- Qt 6.12
- Qt 5 Compatibility APIs: Graphical Effects
- QML Types
- OpacityMask
- Qt 6.12.0 Reference Documentation

# OpacityMask QML Type

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

Import Statement: | `import Qt5Compat.GraphicalEffects`
Since: | QtGraphicalEffects 1.0
Inherits: | Item

- List of all members, including inherited members

## Properties

- cached : bool
- invert : bool
- maskSource : variant
- source : variant

## Detailed Description

Note: The MultiEffect component provides a mask effect with some performance advantages. For new code, it should be considered as an alternative to using Qt Graphical Effects.

Source | MaskSource | Effect applied
--- | --- | ---

## Example

The following example shows how to apply the effect.

     import QtQuick
     import Qt5Compat.GraphicalEffects

     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`.

### 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.

Original | Mask | Effect 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.