Create SkBitmapChecksummer and associated SkBitmapTransformer

As needed to start capturing gm image checksums.
Review URL: https://codereview.appspot.com/6920050

git-svn-id: http://skia.googlecode.com/svn/trunk@6759 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/ChecksumTest.cpp b/tests/ChecksumTest.cpp
index e8a2f253b0..03194907f5 100644
--- a/tests/ChecksumTest.cpp
+++ b/tests/ChecksumTest.cpp
@@ -6,8 +6,12 @@
  * found in the LICENSE file.
  */
 #include "Test.h"
+
+#include "SkBitmap.h"
+#include "SkBitmapChecksummer.h"
 #include "SkChecksum.h"
 #include "SkCityHash.h"
+#include "SkColor.h"
 
 // Word size that is large enough to hold results of any checksum type.
 typedef uint64_t checksum_result;
@@ -103,6 +107,15 @@ namespace skiatest {
             return result;
         }
 
+        // Fill in bitmap with test data.
+        void CreateTestBitmap(SkBitmap &bitmap, SkBitmap::Config config, int width, int height,
+                              SkColor color) {
+            bitmap.setConfig(config, width, height);
+            REPORTER_ASSERT(fReporter, bitmap.allocPixels());
+            bitmap.setIsOpaque(true);
+            bitmap.eraseColor(color);
+        }
+
         void RunTest() {
             // Test self-consistency of checksum algorithms.
             fWhichAlgorithm = kSkChecksum;
@@ -143,6 +156,25 @@ namespace skiatest {
                 GetTestDataChecksum(128) == GetTestDataChecksum(256));
             REPORTER_ASSERT(fReporter,
                 GetTestDataChecksum(132) == GetTestDataChecksum(260));
+
+            // Test SkBitmapChecksummer
+            SkBitmap bitmap;
+            // initial test case
+            CreateTestBitmap(bitmap, SkBitmap::kARGB_8888_Config, 333, 555, SK_ColorBLUE);
+            REPORTER_ASSERT(fReporter,
+                            SkBitmapChecksummer::Compute64(bitmap) == 0x18f9df68b1b02f38ULL);
+            // same pixel data but different dimensions should yield a different checksum
+            CreateTestBitmap(bitmap, SkBitmap::kARGB_8888_Config, 555, 333, SK_ColorBLUE);
+            REPORTER_ASSERT(fReporter,
+                            SkBitmapChecksummer::Compute64(bitmap) == 0x6b0298183f786c8eULL);
+            // same dimensions but different color should yield a different checksum
+            CreateTestBitmap(bitmap, SkBitmap::kARGB_8888_Config, 555, 333, SK_ColorGREEN);
+            REPORTER_ASSERT(fReporter,
+                            SkBitmapChecksummer::Compute64(bitmap) == 0xc6b4b3f6fadaaf37ULL);
+            // same pixel colors in a different config should yield the same checksum
+            CreateTestBitmap(bitmap, SkBitmap::kARGB_4444_Config, 555, 333, SK_ColorGREEN);
+            REPORTER_ASSERT(fReporter,
+                            SkBitmapChecksummer::Compute64(bitmap) == 0xc6b4b3f6fadaaf37ULL);
         }
 
         Reporter* fReporter;