1 files changed, 148 insertions, 0 deletions
diff --git a/base/gfx/image_operations_unittest.cc b/base/gfx/image_operations_unittest.cc
new file mode 100644
index 0000000..a15e648
--- /dev/null
+++ b/base/gfx/image_operations_unittest.cc
@@ -0,0 +1,148 @@
+// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdlib.h>
+
+#include "base/gfx/image_operations.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "SkBitmap.h"
+
+namespace {
+
+// Computes the average pixel value for the given range, inclusive.
+uint32_t AveragePixel(const SkBitmap& bmp,
+                      int x_min, int x_max,
+                      int y_min, int y_max) {
+  float accum[4] = {0, 0, 0, 0};
+  int count = 0;
+  for (int y = y_min; y <= y_max; y++) {
+    for (int x = x_min; x <= x_max; x++) {
+      uint32_t cur = *bmp.getAddr32(x, y);
+      accum[0] += SkColorGetB(cur);
+      accum[1] += SkColorGetG(cur);
+      accum[2] += SkColorGetR(cur);
+      accum[3] += SkColorGetA(cur);
+      count++;
+    }
+  }
+
+  return SkColorSetARGB(static_cast<unsigned char>(accum[3] / count),
+                        static_cast<unsigned char>(accum[2] / count),
+                        static_cast<unsigned char>(accum[1] / count),
+                        static_cast<unsigned char>(accum[0] / count));
+}
+
+// Returns true if each channel of the given two colors are "close." This is
+// used for comparing colors where rounding errors may cause off-by-one.
+bool ColorsClose(uint32_t a, uint32_t b) {
+  return abs(static_cast<int>(SkColorGetB(a) - SkColorGetB(b))) < 2 &&
+         abs(static_cast<int>(SkColorGetG(a) - SkColorGetG(b))) < 2 &&
+         abs(static_cast<int>(SkColorGetR(a) - SkColorGetR(b))) < 2 &&
+         abs(static_cast<int>(SkColorGetA(a) - SkColorGetA(b))) < 2;
+}
+
+void FillDataToBitmap(int w, int h, SkBitmap* bmp) {
+  bmp->setConfig(SkBitmap::kARGB_8888_Config, w, h);
+  bmp->allocPixels();
+
+  unsigned char* src_data =
+      reinterpret_cast<unsigned char*>(bmp->getAddr32(0, 0));
+  for (int i = 0; i < w * h; i++) {
+    src_data[i * 4 + 0] = static_cast<unsigned char>(i % 255);
+    src_data[i * 4 + 1] = static_cast<unsigned char>(i % 255);
+    src_data[i * 4 + 2] = static_cast<unsigned char>(i % 255);
+    src_data[i * 4 + 3] = static_cast<unsigned char>(i % 255);
+  }
+}
+
+}  // namespace
+
+// Makes the bitmap 50% the size as the original using a box filter. This is
+// an easy operation that we can check the results for manually.
+TEST(ImageOperations, Halve) {
+  // Make our source bitmap.
+  int src_w = 30, src_h = 38;
+  SkBitmap src;
+  FillDataToBitmap(src_w, src_h, &src);
+
+  // Do a halving of the full bitmap.
+  SkBitmap actual_results = gfx::ImageOperations::Resize(
+      src, gfx::ImageOperations::RESIZE_BOX, gfx::Size(src_w / 2, src_h / 2));
+  ASSERT_EQ(src_w / 2, actual_results.width());
+  ASSERT_EQ(src_h / 2, actual_results.height());
+
+  // Compute the expected values & compare.
+  SkAutoLockPixels lock(actual_results);
+  for (int y = 0; y < actual_results.height(); y++) {
+    for (int x = 0; x < actual_results.width(); x++) {
+      int first_x = std::max(0, x * 2 - 1);
+      int last_x = std::min(src_w - 1, x * 2);
+
+      int first_y = std::max(0, y * 2 - 1);
+      int last_y = std::min(src_h - 1, y * 2);
+
+      uint32_t expected_color = AveragePixel(src,
+                                             first_x, last_x, first_y, last_y);
+      EXPECT_TRUE(ColorsClose(expected_color, *actual_results.getAddr32(x, y)));
+    }
+  }
+}
+
+TEST(ImageOperations, HalveSubset) {
+  // Make our source bitmap.
+  int src_w = 16, src_h = 34;
+  SkBitmap src;
+  FillDataToBitmap(src_w, src_h, &src);
+
+  // Do a halving of the full bitmap.
+  SkBitmap full_results = gfx::ImageOperations::Resize(
+      src, gfx::ImageOperations::RESIZE_BOX, gfx::Size(src_w / 2, src_h / 2));
+  ASSERT_EQ(src_w / 2, full_results.width());
+  ASSERT_EQ(src_h / 2, full_results.height());
+
+  // Now do a halving of a a subset, recall the destination subset is in the
+  // destination coordinate system (max = half of the original image size).
+  gfx::Rect subset_rect(2, 3, 3, 6);
+  SkBitmap subset_results = gfx::ImageOperations::Resize(
+      src, gfx::ImageOperations::RESIZE_BOX,
+      gfx::Size(src_w / 2, src_h / 2), subset_rect);
+  ASSERT_EQ(subset_rect.width(), subset_results.width());
+  ASSERT_EQ(subset_rect.height(), subset_results.height());
+
+  // The computed subset and the corresponding subset of the original image
+  // should be the same.
+  SkAutoLockPixels full_lock(full_results);
+  SkAutoLockPixels subset_lock(subset_results);
+  for (int y = 0; y < subset_rect.height(); y++) {
+    for (int x = 0; x < subset_rect.width(); x++) {
+      ASSERT_EQ(
+          *full_results.getAddr32(x + subset_rect.x(), y + subset_rect.y()),
+          *subset_results.getAddr32(x, y));
+    }
+  }
+}
+
+// Resamples an iamge to the same image, it should give almost the same result.
+TEST(ImageOperations, ResampleToSame) {
+  // Make our source bitmap.
+  int src_w = 16, src_h = 34;
+  SkBitmap src;
+  FillDataToBitmap(src_w, src_h, &src);
+
+  // Do a resize of the full bitmap to the same size. The lanczos filter is good
+  // enough that we should get exactly the same image for output.
+  SkBitmap results = gfx::ImageOperations::Resize(
+      src, gfx::ImageOperations::RESIZE_LANCZOS3, gfx::Size(src_w, src_h));
+  ASSERT_EQ(src_w, results.width());
+  ASSERT_EQ(src_h, results.height());
+
+  SkAutoLockPixels src_lock(src);
+  SkAutoLockPixels results_lock(results);
+  for (int y = 0; y < src_h; y++) {
+    for (int x = 0; x < src_w; x++) {
+      EXPECT_EQ(*src.getAddr32(x, y), *results.getAddr32(x, y));
+    }
+  }
+}
+