blob: 19d5df9deef1920befe6f4d1ac895525f3ac1868 [file] [log] [blame]
// 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 <algorithm>
#include <vector>
#include <string>
#include <iostream>
#include "base/basictypes.h"
#include "base/command_line.h"
#include "base/file_path.h"
#include "base/file_util.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/process_util.h"
#include "base/string_util.h"
#include "base/utf_string_conversions.h"
#include "ui/gfx/codec/png_codec.h"
#include "ui/gfx/size.h"
#if defined(OS_WIN)
#include "windows.h"
#endif
// Causes the app to remain open, waiting for pairs of filenames on stdin.
// The caller is then responsible for terminating this app.
static const char kOptionPollStdin[] = "use-stdin";
static const char kOptionGenerateDiff[] = "diff";
// 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 RGBA_RED = 0x000000ff;
static const uint32 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 stdin with the given data length. On success, it
// will return true. On failure, no other methods should be accessed.
bool CreateFromStdin(size_t byte_length) {
if (byte_length == 0)
return false;
scoped_array<unsigned char> source(new unsigned char[byte_length]);
if (fread(source.get(), 1, byte_length, stdin) != byte_length)
return false;
if (!gfx::PNGCodec::Decode(source.get(), byte_length,
gfx::PNGCodec::FORMAT_RGBA,
&data_, &w_, &h_)) {
Clear();
return false;
}
return true;
}
// Creates the image from the given filename on disk, and returns true on
// success.
bool CreateFromFilename(const FilePath& path) {
FILE* f = file_util::OpenFile(path, "rb");
if (!f)
return false;
std::vector<unsigned char> compressed;
const int buf_size = 1024;
unsigned char buf[buf_size];
size_t num_read = 0;
while ((num_read = fread(buf, 1, buf_size, f)) > 0) {
compressed.insert(compressed.end(), buf, buf + num_read);
}
file_util::CloseFile(f);
if (!gfx::PNGCodec::Decode(&compressed[0], compressed.size(),
gfx::PNGCodec::FORMAT_RGBA, &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 pixel_at(int x, int y) const {
DCHECK(x >= 0 && x < w_);
DCHECK(y >= 0 && y < h_);
return *reinterpret_cast<const uint32*>(&(data_[(y * w_ + x) * 4]));
}
void set_pixel_at(int x, int y, uint32 color) const {
DCHECK(x >= 0 && x < w_);
DCHECK(y >= 0 && y < h_);
void* addr = &const_cast<unsigned char*>(&data_.front())[(y * w_ + x) * 4];
*reinterpret_cast<uint32*>(addr) = color;
}
private:
// pixel dimensions of the image
int w_, h_;
std::vector<unsigned char> data_;
};
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++;
}
}
// 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());
// ...pixels off the right side, but not including the lower right corner
pixels_different += (max_w - w) * h;
// ...pixels along the bottom, including the lower right corner
pixels_different += (max_h - h) * max_w;
// 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)
return 100.0f; // when the bitmap is empty, they are 100% different
return static_cast<float>(pixels_different) / total_pixels * 100;
}
void PrintHelp() {
fprintf(stderr,
"Usage:\n"
" image_diff <compare file> <reference file>\n"
" Compares two files on disk, returning 0 when they are the same\n"
" image_diff --use-stdin\n"
" Stays open reading pairs of filenames from stdin, comparing them,\n"
" and sending 0 to stdout when they are the same\n"
" image_diff --diff <compare file> <reference file> <output file>\n"
" Compares two files on disk, outputs an image that visualizes the"
" difference to <output file>\n");
/* For unfinished webkit-like-mode (see below)
"\n"
" image_diff -s\n"
" Reads stream input from stdin, should be EXACTLY of the format\n"
" \"Content-length: <byte length> <data>Content-length: ...\n"
" it will take as many file pairs as given, and will compare them as\n"
" (cmp_file, reference_file) pairs\n");
*/
}
int CompareImages(const FilePath& file1, const FilePath& file2) {
Image actual_image;
Image baseline_image;
if (!actual_image.CreateFromFilename(file1)) {
fprintf(stderr, "image_diff: Unable to open file \"%" PRFilePath "\"\n",
file1.value().c_str());
return kStatusError;
}
if (!baseline_image.CreateFromFilename(file2)) {
fprintf(stderr, "image_diff: Unable to open file \"%" PRFilePath "\"\n",
file2.value().c_str());
return kStatusError;
}
float percent = PercentageDifferent(actual_image, baseline_image);
if (percent > 0.0) {
// failure: The WebKit version also writes the difference image to
// stdout, which seems excessive for our needs.
