vispy.scene.cameras.panzoom module

class vispy.scene.cameras.panzoom.PanZoomCamera(rect=(0, 0, 1, 1), aspect=None, **kwargs)

Bases: BaseCamera

Camera implementing 2D pan/zoom mouse interaction.

For this camera, the scale_factor indicates the zoom level, and the center indicates the center position of the view.

By default, this camera inverts the y axis of the scene. This usually results in the scene +y axis pointing upward because widgets (including ViewBox) have their +y axis pointing downward.

Parameters:

rectRect

A Rect object or 4-element tuple that specifies the rectangular area to show.

aspectfloat | None

The aspect ratio (i.e. scaling) between x and y dimension of the scene. E.g. to show a square image as square, the aspect should be 1. If None (default) the x and y dimensions are scaled independently.

**kwargsdict

Keyword arguments to pass to BaseCamera.

Notes

Interaction:

• LMB: pan the view

• RMB or scroll: zooms the view

property aspect

The ratio between the x and y dimension. E.g. to show a square image as square, the aspect should be 1. If None, the dimensions are scaled automatically, dependening on the available space. Otherwise the ratio between the dimensions is fixed.

property center

The center location for this camera

The exact meaning of this value differs per type of camera, but generally means the point of interest or the rotation point.

pan(*pan)

Pan the view.

Parameters:

*panlength-2 sequence

The distance to pan the view, in the coordinate system of the scene.

property rect

The rectangular border of the ViewBox visible area.

This is expressed in the coordinate system of the scene. See Rect for different ways this can be specified.

Note that the rectangle can have negative width or height, in which case the corresponding dimension is flipped (this flipping is independent from the camera’s flip property).

viewbox_mouse_event(event)

The SubScene received a mouse event; update transform accordingly.

Parameters:

eventinstance of Event

The event.

viewbox_resize_event(event)

Modify the data aspect and scale factor, to adjust to the new window size.

Parameters:

eventinstance of Event

The event.

zoom(factor, center=None)

Zoom in (or out) at the given center

Parameters:

factorfloat or tuple

Fraction by which the scene should be zoomed (e.g. a factor of 2 causes the scene to appear twice as large).

centertuple of 2-4 elements

The center of the view. If not given or None, use the current center.