Qt Documentation

Contents

OpacityMask QML Type

Masks the source item with another item. More...

Import Statement: import QtGraphicalEffects 1.14
Since: QtGraphicalEffects 1.0
Inherits:

Item

Properties

Detailed Description

SourceMaskSourceEffect applied

Note: This effect is available when running with OpenGL.

Example

The following example shows how to apply the effect.

import QtQuick 2.12
import QtGraphicalEffects 1.12

Item {
    width: 300
    height: 300

    Image {
        id: bug
        source: "images/bug.jpg"
        sourceSize: Qt.size(parent.width, parent.height)
        smooth: true
        visible: false
    }

    Image {
        id: mask
        source: "images/butterfly.png"
        sourceSize: Qt.size(parent.width, parent.height)
        smooth: true
        visible: false
    }

    OpacityMask {
        anchors.fill: bug
        source: bug
        maskSource: mask
    }
}

Property Documentation

cached : bool

This property allows the effect output pixels to be cached in order to improve the rendering performance.

Every time the source or effect properties are changed, the pixels in the cache must be updated. Memory consumption is increased, because an extra buffer of memory is required for storing the effect output.

It is recommended to disable the cache when the source or the effect properties are animated.

By default, the property is set to false.

Note: It is not supported to let the effect include itself, for instance by setting maskSource to the effect's parent.


invert : bool

This property controls how the alpha values of the sourceMask will behave.

If this property is false, the resulting opacity is the source alpha multiplied with the mask alpha, As * Am.

If this property is true, the resulting opacity is the source alpha multiplied with the inverse of the mask alpha, As * (1 - Am).

The default is false.

This property was introduced in Qt 5.7.


maskSource : variant

This property defines the item that is going to be used as the mask. The mask item gets rendered into an intermediate pixel buffer and the alpha values from the result are used to determine the source item's pixels visibility in the display.

OriginalMaskEffect applied


source : variant

This property defines the source item that is going to be masked.

Note: It is not supported to let the effect include itself, for instance by setting source to the effect's parent.


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