printf("diff: %01.2f%% failed\n", percent);
return kStatusDifferent;
}
// success
printf("diff: %01.2f%% passed\n", percent);
return kStatusSame;
/* Untested mode that acts like WebKit's image comparator. I wrote this but
decided it's too complicated. We may use it in the future if it looks useful
char buffer[2048];
while (fgets(buffer, sizeof(buffer), stdin)) {
if (strncmp("Content-length: ", buffer, 16) == 0) {
char* context;
strtok_s(buffer, " ", &context);
int image_size = strtol(strtok_s(NULL, " ", &context), NULL, 10);
bool success = false;
if (image_size > 0 && actual_image.has_image() == 0) {
if (!actual_image.CreateFromStdin(image_size)) {
fputs("Error, input image can't be decoded.\n", stderr);
return 1;
}
} else if (image_size > 0 && baseline_image.has_image() == 0) {
if (!baseline_image.CreateFromStdin(image_size)) {
fputs("Error, baseline image can't be decoded.\n", stderr);
return 1;
}
} else {
fputs("Error, image size must be specified.\n", stderr);
return 1;
}
}
if (actual_image.has_image() && baseline_image.has_image()) {
float percent = PercentageDifferent(actual_image, baseline_image);
if (percent > 0.0) {
// failure: The WebKit version also writes the difference image to
// stdout, which seems excessive for our needs.
printf("diff: %01.2f%% failed\n", percent);
} else {
// success
printf("diff: %01.2f%% passed\n", percent);
}
actual_image.Clear();
baseline_image.Clear();
}
fflush(stdout);
}
*/
}
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 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 alpha = base_pixel & RGBA_ALPHA;
uint32 new_pixel = base_pixel - ((alpha / 2) & RGBA_ALPHA);
out->set_pixel_at(x, y, new_pixel);
}
}
}
return same;
}
int DiffImages(const FilePath& file1, const FilePath& file2,
const FilePath& out_file) {
Image actual_image;
Image baseline_image;
if (!actual_image.CreateFromFilename(file1)) {
fprintf(stderr, "image_diff: Unable to open file \"%" PRFilePath "\"\n",
file1.value().c_str());
return kStatusError;
}
if (!baseline_image.CreateFromFilename(file2)) {
fprintf(stderr, "image_diff: Unable to open file \"%" PRFilePath "\"\n",
file2.value().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;
gfx::PNGCodec::Encode(diff_image.data(), gfx::PNGCodec::FORMAT_RGBA,
gfx::Size(diff_image.w(), diff_image.h()),
diff_image.w() * 4, false,
std::vector<gfx::PNGCodec::Comment>(), &png_encoding);
if (file_util::WriteFile(out_file,
reinterpret_cast<char*>(&png_encoding.front()), png_encoding.size()) < 0)
return kStatusError;
return kStatusDifferent;
}
// It isn't strictly correct to only support ASCII paths, but this
// program reads paths on stdin and the program that spawns it outputs
// paths as non-wide strings anyway.
FilePath FilePathFromASCII(const std::string& str) {
#if defined(OS_WIN)
return FilePath(ASCIIToWide(str));
#else
return FilePath(str);
#endif
}
int main(int argc, const char* argv[]) {
base::EnableTerminationOnHeapCorruption();
CommandLine::Init(argc, argv);
const CommandLine& parsed_command_line = *CommandLine::ForCurrentProcess();
if (parsed_command_line.HasSwitch(kOptionPollStdin)) {
// Watch stdin for filenames.
std::string stdin_buffer;
FilePath filename1;
while (std::getline(std::cin, stdin_buffer)) {
if (stdin_buffer.empty())
continue;
if (!filename1.empty()) {
// CompareImages writes results to stdout unless an error occurred.
FilePath filename2 = FilePathFromASCII(stdin_buffer);
if (CompareImages(filename1, filename2) == kStatusError)
printf("error\n");
fflush(stdout);
filename1 = FilePath();
} else {
// Save the first filename in another buffer and wait for the second
// filename to arrive via stdin.
filename1 = FilePathFromASCII(stdin_buffer);
}
}
return 0;
}
const CommandLine::StringVector& args = parsed_command_line.GetArgs();
if (parsed_command_line.HasSwitch(kOptionGenerateDiff)) {
if (args.size() == 3) {
return DiffImages(FilePath(args[0]),
FilePath(args[1]),
FilePath(args[2]));
}
} else if (args.size() == 2) {
return CompareImages(FilePath(args[0]), FilePath(args[1]));
}
PrintHelp();
return kStatusError;
}