qopenglwidget.cpp

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39 -

40 #include "qopenglwidget.h" -

41 #include <QtGui/QOpenGLContext> -

42 #include <QtGui/QOpenGLFramebufferObject> -

43 #include <QtGui/QOffscreenSurface> -

44 #include <QtGui/QOpenGLFunctions> -

45 #include <QtGui/QWindow> -

46 #include <QtGui/QGuiApplication> -

47 #include <QtGui/QScreen> -

48 #include <QtGui/QOpenGLPaintDevice> -

49 #include <QtGui/qpa/qplatformwindow.h> -

50 #include <QtGui/qpa/qplatformintegration.h> -

51 #include <QtGui/private/qguiapplication_p.h> -

52 #include <QtGui/private/qopenglextensions_p.h> -

53 #include <QtGui/private/qfont_p.h> -

54 #include <QtGui/private/qopenglpaintdevice_p.h> -

55 #include <QtGui/private/qopenglcontext_p.h> -

56 #include <QtWidgets/private/qwidget_p.h> -

57 -

58 QT_BEGIN_NAMESPACE -

59 -

60 /*! -

61 \class QOpenGLWidget -

62 \inmodule QtWidgets -

63 \since 5.4 -

64 -

65 \brief The QOpenGLWidget class is a widget for rendering OpenGL graphics. -

66 -

67 QOpenGLWidget provides functionality for displaying OpenGL graphics -

68 integrated into a Qt application. It is very simple to use: Make -

69 your class inherit from it and use the subclass like any other -

70 QWidget, except that you have the choice between using QPainter and -

71 standard OpenGL rendering commands. -

72 -

73 QOpenGLWidget provides three convenient virtual functions that you -

74 can reimplement in your subclass to perform the typical OpenGL -

75 tasks: -

76 -

77 \list -

78 \li paintGL() - Renders the OpenGL scene. Gets called whenever the widget -

79 needs to be updated. -

80 \li resizeGL() - Sets up the OpenGL viewport, projection, etc. Gets -

81 called whenever the widget has been resized (and also when it -

82 is shown for the first time because all newly created widgets get a -

83 resize event automatically). -

84 \li initializeGL() - Sets up the OpenGL resources and state. Gets called -

85 once before the first time resizeGL() or paintGL() is called. -

86 \endlist -

87 -

88 If you need to trigger a repaint from places other than paintGL() (a -

89 typical example is when using \l{QTimer}{timers} to animate scenes), -

90 you should call the widget's update() function to schedule an update. -

91 -

92 Your widget's OpenGL rendering context is made current when -

93 paintGL(), resizeGL(), or initializeGL() is called. If you need to -

94 call the standard OpenGL API functions from other places (e.g. in -

95 your widget's constructor or in your own paint functions), you -

96 must call makeCurrent() first. -

97 -

98 All rendering happens into an OpenGL framebuffer -

99 object. makeCurrent() ensure that it is bound in the context. Keep -

100 this in mind when creating and binding additional framebuffer -

101 objects in the rendering code in paintGL(). Never re-bind the -

102 framebuffer with ID 0. Instead, call defaultFramebufferObject() to -

103 get the ID that should be bound. -

104 -

105 QOpenGLWidget allows using different OpenGL versions and profiles -

106 when the platform supports it. Just set the requested format via -

107 setFormat(). Keep in mind however that having multiple QOpenGLWidget -

108 instances in the same window requires that they all use the same -

109 format, or at least formats that do not make the contexts -

110 non-sharable. To overcome this issue, prefer using -

111 QSurfaceFormat::setDefaultFormat() instead of setFormat(). -

112 -

113 \note Calling QSurfaceFormat::setDefaultFormat() before constructing -

114 the QApplication instance is mandatory on some platforms (for example, -

115 \macos) when an OpenGL core profile context is requested. This is to -

116 ensure that resource sharing between contexts stays functional as all -

117 internal contexts are created using the correct version and profile. -

118 -

119 \section1 Painting Techniques -

120 -

121 As described above, subclass QOpenGLWidget to render pure 3D content in the -

122 following way: -

123 -

124 \list -

125 -

126 \li Reimplement the initializeGL() and resizeGL() functions to -

127 set up the OpenGL state and provide a perspective transformation. -

128 -

129 \li Reimplement paintGL() to paint the 3D scene, calling only -

130 OpenGL functions. -

131 -

132 \endlist -

133 -

134 It is also possible to draw 2D graphics onto a QOpenGLWidget subclass using QPainter: -

135 -

136 \list -

137 -

138 \li In paintGL(), instead of issuing OpenGL commands, construct a QPainter -

139 object for use on the widget. -

140 -

141 \li Draw primitives using QPainter's member functions. -

142 -

143 \li Direct OpenGL commands can still be issued. However, you must make sure -

144 these are enclosed by a call to the painter's beginNativePainting() and -

145 endNativePainting(). -

146 -

147 \endlist -

148 -

149 When performing drawing using QPainter only, it is also possible to perform -

150 the painting like it is done for ordinary widgets: by reimplementing paintEvent(). -

151 -

152 \list -

153 -

154 \li Reimplement the paintEvent() function. -

155 -

156 \li Construct a QPainter object targeting the widget. Either pass the widget to the -

157 constructor or the QPainter::begin() function. -

158 -

159 \li Draw primitives using QPainter's member functions. -

160 -

161 \li Painting finishes then the QPainter instance is destroyed. Alternatively, -

162 call QPainter::end() explicitly. -

163 -

164 \endlist -

165 -

166 \section1 OpenGL Function Calls, Headers and QOpenGLFunctions -

167 -

168 When making OpenGL function calls, it is strongly recommended to avoid calling -

169 the functions directly. Instead, prefer using QOpenGLFunctions (when making -

170 portable applications) or the versioned variants (for example, -

171 QOpenGLFunctions_3_2_Core and similar, when targeting modern, desktop-only -

172 OpenGL). This way the application will work correctly in all Qt build -

173 configurations, including the ones that perform dynamic OpenGL implementation -

174 loading which means applications are not directly linking to an GL -

175 implementation and thus direct function calls are not feasible. -

176 -

177 In paintGL() the current context is always accessible by caling -

178 QOpenGLContext::currentContext(). From this context an already initialized, -

179 ready-to-be-used QOpenGLFunctions instance is retrievable by calling -

180 QOpenGLContext::functions(). An alternative to prefixing every GL call is to -

181 inherit from QOpenGLFunctions and call -

182 QOpenGLFunctions::initializeOpenGLFunctions() in initializeGL(). -

183 -

184 As for the OpenGL headers, note that in most cases there will be no need to -

185 directly include any headers like GL.h. The OpenGL-related Qt headers will -

186 include qopengl.h which will in turn include an appropriate header for the -

187 system. This might be an OpenGL ES 3.x or 2.0 header, the highest version that -

188 is available, or a system-provided gl.h. In addition, a copy of the extension -

189 headers (called glext.h on some systems) is provided as part of Qt both for -

190 OpenGL and OpenGL ES. These will get included automatically on platforms where -

191 feasible. This means that constants and function pointer typedefs from ARB, -

192 EXT, OES extensions are automatically available. -

193 -

194 \section1 Code Examples -

195 -

196 To get started, the simplest QOpenGLWidget subclass could like like the following: -

197 -

198 \snippet code/doc_gui_widgets_qopenglwidget.cpp 0 -

199 -

200 Alternatively, the prefixing of each and every OpenGL call can be avoided by deriving -

201 from QOpenGLFunctions instead: -

202 -

203 \snippet code/doc_gui_widgets_qopenglwidget.cpp 1 -

204 -

205 To get a context compatible with a given OpenGL version or profile, or to -

206 request depth and stencil buffers, call setFormat(): -

207 -

208 \snippet code/doc_gui_widgets_qopenglwidget.cpp 2 -

209 -

210 With OpenGL 3.0+ contexts, when portability is not important, the versioned -

211 QOpenGLFunctions variants give easy access to all the modern OpenGL functions -

212 available in a given version: -

213 -

214 \snippet code/doc_gui_widgets_qopenglwidget.cpp 3 -

215 -

216 As described above, it is simpler and more robust to set the requested format -

217 globally so that it applies to all windows and contexts during the lifetime of -

