Move image_diff code into testing/image_diff/

It is not actually a sample program to demonstrate how to use PDFium
APIs. It is more of a test utility program.

Remove header include dependency from samples/ to core/, to set a good
example.

Change-Id: Idd5d567c82314bcf0e4a7bec8a3210e7d57226ee
Reviewed-on: https://pdfium-review.googlesource.com/6871
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

1 files changed, 0 insertions, 352 deletions

diff --git a/samples/image_diff.cc b/samples/image_diff.cc
deleted file mode 100644
index 21460f5a62..0000000000
--- a/samples/image_diff.cc
+++ /dev/null
@@ -1,352 +0,0 @@
-// Copyright (c) 2011 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.
-
-// This file input format is based loosely on
-// Tools/DumpRenderTree/ImageDiff.m
-
-// The exact format of this tool's output to stdout is important, to match
-// what the run-webkit-tests script expects.
-
-#include <assert.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <string.h>
-
-#include <algorithm>
-#include <iostream>
-#include <map>
-#include <string>
-#include <vector>
-
-#include "core/fxcrt/fx_memory.h"
-#include "samples/image_diff_png.h"
-#include "third_party/base/logging.h"
-#include "third_party/base/numerics/safe_conversions.h"
-
-#if defined(OS_WIN)
-#include <windows.h>
-#endif
-
-// Return codes used by this utility.
-static const int kStatusSame = 0;
-static const int kStatusDifferent = 1;
-static const int kStatusError = 2;
-
-// Color codes.
-static const uint32_t RGBA_RED = 0x000000ff;
-static const uint32_t RGBA_ALPHA = 0xff000000;
-
-class Image {
- public:
-  Image() : w_(0), h_(0) {
-  }
-
-  Image(const Image& image)
-      : w_(image.w_),
-        h_(image.h_),
-        data_(image.data_) {
-  }
-
-  bool has_image() const {
-    return w_ > 0 && h_ > 0;
-  }
-
-  int w() const {
-    return w_;
-  }
-
-  int h() const {
-    return h_;
-  }
-
-  const unsigned char* data() const {
-    return &data_.front();
-  }
-
-  // Creates the image from the given filename on disk, and returns true on
-  // success.
-  bool CreateFromFilename(const std::string& path) {
-    FILE* f = fopen(path.c_str(), "rb");
-    if (!f)
-      return false;
-
-    std::vector<unsigned char> compressed;
-    const size_t kBufSize = 1024;
-    unsigned char buf[kBufSize];
-    size_t num_read = 0;
-    while ((num_read = fread(buf, 1, kBufSize, f)) > 0) {
-      compressed.insert(compressed.end(), buf, buf + num_read);
-    }
-
-    fclose(f);
-
-    if (!image_diff_png::DecodePNG(compressed.data(), compressed.size(), &data_,
-                                   &w_, &h_)) {
-      Clear();
-      return false;
-    }
-    return true;
-  }
-
-  void Clear() {
-    w_ = h_ = 0;
-    data_.clear();
-  }
-
-  // Returns the RGBA value of the pixel at the given location
-  uint32_t pixel_at(int x, int y) const {
-    if (!pixel_in_bounds(x, y))
-      return 0;
-    return *reinterpret_cast<const uint32_t*>(&(data_[pixel_address(x, y)]));
-  }
-
-  void set_pixel_at(int x, int y, uint32_t color) {
-    if (!pixel_in_bounds(x, y))
-      return;
-
-    void* addr = &data_[pixel_address(x, y)];
-    *reinterpret_cast<uint32_t*>(addr) = color;
-  }
-
- private:
-  bool pixel_in_bounds(int x, int y) const {
-    return x >= 0 && x < w_ && y >= 0 && y < h_;
-  }
-
-  size_t pixel_address(int x, int y) const { return (y * w_ + x) * 4; }
-
-  // Pixel dimensions of the image.
-  int w_;
-  int h_;
-
-  std::vector<unsigned char> data_;
-};
-
-float CalculateDifferencePercentage(const Image& actual, int pixels_different) {
-  // Like the WebKit ImageDiff tool, we define percentage different in terms
-  // of the size of the 'actual' bitmap.
-  float total_pixels =
-      static_cast<float>(actual.w()) * static_cast<float>(actual.h());
