Q3CanvasSpline Class

The Q3CanvasSpline class provides multi-bezier splines on a Q3Canvas . 更多...

头：	#include <Q3CanvasSpline>
继承：	Q3CanvasPolygon

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公共函数

	Q3CanvasSpline (Q3Canvas * canvas )
	~Q3CanvasSpline ()
bool	closed () const
Q3PointArray	controlPoints () const
void	setControlPoints (Q3PointArray ctrl , bool close = true)

重实现公共函数

virtual int

rtti () const

5 public functions inherited from Q3CanvasPolygon
9 公共函数继承自 Q3CanvasPolygonalItem
34 公共函数继承自 Q3CanvasItem

额外继承成员

1 保护函数继承自 Q3CanvasPolygon
6 保护函数继承自 Q3CanvasPolygonalItem
1 保护函数继承自 Q3CanvasItem

详细描述

The Q3CanvasSpline class provides multi-bezier splines on a Q3Canvas .

A Q3CanvasSpline is a sequence of 4-point bezier curves joined together to make a curved shape.

You set the control points of the spline with setControlPoints ().

If the bezier is closed (), then the first control point will be re-used as the last control point. Therefore, a closed bezier must have a multiple of 3 control points and an open bezier must have one extra point.

The beziers are not necessarily joined "smoothly". To ensure this, set control points appropriately (general reference texts about beziers will explain this in detail).

Like any other canvas item splines can be moved with Q3CanvasItem::move () 和 Q3CanvasItem::moveBy (), or by setting coordinates with Q3CanvasItem::setX (), Q3CanvasItem::setY () 和 Q3CanvasItem::setZ ().

另请参阅 QtCanvas and Porting to Graphics View .

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Q3CanvasSpline:: Q3CanvasSpline ( Q3Canvas * canvas )

Create a spline with no control points on the canvas canvas .

另请参阅 setControlPoints ().

Q3CanvasSpline:: ~Q3CanvasSpline ()

Destroy the spline.

bool Q3CanvasSpline:: closed () const

Returns true if the control points are a closed set; otherwise returns false.

Q3PointArray Q3CanvasSpline:: controlPoints () const

Returns the current set of control points.

另请参阅 setControlPoints () 和 closed ().

`[虚拟]` int Q3CanvasSpline:: rtti () const

重实现自 Q3CanvasItem::rtti ().

Returns 8 ( Q3CanvasItem::Rtti_Spline ).

另请参阅 Q3CanvasItem::rtti ().

void Q3CanvasSpline:: setControlPoints ( Q3PointArray ctrl , bool close = true)

Set the spline control points to ctrl .

若 close is true, then the first point in ctrl will be re-used as the last point, and the number of control points must be a multiple of 3. If close is false, one additional control point is required, and the number of control points must be one of (4, 7, 10, 13, ...).

If the number of control points doesn't meet the above conditions, the number of points will be truncated to the largest number of points that do meet the requirement.

另请参阅 controlPoints ().

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