218 the application. Below is an example of this: -

219 -

220 \snippet code/doc_gui_widgets_qopenglwidget.cpp 6 -

221 -

222 \section1 Relation to QGLWidget -

223 -

224 The legacy QtOpenGL module (classes prefixed with QGL) provides a widget -

225 called QGLWidget. QOpenGLWidget is intended to be a modern replacement for -

226 it. Therefore, especially in new applications, the general recommendation is -

227 to use QOpenGLWidget. -

228 -

229 While the API is very similar, there is an important difference between the -

230 two: QOpenGLWidget always renders offscreen, using framebuffer -

231 objects. QGLWidget on the other hand uses a native window and surface. The -

232 latter causes issues when using it in complex user interfaces since, depending -

233 on the platform, such native child widgets may have various limitations, -

234 regarding stacking orders for example. QOpenGLWidget avoids this by not -

235 creating a separate native window. -

236 -

237 Due to being backed by a framebuffer object, the behavior of QOpenGLWidget is -

238 very similar to QOpenGLWindow with the update behavior set to \c -

239 PartialUpdateBlit or \c PartialUpdateBlend. This means that the contents are -

240 preserved between paintGL() calls so that incremental rendering is -

241 possible. With QGLWidget (and naturally QOpenGLWindow with the default update -

242 behavior) this is usually not the case because swapping the buffers leaves the -

243 back buffer with undefined contents. -

244 -

245 \note Most applications do not need incremental rendering because they will -

246 render everything in the view on every paint call. In this case it is -

247 important to call glClear() as early as possible in paintGL(). This helps -

248 mobile GPUs that use a tile-based architecture to recognize that the tile -

249 buffer does not need to be reloaded with the framebuffer's previous -

250 contents. Omitting the clear call can lead to significant performance drops on -

251 such systems. -

252 -

253 \note Avoid calling winId() on a QOpenGLWidget. This function triggers the creation of -

254 a native window, resulting in reduced performance and possibly rendering glitches. -

255 -

256 \section1 Differences to QGLWidget -

257 -

258 Besides the main conceptual difference of being backed by a framebuffer object, there -

259 are a number of smaller, internal differences between QOpenGLWidget and the older -

260 QGLWidget: -

261 -

262 \list -

263 -

264 \li OpenGL state when invoking paintGL(). QOpenGLWidget sets up the viewport via -

265 glViewport(). It does not perform any clearing. -

266 -

267 \li Clearing when starting to paint via QPainter. Unlike regular widgets, QGLWidget -

268 defaulted to a value of \c true for -

269 \l{QWidget::autoFillBackground()}{autoFillBackground}. It then performed clearing to the -

270 palette's background color every time QPainter::begin() was used. QOpenGLWidget does not -

271 follow this: \l{QWidget::autoFillBackground()}{autoFillBackground} defaults to false, -

272 like for any other widget. The only exception is when being used as a viewport for other -

273 widgets like QGraphicsView. In such a case autoFillBackground will be automatically set -

274 to true to ensure compatibility with QGLWidget-based viewports. -

275 -

276 \endlist -

277 -

278 \section1 Multisampling -

279 -

280 To enable multisampling, set the number of requested samples on the -

281 QSurfaceFormat that is passed to setFormat(). On systems that do not support -

282 it the request may get ignored. -

283 -

284 Multisampling support requires support for multisampled renderbuffers and -

285 framebuffer blits. On OpenGL ES 2.0 implementations it is likely that these -

286 will not be present. This means that multisampling will not be available. With -

287 modern OpenGL versions and OpenGL ES 3.0 and up this is usually not a problem -

288 anymore. -

289 -

290 \section1 Threading -

291 -

292 Performing offscreen rendering on worker threads, for example to generate -

293 textures that are then used in the GUI/main thread in paintGL(), are supported -

294 by exposing the widget's QOpenGLContext so that additional contexts sharing -

295 with it can be created on each thread. -

296 -

297 Drawing directly to the QOpenGLWidget's framebuffer outside the GUI/main -

298 thread is possible by reimplementing paintEvent() to do nothing. The context's -

299 thread affinity has to be changed via QObject::moveToThread(). After that, -

300 makeCurrent() and doneCurrent() are usable on the worker thread. Be careful to -

301 move the context back to the GUI/main thread afterwards. -

302 -

303 Unlike QGLWidget, triggering a buffer swap just for the QOpenGLWidget is not -

304 possible since there is no real, onscreen native surface for it. Instead, it -

305 is up to the widget stack to manage composition and buffer swaps on the gui -

306 thread. When a thread is done updating the framebuffer, call update() \b{on -

307 the GUI/main thread} to schedule composition. -

308 -

309 Extra care has to be taken to avoid using the framebuffer when the GUI/main -

310 thread is performing compositing. The signals aboutToCompose() and -

311 frameSwapped() will be emitted when the composition is starting and -

312 ending. They are emitted on the GUI/main thread. This means that by using a -

313 direct connection aboutToCompose() can block the GUI/main thread until the -

314 worker thread has finished its rendering. After that, the worker thread must -

315 perform no further rendering until the frameSwapped() signal is emitted. If -

316 this is not acceptable, the worker thread has to implement a double buffering -

317 mechanism. This involves drawing using an alternative render target, that is -

318 fully controlled by the thread, e.g. an additional framebuffer object, and -

319 blitting to the QOpenGLWidget's framebuffer at a suitable time. -

320 -

321 \section1 Context Sharing -

322 -

323 When multiple QOpenGLWidgets are added as children to the same top-level -

324 widget, their contexts will share with each other. This does not apply for -

325 QOpenGLWidget instances that belong to different windows. -

326 -

327 This means that all QOpenGLWidgets in the same window can access each other's -

328 sharable resources, like textures, and there is no need for an extra "global -

329 share" context, as was the case with QGLWidget. -

330 -

331 To set up sharing between QOpenGLWidget instances belonging to different -

332 windows, set the Qt::AA_ShareOpenGLContexts application attribute before -

333 instantiating QApplication. This will trigger sharing between all -

334 QOpenGLWidget instances without any further steps. -

335 -

336 Creating extra QOpenGLContext instances that share resources like textures -

337 with the QOpenGLWidget's context is also possible. Simply pass the pointer -

338 returned from context() to QOpenGLContext::setShareContext() before calling -

339 QOpenGLContext::create(). The resulting context can also be used on a -

340 different thread, allowing threaded generation of textures and asynchronous -

341 texture uploads. -

342 -

343 Note that QOpenGLWidget expects a standard conformant implementation of -

344 resource sharing when it comes to the underlying graphics drivers. For -

345 example, some drivers, in particular for mobile and embedded hardware, have -

346 issues with setting up sharing between an existing context and others that are -

347 created later. Some other drivers may behave in unexpected ways when trying to -

348 utilize shared resources between different threads. -

349 -

350 \section1 Resource Initialization and Cleanup -

351 -

352 The QOpenGLWidget's associated OpenGL context is guaranteed to be current -

353 whenever initializeGL() and paintGL() are invoked. Do not attempt to create -

354 OpenGL resources before initializeGL() is called. For example, attempting to -

355 compile shaders, initialize vertex buffer objects or upload texture data will -

356 fail when done in a subclass's constructor. These operations must be deferred -

357 to initializeGL(). Some of Qt's OpenGL helper classes, like QOpenGLBuffer or -

358 QOpenGLVertexArrayObject, have a matching deferred behavior: they can be -

359 instantiated without a context, but all initialization is deferred until a -

360 create(), or similar, call. This means that they can be used as normal -

361 (non-pointer) member variables in a QOpenGLWidget subclass, but the create() -

362 or similar function can only be called from initializeGL(). Be aware however -

363 that not all classes are designed like this. When in doubt, make the member -

364 variable a pointer and create and destroy the instance dynamically in -

365 initializeGL() and the destructor, respectively. -

366 -

367 Releasing the resources also needs the context to be current. Therefore -

368 destructors that perform such cleanup are expected to call makeCurrent() -

369 before moving on to destroy any OpenGL resources or wrappers. Avoid deferred -