-  if (total_pixels == 0) {
-    // When the bitmap is empty, they are 100% different.
-    return 100.0f;
-  }
-  return 100.0f * pixels_different / total_pixels;
-}
-
-void CountImageSizeMismatchAsPixelDifference(const Image& baseline,
-                                             const Image& actual,
-                                             int* pixels_different) {
-  int w = std::min(baseline.w(), actual.w());
-  int h = std::min(baseline.h(), actual.h());
-
-  // Count pixels that are a difference in size as also being different.
-  int max_w = std::max(baseline.w(), actual.w());
-  int max_h = std::max(baseline.h(), actual.h());
-  // These pixels are off the right side, not including the lower right corner.
-  *pixels_different += (max_w - w) * h;
-  // These pixels are along the bottom, including the lower right corner.
-  *pixels_different += (max_h - h) * max_w;
-}
-
-float PercentageDifferent(const Image& baseline, const Image& actual) {
-  int w = std::min(baseline.w(), actual.w());
-  int h = std::min(baseline.h(), actual.h());
-
-  // Compute pixels different in the overlap.
-  int pixels_different = 0;
-  for (int y = 0; y < h; ++y) {
-    for (int x = 0; x < w; ++x) {
-      if (baseline.pixel_at(x, y) != actual.pixel_at(x, y))
-        ++pixels_different;
-    }
-  }
-
-  CountImageSizeMismatchAsPixelDifference(baseline, actual, &pixels_different);
-  return CalculateDifferencePercentage(actual, pixels_different);
-}
-
-float HistogramPercentageDifferent(const Image& baseline, const Image& actual) {
-  // TODO(johnme): Consider using a joint histogram instead, as described in
-  // "Comparing Images Using Joint Histograms" by Pass & Zabih
-  // http://www.cs.cornell.edu/~rdz/papers/pz-jms99.pdf
-
-  int w = std::min(baseline.w(), actual.w());
-  int h = std::min(baseline.h(), actual.h());
-
-  // Count occurences of each RGBA pixel value of baseline in the overlap.
-  std::map<uint32_t, int32_t> baseline_histogram;
-  for (int y = 0; y < h; ++y) {
-    for (int x = 0; x < w; ++x) {
-      // hash_map operator[] inserts a 0 (default constructor) if key not found.
-      ++baseline_histogram[baseline.pixel_at(x, y)];
-    }
-  }
-
-  // Compute pixels different in the histogram of the overlap.
-  int pixels_different = 0;
-  for (int y = 0; y < h; ++y) {
-    for (int x = 0; x < w; ++x) {
-      uint32_t actual_rgba = actual.pixel_at(x, y);
-      auto it = baseline_histogram.find(actual_rgba);
-      if (it != baseline_histogram.end() && it->second > 0)
-        --it->second;
-      else
-        ++pixels_different;
-    }
-  }
-
-  CountImageSizeMismatchAsPixelDifference(baseline, actual, &pixels_different);
-  return CalculateDifferencePercentage(actual, pixels_different);
-}
-
-void PrintHelp() {
-  fprintf(stderr,
-    "Usage:\n"
-    "  image_diff [--histogram] <compare file> <reference file>\n"
-    "    Compares two files on disk, returning 0 when they are the same;\n"
-    "    passing \"--histogram\" additionally calculates a diff of the\n"
-    "    RGBA value histograms (which is resistant to shifts in layout)\n"
-    "  image_diff --diff <compare file> <reference file> <output file>\n"
-    "    Compares two files on disk, outputs an image that visualizes the\n"
-    "    difference to <output file>\n");
-}
-
-int CompareImages(const std::string& file1,
-                  const std::string& file2,
-                  bool compare_histograms) {
-  Image actual_image;
-  Image baseline_image;
-
-  if (!actual_image.CreateFromFilename(file1)) {
-    fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file1.c_str());
-    return kStatusError;
-  }
-  if (!baseline_image.CreateFromFilename(file2)) {
