190 lines
6.9 KiB
QML
190 lines
6.9 KiB
QML
/****************************************************************************
|
|
**
|
|
** Copyright (C) 2017 The Qt Company Ltd.
|
|
** Contact: https://www.qt.io/licensing/
|
|
**
|
|
** This file is part of the Qt Graphical Effects module.
|
|
**
|
|
** $QT_BEGIN_LICENSE:LGPL$
|
|
** Commercial License Usage
|
|
** Licensees holding valid commercial Qt licenses may use this file in
|
|
** accordance with the commercial license agreement provided with the
|
|
** Software or, alternatively, in accordance with the terms contained in
|
|
** a written agreement between you and The Qt Company. For licensing terms
|
|
** and conditions see https://www.qt.io/terms-conditions. For further
|
|
** information use the contact form at https://www.qt.io/contact-us.
|
|
**
|
|
** GNU Lesser General Public License Usage
|
|
** Alternatively, this file may be used under the terms of the GNU Lesser
|
|
** General Public License version 3 as published by the Free Software
|
|
** Foundation and appearing in the file LICENSE.LGPL3 included in the
|
|
** packaging of this file. Please review the following information to
|
|
** ensure the GNU Lesser General Public License version 3 requirements
|
|
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
|
|
**
|
|
** GNU General Public License Usage
|
|
** Alternatively, this file may be used under the terms of the GNU
|
|
** General Public License version 2.0 or (at your option) the GNU General
|
|
** Public license version 3 or any later version approved by the KDE Free
|
|
** Qt Foundation. The licenses are as published by the Free Software
|
|
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
|
|
** included in the packaging of this file. Please review the following
|
|
** information to ensure the GNU General Public License requirements will
|
|
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
|
|
** https://www.gnu.org/licenses/gpl-3.0.html.
|
|
**
|
|
** $QT_END_LICENSE$
|
|
**
|
|
****************************************************************************/
|
|
|
|
import QtQuick 2.12
|
|
import QtGraphicalEffects.private 1.12
|
|
|
|
/*!
|
|
\qmltype Displace
|
|
\inqmlmodule QtGraphicalEffects
|
|
\since QtGraphicalEffects 1.0
|
|
\inherits QtQuick2::Item
|
|
\ingroup qtgraphicaleffects-distortion
|
|
\brief Moves the pixels of the source item according to the given
|
|
displacement map.
|
|
|
|
\table
|
|
\header
|
|
\li Source
|
|
\li DisplacementSource
|
|
\li Effect applied
|
|
\row
|
|
\li \image Original_bug.png
|
|
\li \image Displace_map.png
|
|
\li \image Displace_bug.png
|
|
\endtable
|
|
|
|
\note This effect is available when running with OpenGL.
|
|
|
|
\section1 Example
|
|
|
|
The following example shows how to apply the effect.
|
|
\snippet Displace-example.qml example
|
|
|
|
*/
|
|
Item {
|
|
id: rootItem
|
|
|
|
/*!
|
|
This property defines the source item for the pixels that are going to
|
|
be displaced according to the data from
|
|
\l{Displace::displacementSource}{displacementSource}.
|
|
|
|
\note It is not supported to let the effect include itself, for
|
|
instance by setting source to the effect's parent.
|
|
*/
|
|
property variant source
|
|
|
|
/*!
|
|
This property defines the item that is going to be used as the
|
|
displacement map. The displacementSource item gets rendered into the
|
|
intermediate pixel buffer. The red and green component values from the
|
|
result determine the displacement of the pixels from the source item.
|
|
|
|
The format for the displacement map is similar to the tangent space
|
|
normal maps, which can be created with most 3D-modeling tools. Many
|
|
image processing tools include the support for generating normal maps.
|
|
Alternatively, the displacement map for this effect can also be a QML
|
|
element which is colored appropriately. Like any QML element, it can be
|
|
animated. It is recommended that the size of the diplacement map matches
|
|
the size of the \l{Displace::source}{source}.
|
|
|
|
The displace data is interpreted in the RGBA format. For every pixel:
|
|
the red channel stores the x-axis displacement, and the green channel
|
|
stores the y-axis displacement. Blue and alpha channels are ignored for
|
|
this effect.
|
|
|
|
Assuming that red channel value 1.0 is fully red (0.0 having no red at
|
|
all), this effect considers pixel component value 0.5 to cause no
|
|
displacement at all. Values above 0.5 shift pixels to the left, values
|
|
below 0.5 do the shift to the right. In a similar way, green channel
|
|
values above 0.5 displace the pixels upwards, and values below 0.5 shift
|
|
the pixels downwards. The actual amount of displacement in pixels
|
|
depends on the \l displacement property.
|
|
|
|
*/
|
|
property variant displacementSource
|
|
|
|
/*!
|
|
This property defines the scale for the displacement. The bigger scale,
|
|
the bigger the displacement of the pixels. The value set to 0.0 causes
|
|
no displacement.
|
|
|
|
The value ranges from -1.0 (inverted maximum shift, according to
|
|
displacementSource) to 1.0 (maximum shift, according to
|
|
displacementSource). By default, the property is set to \c 0.0 (no
|
|
displacement).
|
|
|
|
\table
|
|
\header
|
|
\li Output examples with different displacement values
|
|
\li
|
|
\li
|
|
\row
|
|
\li \image Displace_displacement1.png
|
|
\li \image Displace_displacement2.png
|
|
\li \image Displace_displacement3.png
|
|
\row
|
|
\li \b { displacement: -0.2 }
|
|
\li \b { displacement: 0.0 }
|
|
\li \b { displacement: 0.2 }
|
|
\endtable
|
|
|
|
*/
|
|
property real displacement: 0.0
|
|
|
|
/*!
|
|
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.
|
|
|
|
*/
|
|
property bool cached: false
|
|
|
|
SourceProxy {
|
|
id: sourceProxy
|
|
input: rootItem.source
|
|
}
|
|
|
|
SourceProxy {
|
|
id: displacementSourceProxy
|
|
input: rootItem.displacementSource
|
|
}
|
|
|
|
ShaderEffectSource {
|
|
id: cacheItem
|
|
anchors.fill: parent
|
|
visible: rootItem.cached
|
|
smooth: true
|
|
sourceItem: shaderItem
|
|
live: true
|
|
hideSource: visible
|
|
}
|
|
|
|
ShaderEffect {
|
|
id: shaderItem
|
|
property variant source: sourceProxy.output
|
|
property variant displacementSource: displacementSourceProxy.output
|
|
property real displacement: rootItem.displacement
|
|
property real xPixel: 1.0/width
|
|
property real yPixel: 1.0/height
|
|
|
|
anchors.fill: parent
|
|
|
|
fragmentShader: "qrc:/qt-project.org/imports/QtGraphicalEffects/shaders/displace.frag"
|
|
}
|
|
}
|