software: Add support for QSGRenderNode

Have to change getResource() a bit since it turns out it is not suitable
currently for backends that do not have a per-window rendercontext and do
not implement the interface on the rendercontext. Pass in the window to
make sure it can always figure out which window we want the resources for.
(we do not want rendererInterface() to return window-specific instances
created on the fly, with ownership issues, so stick with the simple model
where backends implement the interface on one of their existing classes)

To support clipping, QSGRenderNode::RenderState is extended accordingly.
Also updated the docs since some claims in the rendernode docs are not true
since Qt 5.3.

Change-Id: I34779c83926f5231b888fcab7131e873ae97964f
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

10 files changed, 106 insertions, 9 deletions

diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarecontext.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarecontext.cpp
index 94e9c81f70..80112c1121 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarecontext.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarecontext.cpp
@@ -53,6 +53,7 @@
 #include <QtCore/QElapsedTimer>
 
 #include <QtGui/QWindow>
+#include <QtQuick/private/qquickwindow_p.h>
 
 // Used for very high-level info about the renderering and gl context
 // Includes GL_VERSION, type of render loop, atlas size, etc.
@@ -82,8 +83,10 @@ QT_BEGIN_NAMESPACE
 QSGSoftwareRenderContext::QSGSoftwareRenderContext(QSGContext *ctx)
     : QSGRenderContext(ctx)
     , m_initialized(false)
+    , m_activePainter(nullptr)
 {
 }
+
 QSGSoftwareContext::QSGSoftwareContext(QObject *parent)
     : QSGContext(parent)
 {
@@ -206,4 +209,12 @@ QSGRendererInterface::ShaderSourceTypes QSGSoftwareContext::shaderSourceType() c
     return 0;
 }
 
+void *QSGSoftwareContext::getResource(QQuickWindow *window, Resource resource) const
+{
+    if (resource == Painter && window && window->isSceneGraphInitialized())
+        return static_cast<QSGSoftwareRenderContext *>(QQuickWindowPrivate::get(window)->context)->m_activePainter;
+
+    return nullptr;
+}
+
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarecontext_p.h b/src/quick/scenegraph/adaptations/software/qsgsoftwarecontext_p.h
index 3c3686c268..dcc137b4b4 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarecontext_p.h
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarecontext_p.h
@@ -78,6 +78,7 @@ public:
     int maxTextureSize() const override;
 
     bool m_initialized;
+    QPainter *m_activePainter;
 };
 
 class QSGSoftwareContext : public QSGContext, public QSGRendererInterface
@@ -103,6 +104,7 @@ public:
     ShaderType shaderType() const override;
     ShaderCompilationTypes shaderCompilationType() const override;
     ShaderSourceTypes shaderSourceType() const override;
+    void *getResource(QQuickWindow *window, Resource resource) const override;
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarepixmaprenderer.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarepixmaprenderer.cpp
index 304106a84d..f8c1a3d90b 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarepixmaprenderer.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarepixmaprenderer.cpp
@@ -38,6 +38,7 @@
 ****************************************************************************/
 
 #include "qsgsoftwarepixmaprenderer_p.h"
+#include "qsgsoftwarecontext_p.h"
 
 #include <QtQuick/QSGSimpleRectNode>
 
@@ -84,6 +85,9 @@ void QSGSoftwarePixmapRenderer::render(QPaintDevice *target)
     QPainter painter(target);
     painter.setRenderHint(QPainter::Antialiasing);
     painter.setWindow(m_projectionRect);
+    auto rc = static_cast<QSGSoftwareRenderContext *>(context());
+    QPainter *prevPainter = rc->m_activePainter;
+    rc->m_activePainter = &painter;
 
     renderTimer.start();
     buildRenderList();
@@ -100,6 +104,7 @@ void QSGSoftwarePixmapRenderer::render(QPaintDevice *target)
     QRegion paintedRegion = renderNodes(&painter);
     qint64 renderTime = renderTimer.elapsed();
 
+    rc->m_activePainter = prevPainter;
     qCDebug(lcPixmapRenderer) << "pixmapRender" << paintedRegion << buildRenderListTime << optimizeRenderListTime << renderTime;
 }
 
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenode.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenode.cpp
index 1b2a836dfa..032a06f946 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenode.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenode.cpp
@@ -47,8 +47,9 @@
 #include "qsgsoftwarepixmaptexture_p.h"
 #include "qsgsoftwarespritenode_p.h"
 
-#include <QtQuick/QSGSimpleRectNode>
-#include <QtQuick/qsgsimpletexturenode.h>
+#include <qsgsimplerectnode.h>
+#include <qsgsimpletexturenode.h>
+#include <private/qsgrendernode_p.h>
 #include <private/qsgtexture_p.h>
 
