Wow! Documentation for Qt 5.4 has massively improved! Never thought about looking at the 5.4 branch for docs though, as I'm developing for SailfishOS exclusively and it's still 5.2 based; but from now on I will for sure, it's sooo much better, thank you for pointing this out!
On Wed, Feb 11, 2015 at 8:07 PM, Gunnar Sletta <gunnar.sle...@jolla.com> wrote: > > On 11 Feb 2015, at 10:46, Luca Donaggio <donag...@gmail.com> wrote: > > Thank you Gunnar! > > I completely misunderstood the "layer" property of the Item element! I > thought its purpouse was to apply an effect (or a texture) to an Item > before rendering it on the scene, not to render any Item as an out-of-scene > texture which could then be used as the source for a ShaderEffect! > > > A convenient way of adding an effect is one usecase certainly. You can > use it for other things though. The Qt 5.4 docs should have a fairly good > explanation of how it works. > http://doc-snapshot.qt-project.org/qt5-5.4/qml-qtquick-item.html#item-layers > > I thought that's what ShaderEffectSource does! > > > layer is a more convenient ShaderEffectSource which doesn’t require you > to add items into the sibling hierarchy. > > > In my defense I must say that Qt documentation is not very clear, nor > there are many examples available :-) > > > In pre Qt 5.4, yes. Very much so :) If you find the 5.4 docs lacking, > please let me know. > > > Just out of curiosity then: why do you think my first code example works > in the Emulator? > > > Using the FBO as a source texture while writing to it is supported on > many graphics cards. > > > > On Tue, Feb 10, 2015 at 9:04 PM, Gunnar Sletta <gunnar.sle...@jolla.com> > wrote: > >> Hi Luca, >> >> The application code is not doing the right thing :) >> >> If the ShaderEffectSource depends on itself, it needs to have the >> “recursive” property set to true, and that is still probably not what you >> want. What you probably want is to set “layer.enabled: true; layer.smooth: >> true” on the gradientSource and then use it directly in the ShaderEffect. >> That should do what you want and comes without consequence. >> >> cheers, >> Gunnar >> >> >> On 10 Feb 2015, at 11:54, Luca Donaggio <donag...@gmail.com> wrote: >> >> Thanks Andrey. >> >> I'll report this on TJC as well, trying to get more visibility. I hope >> that some Sailor will notice it: it's not that important, but it's >> disturbing nonetheless. >> >> >> On Tue, Feb 10, 2015 at 11:39 AM, Andrey Kozhevnikov < >> coderusin...@gmail.com> wrote: >> >>> yes i can confirm this behaviour. >>> >>> 10.02.2015 15:24, Luca Donaggio пишет: >>> >>> Hi Andrey, thanks for your reply. >>> >>> Still, can you try both tests on your Jolla? >>> The first shouldn't work, while the second does. >>> >>> On Tue, Feb 10, 2015 at 10:32 AM, Andrey Kozhevnikov < >>> coderusin...@gmail.com> wrote: >>> >>>> sorry, not using emulator at all. >>>> >>>> 10.02.2015 14:28, Luca Donaggio пишет: >>>> >>>> Anybody is willing to try my test code and confirm or deny my finding? >>>> >>>> On Fri, Feb 6, 2015 at 2:12 PM, Luca Donaggio <donag...