370 deletion via \l{QObject::deleteLater()}{deleteLater()} or the parenting -

371 mechanism of QObject. There is no guarantee the correct context will be -

372 current at the time the instance in question is really destroyed. -

373 -

374 A typical subclass will therefore often look like the following when it comes -

375 to resource initialization and destruction: -

376 -

377 \snippet code/doc_gui_widgets_qopenglwidget.cpp 4 -

378 -

379 This is naturally not the only possible solution. One alternative is to use -

380 the \l{QOpenGLContext::aboutToBeDestroyed()}{aboutToBeDestroyed()} signal of -

381 QOpenGLContext. By connecting a slot, using direct connection, to this signal, -

382 it is possible to perform cleanup whenever the the underlying native context -

383 handle, or the entire QOpenGLContext instance, is going to be released. The -

384 following snippet is in principal equivalent to the previous one: -

385 -

386 \snippet code/doc_gui_widgets_qopenglwidget.cpp 5 -

387 -

388 \note For widgets that change their associated top-level window multiple times -

389 during their lifetime, a combined approach is essential. Whenever the widget -

390 or a parent of it gets reparented so that the top-level window becomes -

391 different, the widget's associated context is destroyed and a new one is -

392 created. This is then followed by a call to initializeGL() where all OpenGL -

393 resources must get reinitialized. Due to this the only option to perform -

394 proper cleanup is to connect to the context's aboutToBeDestroyed() -

395 signal. Note that the context in question may not be the current one when the -

396 signal gets emitted. Therefore it is good practice to call makeCurrent() in -

397 the connected slot. Additionally, the same cleanup steps must be performed -

398 from the derived class' destructor, since the slot connected to the signal -

399 will not get invoked when the widget is being destroyed. -

400 -

401 \note When Qt::AA_ShareOpenGLContexts is set, the widget's context never -

402 changes, not even when reparenting because the widget's associated texture is -

403 guaranteed to be accessible also from the new top-level's context. -

404 -

405 Proper cleanup is especially important due to context sharing. Even though -

406 each QOpenGLWidget's associated context is destroyed together with the -

407 QOpenGLWidget, the sharable resources in that context, like textures, will -

408 stay valid until the top-level window, in which the QOpenGLWidget lived, is -

409 destroyed. Additionally, settings like Qt::AA_ShareOpenGLContexts and some Qt -

410 modules may trigger an even wider scope for sharing contexts, potentially -

411 leading to keeping the resources in question alive for the entire lifetime of -

412 the application. Therefore the safest and most robust is always to perform -

413 explicit cleanup for all resources and resource wrappers used in the -

414 QOpenGLWidget. -

415 -

416 \section1 Limitations -

417 -

418 Putting other widgets underneath and making the QOpenGLWidget transparent will -

419 not lead to the expected results: The widgets underneath will not be -

420 visible. This is because in practice the QOpenGLWidget is drawn before all -

421 other regular, non-OpenGL widgets, and so see-through type of solutions are -

422 not feasible. Other type of layouts, like having widgets on top of the -

423 QOpenGLWidget, will function as expected. -

424 -

425 When absolutely necessary, this limitation can be overcome by setting the -

426 Qt::WA_AlwaysStackOnTop attribute on the QOpenGLWidget. Be aware however that -

427 this breaks stacking order, for example it will not be possible to have other -

428 widgets on top of the QOpenGLWidget, so it should only be used in situations -

429 where a semi-transparent QOpenGLWidget with other widgets visible underneath -

430 is required. -

431 -

432 Note that this does not apply when there are no other widgets underneath and -

433 the intention is to have a semi-transparent window. In that case the -

434 traditional approach of setting Qt::WA_TranslucentBackground -

435 on the top-level window is sufficient. Note that if the transparent areas are -

436 only desired in the QOpenGLWidget, then Qt::WA_NoSystemBackground will need -

437 to be turned back to \c false after enabling Qt::WA_TranslucentBackground. -

438 Additionally, requesting an alpha channel for the QOpenGLWidget's context via -

439 setFormat() may be necessary too, depending on the system. -

440 -

441 QOpenGLWidget supports multiple update behaviors, just like QOpenGLWindow. In -

442 preserved mode the rendered content from the previous paintGL() call is -

443 available in the next one, allowing incremental rendering. In non-preserved -

444 mode the content is lost and paintGL() implementations are expected to redraw -

445 everything in the view. -

446 -

447 Before Qt 5.5 the default behavior of QOpenGLWidget was to preserve the -

448 rendered contents between paintGL() calls. Since Qt 5.5 the default behavior -

449 is non-preserved because this provides better performance and the majority of -

450 applications have no need for the previous content. This also resembles the -

451 semantics of an OpenGL-based QWindow and matches the default behavior of -

452 QOpenGLWindow in that the color and ancillary buffers are invalidated for -

453 each frame. To restore the preserved behavior, call setUpdateBehavior() with -

454 \c PartialUpdate. -

455 -

456 \section1 Alternatives -

457 -

458 Adding a QOpenGLWidget into a window turns on OpenGL-based -

459 compositing for the entire window. In some special cases this may -

460 not be ideal, and the old QGLWidget-style behavior with a separate, -

461 native child window is desired. Desktop applications that understand -

462 the limitations of this approach (for example when it comes to -

463 overlaps, transparency, scroll views and MDI areas), can use -

464 QOpenGLWindow with QWidget::createWindowContainer(). This is a -

465 modern alternative to QGLWidget and is faster than QOpenGLWidget due -

466 to the lack of the additional composition step. It is strongly -

467 recommended to limit the usage of this approach to cases where there -

468 is no other choice. Note that this option is not suitable for most -

469 embedded and mobile platforms, and it is known to have issues on -

470 certain desktop platforms (e.g. \macos) too. The stable, -

471 cross-platform solution is always QOpenGLWidget. -

472 -

473 \e{OpenGL is a trademark of Silicon Graphics, Inc. in the United States and other -

474 countries.} -

475 -

476 \sa QOpenGLFunctions, QOpenGLWindow, Qt::AA_ShareOpenGLContexts, UpdateBehavior -

477 */ -

478 -

479 /*! -

480 \fn void QOpenGLWidget::aboutToCompose() -

481 -

482 This signal is emitted when the widget's top-level window is about to begin -

483 composing the textures of its QOpenGLWidget children and the other widgets. -

484 */ -

485 -

486 /*! -

487 \fn void QOpenGLWidget::frameSwapped() -

488 -

489 This signal is emitted after the widget's top-level window has finished -

490 composition and returned from its potentially blocking -

491 QOpenGLContext::swapBuffers() call. -

492 */ -

493 -

494 /*! -

495 \fn void QOpenGLWidget::aboutToResize() -

496 -

497 This signal is emitted when the widget's size is changed and therefore the -

498 framebuffer object is going to be recreated. -

499 */ -

500 -

501 /*! -

502 \fn void QOpenGLWidget::resized() -

503 -

504 This signal is emitted right after the framebuffer object has been recreated -

505 due to resizing the widget. -

506 */ -

507 -

508 /*! -

509 \enum QOpenGLWidget::UpdateBehavior -

510 \since 5.5 -

511 -

512 This enum describes the update semantics of QOpenGLWidget. -

513 -

514 \value NoPartialUpdate QOpenGLWidget will discard the -

515 contents of the color buffer and the ancillary buffers after the -

516 QOpenGLWidget is rendered to screen. This is the same behavior that can be -

517 expected by calling QOpenGLContext::swapBuffers with a default opengl -

518 enabled QWindow as the argument. NoPartialUpdate can have some performance -

519 benefits on certain hardware architectures common in the mobile and -

520 embedded space when a framebuffer object is used as the rendering target. -

521 The framebuffer object is invalidated between frames with -

522 glDiscardFramebufferEXT if supported or a glClear. Please see the -

523 documentation of EXT_discard_framebuffer for more information: -

524 https://www.khronos.org/registry/gles/extensions/EXT/EXT_discard_framebuffer.txt -

