FreeMat

- Main Page
- Related Pages

vtkCoordinate

Section: Visualization Toolkit Filtering Classes

# Usage

vtkCoordinate represents position in a variety of coordinate systems, and converts position to other coordinate systems. It also supports relative positioning, so you can create a cascade of vtkCoordinate objects (no loops please!) that refer to each other. The typical usage of this object is to set the coordinate system in which to represent a position (e.g., SetCoordinateSystemToNormalizedDisplay()), set the value of the coordinate (e.g., SetValue()), and then invoke the appropriate method to convert to another coordinate system (e.g., GetComputedWorldValue()).

The coordinate systems in vtk are as follows:

      DISPLAY -             x-y pixel values in window
      NORMALIZED DISPLAY -  x-y (0,1) normalized values
      VIEWPORT -            x-y pixel values in viewport
      NORMALIZED VIEWPORT - x-y (0,1) normalized value in viewport
      VIEW -                x-y-z (-1,1) values in camera coordinates. (z is depth)
      WORLD -               x-y-z global coordinate values
      USERDEFINED -         x-y-z in User defined space

If you cascade vtkCoordinate objects, you refer to another vtkCoordinate object which in turn can refer to others, and so on. This allows you to create composite groups of things like vtkActor2D that are positioned relative to one another. Note that in cascaded sequences, each vtkCoordinate object may be specified in different coordinate systems!

To create an instance of class vtkCoordinate, simply invoke its constructor as follows

      obj = vtkCoordinate

# Methods

The class vtkCoordinate has several methods that can be used. They are listed below. Note that the documentation is translated automatically from the VTK sources, and may not be completely intelligible. When in doubt, consult the VTK website. In the methods listed below, `obj` is an instance of the vtkCoordinate class.

- `string = obj.GetClassName ()`
- `int = obj.IsA (string name)`
- `vtkCoordinate = obj.NewInstance ()`
- `vtkCoordinate = obj.SafeDownCast (vtkObject o)`
- `obj.SetCoordinateSystem (int )` - Set/get the coordinate system which this coordinate is defined in. The options are Display, Normalized Display, Viewport, Normalized Viewport, View, and World.
- `int = obj.GetCoordinateSystem ()` - Set/get the coordinate system which this coordinate is defined in. The options are Display, Normalized Display, Viewport, Normalized Viewport, View, and World.
- `obj.SetCoordinateSystemToDisplay ()` - Set/get the coordinate system which this coordinate is defined in. The options are Display, Normalized Display, Viewport, Normalized Viewport, View, and World.
- `obj.SetCoordinateSystemToNormalizedDisplay ()` - Set/get the coordinate system which this coordinate is defined in. The options are Display, Normalized Display, Viewport, Normalized Viewport, View, and World.
- `obj.SetCoordinateSystemToViewport ()` - Set/get the coordinate system which this coordinate is defined in. The options are Display, Normalized Display, Viewport, Normalized Viewport, View, and World.
- `obj.SetCoordinateSystemToNormalizedViewport ()` - Set/get the coordinate system which this coordinate is defined in. The options are Display, Normalized Display, Viewport, Normalized Viewport, View, and World.
- `obj.SetCoordinateSystemToView ()` - Set/get the coordinate system which this coordinate is defined in. The options are Display, Normalized Display, Viewport, Normalized Viewport, View, and World.
- `obj.SetCoordinateSystemToWorld ()`
- `string = obj.GetCoordinateSystemAsString ()`
- `obj.SetValue (double , double , double )` - Set/get the value of this coordinate. This can be thought of as the position of this coordinate in its coordinate system.
- `obj.SetValue (double a[3])` - Set/get the value of this coordinate. This can be thought of as the position of this coordinate in its coordinate system.
- `double = obj. GetValue ()` - Set/get the value of this coordinate. This can be thought of as the position of this coordinate in its coordinate system.
- `obj.SetValue (double a, double b)` - If this coordinate is relative to another coordinate, then specify that coordinate as the ReferenceCoordinate. If this is NULL the coordinate is assumed to be absolute.
- `obj.SetReferenceCoordinate (vtkCoordinate )` - If this coordinate is relative to another coordinate, then specify that coordinate as the ReferenceCoordinate. If this is NULL the coordinate is assumed to be absolute.
- `vtkCoordinate = obj.GetReferenceCoordinate ()` - If this coordinate is relative to another coordinate, then specify that coordinate as the ReferenceCoordinate. If this is NULL the coordinate is assumed to be absolute.
- `obj.SetViewport (vtkViewport viewport)` - If you want this coordinate to be relative to a specific vtkViewport (vtkRenderer) then you can specify that here. NOTE: this is a raw pointer, not a weak pointer not a reference counted object to avoid reference cycle loop between rendering classes and filter classes.
- `vtkViewport = obj.GetViewport ()` - If you want this coordinate to be relative to a specific vtkViewport (vtkRenderer) then you can specify that here. NOTE: this is a raw pointer, not a weak pointer not a reference counted object to avoid reference cycle loop between rendering classes and filter classes.
- `double = obj.GetComputedWorldValue (vtkViewport )` - Return the computed value in a specified coordinate system.
- `int = obj.GetComputedViewportValue (vtkViewport )` - Return the computed value in a specified coordinate system.
- `int = obj.GetComputedDisplayValue (vtkViewport )` - Return the computed value in a specified coordinate system.
- `int = obj.GetComputedLocalDisplayValue (vtkViewport )` - Return the computed value in a specified coordinate system.
- `double = obj.GetComputedDoubleViewportValue (vtkViewport )`
- `double = obj.GetComputedDoubleDisplayValue (vtkViewport )`