The QSGNode class is the base class for all nodes in the scene graph. 更多...
| 头： | #include <QSGNode> |
| qmake: | QT += quick |
| 继承者： | QSGBasicGeometryNode , QSGOpacityNode , QSGRenderNode ，和 QSGTransformNode |
| flags | DirtyState |
| enum | DirtyStateBit { DirtyMatrix, DirtyNodeAdded, DirtyNodeRemoved, DirtyGeometry, ..., DirtySubtreeBlocked } |
| enum | Flag { OwnedByParent, UsePreprocess, OwnsGeometry, OwnsMaterial, OwnsOpaqueMaterial, InternalReserved } |
| flags | Flags |
| enum | NodeType { BasicNodeType, GeometryNodeType, TransformNodeType, ClipNodeType, OpacityNodeType, RenderNodeType } |
| QSGNode () | |
| virtual | ~QSGNode () |
| void | appendChildNode (QSGNode * node ) |
| QSGNode * | childAtIndex (int i ) const |
| int | childCount () const |
| QSGNode * | firstChild () const |
| Flags | flags () const |
| void | insertChildNodeAfter (QSGNode * node , QSGNode * after ) |
| void | insertChildNodeBefore (QSGNode * node , QSGNode * before ) |
| virtual bool | isSubtreeBlocked () const |
| QSGNode * | lastChild () const |
| void | markDirty (DirtyState bits ) |
| QSGNode * | nextSibling () const |
| QSGNode * | parent () const |
| void | prependChildNode (QSGNode * node ) |
| virtual void | preprocess () |
| QSGNode * | previousSibling () const |
| void | removeAllChildNodes () |
| void | removeChildNode (QSGNode * node ) |
| void | setFlag (Flag f , bool enabled = true) |
| void | setFlags (Flags f , bool enabled = true) |
| NodeType | type () const |
The QSGNode class is the base class for all nodes in the scene graph.
The QSGNode class can be used as a child container. Children are added with the appendChildNode (), prependChildNode (), insertChildNodeBefore () 和 insertChildNodeAfter (). The order of nodes is important as geometry nodes are rendered according to their ordering in the scene graph.
The scene graph nodes contains a mechanism to describe which parts of the scene has changed. This includes the combined matrices, accumulated opacity, changes to the node hierarchy, and so on. This information can be used for optimizations inside the scene graph renderer. For the renderer to properly render the nodes, it is important that users call QSGNode::markDirty () with the correct flags when nodes are changed. Most of the functions on the node classes will implicitly call markDirty (). For example, QSGNode::appendChildNode () will call markDirty () passing in QSGNode::DirtyNodeAdded .
If nodes change every frame, the preprocess () function can be used to apply changes to a node for every frame it is rendered. The use of preprocess () must be explicitly enabled by setting the QSGNode::UsePreprocess flag on the node.
虚拟 isSubtreeBlocked () function can be used to disable a subtree all together. Nodes in a blocked subtree will not be preprocessed() and not rendered.
注意： 所有带有 QSG 前缀的类只应用于场景图形渲染线程。见 场景图形和渲染 了解更多信息。
用于 QSGNode::markDirty () to indicate how the scene graph has changed.
| 常量 | 值 | 描述 |
|---|---|---|
QSGNode::DirtyMatrix
|
0x0100
|
The matrix in a QSGTransformNode 已改变。 |
QSGNode::DirtyNodeAdded
|
0x0400
|
A node was added. |
QSGNode::DirtyNodeRemoved
|
0x0800
|
A node was removed. |
QSGNode::DirtyGeometry
|
0x1000
|
The geometry of a QSGGeometryNode 已改变。 |
QSGNode::DirtyMaterial
|
0x2000
|
The material of a QSGGeometryNode 已改变。 |
QSGNode::DirtyOpacity
|
0x4000
|
The opacity of a QSGOpacityNode 已改变。 |
QSGNode::DirtySubtreeBlocked
|
0x0080
|
The subtree has been blocked. |
DirtyState 类型是 typedef 对于 QFlags <DirtyStateBit>. It stores an OR combination of DirtyStateBit values.
另请参阅 QSGNode::markDirty ().
