Qwt3DPlotItem Class Reference

Base class for all 3D plot items. More...

#include <qwt3d_plotitem.h>

Inheritance diagram for Qwt3DPlotItem:

Classes
class	PrivateData

Public Member Functions
	Qwt3DPlotItem ()
	Default constructor.
virtual	~Qwt3DPlotItem ()
	Destructor — detaches from any plot.
void	attach (Qwt3DPlot *plot)
	Attach the item to a plot.
void	detach ()
	Detach the item from its plot.
Qwt3DPlot *	plot () const
	Get the plot this item is attached to.
virtual void	draw ()=0
	Draw the item using the current GL context.
virtual ParallelEpiped	hull () const =0
	Get the bounding hull of the item in 3D space.
void	setTitle (const QString &title)
	Set the item title.
QString	title () const
	Get the item title.
void	setZ (double z)
	Set the z-order value (controls draw sequence)
double	z () const
	Get the z-order value.
void	setVisible (bool on)
	Set item visibility.
bool	isVisible () const
	Check if the item is visible.
virtual int	rtti () const
	Runtime type information.
virtual void	itemChanged ()
	Notify the plot that the item has changed.
virtual void	populateLegendColors (ColorVector &colors) const
	Populate the legend color vector from the item's color functor.

Detailed Description

Base class for all 3D plot items.

A Qwt3DPlotItem is "something", that can be drawn within the GL context of a Qwt3DPlot widget. Items are not widgets themselves; they are pure data + drawing logic objects that are attached to a Qwt3DPlot via attach() and rendered during Qwt3DPlot::paintGL().

The rendering pipeline calls draw() for each attached item in order of ascending z-value. Items manage their own data, geometry caching (VBO/VAO), and color/style. The view transformation, projection, and lighting are set up by Qwt3DPlot before draw() is called.

To implement a custom 3D plot item, derive from Qwt3DPlotItem and implement the pure virtual draw() and hull() methods:

class MyItem : public Qwt3DPlotItem
{
public:
    void draw() override
    {
        // Issue GL drawing calls using the current GL context
    }
 
    ParallelEpiped hull() const override
    {
        return m_hull;
    }
 
private:
    ParallelEpiped m_hull;
};
 
// Usage:
auto plot = new Qwt3DPlot(parent);
auto item = new MyItem();
item->attach(plot);

See also

Qwt3DPlot, QwtPlotItem (2D counterpart)

Constructor & Destructor Documentation

Qwt3DPlotItem()

Qwt3DPlotItem::Qwt3DPlotItem

(

)

Default constructor.

Constructs a Qwt3DPlotItem with default settings.

Destructor

Destroys the Qwt3DPlotItem and detaches it from any plot.

Member Function Documentation

attach()

void Qwt3DPlotItem::attach

(

Qwt3DPlot *

plot

)

Attach the item to a plot.

Parameters

[in]

plot

Plot widget to attach to

This method attaches a Qwt3DPlotItem to the Qwt3DPlot argument. It will first detach the Qwt3DPlotItem from any plot from a previous call to attach (if necessary). If a nullptr argument is passed, it will detach from any Qwt3DPlot it was attached to.

detach()

void Qwt3DPlotItem::detach

(

)

Detach the item from its plot.

Detach the item from the plot.

This method detaches a Qwt3DPlotItem from any Qwt3DPlot it has been associated with. detach() is equivalent to calling attach(nullptr).

draw()

virtual void Qwt3DPlotItem::draw ( )

pure virtual

Draw the item using the current GL context.

Implemented in Qwt3DBar, Qwt3DLine, and Qwt3DSurface.

hull()

virtual ParallelEpiped Qwt3DPlotItem::hull ( ) const

pure virtual

Get the bounding hull of the item in 3D space.

Implemented in Qwt3DBar, Qwt3DLine, and Qwt3DSurface.

isVisible()

bool Qwt3DPlotItem::isVisible

(

)

const

Check if the item is visible.

Returns

true if visible, false otherwise

See also

setVisible()

itemChanged()

void Qwt3DPlotItem::itemChanged ( )

virtual

Notify the plot that the item has changed.

Triggers a plot update so the item is redrawn.

plot()

Qwt3DPlot * Qwt3DPlotItem::plot

(

)

const

Get the plot this item is attached to.

Get the plot the item is attached to.

Returns

Attached plot, or nullptr if not attached

populateLegendColors()

void Qwt3DPlotItem::populateLegendColors ( ColorVector &  colors ) const

virtual

Populate the legend color vector from the item's color functor.

Reimplemented in Qwt3DBar, Qwt3DLine, and Qwt3DSurface.

rtti()

int Qwt3DPlotItem::rtti ( ) const

virtual

Runtime type information.

运行时类型信息

Returns

返回 Rtti_Plot3DItem (= 0)，子类应 override 此方法返回各自的 RTTI 值

用于运行时类型识别，支持安全向下转型、设置面板工厂路由和序列化分发。 设计与 2D QwtPlotItem::rtti() 完全对齐。

See also

Rtti3DValues, QwtPlotItem::rtti()

Reimplemented in Qwt3DBar, Qwt3DLine, and Qwt3DSurface.

setTitle()

void Qwt3DPlotItem::setTitle

(

const QString &

title

)

Set the item title.

Parameters

[in]

title

Title text

See also

title()

setVisible()

void Qwt3DPlotItem::setVisible

(

bool

on

)

Set item visibility.

Parameters

[in]

on

Show if true, otherwise hide

See also

isVisible()

setZ()

void Qwt3DPlotItem::setZ

(

double

z

)

Set the z-order value (controls draw sequence)

Set the z-order value.

Parameters

[in]

z

Z-value for the item

Plot items are drawn in increasing z-order.

See also

z()

title()

QString Qwt3DPlotItem::title

(

)

const

Get the item title.

Get the title of the item.

Returns

Title of the item

See also

setTitle()

z()

double Qwt3DPlotItem::z

(

)

const

Get the z-order value.

Returns

Z-value of the item

Plot items are drawn in increasing z-order.

See also

setZ()

---

The documentation for this class was generated from the following files:

• /home/runner/work/QWT/QWT/src/plot3d/qwt3d_plotitem.h
• /home/runner/work/QWT/QWT/src/plot3d/qwt3d_plotitem.cpp