/*
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// This file input format is based loosely on
// WebKitTools/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 "config.h"
#include "gfx/codec/png_codec.h"
#include <algorithm>
#include <stdio.h>
#include <string.h>
#include <vector>
#include <wtf/OwnArrayPtr.h>
#include <wtf/Vector.h>
#if OS(WINDOWS)
#include <windows.h>
#define PATH_MAX MAX_PATH
#endif
using namespace gfx;
using namespace std;
// 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 optionPollStdin[] = "--use-stdin";
static const char optionGenerateDiff[] = "--diff";
// Return codes used by this utility.
static const int statusSame = 0;
static const int statusDifferent = 1;
static const int statusError = 2;
// Color codes.
static const uint32_t rgbaRed = 0x000000ff;
static const uint32_t rgbaAlpha = 0xff000000;
class Image {
public:
Image()
: m_width(0)
, m_height(0) {}
Image(const Image& image)
: m_width(image.m_width)
, m_height(image.m_height)
, m_data(image.m_data) {}
bool hasImage() const { return m_width > 0 && m_height > 0; }
int width() const { return m_width; }
int height() const { return m_height; }
const unsigned char* data() const { return &m_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 craeteFromStdin(size_t byteLength)
{
if (!byteLength)
return false;
OwnArrayPtr<unsigned char> source(new unsigned char[byteLength]);
if (fread(source.get(), 1, byteLength, stdin) != byteLength)
return false;
if (!PNGCodec::Decode(source.get(), byteLength, PNGCodec::FORMAT_RGBA,
&m_data, &m_width, &m_height)) {
clear();
return false;
}
return true;
}
// Creates the image from the given filename on disk, and returns true on
// success.
bool createFromFilename(const char* filename)
{
FILE* f = fopen(filename, "rb");
if (!f)
return false;
vector<unsigned char> compressed;
const int bufSize = 1024;
unsigned char buf[bufSize];
size_t numRead = 0;
while ((numRead = fread(buf, 1, bufSize, f)) > 0)
std::copy(buf, &buf[numRead], std::back_inserter(compressed));
fclose(f);
if (!PNGCodec::Decode(&compressed[0], compressed.size(),
PNGCodec::FORMAT_RGBA, &m_data, &m_width, &m_height)) {
clear();
return false;
}
return true;
}
void clear()
{
m_width = m_height = 0;
m_data.clear();
}
// Returns the RGBA value of the pixel at the given location
const uint32_t pixelAt(int x, int y) const
{
ASSERT(x >= 0 && x < m_width);
ASSERT(y >= 0 && y < m_height);
return *reinterpret_cast<const uint32_t*>(&(m_data[(y * m_width + x) * 4]));
}
void setPixelAt(int x, int y, uint32_t color) const
{
ASSERT(x >= 0 && x < m_width);
ASSERT(y >= 0 && y < m_height);
void* addr = &const_cast<unsigned char*>(&m_data.front())[(y * m_width + x) * 4];
*reinterpret_cast<uint32_t*>(addr) = color;
}
private:
// pixel dimensions of the image
int m_width, m_height;
vector<unsigned char> m_data;
};
float percentageDifferent(const Image& baseline, const Image& actual)
{
int w = min(baseline.width(), actual.width());
int h = min(baseline.height(), actual.height());
// Compute pixels different in the overlap
int pixelsDifferent = 0;
for (int y = 0; y < h; y++) {
for (int x = 0; x < w; x++) {
if (baseline.pixelAt(x, y) != actual.pixelAt(x, y))
pixelsDifferent++;
}
}
// Count pixels that are a difference in size as also being different
int maxWidth = max(baseline.width(), actual.width());
int maxHeight = max(baseline.height(), actual.height());
// ...pixels off the right side, but not including the lower right corner
pixelsDifferent += (maxWidth - w) * h;
// ...pixels along the bottom, including the lower right corner
pixelsDifferent += (maxHeight - h) * maxWidth;
// Like the WebKit ImageDiff tool, we define percentage different in terms
// of the size of the 'actual' bitmap.
float totalPixels = static_cast<float>(actual.width()) * static_cast<float>(actual.height());
if (!totalPixels)
return 100.0f; // When the bitmap is empty, they are 100% different.
return static_cast<float>(pixelsDifferent) / totalPixels * 100;
}
void printHelp()
{
fprintf(stderr,
"Usage:\n"
" ImageDiff <compare file> <reference file>\n"
" Compares two files on disk, returning 0 when they are the same\n"
" ImageDiff --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"
" ImageDiff --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"
" ImageDiff -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 char* file1, const char* file2)
{
Image actualImage;
Image baselineImage;
if (!actualImage.createFromFilename(file1)) {
fprintf(stderr, "ImageDiff: Unable to open file \"%s\"\n", file1);
return statusError;
}
if (!baselineImage.createFromFilename(file2)) {
fprintf(stderr, "ImageDiff: Unable to open file \"%s\"\n", file2);
return statusError;
}
float percent = percentageDifferent(actualImage, baselineImage);
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 statusDifferent;
}
// success
printf("diff: %01.2f%% passed\n", percent);
return statusSame;
}
// 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.