525 -

526 \value PartialUpdate The framebuffer objects color buffer and ancillary -

527 buffers are not invalidated between frames. -

528 -

529 \sa updateBehavior(), setUpdateBehavior() -

530 */ -

531 -

532 class QOpenGLWidgetPaintDevicePrivate : public QOpenGLPaintDevicePrivate -

533 { -

534 public: -

535 QOpenGLWidgetPaintDevicePrivate(QOpenGLWidget *widget) -

536 : QOpenGLPaintDevicePrivate(QSize()), -

537

w(widget) { }

never executed: end of block

538 -

539 void beginPaint() Q_DECL_OVERRIDE; -

540 -

541 QOpenGLWidget *w; -

542 }; -

543 -

544 class QOpenGLWidgetPaintDevice : public QOpenGLPaintDevice -

545 { -

546 public: -

547 QOpenGLWidgetPaintDevice(QOpenGLWidget *widget) -

548

: QOpenGLPaintDevice(*new QOpenGLWidgetPaintDevicePrivate(widget)) { }

never executed: end of block

549 void ensureActiveTarget() Q_DECL_OVERRIDE; -

550 }; -

551 -

552 class QOpenGLWidgetPrivate : public QWidgetPrivate -

553 { -

554 Q_DECLARE_PUBLIC(QOpenGLWidget) -

555 public: -

556 QOpenGLWidgetPrivate() -

557 : context(0), -

558 fbo(0), -

559 resolvedFbo(0), -

560 surface(0), -

561 initialized(false), -

562 fakeHidden(false), -

563 inBackingStorePaint(false), -

564 hasBeenComposed(false), -

565 flushPending(false), -

566 paintDevice(0), -

567 updateBehavior(QOpenGLWidget::NoPartialUpdate), -

568 requestedSamples(0), -

569 inPaintGL(false) -

570 { -

571 requestedFormat = QSurfaceFormat::defaultFormat(); -

572

}

never executed: end of block

573 -

574 ~QOpenGLWidgetPrivate() -

575 { -

576 reset(); -

577

}

never executed: end of block

578 -

579 void reset(); -

580 void recreateFbo(); -

581 -

582 GLuint textureId() const Q_DECL_OVERRIDE; -

583 -

584 void initialize(); -

585 void invokeUserPaint(); -

586 void render(); -

587 -

588 void invalidateFbo(); -

589 -

590 QImage grabFramebuffer() Q_DECL_OVERRIDE; -

591

void beginBackingStorePainting() Q_DECL_OVERRIDE { inBackingStorePaint = true; }

never executed: end of block

592

void endBackingStorePainting() Q_DECL_OVERRIDE { inBackingStorePaint = false; }

never executed: end of block

593 void beginCompose() Q_DECL_OVERRIDE; -

594 void endCompose() Q_DECL_OVERRIDE; -

595 void initializeViewportFramebuffer() Q_DECL_OVERRIDE; -

596 void resizeViewportFramebuffer() Q_DECL_OVERRIDE; -

597 void resolveSamples() Q_DECL_OVERRIDE; -

598 -

599 QOpenGLContext *context; -

600 QOpenGLFramebufferObject *fbo; -

601 QOpenGLFramebufferObject *resolvedFbo; -

602 QOffscreenSurface *surface; -

603 bool initialized; -

604 bool fakeHidden; -

605 bool inBackingStorePaint; -

606 bool hasBeenComposed; -

607 bool flushPending; -

608 QOpenGLPaintDevice *paintDevice; -

609 QSurfaceFormat requestedFormat; -

610 QOpenGLWidget::UpdateBehavior updateBehavior; -

611 int requestedSamples; -

612 bool inPaintGL; -

613 }; -

614 -

615 void QOpenGLWidgetPaintDevicePrivate::beginPaint() -

616 { -

617 // NB! autoFillBackground is and must be false by default. Otherwise we would clear on -

618 // every QPainter begin() which is not desirable. This is only for legacy use cases, -

619 // like using QOpenGLWidget as the viewport of a graphics view, that expect clearing -

620 // with the palette's background color. -

621

if (w->autoFillBackground()) {

w->autoFillBackground()	Description
TRUE	never evaluated
FALSE	never evaluated

622 QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions(); -

623

if (w->format().hasAlpha()) {

w->format().hasAlpha()	Description
TRUE	never evaluated
FALSE	never evaluated

624 f->glClearColor(0, 0, 0, 0); -

625

} else {

never executed: end of block

626 QColor c = w->palette().brush(w->backgroundRole()).color(); -

627 float alpha = c.alphaF(); -

628 f->glClearColor(c.redF() * alpha, c.greenF() * alpha, c.blueF() * alpha, alpha); -

629

}

never executed: end of block

630 f->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); -

631

}

never executed: end of block

632

}

never executed: end of block

633 -

634 void QOpenGLWidgetPaintDevice::ensureActiveTarget() -

635 { -

636 QOpenGLWidgetPaintDevicePrivate *d = static_cast<QOpenGLWidgetPaintDevicePrivate *>(d_ptr.data()); -

637 QOpenGLWidgetPrivate *wd = static_cast<QOpenGLWidgetPrivate *>(QWidgetPrivate::get(d->w)); -

638

if (!wd->initialized)

!wd->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

639

return;

never executed: return;

640 -

641

if (QOpenGLContext::currentContext() != wd->context)

QOpenGLContext...!= wd->context	Description
TRUE	never evaluated
FALSE	never evaluated

642

d->w->makeCurrent();

never executed: d->w->makeCurrent();

643 else -

644

wd->fbo->bind();

never executed: wd->fbo->bind();

645 -

646 // When used as a viewport, drawing is done via opening a QPainter on the widget -

647 // without going through paintEvent(). We will have to make sure a glFlush() is done -

648 // before the texture is accessed also in this case. -

649 wd->flushPending = true; -

650

}

never executed: end of block

651 -

652 GLuint QOpenGLWidgetPrivate::textureId() const -

653 { -

654

return resolvedFbo ? resolvedFbo->texture() : (fbo ? fbo->texture() : 0);

never executed: return resolvedFbo ? resolvedFbo->texture() : (fbo ? fbo->texture() : 0);

655 } -

656 -

657 void QOpenGLWidgetPrivate::reset() -

658 { -

659 Q_Q(QOpenGLWidget); -

660 -

661 // Destroy the OpenGL resources first. These need the context to be current. -

662

if (initialized)

initialized	Description
TRUE	never evaluated
FALSE	never evaluated

663

q->makeCurrent();

never executed: q->makeCurrent();

664 -

665 delete paintDevice; -

666 paintDevice = 0; -

667 delete fbo; -

668 fbo = 0; -

669 delete resolvedFbo; -

670 resolvedFbo = 0; -

671 -

672

if (initialized)

initialized	Description
TRUE	never evaluated
FALSE	never evaluated

673

q->doneCurrent();

never executed: q->doneCurrent();

674 -

675 // Delete the context first, then the surface. Slots connected to -

676 // the context's aboutToBeDestroyed() may still call makeCurrent() -

677 // to perform some cleanup. -

678 delete context; -

679 context = 0; -

680 delete surface; -

681 surface = 0; -

682 initialized = fakeHidden = inBackingStorePaint = false; -

683

}

never executed: end of block

684 -

685 void QOpenGLWidgetPrivate::recreateFbo() -

686 { -

687 Q_Q(QOpenGLWidget); -

688 -

689 emit q->aboutToResize(); -

690 -

691 context->makeCurrent(surface); -

692 -

693 delete fbo; -

694 fbo = 0; -

695 delete resolvedFbo; -

696 resolvedFbo = 0; -

697 -

698 int samples = requestedSamples; -

699 QOpenGLExtensions *extfuncs = static_cast<QOpenGLExtensions *>(context->functions()); -

700

if (!extfuncs->hasOpenGLExtension(QOpenGLExtensions::FramebufferMultisample))

!extfuncs->has...erMultisample)	Description
TRUE	never evaluated
FALSE	never evaluated

701

samples = 0;

never executed: samples = 0;

