skia2/tools/skpdiff/SkDifferentPixelsMetric_cpu.cpp

122 lines
4.8 KiB
C++

/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkDifferentPixelsMetric.h"
#include "SkBitmap.h"
#include "skpdiff_util.h"
const char* SkDifferentPixelsMetric::getName() const {
return "different_pixels";
}
bool SkDifferentPixelsMetric::diff(SkBitmap* baseline, SkBitmap* test,
const BitmapsToCreate& bitmapsToCreate,
Result* result) const {
double startTime = get_seconds();
// Ensure the images are comparable
if (baseline->width() != test->width() || baseline->height() != test->height() ||
baseline->width() <= 0 || baseline->height() <= 0 ||
baseline->colorType() != test->colorType()) {
SkASSERT(baseline->width() == test->width());
SkASSERT(baseline->height() == test->height());
SkASSERT(baseline->width() > 0);
SkASSERT(baseline->height() > 0);
SkASSERT(baseline->colorType() == test->colorType());
return false;
}
int width = baseline->width();
int height = baseline->height();
int maxRedDiff = 0;
int maxGreenDiff = 0;
int maxBlueDiff = 0;
// Prepare any bitmaps we will be filling in
if (bitmapsToCreate.alphaMask) {
result->poiAlphaMask.allocPixels(SkImageInfo::MakeA8(width, height));
result->poiAlphaMask.eraseARGB(SK_AlphaOPAQUE, 0, 0, 0);
}
if (bitmapsToCreate.rgbDiff) {
result->rgbDiffBitmap.allocPixels(SkImageInfo::Make(width, height, baseline->colorType(),
kPremul_SkAlphaType));
result->rgbDiffBitmap.eraseARGB(SK_AlphaTRANSPARENT, 0, 0, 0);
}
if (bitmapsToCreate.whiteDiff) {
result->whiteDiffBitmap.allocPixels(SkImageInfo::MakeN32Premul(width, height));
result->whiteDiffBitmap.eraseARGB(SK_AlphaOPAQUE, 0, 0, 0);
}
// Prepare the pixels for comparison
result->poiCount = 0;
baseline->lockPixels();
test->lockPixels();
for (int y = 0; y < height; y++) {
// Grab a row from each image for easy comparison
// TODO(epoger): The code below already assumes 4 bytes per pixel, so I think
// we could just call getAddr32() to save a little time.
// OR, if we want to play it safe, call ComputeBytesPerPixel instead
// of assuming 4 bytes per pixel.
uint32_t* baselineRow = static_cast<uint32_t *>(baseline->getAddr(0, y));
uint32_t* testRow = static_cast<uint32_t *>(test->getAddr(0, y));
for (int x = 0; x < width; x++) {
// Compare one pixel at a time so each differing pixel can be noted
// TODO(epoger): This loop looks like a good place to work on performance,
// but we should run the code through a profiler to be sure.
uint32_t baselinePixel = baselineRow[x];
uint32_t testPixel = testRow[x];
if (baselinePixel != testPixel) {
result->poiCount++;
int redDiff = abs(static_cast<int>(SkColorGetR(baselinePixel) -
SkColorGetR(testPixel)));
if (redDiff > maxRedDiff) {maxRedDiff = redDiff;}
int greenDiff = abs(static_cast<int>(SkColorGetG(baselinePixel) -
SkColorGetG(testPixel)));
if (greenDiff > maxGreenDiff) {maxGreenDiff = greenDiff;}
int blueDiff = abs(static_cast<int>(SkColorGetB(baselinePixel) -
SkColorGetB(testPixel)));
if (blueDiff > maxBlueDiff) {maxBlueDiff = blueDiff;}
if (bitmapsToCreate.alphaMask) {
*result->poiAlphaMask.getAddr8(x,y) = SK_AlphaTRANSPARENT;
}
if (bitmapsToCreate.rgbDiff) {
*result->rgbDiffBitmap.getAddr32(x,y) =
SkColorSetRGB(redDiff, greenDiff, blueDiff);
}
if (bitmapsToCreate.whiteDiff) {
*result->whiteDiffBitmap.getAddr32(x,y) = SK_ColorWHITE;
}
}
}
}
test->unlockPixels();
baseline->unlockPixels();
result->maxRedDiff = maxRedDiff;
result->maxGreenDiff = maxGreenDiff;
result->maxBlueDiff = maxBlueDiff;
if (bitmapsToCreate.alphaMask) {
result->poiAlphaMask.unlockPixels();
}
if (bitmapsToCreate.rgbDiff) {
result->rgbDiffBitmap.unlockPixels();
}
if (bitmapsToCreate.whiteDiff) {
result->whiteDiffBitmap.unlockPixels();
}
// Calculates the percentage of identical pixels
result->result = 1.0 - ((double)result->poiCount / (width * height));
result->timeElapsed = get_seconds() - startTime;
return true;
}