The QSGNode::Flag enum describes flags on the QSGNode
| 常量 | 值 | 描述 |
|---|---|---|
QSGNode::OwnedByParent
|
0x0001
|
The node is owned by its parent and will be deleted when the parent is deleted. |
QSGNode::UsePreprocess
|
0x0002
|
The node's virtual preprocess () function will be called before rendering starts. |
QSGNode::OwnsGeometry
|
0x00010000
|
Only valid for QSGGeometryNode and QSGClipNode . The node has ownership over the QSGGeometry instance and will delete it when the node is destroyed or a geometry is assigned. |
QSGNode::OwnsMaterial
|
0x00020000
|
Only valid for QSGGeometryNode . The node has ownership over the material and will delete it when the node is destroyed or a material is assigned. |
QSGNode::OwnsOpaqueMaterial
|
0x00040000
|
Only valid for QSGGeometryNode . The node has ownership over the opaque material and will delete it when the node is destroyed or a material is assigned. |
QSGNode::InternalReserved
|
0x01000000
|
Reserved for internal use. |
Flags 类型是 typedef 对于 QFlags <Flag>。它存储 Flag 值的 OR 组合。
Can be used to figure out the type of node.
| 常量 | 值 | 描述 |
|---|---|---|
QSGNode::BasicNodeType
|
0
|
The type of QSGNode |
QSGNode::GeometryNodeType
|
1
|
The type of QSGGeometryNode |
QSGNode::TransformNodeType
|
2
|
The type of QSGTransformNode |
QSGNode::ClipNodeType
|
3
|
The type of QSGClipNode |
QSGNode::OpacityNodeType
|
4
|
The type of QSGOpacityNode |
QSGNode::RenderNodeType
|
5
|
The type of QSGRenderNode |
另请参阅 type ().
Constructs a new node
[虚拟]
QSGNode::
~QSGNode
()
Destroys the node.
Every child of this node that has the flag QSGNode::OwnedByParent set, will also be deleted.
追加 node to this node's list of children.
Ordering of nodes is important as geometry nodes will be rendered in the order they are added to the scene graph.
Returns the child at index i .
Children are stored internally as a linked list, so iterating over the children via the index is suboptimal.
Returns the number of child nodes.
Returns the first child of this node.
The children are stored in a linked list.
Returns the set of flags for this node.
另请参阅 setFlags ().
插入 node to this node's list of children after the node specified with after .
Ordering of nodes is important as geometry nodes will be rendered in the order they are added to the scene graph.
插入 node to this node's list of children before the node specified with before .
Ordering of nodes is important as geometry nodes will be rendered in the order they are added to the scene graph.
[虚拟]
bool
QSGNode::
isSubtreeBlocked
() const
Returns whether this node and its subtree is available for use.
Blocked subtrees will not get their dirty states updated and they will not be rendered.
The QSGOpacityNode will return a blocked subtree when accumulated opacity is 0, for instance.
Returns the last child of this node.
The children are stored as a linked list.
Notifies all connected renderers that the node has dirty bits .
Returns the node after this in the parent's list of children.
The children are stored as a linked list.
Returns the parent node of this node.
前置 node to this node's the list of children.
Ordering of nodes is important as geometry nodes will be rendered in the order they are added to the scene graph.
[虚拟]
void
QSGNode::
preprocess
()
Override this function to do processing on the node before it is rendered.
Preprocessing needs to be explicitly enabled by setting the flag QSGNode::UsePreprocess . The flag needs to be set before the node is added to the scene graph and will cause the preprocess() function to be called for every frame the node is rendered.
警告： Beware of deleting nodes while they are being preprocessed. It is possible, with a small performance hit, to delete a single node during its own preprocess call. Deleting a subtree which has nodes that also use preprocessing may result in a segmentation fault. This is done for performance reasons.
Returns the node before this in the parent's list of children.
The children are stored as a linked list.
Removes all child nodes from this node's list of children.
移除 node from this node's list of children.
Sets the flag f on this node if enabled 为 true；否则清零标志。
另请参阅 flags ().
Sets the flags f on this node if enabled is true; otherwise clears the flags.
另请参阅 flags ().
Returns the type of this node. The node type must be one of the predefined types defined in QSGNode::NodeType and can safely be used to cast to the corresponding class.