Remove QSGEngine and move QSGAbstractRenderer back to private

QSGEngine goes away. Same for the associated example, which is the only
place this is used anywhere in Qt.

As a consequence, the renderer base class can be moved back to private:
there is no use for it to be public anymore, since that made sense only
in combination with QSGEngine. With the RHI-based rendering path driving
a renderer directly is more complicated than before so it is not
reasonable to allow the QSGEngine-style access anymore.

Instead, one has QQuickRenderControl, which allows redirecting and
manually driving the rendering of a QQuickWindow, thus providing an
alternative to the legacy QSGEngine approach.

Task-number: QTBUG-78596
Change-Id: If57c6b657b2053da1c4e545e517026382a71d998
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 60 insertions, 19 deletions

diff --git a/src/quick/scenegraph/coreapi/qsgabstractrenderer_p.h b/src/quick/scenegraph/coreapi/qsgabstractrenderer_p.h
index bbc4289b2c..5d48f18310 100644
--- a/src/quick/scenegraph/coreapi/qsgabstractrenderer_p.h
+++ b/src/quick/scenegraph/coreapi/qsgabstractrenderer_p.h
@@ -51,37 +51,78 @@
 // We mean it.
 //
 
-#include "qsgabstractrenderer.h"
-
-#include "qsgnode.h"
-#include <qcolor.h>
-
-#include <QtCore/private/qobject_p.h>
 #include <QtQuick/private/qtquickglobal_p.h>
+#include <QtQuick/qsgnode.h>
+
+#ifndef GLuint
+#define GLuint uint
+#endif
 
 QT_BEGIN_NAMESPACE
 
-class Q_QUICK_PRIVATE_EXPORT QSGAbstractRendererPrivate : public QObjectPrivate
+class QSGAbstractRendererPrivate;
+
+class Q_QUICK_PRIVATE_EXPORT QSGAbstractRenderer : public QObject
 {
-    Q_DECLARE_PUBLIC(QSGAbstractRenderer)
+    Q_OBJECT
 public:
-    static const QSGAbstractRendererPrivate *get(const QSGAbstractRenderer *q) { return q->d_func(); }
+    enum ClearModeBit
+    {
+        ClearColorBuffer    = 0x0001,
+        ClearDepthBuffer    = 0x0002,
+        ClearStencilBuffer  = 0x0004
+    };
+    Q_DECLARE_FLAGS(ClearMode, ClearModeBit)
+    Q_FLAG(ClearMode)
+
+    enum MatrixTransformFlag
+    {
+        MatrixTransformFlipY = 0x01
+    };
+    Q_DECLARE_FLAGS(MatrixTransformFlags, MatrixTransformFlag)
+    Q_FLAG(MatrixTransformFlags)
+
+    ~QSGAbstractRenderer() override;
 
-    QSGAbstractRendererPrivate();
-    void updateProjectionMatrix();
+    void setRootNode(QSGRootNode *node);
+    QSGRootNode *rootNode() const;
+    void setDeviceRect(const QRect &rect);
+    inline void setDeviceRect(const QSize &size) { setDeviceRect(QRect(QPoint(), size)); }
+    QRect deviceRect() const;
 
-    QSGRootNode *m_root_node;
-    QColor m_clear_color;
-    QSGAbstractRenderer::ClearMode m_clear_mode;
+    void setViewportRect(const QRect &rect);
+    inline void setViewportRect(const QSize &size) { setViewportRect(QRect(QPoint(), size)); }
+    QRect viewportRect() const;
 
-    QRect m_device_rect;
-    QRect m_viewport_rect;
+    void setProjectionMatrixToRect(const QRectF &rect);
+    void setProjectionMatrixToRect(const QRectF &rect, MatrixTransformFlags flags);
+    void setProjectionMatrix(const QMatrix4x4 &matrix);
+    void setProjectionMatrixWithNativeNDC(const QMatrix4x4 &matrix);
+    QMatrix4x4 projectionMatrix() const;
+    QMatrix4x4 projectionMatrixWithNativeNDC() const;
 
-    QMatrix4x4 m_projection_matrix;
-    QMatrix4x4 m_projection_matrix_native_ndc;
-    uint m_mirrored : 1;
+    void setClearColor(const QColor &color);
+    QColor clearColor() const;
+
+    void setClearMode(ClearMode mode);
+    ClearMode clearMode() const;
+
+    virtual void renderScene(GLuint fboId = 0) = 0;
+
+Q_SIGNALS:
+    void sceneGraphChanged();
+
+protected:
+    explicit QSGAbstractRenderer(QObject *parent = nullptr);
+    virtual void nodeChanged(QSGNode *node, QSGNode::DirtyState state) = 0;
+
+private:
+    Q_DECLARE_PRIVATE(QSGAbstractRenderer)
+    friend class QSGRootNode;
 };
 
+Q_DECLARE_OPERATORS_FOR_FLAGS(QSGAbstractRenderer::ClearMode)
+
 QT_END_NAMESPACE
 
 #endif