-    fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file2.c_str());
-    return kStatusError;
-  }
-
-  if (compare_histograms) {
-    float percent = HistogramPercentageDifferent(actual_image, baseline_image);
-    const char* passed = percent > 0.0 ? "failed" : "passed";
-    printf("histogram diff: %01.2f%% %s\n", percent, passed);
-  }
-
-  const char* const diff_name = compare_histograms ? "exact diff" : "diff";
-  float percent = PercentageDifferent(actual_image, baseline_image);
-  const char* const passed = percent > 0.0 ? "failed" : "passed";
-  printf("%s: %01.2f%% %s\n", diff_name, percent, passed);
-
-  if (percent > 0.0) {
-    // failure: The WebKit version also writes the difference image to
-    // stdout, which seems excessive for our needs.
-    return kStatusDifferent;
-  }
-  // success
-  return kStatusSame;
-}
-
-bool CreateImageDiff(const Image& image1, const Image& image2, Image* out) {
-  int w = std::min(image1.w(), image2.w());
-  int h = std::min(image1.h(), image2.h());
-  *out = Image(image1);
-  bool same = (image1.w() == image2.w()) && (image1.h() == image2.h());
-
-  // TODO(estade): do something with the extra pixels if the image sizes
-  // are different.
-  for (int y = 0; y < h; ++y) {
-    for (int x = 0; x < w; ++x) {
-      uint32_t base_pixel = image1.pixel_at(x, y);
-      if (base_pixel != image2.pixel_at(x, y)) {
-        // Set differing pixels red.
-        out->set_pixel_at(x, y, RGBA_RED | RGBA_ALPHA);
-        same = false;
-      } else {
-        // Set same pixels as faded.
-        uint32_t alpha = base_pixel & RGBA_ALPHA;
-        uint32_t new_pixel = base_pixel - ((alpha / 2) & RGBA_ALPHA);
-        out->set_pixel_at(x, y, new_pixel);
-      }
-    }
-  }
-
-  return same;
-}
-
-int DiffImages(const std::string& file1,
-               const std::string& file2,
-               const std::string& out_file) {
-  Image actual_image;
-  Image baseline_image;
-
-  if (!actual_image.CreateFromFilename(file1)) {
-    fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file1.c_str());
-    return kStatusError;
-  }
-  if (!baseline_image.CreateFromFilename(file2)) {
-    fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file2.c_str());
-    return kStatusError;
-  }
-
-  Image diff_image;
-  bool same = CreateImageDiff(baseline_image, actual_image, &diff_image);
-  if (same)
-    return kStatusSame;
-
-  std::vector<unsigned char> png_encoding;
-  image_diff_png::EncodeRGBAPNG(
-      diff_image.data(), diff_image.w(), diff_image.h(),
-      diff_image.w() * 4, &png_encoding);
-
-  FILE* f = fopen(out_file.c_str(), "wb");
-  if (!f)
-    return kStatusError;
-
-  size_t size = png_encoding.size();
-  char* ptr = reinterpret_cast<char*>(&png_encoding.front());
-  if (fwrite(ptr, 1, size, f) != size)
-    return kStatusError;
-
-  return kStatusDifferent;
-}
-
-int main(int argc, const char* argv[]) {
-  FXMEM_InitializePartitionAlloc();
-
-  bool histograms = false;
-  bool produce_diff_image = false;
-  std::string filename1;
-  std::string filename2;
-  std::string diff_filename;
-
-  int i;
-  for (i = 1; i < argc; ++i) {
-    const char* arg = argv[i];
-    if (strstr(arg, "--") != arg)
-      break;
-    if (strcmp(arg, "--histogram") == 0) {
-      histograms = true;
-    } else if (strcmp(arg, "--diff") == 0) {
-      produce_diff_image = true;
-    }
-  }
-  if (i < argc)
-    filename1 = argv[i++];
-  if (i < argc)
-    filename2 = argv[i++];
-  if (i < argc)
-    diff_filename = argv[i++];
-
-  if (produce_diff_image) {
-    if (!diff_filename.empty()) {
-      return DiffImages(filename1, filename2, diff_filename);
-    }
-  } else if (!filename2.empty()) {
-    return CompareImages(filename1, filename2, histograms);
-  }
-
-  PrintHelp();
-  return kStatusError;
-}