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 Add-On 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 LevelAdjust 45 \inqmlmodule QtGraphicalEffects 46 \since QtGraphicalEffects 1.0 47 \inherits QtQuick2::Item 48 \ingroup qtgraphicaleffects-color 49 \brief Adjusts color levels in the RGBA color space. 50 51 This effect adjusts the source item colors separately for each color 52 channel. Source item contrast can be adjusted and color balance altered. 53 54 \table 55 \header 56 \li Source 57 \li Effect applied 58 \row 59 \li \image Original_butterfly.png 60 \li \image LevelAdjust_butterfly.png 61 \endtable 62 63 \note This effect is available when running with OpenGL. 64 65 \section1 Example 66 67 The following example shows how to apply the effect. 68 \snippet LevelAdjust-example.qml example 69 70*/ 71Item { 72 id: rootItem 73 74 /*! 75 This property defines the source item that provides the source pixels 76 for the effect. 77 78 \note It is not supported to let the effect include itself, for 79 instance by setting source to the effect's parent. 80 */ 81 property variant source 82 83 /*! 84 This property defines the change factor for how the value of each pixel 85 color channel is altered according to the equation: 86 87 \code 88 result.rgb = pow(original.rgb, 1.0 / gamma.rgb); 89 \endcode 90 91 Setting the gamma values under QtVector3d(1.0, 1.0, 1.0) makes the image 92 darker, the values above QtVector3d(1.0, 1.0, 1.0) lighten it. 93 94 The value ranges from QtVector3d(0.0, 0.0, 0.0) (darkest) to inf 95 (lightest). By default, the property is set to \c QtVector3d(1.0, 1.0, 96 1.0) (no change). 97 98 \table 99 \header 100 \li Output examples with different gamma values 101 \li 102 \li 103 \row 104 \li \image LevelAdjust_gamma1.png 105 \li \image LevelAdjust_gamma2.png 106 \li \image LevelAdjust_gamma3.png 107 \row 108 \li \b { gamma: Qt.vector3d(1.0, 1.0, 1.0) } 109 \li \b { gamma: Qt.vector3d(1.0, 0.4, 2.0) } 110 \li \b { gamma: Qt.vector3d(1.0, 0.1, 4.0) } 111 \row 112 \li \l minimumInput: #000000 113 \li \l minimumInput: #000000 114 \li \l minimumInput: #000000 115 \row 116 \li \l maximumInput: #ffffff 117 \li \l maximumInput: #ffffff 118 \li \l maximumInput: #ffffff 119 \row 120 \li \l minimumOutput: #000000 121 \li \l minimumOutput: #000000 122 \li \l minimumOutput: #000000 123 \row 124 \li \l maximumOutput: #ffffff 125 \li \l maximumOutput: #ffffff 126 \li \l maximumOutput: #ffffff 127 \endtable 128 129 \table 130 \header 131 \li Pixel color channel luminance curves of the above images. 132 \li 133 \li 134 \row 135 \li \image LevelAdjust_default_curve.png 136 \li \image LevelAdjust_gamma2_curve.png 137 \li \image LevelAdjust_gamma3_curve.png 138 \row 139 \li X-axis: pixel original luminance 140 \li 141 \li 142 \row 143 \li Y-axis: color channel luminance with effect applied 144 \li 145 \li 146 \endtable 147 */ 148 property variant gamma: Qt.vector3d(1.0, 1.0, 1.0) 149 150 /*! 151 This property defines the minimum input level for each color channel. It 152 sets the black-point, all pixels having lower value than this property 153 are rendered as black (per color channel). Increasing the value darkens 154 the dark areas. 155 156 The value ranges from "#00000000" to "#ffffffff". By default, the 157 property is set to \c "#00000000" (no change). 158 159 \table 160 \header 161 \li Output examples with different minimumInput values 162 \li 163 \li 164 \row 165 \li \image LevelAdjust_minimumInput1.png 166 \li \image LevelAdjust_minimumInput2.png 167 \li \image LevelAdjust_minimumInput3.png 168 \row 169 \li \b { minimumInput: #00000000 } 170 \li \b { minimumInput: #00000040 } 171 \li \b { minimumInput: #00000070 } 172 \row 173 \li \l maximumInput: #ffffff 174 \li \l maximumInput: #ffffff 175 \li \l maximumInput: #ffffff 176 \row 177 \li \l minimumOutput: #000000 178 \li \l minimumOutput: #000000 179 \li \l minimumOutput: #000000 180 \row 181 \li \l maximumOutput: #ffffff 182 \li \l maximumOutput: #ffffff 183 \li \l maximumOutput: #ffffff 184 \row 185 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 186 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 187 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 188 \endtable 189 190 \table 191 \header 192 \li Pixel color channel luminance curves of the above images. 