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39
40 #include "qsgsoftwarerenderer_p.h"
41
42 #include "qsgsoftwarerenderablenodeupdater_p.h"
43 #include "qsgsoftwarerenderlistbuilder_p.h"
44 #include "qsgsoftwarecontext_p.h"
45 #include "qsgsoftwarerenderablenode_p.h"
46
47 #include <QtGui/QPaintDevice>
48 #include <QtGui/QBackingStore>
49 #include <QElapsedTimer>
50
51 Q_LOGGING_CATEGORY(lcRenderer, "qt.scenegraph.softwarecontext.renderer")
52
53 QT_BEGIN_NAMESPACE
54
QSGSoftwareRenderer(QSGRenderContext * context)55 QSGSoftwareRenderer::QSGSoftwareRenderer(QSGRenderContext *context)
56 : QSGAbstractSoftwareRenderer(context)
57 , m_paintDevice(nullptr)
58 , m_backingStore(nullptr)
59 {
60 }
61
~QSGSoftwareRenderer()62 QSGSoftwareRenderer::~QSGSoftwareRenderer()
63 {
64 }
65
setCurrentPaintDevice(QPaintDevice * device)66 void QSGSoftwareRenderer::setCurrentPaintDevice(QPaintDevice *device)
67 {
68 m_paintDevice = device;
69 m_backingStore = nullptr;
70 }
71
currentPaintDevice() const72 QPaintDevice *QSGSoftwareRenderer::currentPaintDevice() const
73 {
74 return m_paintDevice;
75 }
76
setBackingStore(QBackingStore * backingStore)77 void QSGSoftwareRenderer::setBackingStore(QBackingStore *backingStore)
78 {
79 m_backingStore = backingStore;
80 m_paintDevice = nullptr;
81 }
82
flushRegion() const83 QRegion QSGSoftwareRenderer::flushRegion() const
84 {
85 return m_flushRegion;
86 }
87
renderScene(uint)88 void QSGSoftwareRenderer::renderScene(uint)
89 {
90 class B : public QSGBindable
91 {
92 public:
93 void bind() const override { }
94 } bindable;
95 QSGRenderer::renderScene(bindable);
96 }
97
render()98 void QSGSoftwareRenderer::render()
99 {
100 if (!m_paintDevice && !m_backingStore)
101 return;
102
103 // If there is a backingstore, set the current paint device
104 if (m_backingStore) {
105 // For HiDPI QBackingStores, the paint device is not valid
106 // until begin() has been called. See: QTBUG-55875
107 m_backingStore->beginPaint(QRegion());
108 m_paintDevice = m_backingStore->paintDevice();
109 m_backingStore->endPaint();
110 }
111
112 QElapsedTimer renderTimer;
113
114 setBackgroundColor(clearColor());
115 setBackgroundRect(QRect(0, 0,
116 m_paintDevice->width() / m_paintDevice->devicePixelRatioF(),
117 m_paintDevice->height() / m_paintDevice->devicePixelRatioF()),
118 m_paintDevice->devicePixelRatioF());
119
120 // Build Renderlist
121 // The renderlist is created by visiting each node in the tree and when a
122 // renderable node is reach, we find the coorosponding RenderableNode object
123 // and append it to the renderlist. At this point the RenderableNode object
124 // should not need any further updating so it is just a matter of appending
125 // RenderableNodes
126 renderTimer.start();
127 buildRenderList();
128 qint64 buildRenderListTime = renderTimer.restart();
129
130 // Optimize Renderlist
131 // This is a pass through the renderlist to determine what actually needs to
132 // be painted. Without this pass the renderlist will simply render each item
133 // from back to front, with a high potential for overdraw. It would also lead
134 // to the entire window being flushed every frame. The objective of the
135 // optimization pass is to only paint dirty nodes that are not occuluded. A
136 // side effect of this is that additional nodes may need to be marked dirty to
137 // force a repaint. It is also important that any item that needs to be
138 // repainted only paints what is needed, via the use of clip regions.
139 const QRegion updateRegion = optimizeRenderList();
140 qint64 optimizeRenderListTime = renderTimer.restart();
141
142 // If Rendering to a backingstore, prepare it to be updated
143 if (m_backingStore != nullptr) {
144 m_backingStore->beginPaint(updateRegion);
145 // It is possible that a QBackingStore's paintDevice() will change
146 // when begin() is called.
147 m_paintDevice = m_backingStore->paintDevice();
148 }
149
150 QPainter painter(m_paintDevice);
151 painter.setRenderHint(QPainter::Antialiasing);
152 auto rc = static_cast<QSGSoftwareRenderContext *>(context());
153 QPainter *prevPainter = rc->m_activePainter;
154 rc->m_activePainter = &painter;
155
156 // Render the contents Renderlist
157 m_flushRegion = renderNodes(&painter);
158 qint64 renderTime = renderTimer.elapsed();
159
160 painter.end();
161 if (m_backingStore != nullptr)
162 m_backingStore->endPaint();
163
164 rc->m_activePainter = prevPainter;
165 qCDebug(lcRenderer) << "render" << m_flushRegion << buildRenderListTime << optimizeRenderListTime << renderTime;
166 }
167
168 QT_END_NAMESPACE
169