702 -

703 QOpenGLFramebufferObjectFormat format; -

704 format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil); -

705 format.setSamples(samples); -

706 -

707 const QSize deviceSize = q->size() * q->devicePixelRatioF(); -

708 fbo = new QOpenGLFramebufferObject(deviceSize, format); -

709

if (samples > 0)

samples > 0	Description
TRUE	never evaluated
FALSE	never evaluated

710

resolvedFbo = new QOpenGLFramebufferObject(deviceSize);

never executed: resolvedFbo = new QOpenGLFramebufferObject(deviceSize);

711 -

712 fbo->bind(); -

713 context->functions()->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); -

714 -

715 paintDevice->setSize(deviceSize); -

716 paintDevice->setDevicePixelRatio(q->devicePixelRatioF()); -

717 -

718 emit q->resized(); -

719

}

never executed: end of block

720 -

721 void QOpenGLWidgetPrivate::beginCompose() -

722 { -

723 Q_Q(QOpenGLWidget); -

724

if (flushPending) {

flushPending	Description
TRUE	never evaluated
FALSE	never evaluated

725 flushPending = false; -

726 q->makeCurrent(); -

727 static_cast<QOpenGLExtensions *>(context->functions())->flushShared(); -

728

}

never executed: end of block

729 hasBeenComposed = true; -

730 emit q->aboutToCompose(); -

731

}

never executed: end of block

732 -

733 void QOpenGLWidgetPrivate::endCompose() -

734 { -

735 Q_Q(QOpenGLWidget); -

736 emit q->frameSwapped(); -

737

}

never executed: end of block

738 -

739 void QOpenGLWidgetPrivate::initialize() -

740 { -

741 Q_Q(QOpenGLWidget); -

742

if (initialized)

initialized	Description
TRUE	never evaluated
FALSE	never evaluated

743

return;

never executed: return;

744 -

745 // Get our toplevel's context with which we will share in order to make the -

746 // texture usable by the underlying window's backingstore. -

747 QWidget *tlw = q->window(); -

748 QOpenGLContext *shareContext = get(tlw)->shareContext(); -

749

if (Q_UNLIKELY(!shareContext)) {

__builtin_expe...ntext), false)	Description
TRUE	never evaluated
FALSE	never evaluated

750 qWarning("QOpenGLWidget: Cannot be used without a context shared with the toplevel."); -

751

return;

never executed: return;

752 } -

753 -

754 // Do not include the sample count. Requesting a multisampled context is not necessary -

755 // since we render into an FBO, never to an actual surface. What's more, attempting to -

756 // create a pbuffer with a multisampled config crashes certain implementations. Just -

757 // avoid the entire hassle, the result is the same. -

758 requestedSamples = requestedFormat.samples(); -

759 requestedFormat.setSamples(0); -

760 -

761 QScopedPointer<QOpenGLContext> ctx(new QOpenGLContext); -

762 ctx->setShareContext(shareContext); -

763 ctx->setFormat(requestedFormat); -

764 ctx->setScreen(shareContext->screen()); -

765

if (Q_UNLIKELY(!ctx->create())) {

__builtin_expe...ate()), false)	Description
TRUE	never evaluated
FALSE	never evaluated

766 qWarning("QOpenGLWidget: Failed to create context"); -

767

return;

never executed: return;

768 } -

769 -

770 // Propagate settings that make sense only for the tlw. -

771 QSurfaceFormat tlwFormat = tlw->windowHandle()->format(); -

772

if (requestedFormat.swapInterval() != tlwFormat.swapInterval()) {

requestedForma...swapInterval()	Description
TRUE	never evaluated
FALSE	never evaluated

773 // Most platforms will pick up the changed swap interval on the next -

774 // makeCurrent or swapBuffers. -

775 tlwFormat.setSwapInterval(requestedFormat.swapInterval()); -

776 tlw->windowHandle()->setFormat(tlwFormat); -

777

}

never executed: end of block

778

if (requestedFormat.swapBehavior() != tlwFormat.swapBehavior()) {

requestedForma...swapBehavior()	Description
TRUE	never evaluated
FALSE	never evaluated

779 tlwFormat.setSwapBehavior(requestedFormat.swapBehavior()); -

780 tlw->windowHandle()->setFormat(tlwFormat); -

781

}

never executed: end of block

782 -

783 // The top-level window's surface is not good enough since it causes way too -

784 // much trouble with regards to the QSurfaceFormat for example. So just like -

785 // in QQuickWidget, use a dedicated QOffscreenSurface. -

786 surface = new QOffscreenSurface; -

787 surface->setFormat(ctx->format()); -

788 surface->setScreen(ctx->screen()); -

789 surface->create(); -

790 -

791

if (Q_UNLIKELY(!ctx->makeCurrent(surface))) {

__builtin_expe...face)), false)	Description
TRUE	never evaluated
FALSE	never evaluated

792 qWarning("QOpenGLWidget: Failed to make context current"); -

793

return;

never executed: return;

794 } -

795 -

796 paintDevice = new QOpenGLWidgetPaintDevice(q); -

797 paintDevice->setSize(q->size() * q->devicePixelRatioF()); -

798 paintDevice->setDevicePixelRatio(q->devicePixelRatioF()); -

799 -

800 context = ctx.take(); -

801 initialized = true; -

802 -

803 q->initializeGL(); -

804

}

never executed: end of block

805 -

806 void QOpenGLWidgetPrivate::resolveSamples() -

807 { -

808 Q_Q(QOpenGLWidget); -

809

if (resolvedFbo) {

resolvedFbo	Description
TRUE	never evaluated
FALSE	never evaluated

810 q->makeCurrent(); -

811 QRect rect(QPoint(0, 0), fbo->size()); -

812 QOpenGLFramebufferObject::blitFramebuffer(resolvedFbo, rect, fbo, rect); -

813 flushPending = true; -

814

}

never executed: end of block

815

}

never executed: end of block

816 -

817 void QOpenGLWidgetPrivate::invokeUserPaint() -

818 { -

819 Q_Q(QOpenGLWidget); -

820 -

821 QOpenGLContext *ctx = QOpenGLContext::currentContext(); -

822 Q_ASSERT(ctx && fbo); -

823 -

824 QOpenGLFunctions *f = ctx->functions(); -

825 QOpenGLContextPrivate::get(ctx)->defaultFboRedirect = fbo->handle(); -

826 -

827 f->glViewport(0, 0, q->width() * q->devicePixelRatioF(), q->height() * q->devicePixelRatioF()); -

828 inPaintGL = true; -

829 q->paintGL(); -

830 inPaintGL = false; -

831 flushPending = true; -

832 -

833 QOpenGLContextPrivate::get(ctx)->defaultFboRedirect = 0; -

834

}

never executed: end of block

835 -

836 void QOpenGLWidgetPrivate::render() -

837 { -

838 Q_Q(QOpenGLWidget); -

839 -

840

if (fakeHidden || !initialized)

fakeHidden	Description
TRUE	never evaluated
FALSE	never evaluated

!initialized	Description
TRUE	never evaluated
FALSE	never evaluated

841

return;

never executed: return;

842 -

843 q->makeCurrent(); -

844 -

845

if (updateBehavior == QOpenGLWidget::NoPartialUpdate && hasBeenComposed) {

updateBehavior...oPartialUpdate	Description
TRUE	never evaluated
FALSE	never evaluated

hasBeenComposed	Description
TRUE	never evaluated
FALSE	never evaluated

846 invalidateFbo(); -

847 hasBeenComposed = false; -

848

}

never executed: end of block

849 -

850 invokeUserPaint(); -

851

}

never executed: end of block

852 -

853 void QOpenGLWidgetPrivate::invalidateFbo() -

854 { -

855 QOpenGLExtensions *f = static_cast<QOpenGLExtensions *>(QOpenGLContext::currentContext()->functions()); -

856

if (f->hasOpenGLExtension(QOpenGLExtensions::DiscardFramebuffer)) {

f->hasOpenGLEx...rdFramebuffer)	Description
TRUE	never evaluated
FALSE	never evaluated

