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! I
thought that's what ShaderEffectSource does!
In my defense I must say that Qt documentation is not very clear, nor there
are many examples available :-)
Just out of curiosity then: why do you think my first code example works in
the Emulator?
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 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
> _______________________________________________
> 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
