add readPixels() to SkBitmap

tests/BitmapCopyTest.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkRect.h"
 #include "Test.h"
@@ skipping 167 matching lines @@
 
 // Writes unique pixel values at locations specified by coords.
 static void writeCoordPixels(SkBitmap& bm, const Coordinates& coords) {
     for (int i = 0; i < coords.length; ++i)
         setPixel(coords[i]->fX, coords[i]->fY, i, bm);
 }
 
 static const Pair gPairs[] = {
     { kUnknown_SkColorType,     "000000"  },
     { kAlpha_8_SkColorType,     "010101"  },
-    { kIndex_8_SkColorType,     "011101"  },
+    { kIndex_8_SkColorType,     "011111"  },
     { kRGB_565_SkColorType,     "010101"  },
     { kARGB_4444_SkColorType,   "010111"  },
     { kN32_SkColorType,         "010111"  },
 };
 
 static const int W = 20;
 static const int H = 33;
 
 static void setup_src_bitmaps(SkBitmap* srcOpaque, SkBitmap* srcPremul,
                               SkColorType ct) {
@@ skipping 63 matching lines @@
 
         bitmap = srcPremul;
         bitmap.setIsVolatile(false);
         if (bitmap.extractSubset(&subset, r)) {
             REPORTER_ASSERT(reporter, subset.alphaType() == bitmap.alphaType());
             REPORTER_ASSERT(reporter, subset.isVolatile() == false);
         }
     }
 }
 
 DEF_TEST(BitmapCopy, reporter) {

[scroggo, 2014/07/10 15:09:48]

Should we add tests that check for copying a subset using readPixels?

[reed1, 2014/07/10 15:32:16]

Done.

     static const bool isExtracted[] = {
         false, true
     };
 
     for (size_t i = 0; i < SK_ARRAY_COUNT(gPairs); i++) {
         SkBitmap srcOpaque, srcPremul;
         setup_src_bitmaps(&srcOpaque, &srcPremul, gPairs[i].fColorType);
 
         for (size_t j = 0; j < SK_ARRAY_COUNT(gPairs); j++) {
             SkBitmap dst;
@@ skipping 252 matching lines @@
                 // for the transfer.
                 REPORTER_ASSERT(reporter,
                     subset.copyPixelsFrom(buf, 1, subset.rowBytes()) ==
                         false);
 
 #endif
             }
         } // for (size_t copyCase ...
     }
 }