 Q_LOGGING_CATEGORY(lcRenderable, "qt.scenegraph.softwarecontext.renderable")
@@ -93,6 +94,9 @@ QSGSoftwareRenderableNode::QSGSoftwareRenderableNode(NodeType type, QSGNode *nod
     case QSGSoftwareRenderableNode::SpriteNode:
         m_handle.spriteNode = static_cast<QSGSoftwareSpriteNode*>(node);
         break;
+    case QSGSoftwareRenderableNode::RenderNode:
+        m_handle.renderNode = static_cast<QSGRenderNode*>(node);
+        break;
     case QSGSoftwareRenderableNode::Invalid:
         m_handle.simpleRectNode = nullptr;
         break;
@@ -182,6 +186,8 @@ void QSGSoftwareRenderableNode::update()
         m_isOpaque = m_handle.spriteNode->isOpaque();
         boundingRect = m_handle.spriteNode->rect().toRect();
         break;
+    case QSGSoftwareRenderableNode::RenderNode:
+        break;
     default:
         break;
     }
@@ -203,15 +209,50 @@ void QSGSoftwareRenderableNode::update()
     m_dirtyRegion = QRegion(m_boundingRect);
 }
 
+struct RenderNodeState : public QSGRenderNode::RenderState
+{
+    const QMatrix4x4 *projectionMatrix() const override { return &ident; }
+    QRect scissorRect() const { return QRect(); }
+    bool scissorEnabled() const { return false; }
+    int stencilValue() const { return 0; }
+    bool stencilEnabled() const { return false; }
+    const QRegion *clipRegion() const { return &cr; }
+    QMatrix4x4 ident;
+    QRegion cr;
+};
+
 QRegion QSGSoftwareRenderableNode::renderNode(QPainter *painter, bool forceOpaquePainting)
 {
     Q_ASSERT(painter);
 
     // Check for don't paint conditions
-    if (!m_isDirty || qFuzzyIsNull(m_opacity) || m_dirtyRegion.isEmpty()) {
-        m_isDirty = false;
-        m_dirtyRegion = QRegion();
-        return QRegion();
+    if (m_nodeType != RenderNode) {
+        if (!m_isDirty || qFuzzyIsNull(m_opacity) || m_dirtyRegion.isEmpty()) {
+            m_isDirty = false;
+            m_dirtyRegion = QRegion();
+            return QRegion();
+        }
+    } else {
+        if (!m_isDirty || qFuzzyIsNull(m_opacity)) {
+            m_isDirty = false;
+            m_dirtyRegion = QRegion();
+            return QRegion();
+        } else {
+            QSGRenderNodePrivate *rd = QSGRenderNodePrivate::get(m_handle.renderNode);
+            QMatrix4x4 m = m_transform;
+            rd->m_matrix = &m;
+            rd->m_opacity = m_opacity;
+            RenderNodeState rs;
+            rs.cr = m_clipRegion;
+            painter->save();
+            m_handle.renderNode->render(&rs);
+            painter->restore();
+            const QRect fullRect = QRect(0, 0, painter->device()->width(), painter->device()->height());
+            m_previousDirtyRegion = fullRect;
+            m_isDirty = false;
+            m_dirtyRegion = QRegion();
+            return fullRect;
+        }
     }
 
     painter->save();
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenode_p.h b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenode_p.h
index dc224be2c0..0626b1e657 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenode_p.h
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenode_p.h
@@ -68,6 +68,7 @@ class QSGSoftwareInternalRectangleNode;
 class QSGSoftwareGlyphNode;
 class QSGSoftwareNinePatchNode;
 class QSGSoftwareSpriteNode;
+class QSGRenderNode;
 
 class QSGSoftwareRenderableNode
 {
@@ -83,7 +84,8 @@ public:
         NinePatch,
         SimpleRectangle,
         SimpleImage,
-        SpriteNode
+        SpriteNode,
+        RenderNode
     };
 
     QSGSoftwareRenderableNode(NodeType type, QSGNode *node);
@@ -126,6 +128,7 @@ private:
         QSGRectangleNode *simpleRectangleNode;
         QSGImageNode *simpleImageNode;
         QSGSoftwareSpriteNode *spriteNode;
+        QSGRenderNode *renderNode;
     };
 
     const NodeType m_nodeType;
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenodeupdater.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenodeupdater.cpp
index cb866bec12..82f8623b74 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenodeupdater.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenodeupdater.cpp
@@ -47,8 +47,9 @@
 #include "qsgsoftwarepainternode_p.h"
 #include "qsgsoftwarepixmaptexture_p.h"
 