@gmail.com> >>>> wrote: >>>> >>>>> The following code works fine in Emulator, changing the gradient of >>>>> the Rectangle correctly updates the nested ShaderEffectSource and it is >>>>> reflected on the ShaderEffect which uses it as its texture: >>>>> >>>>> Page { >>>>> id: page >>>>> >>>>> SilicaFlickable { >>>>> anchors.fill: parent >>>>> >>>>> contentHeight: column.height >>>>> >>>>> Column { >>>>> id: column >>>>> >>>>> anchors { top: parent.top; left: parent.left; right: >>>>> parent.right; leftMargin: Theme.paddingLarge; rightMargin: >>>>> Theme.paddingLarge; } >>>>> spacing: Theme.paddingLarge >>>>> >>>>> PageHeader { >>>>> title: qsTr("ShaderEffect Test") >>>>> } >>>>> >>>>> Row { >>>>> anchors.horizontalCenter: parent.horizontalCenter >>>>> spacing: Theme.paddingLarge >>>>> >>>>> Column { >>>>> spacing: Theme.paddingSmall >>>>> >>>>> Rectangle { >>>>> id: gradientSource >>>>> >>>>> property list<Gradient> gradients: [ >>>>> Gradient { >>>>> GradientStop { position: 0.0; color: >>>>> "black"; } >>>>> GradientStop { position: 1.0; color: >>>>> "blue"; } >>>>> }, >>>>> >>>>> Gradient { >>>>> GradientStop { position: 0.0; color: >>>>> "black"; } >>>>> GradientStop { position: 1.0; color: >>>>> "red"; } >>>>> } >>>>> ] >>>>> >>>>> width: 100 >>>>> height: 100 >>>>> >>>>> gradient: gradients[0] >>>>> >>>>> ShaderEffectSource { >>>>> id: gradientTexture >>>>> >>>>> anchors.fill: parent >>>>> sourceItem: gradientSource >>>>> hideSource: false >>>>> live: true >>>>> } >>>>> } >>>>> >>>>> Label { >>>>> font.pixelSize: Theme.fontSizeExtraSmall >>>>> wrapMode: Text.WordWrap >>>>> text: "Rectangle\nShaderEffectSource" >>>>> } >>>>> } >>>>> >>>>> Column { >>>>> spacing: Theme.paddingSmall >>>>> >>>>> ShaderEffect { >>>>> property variant source: gradientTexture >>>>> >>>>> width: 100 >>>>> height: 100 >>>>> >>>>> blending: false >>>>> cullMode: ShaderEffect.BackFaceCulling >>>>> fragmentShader: " >>>>> varying highp vec2 qt_TexCoord0; >>>>> uniform lowp float qt_Opacity; >>>>> uniform sampler2D source; >>>>> >>>>> void main() { >>>>> gl_FragColor = texture2D(source, >>>>> qt_TexCoord0) * qt_Opacity; >>>>> }" >>>>> } >>>>> >>>>> Label { >>>>> font.pixelSize: Theme.fontSizeExtraSmall >>>>> text: "ShaderEffect" >>>>> } >>>>> } >>>>> } >>>>> >>>>> Button { >>>>> anchors.horizontalCenter: parent.horizontalCenter >>>>> text: "Blue gradient" >>>>> >>>>> onClicked: gradientSource.gradient = >>>>> gradientSource.gradients[0] >>>>> } >>>>> >>>>> Button { >>>>> anchors.horizontalCenter: parent.horizontalCenter >>>>> text: "Red gradient" >>>>> >>>>> onClicked: gradientSource.gradient = >>>>> gradientSource.gradients[1] >>>>> } >>>>> } >>>>> } >>>>> } >>>>> >>>>> It doesn't work on device though (changing Reactangle's gradient >>>>> doesn't update the ShaderEffectSource). >>>>> >>>>> Un-nesting the ShaderEffectSource from its source item (the >>>>> Rectangle) works fine both on emulator and on device: >>>>> >>>>> Page { >>>>> id: page >>>>> >>>>> SilicaFlickable { >>>>> anchors.fill: parent >>>>> >>>>> contentHeight: column.height >>>>> >>>>> Column { >>>>> id: column >>>>> >>>>> anchors { top: parent.top; left: parent.left; right: >>>>> parent.right; leftMargin: Theme.paddingLarge; rightMargin: >>>>> Theme.paddingLarge; } >>>>> spacing: Theme.paddingLarge >>>>> >>>>> PageHeader { >>>>> title: qsTr("ShaderEffect Test") >>>>> } >>>>> >>>>> Row { >>>>> anchors.horizontalCenter: parent.horizontalCenter >>>>> spacing: Theme.paddingLarge >>>>> >>>>> Column { >>>>> spacing: Theme.paddingSmall >>>>> >>>>> Rectangle { >>>>> id: gradientSource >>>>> >>>>> property list<Gradient> gradients: [ >>>>> Gradient { >>>>> GradientStop { position: 0.0; color: >>>>> "black"; } >>>>> GradientStop { position: 1.0; color: >>>>> "blue"; } >>>>> }, >>>>> >>>>> Gradient { >>>>> GradientStop { position: 0.0; color: >>>>> "black"; } >>>>> GradientStop { position: 1.0; color: >>>>> "red"; } >>>>> } >>>>> ] >>>>> >>>>> width: 100 >>>>> height: 100 >>>>> >>>>> gradient: gradients[0] >>>>> } >>>>> >>>>> Label { >>>>> font.pixelSize: Theme.fontSizeExtraSmall >>>>> text: "Rectangle" >>>>> } >>>>> } >>>>> >>>>> Column { >>>>> spacing: Theme.paddingSmall >>>>> >>>>> ShaderEffectSource { >>>>> id: gradientTexture >>>>> >>>>> width: 100 >>>>> height: 100 >>>>> sourceItem: gradientSource >>>>> hideSource: false >>>>> live: true >>>>> } >>>>> >>>>> Label { >>>>> font.pixelSize: Theme.fontSizeExtraSmall >>>>> text: "ShaderEffectSource" >>>>> } >>>>> } >>>>> >>>>> Column { >>>>> spacing: Theme.paddingSmall >>>>> >>>>> ShaderEffect { >>>>> property variant source: gradientTexture >>>>> >>>>> width: 100 >>>>> height: 100 >>>>> >>>>> blending: false >>>>> cullMode: ShaderEffect.BackFaceCulling >>>>> fragmentShader: " >>>>> varying highp vec2 qt_TexCoord0; >>>>> uniform lowp float qt_Opacity; >>>>> uniform sampler2D source; >>>>> >>>>> void main() { >>>>> gl_FragColor = texture2D(source, >>>>> qt_TexCoord0) * qt_Opacity; >>>>> }" >>>>> } >>>>> >>>>> Label { >>>>> font.pixelSize: Theme.fontSizeExtraSmall >>>>> text: "ShaderEffect" >>>>> } >>>>> } >>>>> } >>>>> >>>>> Button { >>>>> anchors.horizontalCenter: parent.horizontalCenter >>>>> text: "Blue gradient" >>>>> >>>>> onClicked: gradientSource.gradient = >>>>> gradientSource.gradients[0] >>>>> } >>>>> >>>>> Button { >>>>> anchors.horizontalCenter: parent.horizontalCenter >>>>> text: "Red gradient" >>>>> >>>>> onClicked: gradientSource.gradient = >>>>> gradientSource.gradients[1] >>>>> } >>>>> } >>>>> } >>>>> } >>>>> >>>>> Is it a bug? >>>>> >>>>> -- >>>>> Luca Donaggio >>>>> >>>> >>>> >>>> >>>> -- >>>> Luca Donaggio >>>> >>>> >>>> _______________________________________________SailfishOS.org >>>> <http://sailfishos.org/> Devel mailing list >>>> To unsubscribe, please send a mail to >>>> devel-unsubscr...@lists.sailfishos.org >>>> >>>> >>>> >>>> _______________________________________________ >>>> SailfishOS.org <http://sailfishos.org/> Devel mailing list >>>> To unsubscribe, please send a mail to >>>> devel-unsubscr...@lists.sailfishos.org >>>> >>> >>> >>> >>> -- >>> Luca Donaggio >>> >>> >>> _______________________________________________SailfishOS.org >>> <http://sailfishos.org/> Devel mailing list >>> To unsubscribe, please send a mail to devel-unsubscr...@lists.sailfishos.org >>> >>> >>> >>> _______________________________________________ >>> SailfishOS.org <http://sailfishos.org/> Devel mailing list >>> To unsubscribe, please send a mail to >>> devel-unsubscr...@lists.sailfishos.org >>> >> >> >> >> -- >> Luca Donaggio >> _______________________________________________ >> SailfishOS.org <http://sailfishos.org/> Devel mailing list >> To unsubscribe, please send a mail to >> devel-unsubscr...@lists.sailfishos.org >> >> >> >> _______________________________________________ >> SailfishOS.org Devel mailing list >> To unsubscribe, please send a mail to >> devel-unsubscr...@lists.sailfishos.org >> > > > > -- > Luca Donaggio > _______________________________________________ > SailfishOS.org Devel mailing list > To unsubscribe, please send a mail to > devel-unsubscr...@lists.sailfishos.org > > > > _______________________________________________ > SailfishOS.org Devel mailing list > To unsubscribe, please send a mail to > devel-unsubscr...@lists.sailfishos.org > -- Luca Donaggio
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