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/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Graphical Effects module.
**
** $QT_BEGIN_LICENSE:FDL$
** GNU Free Documentation License
** Alternatively, this file may be used under the terms of the GNU Free
** Documentation License version 1.3 as published by the Free Software
** Foundation and appearing in the file included in the packaging of
** this file.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms
** and conditions contained in a signed written agreement between you
** and Nokia.
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
/*!
\qmlclass ThresholdMask
\inqmlmodule QtGraphicalEffects
\brief Masks the source item with another item and applies a threshold value.
The masking behavior can be controlled with the \l threshold value for the
mask pixels.
\table
\header
\o Source
\o MaskSource
\o Effect applied
\row
\o \image Original_bug.png
\o \image ThresholdMask_mask.png
\o \image ThresholdMask_bug.png
\endtable
\section1 Example
The following example shows how to apply the effect.
\snippet snippets/ThresholdMask-example.qml example
*/
/*!
\qmlproperty variant QtGraphicalEffects::ThresholdMask::source
This property defines the source item that is going to be masked.
*/
/*!
\qmlproperty variant QtGraphicalEffects::ThresholdMask::maskSource
This property defines the item that is going to be used as the mask. 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.
\table
\header
\o Original
\o Mask
\o Effect applied
\row
\o \image Original_bug.png
\o \image ThresholdMask_mask.png
\o \image ThresholdMask_bug.png
\endtable
*/
/*!
\qmlproperty real QtGraphicalEffects::ThresholdMask::threshold
This property defines a threshold value for the mask pixels. The mask pixels that have an alpha value
below this property are used to completely mask away the corresponding pixels from the source item.
The mask pixels that have a higher alpha value are used to alphablend the source item to the display.
The value ranges from 0.0 (alpha value 0) to 1.0 (alpha value 255). By default, the property is set to \c 0.0.
\table
\header
\o Output examples with different threshold values
\o
\o
\row
\o \image ThresholdMask_threshold1.png
\o \image ThresholdMask_threshold2.png
\o \image ThresholdMask_threshold3.png
\row
\o \bold { threshold: 0.0 }
\o \bold { threshold: 0.5 }
\o \bold { threshold: 0.7 }
\row
\o \l spread: 0.2
\o \l spread: 0.2
\o \l spread: 0.2
\endtable
*/
/*!
\qmlproperty real QtGraphicalEffects::ThresholdMask::spread
This property defines the smoothness of the mask edges near the \l threshold
alpha value. Setting spread to 0.0 uses mask normally with the specified
threshold. Setting higher spread values softens the transition from the
transparent mask pixels towards opaque mask pixels by adding interpolated
values between them.
The value ranges from 0.0 (sharp mask edge) to 1.0 (smooth mask edge). By default, the property is set to \c 0.0.
\table
\header
\o Output examples with different spread values
\o
\o
\row
\o \image ThresholdMask_spread1.png
\o \image ThresholdMask_spread2.png
\o \image ThresholdMask_spread3.png
\row
\o \bold { spread: 0.0 }
\o \bold { spread: 0.2 }
\o \bold { spread: 0.8 }
\row
\o \l threshold: 0.4
\o \l threshold: 0.4
\o \l threshold: 0.4
\endtable
*/
/*!
\qmlproperty bool QtGraphicalEffects::ThresholdMask::cached
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 \c false.
*/
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