857 const int gl_color_attachment0 = 0x8CE0; // GL_COLOR_ATTACHMENT0 -

858 const int gl_depth_attachment = 0x8D00; // GL_DEPTH_ATTACHMENT -

859 const int gl_stencil_attachment = 0x8D20; // GL_STENCIL_ATTACHMENT -

860 const GLenum attachments[] = { -

861 gl_color_attachment0, gl_depth_attachment, gl_stencil_attachment -

862 }; -

863 f->glDiscardFramebufferEXT(GL_FRAMEBUFFER, sizeof attachments / sizeof *attachments, attachments); -

864

} else {

never executed: end of block

865 f->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); -

866

}

never executed: end of block

867 } -

868 -

869 extern Q_GUI_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_format, bool include_alpha); -

870 -

871 QImage QOpenGLWidgetPrivate::grabFramebuffer() -

872 { -

873 Q_Q(QOpenGLWidget); -

874

if (!initialized)

!initialized	Description
TRUE	never evaluated
FALSE	never evaluated

875

return QImage();

never executed: return QImage();

876 -

877

if (!inPaintGL)

!inPaintGL	Description
TRUE	never evaluated
FALSE	never evaluated

878

render();

never executed: render();

879 -

880

if (resolvedFbo) {

resolvedFbo	Description
TRUE	never evaluated
FALSE	never evaluated

881 resolveSamples(); -

882 resolvedFbo->bind(); -

883

} else {

never executed: end of block

884 q->makeCurrent(); -

885

}

never executed: end of block

886 -

887 QImage res = qt_gl_read_framebuffer(q->size() * q->devicePixelRatioF(), false, false); -

888 res.setDevicePixelRatio(q->devicePixelRatioF()); -

889 -

890 // While we give no guarantees of what is going to be left bound, prefer the -

891 // multisample fbo instead of the resolved one. Clients may continue to -

892 // render straight after calling this function. -

893

if (resolvedFbo)

resolvedFbo	Description
TRUE	never evaluated
FALSE	never evaluated

894

q->makeCurrent();

never executed: q->makeCurrent();

895 -

896

return res;

never executed: return res;

897 } -

898 -

899 void QOpenGLWidgetPrivate::initializeViewportFramebuffer() -

900 { -

901 Q_Q(QOpenGLWidget); -

902 // Legacy behavior for compatibility with QGLWidget when used as a graphics view -

903 // viewport: enable clearing on each painter begin. -

904 q->setAutoFillBackground(true); -

905

}

never executed: end of block

906 -

907 void QOpenGLWidgetPrivate::resizeViewportFramebuffer() -

908 { -

909 Q_Q(QOpenGLWidget); -

910

if (!initialized)

!initialized	Description
TRUE	never evaluated
FALSE	never evaluated

911

return;

never executed: return;

912 -

913

if (!fbo || q->size() * q->devicePixelRatioF() != fbo->size()) {

!fbo	Description
TRUE	never evaluated
FALSE	never evaluated

q->size() * q-...!= fbo->size()	Description
TRUE	never evaluated
FALSE	never evaluated

914 recreateFbo(); -

915 q->update(); -

916

}

never executed: end of block

917

}

never executed: end of block

918 -

919 /*! -

920 Constructs a widget which is a child of \a parent, with widget flags set to \a f. -

921 */ -

922 QOpenGLWidget::QOpenGLWidget(QWidget *parent, Qt::WindowFlags f) -

923 : QWidget(*(new QOpenGLWidgetPrivate), parent, f) -

924 { -

925 Q_D(QOpenGLWidget); -

926

if (Q_UNLIKELY(!QGuiApplicationPrivate::platformIntegration()->hasCapability(QPlatformIntegration::RasterGLSurface)))

__builtin_expe...face)), false)	Description
TRUE	never evaluated
FALSE	never evaluated

927

qWarning("QOpenGLWidget is not supported on this platform.");

never executed: QMessageLogger(__FILE__, 927, __PRETTY_FUNCTION__).warning("QOpenGLWidget is not supported on this platform.");

928 else -

929

d->setRenderToTexture();

never executed: d->setRenderToTexture();

930 } -

931 -

932 /*! -

933 Destroys the QOpenGLWidget instance, freeing its resources. -

934 -

935 The QOpenGLWidget's context is made current in the destructor, allowing for -

936 safe destruction of any child object that may need to release OpenGL -

937 resources belonging to the context provided by this widget. -

938 -

939 \warning if you have objects wrapping OpenGL resources (such as -

940 QOpenGLBuffer, QOpenGLShaderProgram, etc.) as members of a OpenGLWidget -

941 subclass, you may need to add a call to makeCurrent() in that subclass' -

942 destructor as well. Due to the rules of C++ object destruction, those objects -

943 will be destroyed \e{before} calling this function (but after that the -

944 destructor of the subclass has run), therefore making the OpenGL context -

945 current in this function happens too late for their safe disposal. -

946 -

947 \sa makeCurrent -

948 */ -

949 QOpenGLWidget::~QOpenGLWidget() -

950 { -

951 makeCurrent(); -

952

}

never executed: end of block

953 -

954 /*! -

955 Sets this widget's update behavior to \a updateBehavior. -

956 \since 5.5 -

957 */ -

958 void QOpenGLWidget::setUpdateBehavior(UpdateBehavior updateBehavior) -

959 { -

960 Q_D(QOpenGLWidget); -

961 d->updateBehavior = updateBehavior; -

962

}

never executed: end of block

963 -

964 /*! -

965 \return the update behavior of the widget. -

966 \since 5.5 -

967 */ -

968 QOpenGLWidget::UpdateBehavior QOpenGLWidget::updateBehavior() const -

969 { -

970 Q_D(const QOpenGLWidget); -

971

return d->updateBehavior;

never executed: return d->updateBehavior;

972 } -

973 -

974 /*! -

975 Sets the requested surface \a format. -

976 -

977 When the format is not explicitly set via this function, the format returned by -

978 QSurfaceFormat::defaultFormat() will be used. This means that when having multiple -

979 OpenGL widgets, individual calls to this function can be replaced by one single call to -

980 QSurfaceFormat::setDefaultFormat() before creating the first widget. -

981 -

982 \note Requesting an alpha buffer via this function will not lead to the -

983 desired results when the intention is to make other widgets beneath visible. -

984 Instead, use Qt::WA_AlwaysStackOnTop to enable semi-transparent QOpenGLWidget -

985 instances with other widgets visible underneath. Keep in mind however that -

986 this breaks the stacking order, so it will no longer be possible to have -

987 other widgets on top of the QOpenGLWidget. -

988 -

989 \sa format(), Qt::WA_AlwaysStackOnTop, QSurfaceFormat::setDefaultFormat() -

990 */ -

991 void QOpenGLWidget::setFormat(const QSurfaceFormat &format) -

992 { -

993 Q_UNUSED(format); -

994 Q_D(QOpenGLWidget); -

995

if (Q_UNLIKELY(d->initialized)) {

__builtin_expe...lized), false)	Description
TRUE	never evaluated
FALSE	never evaluated

996 qWarning("QOpenGLWidget: Already initialized, setting the format has no effect"); -

997

return;

never executed: return;

998 } -

999 -

1000 d->requestedFormat = format; -

1001

}

never executed: end of block

1002 -

1003 /*! -

1004 Returns the context and surface format used by this widget and its toplevel -

1005 window. -

1006 -

1007 After the widget and its toplevel have both been created, resized and shown, -

1008 this function will return the actual format of the context. This may differ -

1009 from the requested format if the request could not be fulfilled by the -

1010 platform. It is also possible to get larger color buffer sizes than -

1011 requested. -

1012 -

1013 When the widget's window and the related OpenGL resources are not yet -

1014 initialized, the return value is the format that has been set via -

1015 setFormat(). -

1016 -

1017 \sa setFormat(), context() -

1018 */ -

1019 QSurfaceFormat QOpenGLWidget::format() const -

1020 { -

1021 Q_D(const QOpenGLWidget); -

1022

return d->initialized ? d->context->format() : d->requestedFormat;

never executed: return d->initialized ? d->context->format() : d->requestedFormat;

1023 } -

1024 -

1025 /*! -

1026 \return \e true if the widget and OpenGL resources, like the context, have -

1027 been successfully initialized. Note that the return value is always false -

1028 until the widget is shown. -

1029 */ -

1030 bool QOpenGLWidget::isValid() const -

1031 { -

1032 Q_D(const QOpenGLWidget); -

1033

return d->initialized && d->context->isValid();

never executed: return d->initialized && d->context->isValid();

