Avoid unneeded paint copies in SkDraw::drawBitmap

src/core/SkDraw.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #define __STDC_LIMIT_MACROS
 
 #include "SkDraw.h"
 #include "SkBlitter.h"
@@ skipping 1284 matching lines @@
                         const SkRect* dstBounds, const SkPaint& origPaint) const {
     SkDEBUGCODE(this->validate();)
 
     // nothing to draw
     if (fRC->isEmpty() ||
             bitmap.width() == 0 || bitmap.height() == 0 ||
             bitmap.colorType() == kUnknown_SkColorType) {
         return;
     }
 
-    SkPaint paint(origPaint);
-    paint.setStyle(SkPaint::kFill_Style);
+    SkTCopyOnFirstWrite<SkPaint> paint(origPaint);
+    if (origPaint.getStyle() != SkPaint::kFill_Style) {
+        paint.writable()->setStyle(SkPaint::kFill_Style);
+    }
 
     SkMatrix matrix;
     matrix.setConcat(*fMatrix, prematrix);
 
     if (clipped_out(matrix, *fRC, bitmap.width(), bitmap.height())) {
         return;
     }
 
     if (bitmap.colorType() != kAlpha_8_SkColorType
-        && SkTreatAsSprite(matrix, bitmap.dimensions(), paint)) {
+        && SkTreatAsSprite(matrix, bitmap.dimensions(), *paint)) {
         //
         // It is safe to call lock pixels now, since we know the matrix is
         // (more or less) identity.
         //
         SkAutoPixmapUnlock unlocker;
         if (!bitmap.requestLock(&unlocker)) {
             return;
         }
         const SkPixmap& pmap = unlocker.pixmap();
         int ix = SkScalarRoundToInt(matrix.getTranslateX());
         int iy = SkScalarRoundToInt(matrix.getTranslateY());
         if (clipHandlesSprite(*fRC, ix, iy, pmap)) {
             SkTBlitterAllocator allocator;
             // blitter will be owned by the allocator.
-            SkBlitter* blitter = SkBlitter::ChooseSprite(fDst, paint, pmap, ix, iy, &allocator);
+            SkBlitter* blitter = SkBlitter::ChooseSprite(fDst, *paint, pmap, ix, iy, &allocator);
             if (blitter) {
                 SkScan::FillIRect(SkIRect::MakeXYWH(ix, iy, pmap.width(), pmap.height()),
                                   *fRC, blitter);
                 return;
             }
             // if !blitter, then we fall-through to the slower case
         }
     }
 
     // now make a temp draw on the stack, and use it
     //
     SkDraw draw(*this);
     draw.fMatrix = &matrix;
 
     if (bitmap.colorType() == kAlpha_8_SkColorType) {
-        draw.drawBitmapAsMask(bitmap, paint);
+        draw.drawBitmapAsMask(bitmap, *paint);
     } else {
-        SkAutoBitmapShaderInstall install(bitmap, paint);
+        SkAutoBitmapShaderInstall install(bitmap, *paint);
         const SkPaint& paintWithShader = install.paintWithShader();
         const SkRect srcBounds = SkRect::MakeIWH(bitmap.width(), bitmap.height());
         if (dstBounds) {
             this->drawRect(srcBounds, paintWithShader, &prematrix, dstBounds);
         } else {
             draw.drawRect(srcBounds, paintWithShader);
         }
     }
 }
 
@@ skipping 747 matching lines @@
         mask->fImage = SkMask::AllocImage(size);
         memset(mask->fImage, 0, mask->computeImageSize());
     }
 
     if (SkMask::kJustComputeBounds_CreateMode != mode) {
         draw_into_mask(*mask, devPath, style);
     }
 
     return true;
 }