBytes(), hasColorTable, nullptr)) {
         return nullptr;
     }
 
     sk_sp<SkImage> image;
-    if (kYes_ForceCopyMode == forceCopy || !bm.isImmutable()) {
+    if (kYes_ForceCopyMode == forceCopy ||
+        (!bm.isImmutable() && kNever_ForceCopyMode != forceCopy))
+    {
         SkBitmap tmp(bm);
         tmp.lockPixels();
         SkPixmap pmap;
         if (tmp.getPixels() && tmp.peekPixels(&pmap)) {
             image = SkImage::MakeRasterCopy(pmap);
         }
     } else {
-        image = sk_make_sp<SkImage_Raster>(bm);
+        image = sk_make_sp<SkImage_Raster>(bm, kNever_ForceCopyMode == forceCopy);
     }
     return image;
 }
 
 const SkPixelRef* SkBitmapImageGetPixelRef(const SkImage* image) {
     return ((const SkImage_Raster*)image)->getPixelRef();
 }
 
 bool SkImage_Raster::isOpaque() const {
     return fBitmap.isOpaque();
 }
 
 bool SkImage_Raster::onAsLegacyBitmap(SkBitmap* bitmap, LegacyBitmapMode mode) const {
     if (kRO_LegacyBitmapMode == mode) {
         // When we're a snapshot from a surface, our bitmap may not be marked immutable
         // even though logically always we are, but in that case we can't physically share our
         // pixelref since the caller might call setImmutable() themselves
         // (thus changing our state).
         if (fBitmap.isImmutable()) {
             bitmap->setInfo(fBitmap.info(), fBitmap.rowBytes());
             bitmap->setPixelRef(fBitmap.pixelRef(), fBitmap.pixelRefOrigin());
             return true;
         }
     }
     return this->INHERITED::onAsLegacyBitmap(bitmap, mode);
 }