int untestedCompareImages()
{
Image actualImage;
Image baselineImage;
char buffer[2048];
while (fgets(buffer, sizeof(buffer), stdin)) {
if (!strncmp("Content-length: ", buffer, 16)) {
char* context;
#if OS(WINDOWS)
strtok_s(buffer, " ", &context);
int imageSize = strtol(strtok_s(0, " ", &context), 0, 10);
#else
strtok_r(buffer, " ", &context);
int imageSize = strtol(strtok_r(0, " ", &context), 0, 10);
#endif
bool success = false;
if (imageSize > 0 && !actualImage.hasImage()) {
if (!actualImage.craeteFromStdin(imageSize)) {
fputs("Error, input image can't be decoded.\n", stderr);
return 1;
}
} else if (imageSize > 0 && !baselineImage.hasImage()) {
if (!baselineImage.craeteFromStdin(imageSize)) {
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 (actualImage.hasImage() && baselineImage.hasImage()) {
float percent = percentageDifferent(actualImage, baselineImage);
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);
}
actualImage.clear();
baselineImage.clear();
}
fflush(stdout);
}
return 0;
}
bool createImageDiff(const Image& image1, const Image& image2, Image* out)
{
int w = min(image1.width(), image2.width());
int h = min(image1.height(), image2.height());
*out = Image(image1);
bool same = (image1.width() == image2.width()) && (image1.height() == image2.height());
// FIXME: 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 basePixel = image1.pixelAt(x, y);
if (basePixel != image2.pixelAt(x, y)) {
// Set differing pixels red.
out->setPixelAt(x, y, rgbaRed | rgbaAlpha);
same = false;
} else {
// Set same pixels as faded.
uint32_t alpha = basePixel & rgbaAlpha;
uint32_t newPixel = basePixel - ((alpha / 2) & rgbaAlpha);
out->setPixelAt(x, y, newPixel);
}
}
}
return same;
}
static bool writeFile(const char* outFile, const unsigned char* data, size_t dataSize)
{
FILE* file = fopen(outFile, "wb");
if (!file) {
fprintf(stderr, "ImageDiff: Unable to create file \"%s\"\n", file);
return false;
}
if (dataSize != fwrite(data, 1, dataSize, file)) {
fclose(file);
fprintf(stderr, "ImageDiff: Unable to write data to file \"%s\"\n", file);
return false;
}
fclose(file);
return true;
}
int diffImages(const char* file1, const char* file2, const char* outFile)
{
Image actualImage;
Image baselineImage;
if (!actualImage.createFromFilename(file1)) {
fprintf(stderr, "ImageDiff: Unable to open file \"%s\"\n", file1);
return statusError;
}
if (!baselineImage.createFromFilename(file2)) {
fprintf(stderr, "ImageDiff: Unable to open file \"%s\"\n", file2);
return statusError;
}
Image diffImage;
bool same = createImageDiff(baselineImage, actualImage, &diffImage);
if (same)
return statusSame;
vector<unsigned char> pngData;
PNGCodec::Encode(diffImage.data(), PNGCodec::FORMAT_RGBA, diffImage.width(),
diffImage.height(), diffImage.width() * 4, false, &pngData);
if (!writeFile(outFile, &pngData.front(), pngData.size()))
return statusError;
return statusDifferent;
}
int main(int argc, const char* argv[])
{
Vector<const char*> values;
bool pollStdin = false;
bool generateDiff = false;
for (int i = 1; i < argc; ++i) {
if (!strcmp(argv[i], optionPollStdin))
pollStdin = true;
else if (!strcmp(argv[i], optionGenerateDiff))
generateDiff = true;
else
values.append(argv[i]);
}
if (pollStdin) {
// Watch stdin for filenames.
const size_t bufferSize = PATH_MAX;
char stdinBuffer[bufferSize];
char firstName[bufferSize];
bool haveFirstName = false;
while (fgets(stdinBuffer, bufferSize, stdin)) {
if (!stdinBuffer[0])
continue;
if (haveFirstName) {
// compareImages writes results to stdout unless an error occurred.
if (compareImages(firstName, stdinBuffer) == statusError)
printf("error\n");
fflush(stdout);
haveFirstName = false;
} else {
// Save the first filename in another buffer and wait for the second
// filename to arrive via stdin.
strcpy(firstName, stdinBuffer);
haveFirstName = true;
}
}
return 0;
}
if (generateDiff) {
if (values.size() == 3)
return diffImages(values[0], values[1], values[2]);
} else if (values.size() == 2)
return compareImages(argv[1], argv[2]);
printHelp();
return statusError;
}