QGIS API Documentation 3.35.0-Master (f6e073f0eed)
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qgsoffscreen3dengine.cpp
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1/***************************************************************************
2 qgsoffscreen3dengine.cpp
3 --------------------------------------
4 Date : July 2018
5 Copyright : (C) 2018 by Martin Dobias
6 Email : wonder dot sk at gmail dot com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15
17
18#include "qgsframegraph.h"
19
20#include <QCoreApplication>
21#include <QOffscreenSurface>
22#include <QSurfaceFormat>
23#include <QOpenGLFunctions>
24
25#include <Qt3DCore/QAspectEngine>
26#include <Qt3DLogic/QLogicAspect>
27#include <Qt3DRender/QCamera>
28#include <Qt3DRender/QCameraSelector>
29#include <Qt3DRender/QClearBuffers>
30#include <Qt3DRender/QRenderAspect>
31#include <Qt3DRender/QRenderCapture>
32#include <Qt3DRender/QRenderSettings>
33#include <Qt3DRender/QRenderTarget>
34#include <Qt3DRender/QRenderTargetOutput>
35#include <Qt3DRender/QRenderTargetSelector>
36#include <Qt3DRender/QRenderSurfaceSelector>
37#include <Qt3DRender/QTexture>
38#include <Qt3DRender/QViewport>
39
41{
42 // Set up a camera to point at the shapes.
43 mCamera = new Qt3DRender::QCamera;
44 mCamera->lens()->setPerspectiveProjection( 45.0f, float( mSize.width() ) / float( mSize.height() ), 0.1f, 1000.0f );
45 mCamera->setPosition( QVector3D( 0, 0, 20.0f ) );
46 mCamera->setUpVector( QVector3D( 0, 1, 0 ) );
47 mCamera->setViewCenter( QVector3D( 0, 0, 0 ) );
48
49 // Set up the engine and the aspects that we want to use.
50 mAspectEngine = new Qt3DCore::QAspectEngine();
51
52#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
53 mRenderAspect = new Qt3DRender::QRenderAspect( Qt3DRender::QRenderAspect::Threaded ); // Only threaded mode seems to work right now.
54#else
55 mRenderAspect = new Qt3DRender::QRenderAspect();
56#endif
57
58 mLogicAspect = new Qt3DLogic::QLogicAspect();
59
60 mAspectEngine->registerAspect( mRenderAspect );
61 mAspectEngine->registerAspect( mLogicAspect );
62
63 // Create the root entity of the engine.
64 // This is not the same as the 3D scene root: the QRenderSettings
65 // component must be held by the root of the QEntity tree,
66 // so it is added to this one. The 3D scene is added as a subtree later,
67 // in setRootEntity().
68 mRoot = new Qt3DCore::QEntity;
69 mRenderSettings = new Qt3DRender::QRenderSettings( mRoot );
70 mRoot->addComponent( mRenderSettings );
71
72 mCamera->setParent( mRoot );
73
74 // Create the offscreen frame graph, which will manage all of the resources required
75 // for rendering without a QWindow.
76 mOffscreenSurface = new QOffscreenSurface();
77
78 QSurfaceFormat format;
79
80 //Use default format when shared OpenGL context is enabled
81 if ( QCoreApplication::instance() && QCoreApplication::instance()->testAttribute( Qt::AA_ShareOpenGLContexts ) )
82 {
83 format = QSurfaceFormat::defaultFormat();
84 }
85 //Set the surface format when used outside of QGIS application
86 else
87 {
88 format.setRenderableType( QSurfaceFormat::OpenGL );
89#ifdef Q_OS_MAC
90 format.setVersion( 4, 1 ); //OpenGL is deprecated on MacOS, use last supported version
91 format.setProfile( QSurfaceFormat::CoreProfile );
92#else
93 format.setVersion( 4, 3 );
94 format.setProfile( QSurfaceFormat::CoreProfile );
95#endif
96 format.setDepthBufferSize( 24 );
97 format.setSamples( 4 );
98 format.setStencilBufferSize( 8 );
99 }
100
101 mOffscreenSurface->setFormat( format );
102 mOffscreenSurface->create();
103
104 mFrameGraph = new QgsFrameGraph( mOffscreenSurface, mSize, mCamera, mRoot );
107 // Set this frame graph to be in use.
108 // the render settings also sets itself as the parent of mSurfaceSelector
109 mRenderSettings->setActiveFrameGraph( mFrameGraph->frameGraphRoot() );
110
111 // Set the root entity of the engine. This causes the engine to begin running.
112 mAspectEngine->setRootEntity( Qt3DCore::QEntityPtr( mRoot ) );
113
114}
115
117{
118 delete mAspectEngine;
119 delete mOffscreenSurface;
120}
121
123{
124 mSize = s;
125
126 mFrameGraph->setSize( mSize );
127 mCamera->setAspectRatio( float( mSize.width() ) / float( mSize.height() ) );
128 emit sizeChanged();
129}
130
131void QgsOffscreen3DEngine::setClearColor( const QColor &color )
132{
133 mFrameGraph->setClearColor( color );
134}
135
140
141void QgsOffscreen3DEngine::setRootEntity( Qt3DCore::QEntity *root )
142{
143 // Make sure any existing scene root is unparented.
144 if ( mSceneRoot )
145 {
146 mSceneRoot->setParent( static_cast<Qt3DCore::QNode *>( nullptr ) );
147 }
148
149 // Parent the incoming scene root to our current root entity.
150 mSceneRoot = root;
151 mSceneRoot->setParent( mRoot );
152 root->addComponent( mFrameGraph->forwardRenderLayer() );
153 root->addComponent( mFrameGraph->castShadowsLayer() );
154}
155
156Qt3DRender::QRenderSettings *QgsOffscreen3DEngine::renderSettings()
157{
158 return mRenderSettings;
159}
160
161Qt3DRender::QCamera *QgsOffscreen3DEngine::camera()
162{
163 return mCamera;
164}
165
167{
168 return mSize;
169}
170
172{
173 return mOffscreenSurface;
174}
void sizeChanged()
Emitted after a call to setSize()
QgsFrameGraph * mFrameGraph
Qt3DRender::QLayer * forwardRenderLayer()
Returns a layer object used to indicate that an entity will be rendered during the forward rendering ...
void setRenderCaptureEnabled(bool enabled)
Sets whether it will be possible to render to an image.
Qt3DRender::QFrameGraphNode * frameGraphRoot()
Returns the root of the frame graph object.
void setClearColor(const QColor &clearColor)
Sets the clear color of the scene (background color)
void setFrustumCullingEnabled(bool enabled)
Sets whether frustum culling is enabled.
void setShadowRenderingEnabled(bool enabled)
Sets whether the shadow rendering is enabled.
Qt3DRender::QLayer * castShadowsLayer()
Returns a layer object used to indicate that an entity will cast shadows.
void setSize(QSize s)
Sets the size of the buffers used for rendering.
void setSize(QSize s) override
Sets the size of the rendering area (in pixels)
void setClearColor(const QColor &color) override
Sets background color of the scene.
QSize size() const override
Returns size of the engine's rendering area in pixels.
void setRootEntity(Qt3DCore::QEntity *root) override
Sets root entity of the 3D scene.
void setFrustumCullingEnabled(bool enabled) override
Sets whether frustum culling is enabled (this should make rendering faster by not rendering entities ...
Qt3DRender::QCamera * camera() override
Returns pointer to the engine's camera entity.
Qt3DRender::QRenderSettings * renderSettings() override
Returns access to the engine's render settings (the frame graph can be accessed from here)
QSurface * surface() const override
Returns the surface of the engine.