add bitmap::eraseArea

tests/BitmapGetColorTest.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 "Test.h"
 #include "SkBitmap.h"
+#include "SkRect.h"
+#include "SkRandom.h"
+
+static int nextRand(SkRandom& rand, int min, int max) {
+    return min + (int)rand.nextRangeU(0, max - min);
+}
+
+static void rand_irect(SkIRect* rect, int W, int H, SkRandom& rand) {
+    const int DX = W / 2;
+    const int DY = H / 2;
+
+    rect->fLeft   = nextRand(rand, -DX, W + DX);
+    rect->fTop    = nextRand(rand, -DY, H + DY);
+    rect->fRight  = nextRand(rand, -DX, W + DX);
+    rect->fBottom = nextRand(rand, -DY, H + DY);
+    rect->sort();
+}
+
+static void test_equal(skiatest::Reporter* reporter,

[scroggo, 2013/06/28 19:02:35]

Maybe add a comment explaining that this function assumes specific configs for
each bitmap?

[reed1, 2013/06/28 19:31:54]

Done.

+                       const SkBitmap& bm1, const SkBitmap& bm8) {
+    REPORTER_ASSERT(reporter, bm1.width() == bm8.width());
+    REPORTER_ASSERT(reporter, bm1.height() == bm8.height());
+    for (int y = 0; y < bm1.height(); ++y) {
+        for (int x = 0; x < bm1.width(); ++x) {
+            int p1 = *bm1.getAddr1(x, y) & (1 << (7 - (x & 7)));
+            SkASSERT(SkIsPow2(p1));
+            p1 = p1 ? 0xFF : 0;
+
+            int p8 = *bm8.getAddr8(x, y);
+            SkASSERT(0 == p8 || 0xFF == p8);
+            
+            REPORTER_ASSERT(reporter, p1 == p8);
+        }
+    }
+}
+
+static void test_eraserect_A1(skiatest::Reporter* reporter) {
+    const int W = 43;
+    const int H = 13;
+
+    SkBitmap bm1, bm8;
+    
+    bm1.setConfig(SkBitmap::kA1_Config, W, H);
+    bm1.allocPixels();
+    bm8.setConfig(SkBitmap::kA8_Config, W, H);
+    bm8.allocPixels();
+
+    SkRandom rand;
+    for (int i = 0; i < 10000; ++i) {
+        SkIRect area;
+        rand_irect(&area, W, H, rand);
+        
+        bm1.eraseColor(0);
+        bm8.eraseColor(0);
+        
+        bm1.eraseArea(area, SK_ColorWHITE);
+        bm8.eraseArea(area, SK_ColorWHITE);
+        test_equal(reporter, bm1, bm8);
+    }
+}
 
 static void TestGetColor(skiatest::Reporter* reporter) {
     static const struct Rec {
         SkBitmap::Config    fConfig;
         SkColor             fInColor;
         SkColor             fOutColor;
     } gRec[] = {
         // todo: add some tests that involve alpha, so we exercise the
         // unpremultiply aspect of getColor()
         {   SkBitmap::kA8_Config,           0xFF000000,     0xFF000000  },
         {   SkBitmap::kA8_Config,           0,              0           },
         {   SkBitmap::kRGB_565_Config,      0xFF00FF00,     0xFF00FF00  },
         {   SkBitmap::kRGB_565_Config,      0xFFFF00FF,     0xFFFF00FF  },
         {   SkBitmap::kARGB_8888_Config,    0xFFFFFFFF,     0xFFFFFFFF  },
         {   SkBitmap::kARGB_8888_Config,    0,              0           },
         {   SkBitmap::kARGB_8888_Config,    0xFF224466,     0xFF224466  },
     };
 
+    // specify an area that doesn't touch (0,0) and may extend beyond the
+    // bitmap bounds (to test that we catch that in eraseArea
+    const SkColor initColor = 0xFF0000FF;
+    const SkIRect area = { 1, 1, 3, 3 };
+
     for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); i++) {
         SkBitmap bm;
-        uint32_t storage[1];
-        bm.setConfig(gRec[i].fConfig, 1, 1);
+        uint32_t storage[4];
+        bm.setConfig(gRec[i].fConfig, 2, 2);
         bm.setPixels(storage);
-        bm.eraseColor(gRec[i].fInColor);
 
-        SkColor c = bm.getColor(0, 0);
+        bm.eraseColor(initColor);
+        bm.eraseArea(area, gRec[i].fInColor);
+
+        SkColor c = bm.getColor(1, 1);
         REPORTER_ASSERT(reporter, c == gRec[i].fOutColor);
     }
+    
+    test_eraserect_A1(reporter);
 }
 
 #include "TestClassDef.h"
 DEFINE_TESTCLASS("GetColor", TestGetColorClass, TestGetColor)