-#include <QtQuick/QSGSimpleRectNode>
+#include <QtQuick/qsgsimplerectnode.h>
 #include <QtQuick/qsgsimpletexturenode.h>
+#include <QtQuick/qsgrendernode.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -190,6 +191,15 @@ void QSGSoftwareRenderableNodeUpdater::endVisit(QSGSpriteNode *)
 
 }
 
+bool QSGSoftwareRenderableNodeUpdater::visit(QSGRenderNode *node)
+{
+    return updateRenderableNode(QSGSoftwareRenderableNode::RenderNode, node);
+}
+
+void QSGSoftwareRenderableNodeUpdater::endVisit(QSGRenderNode *)
+{
+}
+
 void QSGSoftwareRenderableNodeUpdater::updateNodes(QSGNode *node, bool isNodeRemoved)
 {
     m_opacityState.clear();
@@ -269,6 +279,13 @@ void QSGSoftwareRenderableNodeUpdater::updateNodes(QSGNode *node, bool isNodeRem
             visitChildren(node);
         break;
     }
+    case QSGNode::RenderNodeType: {
+        QSGRenderNode *r = static_cast<QSGRenderNode*>(node);
+        if (visit(r))
+            visitChildren(r);
+        endVisit(r);
+        break;
+    }
     default:
         Q_UNREACHABLE();
         break;
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenodeupdater_p.h b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenodeupdater_p.h
index 5bc241cce1..f204867236 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenodeupdater_p.h
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderablenodeupdater_p.h
@@ -88,6 +88,8 @@ public:
     void endVisit(QSGRootNode *) override;
     bool visit(QSGSpriteNode *) override;
     void endVisit(QSGSpriteNode *) override;
+    bool visit(QSGRenderNode *) override;
+    void endVisit(QSGRenderNode *) override;
 
     void updateNodes(QSGNode *node, bool isNodeRemoved = false);
 
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderer.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderer.cpp
index 257009472e..ae89ed7d8a 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderer.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderer.cpp
@@ -138,6 +138,9 @@ void QSGSoftwareRenderer::render()
 
     QPainter painter(m_paintDevice);
     painter.setRenderHint(QPainter::Antialiasing);
+    auto rc = static_cast<QSGSoftwareRenderContext *>(context());
+    QPainter *prevPainter = rc->m_activePainter;
+    rc->m_activePainter = &painter;
 
     // Render the contents Renderlist
     m_flushRegion = renderNodes(&painter);
@@ -146,6 +149,7 @@ void QSGSoftwareRenderer::render()
     if (m_backingStore != nullptr)
         m_backingStore->endPaint();
 
+    rc->m_activePainter = prevPainter;
     qCDebug(lcRenderer) << "render" << m_flushRegion << buildRenderListTime << optimizeRenderListTime << renderTime;
 }
 
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderlistbuilder.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderlistbuilder.cpp
index ac00127b35..4e34517dad 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderlistbuilder.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderlistbuilder.cpp
@@ -48,8 +48,9 @@
 #include "qsgsoftwarepainternode_p.h"
 #include "qsgsoftwarepixmaptexture_p.h"
 
-#include <QtQuick/QSGSimpleRectNode>
+#include <QtQuick/qsgsimplerectnode.h>
 #include <QtQuick/qsgsimpletexturenode.h>
+#include <QtQuick/qsgrendernode.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -150,6 +151,15 @@ void QSGSoftwareRenderListBuilder::endVisit(QSGSpriteNode *)
 
 }
 
+bool QSGSoftwareRenderListBuilder::visit(QSGRenderNode *node)
+{
+    return addRenderableNode(node);
+}
+
+void QSGSoftwareRenderListBuilder::endVisit(QSGRenderNode *)
+{
+}
+
 bool QSGSoftwareRenderListBuilder::addRenderableNode(QSGNode *node)
 {
     auto renderableNode = m_renderer->renderableNode(node);
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderlistbuilder_p.h b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderlistbuilder_p.h
index e34cc81e23..807cb7fdbe 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderlistbuilder_p.h
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderlistbuilder_p.h
@@ -82,6 +82,8 @@ public:
     void endVisit(QSGRootNode *) override;
     bool visit(QSGSpriteNode *) override;
     void endVisit(QSGSpriteNode *) override;
+    bool visit(QSGRenderNode *) override;
+    void endVisit(QSGRenderNode *) override;
 
 private:
     bool addRenderableNode(QSGNode *node);