1/**************************************************************************** 2** 3** Copyright (C) 2017 The Qt Company Ltd. 4** Contact: https://www.qt.io/licensing/ 5** 6** This file is part of the Qt Graphical Effects module. 7** 8** $QT_BEGIN_LICENSE:LGPL$ 9** Commercial License Usage 10** Licensees holding valid commercial Qt licenses may use this file in 11** accordance with the commercial license agreement provided with the 12** Software or, alternatively, in accordance with the terms contained in 13** a written agreement between you and The Qt Company. For licensing terms 14** and conditions see https://www.qt.io/terms-conditions. For further 15** information use the contact form at https://www.qt.io/contact-us. 16** 17** GNU Lesser General Public License Usage 18** Alternatively, this file may be used under the terms of the GNU Lesser 19** General Public License version 3 as published by the Free Software 20** Foundation and appearing in the file LICENSE.LGPL3 included in the 21** packaging of this file. Please review the following information to 22** ensure the GNU Lesser General Public License version 3 requirements 23** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. 24** 25** GNU General Public License Usage 26** Alternatively, this file may be used under the terms of the GNU 27** General Public License version 2.0 or (at your option) the GNU General 28** Public license version 3 or any later version approved by the KDE Free 29** Qt Foundation. The licenses are as published by the Free Software 30** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 31** included in the packaging of this file. Please review the following 32** information to ensure the GNU General Public License requirements will 33** be met: https://www.gnu.org/licenses/gpl-2.0.html and 34** https://www.gnu.org/licenses/gpl-3.0.html. 35** 36** $QT_END_LICENSE$ 37** 38****************************************************************************/ 39 40import QtQuick 2.12 41import QtGraphicalEffects.private 1.12 42 43/*! 44 \qmltype RadialBlur 45 \inqmlmodule QtGraphicalEffects 46 \since QtGraphicalEffects 1.0 47 \inherits QtQuick2::Item 48 \ingroup qtgraphicaleffects-motion-blur 49 \brief Applies directional blur in a circular direction around the items 50 center point. 51 52 Effect creates perceived impression that the source item appears to be 53 rotating to the direction of the blur. 54 55 Other available motionblur effects are 56 \l{QtGraphicalEffects::ZoomBlur}{ZoomBlur} and 57 \l{QtGraphicalEffects::DirectionalBlur}{DirectionalBlur}. 58 59 \table 60 \header 61 \li Source 62 \li Effect applied 63 \row 64 \li \image Original_bug.png 65 \li \image RadialBlur_bug.png 66 \endtable 67 68 \note This effect is available when running with OpenGL. 69 70 \section1 Example Usage 71 72 The following example shows how to apply the effect. 73 \snippet RadialBlur-example.qml example 74*/ 75Item { 76 id: rootItem 77 78 /*! 79 This property defines the source item that is going to be blurred. 80 81 \note It is not supported to let the effect include itself, for 82 instance by setting source to the effect's parent. 83 */ 84 property variant source 85 86 /*! 87 This property defines the direction for the blur and at the same time 88 the level of blurring. The larger the angle, the more the result becomes 89 blurred. The quality of the blur depends on 90 \l{RadialBlur::samples}{samples} property. If angle value is large, more 91 samples are needed to keep the visual quality at high level. 92 93 Allowed values are between 0.0 and 360.0. By default the property is set 94 to \c 0.0. 