Hi Ben, I've solved the issue by multiplying width/height to qApp->devicePixelRatio(). That should be 3 on iPhone 6 and should provide the correct result. I'm not sure if that's a bug or it is intended behaviour and I actually didn't investigate the issue a lot since I was just testing stuff.
Hope someone else can confirm it's a bug or expected. Cheers, F. On 11 April 2016 at 14:28, Ben Lau <xben...@gmail.com> wrote: > > > On 11 April 2016 at 20:19, ekke <e...@ekkes-corner.org> wrote: > >> Am 11.04.16 um 14:07 schrieb Ben Lau: >> >> >> On 11 April 2016 at 19:59, ekke <e...@ekkes-corner.org> wrote: >> >>> Am 11.04.16 um 12:38 schrieb Ben Lau: >>> >>> Hi, >>> >>> I am writing an image provider that read all the images to memory at >>> startup. And I found that the behaviour is different from 5.5.1 to 5.6 in >>> iOS. Seems that it is undocumented. I wonder is it an expected behaviour or >>> a bug? >>> >>> That is the example project: >>> https://github.com/benlau/quickcross/tree/master/tests/imageprovider >>> >>> That is the code of my image provider: >>> >>> QImage QCImageProvider::requestImage(const QString &id, QSize *size, c >>> onst QSize &requestedSize) >>> >>> { >>> >>> Q_UNUSED(requestedSize); >>> >>> QCImageLoader* loader = QCImageLoader::instance(); >>> >>> QImage result; >>> >>> if (loader->contains(id)) { >>> >>> result = loader->image(id); >>> >>> *size = result.size(); >>> >>> } >>> >>> return result; >>> >>> } >>> >>> Code to display image: >>> >>> Image { >>> >>> id: image >>> >>> source: "image://arts/Lenna.png" // An 512x512 image >>> >>> } >>> >>> In Qt 5.5.1 with iPhone6, the property of image will be set to: >>> >>> width: 512 >>> >>> height: 512 >>> >>> sourceSize: Qt.size(512,512) >>> >>> However, in Qt 5.6 with iPhone6, it becomes: >>> >>> width: 170.66666 >>> >>> height: 170.66666 >>> >>> sourceSize: Qt.size(512,512) >>> >>> The display size of image is different. >>> >>> >>> now from Qt 5.6 HighDPI is supported for all platforms. >>> iPhone has scaling factor 3 >>> >>> 170.66666 * 3 = 512 >>> >>> >>> ekke >>> >>> >> But Qt 5.5 on iOS also support HighDPI. Their result are different. >> >> >> have you tried to explicitely set >> >> QGuiApplication::setAttribute(Qt::AA_EnableHighDpiScaling); >> >> >> ekke >> > > I have tried to set / not-set this line. It don't make any different. > > > _______________________________________________ > Development mailing list > Development@qt-project.org > http://lists.qt-project.org/mailman/listinfo/development > >
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