1034 } -

1035 -

1036 /*! -

1037 Prepares for rendering OpenGL content for this widget by making the -

1038 corresponding context current and binding the framebuffer object in that -

1039 context. -

1040 -

1041 It is not necessary to call this function in most cases, because it -

1042 is called automatically before invoking paintGL(). -

1043 -

1044 \sa context(), paintGL(), doneCurrent() -

1045 */ -

1046 void QOpenGLWidget::makeCurrent() -

1047 { -

1048 Q_D(QOpenGLWidget); -

1049

if (!d->initialized)

!d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

1050

return;

never executed: return;

1051 -

1052 d->context->makeCurrent(d->surface); -

1053 -

1054

if (d->fbo) // there may not be one if we are in reset()

d->fbo	Description
TRUE	never evaluated
FALSE	never evaluated

1055

d->fbo->bind();

never executed: d->fbo->bind();

1056

}

never executed: end of block

1057 -

1058 /*! -

1059 Releases the context. -

1060 -

1061 It is not necessary to call this function in most cases, since the -

1062 widget will make sure the context is bound and released properly -

1063 when invoking paintGL(). -

1064 */ -

1065 void QOpenGLWidget::doneCurrent() -

1066 { -

1067 Q_D(QOpenGLWidget); -

1068

if (!d->initialized)

!d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

1069

return;

never executed: return;

1070 -

1071 d->context->doneCurrent(); -

1072

}

never executed: end of block

1073 -

1074 /*! -

1075 \return The QOpenGLContext used by this widget or \c 0 if not yet initialized. -

1076 -

1077 \note The context and the framebuffer object used by the widget changes when -

1078 reparenting the widget via setParent(). -

1079 -

1080 \sa QOpenGLContext::setShareContext(), defaultFramebufferObject() -

1081 */ -

1082 QOpenGLContext *QOpenGLWidget::context() const -

1083 { -

1084 Q_D(const QOpenGLWidget); -

1085

return d->context;

never executed: return d->context;

1086 } -

1087 -

1088 /*! -

1089 \return The framebuffer object handle or \c 0 if not yet initialized. -

1090 -

1091 \note The framebuffer object belongs to the context returned by context() -

1092 and may not be accessible from other contexts. -

1093 -

1094 \note The context and the framebuffer object used by the widget changes when -

1095 reparenting the widget via setParent(). In addition, the framebuffer object -

1096 changes on each resize. -

1097 -

1098 \sa context() -

1099 */ -

1100 GLuint QOpenGLWidget::defaultFramebufferObject() const -

1101 { -

1102 Q_D(const QOpenGLWidget); -

1103

return d->fbo ? d->fbo->handle() : 0;

never executed: return d->fbo ? d->fbo->handle() : 0;

1104 } -

1105 -

1106 /*! -

1107 This virtual function is called once before the first call to -

1108 paintGL() or resizeGL(). Reimplement it in a subclass. -

1109 -

1110 This function should set up any required OpenGL resources and state. -

1111 -

1112 There is no need to call makeCurrent() because this has already been -

1113 done when this function is called. Note however that the framebuffer -

1114 is not yet available at this stage, so avoid issuing draw calls from -

1115 here. Defer such calls to paintGL() instead. -

1116 -

1117 \sa paintGL(), resizeGL() -

1118 */ -

1119 void QOpenGLWidget::initializeGL() -

1120 { -

1121 } -

1122 -

1123 /*! -

1124 This virtual function is called whenever the widget has been -

1125 resized. Reimplement it in a subclass. The new size is passed in -

1126 \a w and \a h. -

1127 -

1128 There is no need to call makeCurrent() because this has already been -

1129 done when this function is called. Additionally, the framebuffer is -

1130 also bound. -

1131 -

1132 \sa initializeGL(), paintGL() -

1133 */ -

1134 void QOpenGLWidget::resizeGL(int w, int h) -

1135 { -

1136 Q_UNUSED(w); -

1137 Q_UNUSED(h); -

1138

}

never executed: end of block

1139 -

1140 /*! -

1141 This virtual function is called whenever the widget needs to be -

1142 painted. Reimplement it in a subclass. -

1143 -

1144 There is no need to call makeCurrent() because this has already -

1145 been done when this function is called. -

1146 -

1147 Before invoking this function, the context and the framebuffer are -

1148 bound, and the viewport is set up by a call to glViewport(). No -

1149 other state is set and no clearing or drawing is performed by the -

1150 framework. -

1151 -

1152 \sa initializeGL(), resizeGL() -

1153 */ -

1154 void QOpenGLWidget::paintGL() -

1155 { -

1156 } -

1157 -

1158 /*! -

1159 Handles resize events that are passed in the \a e event parameter. -

1160 Calls the virtual function resizeGL(). -

1161 -

1162 \note Avoid overriding this function in derived classes. If that is not -

1163 feasible, make sure that QOpenGLWidget's implementation is invoked -

1164 too. Otherwise the underlying framebuffer object and related resources will -

1165 not get resized properly and will lead to incorrect rendering. -

1166 */ -

1167 void QOpenGLWidget::resizeEvent(QResizeEvent *e) -

1168 { -

1169 Q_D(QOpenGLWidget); -

1170 -

1171

if (e->size().isEmpty()) {

e->size().isEmpty()	Description
TRUE	never evaluated
FALSE	never evaluated

1172 d->fakeHidden = true; -

1173

return;

never executed: return;

1174 } -

1175 d->fakeHidden = false; -

1176 -

1177 d->initialize(); -

1178

if (!d->initialized)

!d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

1179

return;

never executed: return;

1180 -

1181 d->recreateFbo(); -

1182 resizeGL(width(), height()); -

1183 d->sendPaintEvent(QRect(QPoint(0, 0), size())); -

1184

}

never executed: end of block

1185 -

1186 /*! -

1187 Handles paint events. -

1188 -

1189 Calling QWidget::update() will lead to sending a paint event \a e, -

1190 and thus invoking this function. (NB this is asynchronous and will -

1191 happen at some point after returning from update()). This function -

1192 will then, after some preparation, call the virtual paintGL() to -

1193 update the contents of the QOpenGLWidget's framebuffer. The widget's -

1194 top-level window will then composite the framebuffer's texture with -

1195 the rest of the window. -

1196 */ -

1197 void QOpenGLWidget::paintEvent(QPaintEvent *e) -

1198 { -

1199 Q_UNUSED(e); -

1200 Q_D(QOpenGLWidget); -

1201

if (!d->initialized)

!d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

1202

return;

never executed: return;

1203 -

1204

if (updatesEnabled())

updatesEnabled()	Description
TRUE	never evaluated
FALSE	never evaluated

1205

d->render();

never executed: d->render();

1206

}

never executed: end of block

1207 -

1208 /*! -

1209 Renders and returns a 32-bit RGB image of the framebuffer. -

1210 -

1211 \note This is a potentially expensive operation because it relies on glReadPixels() -

1212 to read back the pixels. This may be slow and can stall the GPU pipeline. -

1213 */ -

1214 QImage QOpenGLWidget::grabFramebuffer() -

1215 { -

1216 Q_D(QOpenGLWidget); -

1217

return d->grabFramebuffer();

never executed: return d->grabFramebuffer();

1218 } -

1219 -

1220 /*! -

1221 \internal -

1222 */ -

1223 int QOpenGLWidget::metric(QPaintDevice::PaintDeviceMetric metric) const -

1224 { -

1225 Q_D(const QOpenGLWidget); -

1226

if (d->inBackingStorePaint)

d->inBackingStorePaint	Description
TRUE	never evaluated
FALSE	never evaluated

1227

return QWidget::metric(metric);

never executed: return QWidget::metric(metric);

1228 -

1229 QWidget *tlw = window(); -

1230

QWindow *window = tlw ? tlw->windowHandle() : 0;

tlw	Description
TRUE	never evaluated
FALSE	never evaluated

1231

QScreen *screen = tlw && tlw->windowHandle() ? tlw->windowHandle()->screen() : 0;

tlw	Description
TRUE	never evaluated
FALSE	never evaluated

tlw->windowHandle()	Description
TRUE	never evaluated
FALSE	never evaluated

1232

if (!screen && QGuiApplication::primaryScreen())