193 \li 194 \li 195 \row 196 \li \image LevelAdjust_default_curve.png 197 \li \image LevelAdjust_minimumInput2_curve.png 198 \li \image LevelAdjust_minimumInput3_curve.png 199 \row 200 \li X-axis: pixel original luminance 201 \li 202 \li 203 \row 204 \li Y-axis: color channel luminance with effect applied 205 \li 206 \li 207 \endtable 208 209 */ 210 property color minimumInput: Qt.rgba(0.0, 0.0, 0.0, 0.0) 211 212 /*! 213 This property defines the maximum input level for each color channel. 214 It sets the white-point, all pixels having higher value than this 215 property are rendered as white (per color channel). 216 Decreasing the value lightens the light areas. 217 218 The value ranges from "#ffffffff" to "#00000000". By default, the 219 property is set to \c "#ffffffff" (no change). 220 221 \table 222 \header 223 \li Output examples with different maximumInput values 224 \li 225 \li 226 \row 227 \li \image LevelAdjust_maximumInput1.png 228 \li \image LevelAdjust_maximumInput2.png 229 \li \image LevelAdjust_maximumInput3.png 230 \row 231 \li \b { maximumInput: #FFFFFFFF } 232 \li \b { maximumInput: #FFFFFF80 } 233 \li \b { maximumInput: #FFFFFF30 } 234 \row 235 \li \l minimumInput: #000000 236 \li \l minimumInput: #000000 237 \li \l minimumInput: #000000 238 \row 239 \li \l minimumOutput: #000000 240 \li \l minimumOutput: #000000 241 \li \l minimumOutput: #000000 242 \row 243 \li \l maximumOutput: #ffffff 244 \li \l maximumOutput: #ffffff 245 \li \l maximumOutput: #ffffff 246 \row 247 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 248 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 249 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 250 \endtable 251 252 \table 253 \header 254 \li Pixel color channel luminance curves of the above images. 255 \li 256 \li 257 \row 258 \li \image LevelAdjust_default_curve.png 259 \li \image LevelAdjust_maximumInput2_curve.png 260 \li \image LevelAdjust_maximumInput3_curve.png 261 \row 262 \li X-axis: pixel original luminance 263 \li 264 \li 265 \row 266 \li Y-axis: color channel luminance with effect applied 267 \li 268 \li 269 \endtable 270 271 */ 272 property color maximumInput: Qt.rgba(1.0, 1.0, 1.0, 1.0) 273 274 /*! 275 This property defines the minimum output level for each color channel. 276 Increasing the value lightens the dark areas, reducing the contrast. 277 278 The value ranges from "#00000000" to "#ffffffff". By default, the 279 property is set to \c "#00000000" (no change). 280 281 \table 282 \header 283 \li Output examples with different minimumOutput values 284 \li 285 \li 286 \row 287 \li \image LevelAdjust_minimumOutput1.png 288 \li \image LevelAdjust_minimumOutput2.png 289 \li \image LevelAdjust_minimumOutput3.png 290 \row 291 \li \b { minimumOutput: #00000000 } 292 \li \b { minimumOutput: #00000070 } 293 \li \b { minimumOutput: #000000A0 } 294 \row 295 \li \l minimumInput: #000000 296 \li \l minimumInput: #000000 297 \li \l minimumInput: #000000 298 \row 299 \li \l maximumInput: #ffffff 300 \li \l maximumInput: #ffffff 301 \li \l maximumInput: #ffffff 302 \row 303 \li \l maximumOutput: #ffffff 304 \li \l maximumOutput: #ffffff 305 \li \l maximumOutput: #ffffff 306 \row 307 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 308 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 309 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 310 \endtable 311 312 \table 313 \header 314 \li Pixel color channel luminance curves of the above images. 