95 96 \table 97 \header 98 \li Output examples with different angle values 99 \li 100 \li 101 \row 102 \li \image RadialBlur_angle1.png 103 \li \image RadialBlur_angle2.png 104 \li \image RadialBlur_angle3.png 105 \row 106 \li \b { angle: 0.0 } 107 \li \b { angle: 15.0 } 108 \li \b { angle: 30.0 } 109 \row 110 \li \l samples: 24 111 \li \l samples: 24 112 \li \l samples: 24 113 \row 114 \li \l horizontalOffset: 0 115 \li \l horizontalOffset: 0 116 \li \l horizontalOffset: 0 117 \row 118 \li \l verticalOffset: 0 119 \li \l verticalOffset: 0 120 \li \l verticalOffset: 0 121 \endtable 122 */ 123 property real angle: 0.0 124 125 /*! 126 This property defines how many samples are taken per pixel when blur 127 calculation is done. Larger value produces better quality, but is slower 128 to render. 129 130 This property is not intended to be animated. Changing this property may 131 cause the underlying OpenGL shaders to be recompiled. 132 133 Allowed values are between 0 and inf (practical maximum depends on GPU). 134 By default the property is set to \c 0 (no samples). 135 136 */ 137 property int samples: 0 138 139 /*! 140 \qmlproperty real QtGraphicalEffects::RadialBlur::horizontalOffset 141 \qmlproperty real QtGraphicalEffects::RadialBlur::verticalOffset 142 143 These properties define the offset in pixels for the perceived center 144 point of the rotation. 145 146 Allowed values are between -inf and inf. 147 By default these properties are set to \c 0. 148 149 \table 150 \header 151 \li Output examples with different horizontalOffset values 152 \li 153 \li 154 \row 155 \li \image RadialBlur_horizontalOffset1.png 156 \li \image RadialBlur_horizontalOffset2.png 157 \li \image RadialBlur_horizontalOffset3.png 158 \row 159 \li \b { horizontalOffset: 75.0 } 160 \li \b { horizontalOffset: 0.0 } 161 \li \b { horizontalOffset: -75.0 } 162 \row 163 \li \l samples: 24 164 \li \l samples: 24 165 \li \l samples: 24 166 \row 167 \li \l angle: 20 168 \li \l angle: 20 169 \li \l angle: 20 170 \row 171 \li \l verticalOffset: 0 172 \li \l verticalOffset: 0 173 \li \l verticalOffset: 0 174 \endtable 175 */ 176 property real horizontalOffset: 0.0 177 property real verticalOffset: 0.0 178 179 /*! 180 This property defines the blur behavior near the edges of the item, 181 where the pixel blurring is affected by the pixels outside the source 182 edges. 183 184 If the property is set to \c true, the pixels outside the source are 185 interpreted to be transparent, which is similar to OpenGL 186 clamp-to-border extension. The blur is expanded slightly outside the 187 effect item area. 188 189 If the property is set to \c false, the pixels outside the source are 190 interpreted to contain the same color as the pixels at the edge of the 191 item, which is similar to OpenGL clamp-to-edge behavior. The blur does 192 not expand outside the effect item area. 193 194 By default, the property is set to \c false. 195 */ 196 property bool transparentBorder: false 197 198 /*! 199 This property allows the effect output pixels to be cached in order to 200 improve the rendering performance. 201 202 Every time the source or effect properties are changed, the pixels in 203 the cache must be updated. Memory consumption is increased, because an 204 extra buffer of memory is required for storing the effect output. 205 206 It is recommended to disable the cache when the source or the effect 207 properties are animated. 208 209 By default, the property is set to \c false. 