void onDrawContent(SkCanvas* canvas) override {
SkPaint paint;
paint.setAntiAlias(true);
paint.setTextSize(SkIntToScalar(24));
SkAutoTUnref<SkBlurDrawLooper> looper(
SkBlurDrawLooper::Create(SK_ColorBLUE,
SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(2)),
0, 0));
paint.setLooper(looper);
SkScalar height = paint.getFontMetrics(nullptr);
if (!fDecodeSucceeded) {
SkString failure;
if (fResPath.size() == 0) {
failure.printf("resource path is required!");
} else {
failure.printf("Failed to decode %s", fCurrFile.c_str());
}
canvas->drawText(failure.c_str(), failure.size(), 0, height, paint);
return;
}
// Name, size of the file, and whether or not it is premultiplied.
SkString header(SkOSPath::Basename(fCurrFile.c_str()));
header.appendf(" [%dx%d] %s", fBitmap.width(), fBitmap.height(),
(fPremul ? "premultiplied" : "unpremultiplied"));
canvas->drawText(header.c_str(), header.size(), 0, height, paint);
canvas->translate(0, height);
// Help messages
header.printf("Press '%c' to move to the next image.'", fNextImageChar);
canvas->drawText(header.c_str(), header.size(), 0, height, paint);
canvas->translate(0, height);
header.printf("Press '%c' to toggle premultiplied decode.", fTogglePremulChar);
canvas->drawText(header.c_str(), header.size(), 0, height, paint);
// Now draw the image itself.
canvas->translate(height * 2, height * 2);
if (!fPremul) {
// A premultiplied bitmap cannot currently be drawn.
SkAutoLockPixels alp(fBitmap);
// Copy it to a bitmap which can be drawn, converting
// to premultiplied:
SkBitmap bm;
bm.allocN32Pixels(fBitmap.width(), fBitmap.height());
for (int i = 0; i < fBitmap.width(); ++i) {
for (int j = 0; j < fBitmap.height(); ++j) {
*bm.getAddr32(i, j) = premultiply_unpmcolor(*fBitmap.getAddr32(i, j));
}
}
canvas->drawBitmap(bm, 0, 0);
} else {
canvas->drawBitmap(fBitmap, 0, 0);
}
}
/**
* Test decoding an image in premultiplied mode and unpremultiplied mode and compare
* them.
*/
static void compare_unpremul(skiatest::Reporter* reporter, const SkString& filename) {
// Decode a resource:
SkBitmap bm8888;
SkBitmap bm8888Unpremul;
SkFILEStream stream(filename.c_str());
SkImageDecoder::Format format = SkImageDecoder::GetStreamFormat(&stream);
if (skip_image_format(format)) {
return;
}
SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(&stream));
if (NULL == decoder.get()) {
SkDebugf("couldn't decode %s\n", filename.c_str());
return;
}
bool success = decoder->decode(&stream, &bm8888, SkBitmap::kARGB_8888_Config,
SkImageDecoder::kDecodePixels_Mode);
if (!success) {
return;
}
success = stream.rewind();
REPORTER_ASSERT(reporter, success);
if (!success) {
return;
}
decoder->setRequireUnpremultipliedColors(true);
success = decoder->decode(&stream, &bm8888Unpremul, SkBitmap::kARGB_8888_Config,
SkImageDecoder::kDecodePixels_Mode);
if (!success) {
return;
}
bool dimensionsMatch = bm8888.width() == bm8888Unpremul.width()
&& bm8888.height() == bm8888Unpremul.height();
REPORTER_ASSERT(reporter, dimensionsMatch);
if (!dimensionsMatch) {
return;
}
// Only do the comparison if the two bitmaps are both 8888.
if (bm8888.config() != SkBitmap::kARGB_8888_Config
|| bm8888Unpremul.config() != SkBitmap::kARGB_8888_Config) {
return;
}
// Now compare the two bitmaps.
for (int i = 0; i < bm8888.width(); ++i) {
for (int j = 0; j < bm8888.height(); ++j) {
// "c0" is the color of the premultiplied bitmap at (i, j).
const SkPMColor c0 = *bm8888.getAddr32(i, j);
// "c1" is the result of premultiplying the color of the unpremultiplied
// bitmap at (i, j).
const SkPMColor c1 = premultiply_unpmcolor(*bm8888Unpremul.getAddr32(i, j));
// Compute the difference for each component.
int da = SkAbs32(SkGetPackedA32(c0) - SkGetPackedA32(c1));
int dr = SkAbs32(SkGetPackedR32(c0) - SkGetPackedR32(c1));
int dg = SkAbs32(SkGetPackedG32(c0) - SkGetPackedG32(c1));
int db = SkAbs32(SkGetPackedB32(c0) - SkGetPackedB32(c1));
// Alpha component must be exactly the same.
REPORTER_ASSERT(reporter, 0 == da);
// Color components may not match exactly due to rounding error.
REPORTER_ASSERT(reporter, dr <= 1);
REPORTER_ASSERT(reporter, dg <= 1);
REPORTER_ASSERT(reporter, db <= 1);
}
}
}