!screen	Description
TRUE	never evaluated
FALSE	never evaluated

QGuiApplicatio...rimaryScreen()	Description
TRUE	never evaluated
FALSE	never evaluated

1233

screen = QGuiApplication::primaryScreen();

never executed: screen = QGuiApplication::primaryScreen();

1234 -

1235 const float dpmx = qt_defaultDpiX() * 100. / 2.54; -

1236 const float dpmy = qt_defaultDpiY() * 100. / 2.54; -

1237 -

1238 switch (metric) { -

1239

case PdmWidth:

never executed: case PdmWidth:

1240

return width();

never executed: return width();

1241

case PdmHeight:

never executed: case PdmHeight:

1242

return height();

never executed: return height();

1243

case PdmDepth:

never executed: case PdmDepth:

1244

return 32;

never executed: return 32;

1245

case PdmWidthMM:

never executed: case PdmWidthMM:

1246

if (screen)

screen	Description
TRUE	never evaluated
FALSE	never evaluated

1247

return width() * screen->physicalSize().width() / screen->geometry().width();

never executed: return width() * screen->physicalSize().width() / screen->geometry().width();

1248 else -

1249

return width() * 1000 / dpmx;

never executed: return width() * 1000 / dpmx;

1250

case PdmHeightMM:

never executed: case PdmHeightMM:

1251

if (screen)

screen	Description
TRUE	never evaluated
FALSE	never evaluated

1252

return height() * screen->physicalSize().height() / screen->geometry().height();

never executed: return height() * screen->physicalSize().height() / screen->geometry().height();

1253 else -

1254

return height() * 1000 / dpmy;

never executed: return height() * 1000 / dpmy;

1255

case PdmNumColors:

never executed: case PdmNumColors:

1256

return 0;

never executed: return 0;

1257

case PdmDpiX:

never executed: case PdmDpiX:

1258

if (screen)

screen	Description
TRUE	never evaluated
FALSE	never evaluated

1259

return qRound(screen->logicalDotsPerInchX());

never executed: return qRound(screen->logicalDotsPerInchX());

1260 else -

1261

return qRound(dpmx * 0.0254);

never executed: return qRound(dpmx * 0.0254);

1262

case PdmDpiY:

never executed: case PdmDpiY:

1263

if (screen)

screen	Description
TRUE	never evaluated
FALSE	never evaluated

1264

return qRound(screen->logicalDotsPerInchY());

never executed: return qRound(screen->logicalDotsPerInchY());

1265 else -

1266

return qRound(dpmy * 0.0254);

never executed: return qRound(dpmy * 0.0254);

1267

case PdmPhysicalDpiX:

never executed: case PdmPhysicalDpiX:

1268

if (screen)

screen	Description
TRUE	never evaluated
FALSE	never evaluated

1269

return qRound(screen->physicalDotsPerInchX());

never executed: return qRound(screen->physicalDotsPerInchX());

1270 else -

1271

return qRound(dpmx * 0.0254);

never executed: return qRound(dpmx * 0.0254);

1272

case PdmPhysicalDpiY:

never executed: case PdmPhysicalDpiY:

1273

if (screen)

screen	Description
TRUE	never evaluated
FALSE	never evaluated

1274

return qRound(screen->physicalDotsPerInchY());

never executed: return qRound(screen->physicalDotsPerInchY());

1275 else -

1276

return qRound(dpmy * 0.0254);

never executed: return qRound(dpmy * 0.0254);

1277

case PdmDevicePixelRatio:

never executed: case PdmDevicePixelRatio:

1278

if (window)

window	Description
TRUE	never evaluated
FALSE	never evaluated

1279

return int(window->devicePixelRatio());

never executed: return int(window->devicePixelRatio());

1280 else -

1281

return 1.0;

never executed: return 1.0;

1282

case PdmDevicePixelRatioScaled:

never executed: case PdmDevicePixelRatioScaled:

1283

if (window)

window	Description
TRUE	never evaluated
FALSE	never evaluated

1284

return int(window->devicePixelRatio() * devicePixelRatioFScale());

never executed: return int(window->devicePixelRatio() * devicePixelRatioFScale());

1285 else -

1286

return 1.0;

never executed: return 1.0;

1287

default:

never executed: default:

1288 qWarning("QOpenGLWidget::metric(): unknown metric %d", metric); -

1289

return 0;

never executed: return 0;

1290 } -

1291 } -

1292 -

1293 /*! -

1294 \internal -

1295 */ -

1296 QPaintDevice *QOpenGLWidget::redirected(QPoint *p) const -

1297 { -

1298 Q_D(const QOpenGLWidget); -

1299

if (d->inBackingStorePaint)

d->inBackingStorePaint	Description
TRUE	never evaluated
FALSE	never evaluated

1300

return QWidget::redirected(p);

never executed: return QWidget::redirected(p);

1301 -

1302

return d->paintDevice;

never executed: return d->paintDevice;

1303 } -

1304 -

1305 /*! -

1306 \internal -

1307 */ -

1308 QPaintEngine *QOpenGLWidget::paintEngine() const -

1309 { -

1310 Q_D(const QOpenGLWidget); -

1311 // QWidget needs to "punch a hole" into the backingstore. This needs the -

1312 // normal paint engine and device, not the GL one. So in this mode, behave -

1313 // like a normal widget. -

1314

if (d->inBackingStorePaint)

d->inBackingStorePaint	Description
TRUE	never evaluated
FALSE	never evaluated

1315

return QWidget::paintEngine();

never executed: return QWidget::paintEngine();

1316 -

1317

if (!d->initialized)

!d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

1318

return 0;

never executed: return 0;

1319 -

1320

return d->paintDevice->paintEngine();

never executed: return d->paintDevice->paintEngine();

1321 } -

1322 -

1323 /*! -

1324 \internal -

1325 */ -

1326 bool QOpenGLWidget::event(QEvent *e) -

1327 { -

1328 Q_D(QOpenGLWidget); -

1329 switch (e->type()) { -

1330

case QEvent::WindowChangeInternal:

never executed: case QEvent::WindowChangeInternal:

1331

if (qGuiApp->testAttribute(Qt::AA_ShareOpenGLContexts))

(static_cast<Q...penGLContexts)	Description
TRUE	never evaluated
FALSE	never evaluated

1332

break;

never executed: break;

1333

if (d->initialized)

d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

1334

d->reset();

never executed: d->reset();

1335 // FALLTHROUGH -

1336

case QEvent::Show: // reparenting may not lead to a resize so reinitalize on Show too

code before this statement never executed: case QEvent::Show:

never executed: case QEvent::Show:

1337

if (!d->initialized && !size().isEmpty() && window() && window()->windowHandle()) {

!d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

!size().isEmpty()	Description
TRUE	never evaluated
FALSE	never evaluated

window()	Description
TRUE	never evaluated
FALSE	never evaluated

window()->windowHandle()	Description
TRUE	never evaluated
FALSE	never evaluated

1338 d->initialize(); -

1339

if (d->initialized)

d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

1340

d->recreateFbo();

never executed: d->recreateFbo();

1341

}

never executed: end of block

1342

break;

never executed: break;

1343

case QEvent::ScreenChangeInternal:

never executed: case QEvent::ScreenChangeInternal:

1344

if (d->initialized && d->paintDevice->devicePixelRatioF() != devicePixelRatioF())

d->initialized	Description
TRUE	never evaluated
FALSE	never evaluated

d->paintDevice...ePixelRatioF()	Description
TRUE	never evaluated
FALSE	never evaluated

1345

d->recreateFbo();

never executed: d->recreateFbo();

1346

break;

never executed: break;

1347

default:

never executed: default:

1348

break;

never executed: break;

1349 } -

1350

return QWidget::event(e);

never executed: return QWidget::event(e);

1351 } -

1352 -

1353 QT_END_NAMESPACE -

1354 -

1355 #include "moc_qopenglwidget.cpp" -

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