210 211 */ 212 property bool cached: false 213 214 SourceProxy { 215 id: sourceProxy 216 input: rootItem.source 217 sourceRect: shaderItem.transparentBorder ? Qt.rect(-1, -1, parent.width + 2.0, parent.height + 2.0) : Qt.rect(0, 0, 0, 0) 218 } 219 220 ShaderEffectSource { 221 id: cacheItem 222 anchors.fill: shaderItem 223 visible: rootItem.cached 224 smooth: true 225 sourceItem: shaderItem 226 live: true 227 hideSource: visible 228 } 229 230 ShaderEffect { 231 id: shaderItem 232 property variant source: sourceProxy.output 233 property variant center: Qt.point(0.5 + rootItem.horizontalOffset / parent.width, 0.5 + rootItem.verticalOffset / parent.height) 234 property bool transparentBorder: rootItem.transparentBorder && rootItem.samples > 1 235 property int samples: rootItem.samples 236 property real weight: 1.0 / Math.max(1.0, rootItem.samples) 237 property real angleSin: Math.sin(rootItem.angle/2 * Math.PI/180) 238 property real angleCos: Math.cos(rootItem.angle/2 * Math.PI/180) 239 property real angleSinStep: Math.sin(-rootItem.angle * Math.PI/180 / Math.max(1.0, rootItem.samples - 1)) 240 property real angleCosStep: Math.cos(-rootItem.angle * Math.PI/180 / Math.max(1.0, rootItem.samples - 1)) 241 property variant expandPixels: transparentBorder ? Qt.size(0.5 * parent.height, 0.5 * parent.width) : Qt.size(0,0) 242 property variant expand: transparentBorder ? Qt.size(expandPixels.width / width, expandPixels.height / height) : Qt.size(0,0) 243 property variant delta: Qt.size(1.0 / rootItem.width, 1.0 / rootItem.height) 244 property real w: parent.width 245 property real h: parent.height 246 247 x: transparentBorder ? -expandPixels.width - 1 : 0 248 y: transparentBorder ? -expandPixels.height - 1 : 0 249 width: transparentBorder ? parent.width + expandPixels.width * 2.0 + 2 : parent.width 250 height: transparentBorder ? parent.height + expandPixels.height * 2.0 + 2 : parent.height 251 252 property string fragmentShaderSkeleton: " 253 varying highp vec2 qt_TexCoord0; 254 uniform highp float qt_Opacity; 255 uniform lowp sampler2D source; 256 uniform highp float angleSin; 257 uniform highp float angleCos; 258 uniform highp float angleSinStep; 259 uniform highp float angleCosStep; 260 uniform highp float weight; 261 uniform highp vec2 expand; 262 uniform highp vec2 center; 263 uniform highp vec2 delta; 264 uniform highp float w; 265 uniform highp float h; 266 267 void main(void) { 268 highp mat2 m; 269 gl_FragColor = vec4(0.0); 270 mediump vec2 texCoord = qt_TexCoord0; 271 272 PLACEHOLDER_EXPAND_STEPS 273 274 highp vec2 dir = vec2(texCoord.s * w - w * center.x, texCoord.t * h - h * center.y); 275 m[0] = vec2(angleCos, -angleSin); 276 m[1] = vec2(angleSin, angleCos); 277 dir *= m; 278 279 m[0] = vec2(angleCosStep, -angleSinStep); 280 m[1] = vec2(angleSinStep, angleCosStep); 281 282 PLACEHOLDER_UNROLLED_LOOP 283 284 gl_FragColor *= weight * qt_Opacity; 285 } 286 " 287 288 function buildFragmentShader() { 289 var shader = "" 290 if (GraphicsInfo.profile == GraphicsInfo.OpenGLCoreProfile) 291 shader += "#version 150 core\n#define varying in\n#define gl_FragColor fragColor\n#define texture2D texture\nout vec4 fragColor;\n" 292 shader += fragmentShaderSkeleton 293 var expandSteps = "" 294 295 if (transparentBorder) { 296 expandSteps += "texCoord = (texCoord - expand) / (1.0 - 2.0 * expand);" 297 } 298 299 var unrolledLoop = "gl_FragColor += texture2D(source, texCoord);\n" 300 301 if (rootItem.samples > 1) { 302 unrolledLoop = "" 303 for (var i = 0; i < rootItem.samples; i++) 304 unrolledLoop += "gl_FragColor += texture2D(source, center + dir * delta); dir *= m;\n" 305 } 306 307 shader = shader.replace("PLACEHOLDER_EXPAND_STEPS", expandSteps) 308 fragmentShader = shader.replace("PLACEHOLDER_UNROLLED_LOOP", unrolledLoop) 309 } 310 311 onFragmentShaderChanged: sourceChanged() 312 onSamplesChanged: buildFragmentShader() 313 onTransparentBorderChanged: buildFragmentShader() 314 Component.onCompleted: buildFragmentShader() 315 } 316} 317