/**************************************************************************** ** ** 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 2.0 import QtGraphicalEffects.private 1.0 /*! \qmltype RecursiveBlur \inqmlmodule QtGraphicalEffects \since QtGraphicalEffects 1.0 \inherits QtQuick2::Item \ingroup qtgraphicaleffects-blur \brief Blurs repeatedly, providing a strong blur effect. The RecursiveBlur effect softens the image by blurring it with an algorithm that uses a recursive feedback loop to blur the source multiple times. The effect may give more blurry results than \l{QtGraphicalEffects::GaussianBlur}{GaussianBlur} or \l{QtGraphicalEffects::FastBlur}{FastBlur}, but the result is produced asynchronously and takes more time. \table \header \li Source \li Effect applied \row \li \image Original_bug.png \li \image RecursiveBlur_bug.png \endtable \note This effect is available when running with OpenGL. \section1 Example The following example shows how to apply the effect. \snippet RecursiveBlur-example.qml example */ Item { id: rootItem /*! This property defines the source item that is going to be blurred. \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 distance of neighboring pixels which influence the blurring of individual pixels. A larger radius provides better quality, but is slower to render. \b Note: The radius value in this effect is not intended to be changed or animated frequently. The correct way to use it is to set the correct value and keep it unchanged for the whole duration of the iterative blur sequence. The value ranges from (no blur) to 16.0 (maximum blur step). By default, the property is set to \c 0.0 (no blur). \table \header \li Output examples with different radius values \li \li \row \li \image RecursiveBlur_radius1.png \li \image RecursiveBlur_radius2.png \li \image RecursiveBlur_radius3.png \row \li \b { radius: 2.5 } \li \b { radius: 4.5 } \li \b { radius: 7.5 } \row \li \l loops: 20 \li \l loops: 20 \li \l loops: 20 \endtable */ property real radius: 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 /*! This property defines the blur behavior near the edges of the item, where the pixel blurring is affected by the pixels outside the source edges. If the property is set to \c true, the pixels outside the source are interpreted to be transparent, which is similar to OpenGL clamp-to-border extension. The blur is expanded slightly outside the effect item area. If the property is set to \c false, the pixels outside the source are interpreted to contain the same color as the pixels at the edge of the item, which is similar to OpenGL clamp-to-edge behavior. The blur does not expand outside the effect item area. By default, the property is set to \c false. \table \header \li Output examples with different transparentBorder values \li \li \row \li \image RecursiveBlur_transparentBorder1.png \li \image RecursiveBlur_transparentBorder2.png \row \li \b { transparentBorder: false } \li \b { transparentBorder: true } \row \li \l loops: 20 \li \l loops: 20 \row \li \l radius: 7.5 \li \l radius: 7.5 \endtable */ property bool transparentBorder: false /*! This property defines the amount of blur iterations that are going to be performed for the source. When the property changes, the iterative blurring process starts. If the value is decreased or if the value changes from zero to non-zero, a snapshot is taken from the source. The snapshot is used as a starting point for the process. The iteration loop tries to run as fast as possible. The speed might be limited by the VSYNC or the time needed for one blur step, or both. Sometimes it may be desirable to perform the blurring with a slower pace. In that case, it may be convenient to control the property with Animation which increases the value. The value ranges from 0 to inf. By default, the property is set to \c 0. \table \header \li Output examples with different loops values \li \li \row \li \image RecursiveBlur_loops1.png \li \image RecursiveBlur_loops2.png \li \image RecursiveBlur_loops3.png \row \li \b { loops: 4 } \li \b { loops: 20 } \li \b { loops: 70 } \row \li \l radius: 7.5 \li \l radius: 7.5 \li \l radius: 7.5 \endtable */ property int loops: 0 /*! This property holds the progress of asynchronous source blurring process, from 0.0 (nothing blurred) to 1.0 (finished). */ property real progress: loops > 0.0 ? Math.min(1.0, recursionTimer.counter / loops) : 0.0 onLoopsChanged: recursiveSource.scheduleUpdate() onSourceChanged: recursionTimer.reset() onRadiusChanged: recursionTimer.reset() onTransparentBorderChanged: recursionTimer.reset() SourceProxy { id: sourceProxy input: rootItem.source sourceRect: rootItem.transparentBorder ? Qt.rect(-1, -1, parent.width + 2, parent.height + 2) : Qt.rect(0, 0, 0, 0) } ShaderEffectSource { id: cacheItem anchors.fill: verticalBlur smooth: true visible: rootItem.cached hideSource: visible live: true sourceItem: inputItem.visible ? inputItem : verticalBlur } Item { id: recursionTimer property int counter: 0 function reset() { counter = 0 recursiveSource.scheduleUpdate() } function nextFrame() { if (loops < counter) recursionTimer.counter = 0 if (counter > 0) recursiveSource.sourceItem = verticalBlur else recursiveSource.sourceItem = inputItem if (counter < loops) { recursiveSource.scheduleUpdate() counter++ } } } ShaderEffect { id: inputItem property variant source: sourceProxy.output property real expandX: rootItem.transparentBorder ? (horizontalBlur.maximumRadius) / horizontalBlur.width : 0.0 property real expandY: rootItem.transparentBorder ? (horizontalBlur.maximumRadius) / horizontalBlur.height : 0.0 anchors.fill: verticalBlur visible: !verticalBlur.visible vertexShader: "qrc:/qt-project.org/imports/QtGraphicalEffects/shaders/recursiveblur.vert" fragmentShader: "qrc:/qt-project.org/imports/QtGraphicalEffects/shaders/recursiveblur.frag" } ShaderEffectSource { id: recursiveSource visible: false smooth: true hideSource: false live: false sourceItem: inputItem recursive: true onSourceItemChanged: scheduleUpdate() onScheduledUpdateCompleted: recursionTimer.nextFrame() } GaussianDirectionalBlur { id: verticalBlur x: rootItem.transparentBorder ? -horizontalBlur.maximumRadius - 1 : 0 y: rootItem.transparentBorder ? -horizontalBlur.maximumRadius - 1 : 0 width: horizontalBlur.width + 2 height: horizontalBlur.height + 2 horizontalStep: 0.0 verticalStep: 1.0 / parent.height source: ShaderEffectSource { sourceItem: horizontalBlur hideSource: true visible: false smooth: true } deviation: (radius + 1) / 2.3333 radius: rootItem.radius maximumRadius: Math.ceil(rootItem.radius) transparentBorder: false visible: loops > 0 } GaussianDirectionalBlur { id: horizontalBlur width: rootItem.transparentBorder ? parent.width + 2 * maximumRadius + 2 : parent.width height: rootItem.transparentBorder ? parent.height + 2 * maximumRadius + 2 : parent.height horizontalStep: 1.0 / parent.width verticalStep: 0.0 source: recursiveSource deviation: (radius + 1) / 2.3333 radius: rootItem.radius maximumRadius: Math.ceil(rootItem.radius) transparentBorder: false visible: false } }