315 \li 316 \li 317 \row 318 \li \image LevelAdjust_default_curve.png 319 \li \image LevelAdjust_minimumOutput2_curve.png 320 \li \image LevelAdjust_minimumOutput3_curve.png 321 \row 322 \li X-axis: pixel original luminance 323 \li 324 \li 325 \row 326 \li Y-axis: color channel luminance with effect applied 327 \li 328 \li 329 \endtable 330 331 */ 332 property color minimumOutput: Qt.rgba(0.0, 0.0, 0.0, 0.0) 333 334 /*! 335 This property defines the maximum output level for each color channel. 336 Decreasing the value darkens the light areas, reducing the contrast. 337 338 The value ranges from "#ffffffff" to "#00000000". By default, the 339 property is set to \c "#ffffffff" (no change). 340 341 \table 342 \header 343 \li Output examples with different maximumOutput values 344 \li 345 \li 346 \row 347 \li \image LevelAdjust_maximumOutput1.png 348 \li \image LevelAdjust_maximumOutput2.png 349 \li \image LevelAdjust_maximumOutput3.png 350 \row 351 \li \b { maximumOutput: #FFFFFFFF } 352 \li \b { maximumOutput: #FFFFFF80 } 353 \li \b { maximumOutput: #FFFFFF30 } 354 \row 355 \li \l minimumInput: #000000 356 \li \l minimumInput: #000000 357 \li \l minimumInput: #000000 358 \row 359 \li \l maximumInput: #ffffff 360 \li \l maximumInput: #ffffff 361 \li \l maximumInput: #ffffff 362 \row 363 \li \l minimumOutput: #000000 364 \li \l minimumOutput: #000000 365 \li \l minimumOutput: #000000 366 \row 367 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 368 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 369 \li \l gamma: Qt.vector3d(1.0, 1.0, 1.0) 370 \endtable 371 372 \table 373 \header 374 \li Pixel color channel luminance curves of the above images. 375 \li 376 \li 377 \row 378 \li \image LevelAdjust_default_curve.png 379 \li \image LevelAdjust_maximumOutput2_curve.png 380 \li \image LevelAdjust_maximumOutput3_curve.png 381 \row 382 \li X-axis: pixel original luminance 383 \li 384 \li 385 \row 386 \li Y-axis: color channel luminance with effect applied 387 \li 388 \li 389 \endtable 390 */ 391 property color maximumOutput: Qt.rgba(1.0, 1.0, 1.0, 1.0) 392 393 /*! 394 This property allows the effect output pixels to be cached in order to 395 improve the rendering performance. 396 397 Every time the source or effect properties are changed, the pixels in 398 the cache must be updated. Memory consumption is increased, because an 399 extra buffer of memory is required for storing the effect output. 400 401 It is recommended to disable the cache when the source or the effect 402 properties are animated. 403 404 By default, the property is set to \c false. 405 */ 406 property bool cached: false 407 408 SourceProxy { 409 id: sourceProxy 410 input: rootItem.source 411 interpolation: input && input.smooth ? SourceProxy.LinearInterpolation : SourceProxy.NearestInterpolation 412 } 413 414 ShaderEffectSource { 415 id: cacheItem 416 anchors.fill: parent 417 visible: rootItem.cached 418 smooth: true 419 sourceItem: shaderItem 420 live: true 421 hideSource: visible 422 } 423 424 ShaderEffect { 425 id: shaderItem 426 property variant source: sourceProxy.output 427 property variant minimumInputRGB: Qt.vector3d(rootItem.minimumInput.r, rootItem.minimumInput.g, rootItem.minimumInput.b) 428 property variant maximumInputRGB: Qt.vector3d(rootItem.maximumInput.r, rootItem.maximumInput.g, rootItem.maximumInput.b) 429 property real minimumInputAlpha: rootItem.minimumInput.a 430 property real maximumInputAlpha: rootItem.maximumInput.a 431 property variant minimumOutputRGB: Qt.vector3d(rootItem.minimumOutput.r, rootItem.minimumOutput.g, rootItem.minimumOutput.b) 432 property variant maximumOutputRGB: Qt.vector3d(rootItem.maximumOutput.r, rootItem.maximumOutput.g, rootItem.maximumOutput.b) 433 property real minimumOutputAlpha: rootItem.minimumOutput.a 434 property real maximumOutputAlpha: rootItem.maximumOutput.a 435 property variant gamma: Qt.vector3d(1.0 / Math.max(rootItem.gamma.x, 0.0001), 1.0 / Math.max(rootItem.gamma.y, 0.0001), 1.0 / Math.max(rootItem.gamma.z, 0.0001)) 436 anchors.fill: parent 437 438 fragmentShader: "qrc:/qt-project.org/imports/QtGraphicalEffects/shaders/leveladjust.frag" 439 } 440} 441
