uk.ac.starlink.ttools.plot2.layer

Interface MultiPointScribe

@Equality
public interface MultiPointScribe

Knows how to turn a number of offset points to a drawable glyph.

Note that this is not a FunctionalInterface, since instances need in general to implement Equality.

Since:

22 Sep 2021

Author:

Mark Taylor

Method Summary

Modifier and Type	Method and Description
Glyph	createGlyph(int[] xoffs, int[] yoffs) Returns a glyph representing the this object's rendering of a given offset array.

Method Detail

createGlyph

Glyph createGlyph(int[] xoffs,
                  int[] yoffs)

Returns a glyph representing the this object's rendering of a given offset array. The glyph is considered to be centered at the origin, so the offsets will usually surround (0,0). The two input arrays must be of the same size.

A common usage is for error bars; in this case there are typically (2*N) offsets, representing errors in N dimensions. Error bars come in consecutive pairs which describe error bars along the same axis in different directions. Missing error bars are represented as (0,0). The values must come in axis order where that makes sense, but note in some contexts (e.g. 3D) these may be data axes rather than graphics plane axes.

This method is quite likely to get called from time to time with ridiculously large offset arrays. Implementations should try to ensure that they don't attempt graphics operations which may cause the graphics system undue grief, such as filling an ellipse the size of a village.

Parameters:

xoffs - X coordinates of point offsets

yoffs - Y coordinates of point offsets

Returns:

glyph displaying shape