uk.ac.starlink.ttools.plot2.layer

Class LineGlyph

java.lang.Object

uk.ac.starlink.ttools.plot2.layer.DrawingGlyph

uk.ac.starlink.ttools.plot2.layer.LineGlyph

All Implemented Interfaces:

Glyph

public abstract class LineGlyph
extends DrawingGlyph

Glyph partial implementation that facilitates making drawings with variable-thickness lines. The toThicker(uk.ac.starlink.ttools.plot2.layer.PixerFactory, uk.ac.starlink.ttools.plot2.layer.StrokeKit) method is supplied to generate another glyph based on this one but with thicker drawing lines.

Concrete implementations have to be able to supply bounds, and draw the shape onto a supplied PixelDrawing, or to a Graphics context with a given StrokeSet.

Since:

24 Sep 2021

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
LineGlyph()

Method Summary

Modifier and Type	Method and Description
static PixerFactory	createKernel(MarkerShape shape, int nthick) Returns a smoothing kernel derived from a given marker shape.
PixelDrawing	createPixerFactory(Rectangle clip) Returns a PixerFactory that produces the pixels for this glyph.
static PixerFactory	createThickKernel(int nthick) Returns a (roughly circular) smoothing kernel for a thick line.
static StrokeKit	createThickStrokeKit(int nthick) Returns a stroke kit for drawing a thick line.
abstract void	drawShape(PixelDrawing drawing) Draws this shape onto a given drawing, whose bounds have been set appropriately.
abstract Rectangle	getPixelBounds() Returns the boundary rectangle containing the whole of the shape that will be drawn to a PixelDrawing.
void	paintGlyph(Graphics g) Paints a representation of a point considered to be at the origin.
abstract void	paintGlyph(Graphics g, StrokeKit strokeKit) Paints this shape onto a graphics context with given line strokes.
DrawingGlyph	toThicker(PixerFactory kernel, StrokeKit strokeKit) Returns a glyph that is the same as this one, but with thicker pen strokes.

Methods inherited from class uk.ac.starlink.ttools.plot2.layer.DrawingGlyph

createPixer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LineGlyph

public LineGlyph()

Method Detail

getPixelBounds

public abstract Rectangle getPixelBounds()

Returns the boundary rectangle containing the whole of the shape that will be drawn to a PixelDrawing. This is allowed to be an overestimate (though efficiency may suffer), but not an underestimate.

This method is called by createPixerFactory(java.awt.Rectangle), but not by drawShape(uk.ac.starlink.ttools.plot2.layer.PixelDrawing).

Returns:

bounding box

drawShape

public abstract void drawShape(PixelDrawing drawing)

Draws this shape onto a given drawing, whose bounds have been set appropriately. Since a suitable clip will be in place, and PixelDrawing methods will take account of this to avoid unnecessary work, implementations do not generally have to worry concerning correctness or efficiency about graphics operations with potentially oversized coordinate values.

Parameters:

drawing - graphics destination

paintGlyph

public abstract void paintGlyph(Graphics g,
                                StrokeKit strokeKit)

Paints this shape onto a graphics context with given line strokes. If any lines are drawn, they should in general be done with strokes supplied from the given StrokeKit, giving client classes a chance to customise line drawing.

Parameters:

g - graphics context

strokeKit - supplier of line drawing strokes

createPixerFactory

public PixelDrawing createPixerFactory(Rectangle clip)

Returns a PixerFactory that produces the pixels for this glyph.

Specified by:

createPixerFactory in class DrawingGlyph

Parameters:

clip - clip bounds

paintGlyph

public void paintGlyph(Graphics g)

Description copied from interface: Glyph

Paints a representation of a point considered to be at the origin. Typically this means the painting is centred at that point.

Parameters:

g - graphics context

toThicker

public DrawingGlyph toThicker(PixerFactory kernel,
                              StrokeKit strokeKit)

Returns a glyph that is the same as this one, but with thicker pen strokes. The pixel drawing stroke changes are effected by convolving the output drawing with a supplied smoothing kernel, and the graphics context painting is done using a supplied StrokeKit. It is the responsibility of the calling class to ensure that these two are consistent with each other. Note the effect may not be exactly the same for painted and pixellated output even so, since only stroked lines will be thicker in the painting, while all output graphics will be smoothed in the pixels.

Parameters:

kernel - smoothing kernel

strokeKit - line strokes to use for painting

Returns:

derived glyph

createThickKernel

public static PixerFactory createThickKernel(int nthick)

Returns a (roughly circular) smoothing kernel for a thick line.

Parameters:

nthick - line thickness, >=0

Returns:

standard smoothing kernel

createKernel

public static PixerFactory createKernel(MarkerShape shape,
                                        int nthick)

Returns a smoothing kernel derived from a given marker shape.

Parameters:

shape - shape

nthick - thickness index >=0

Returns:

smoothing kernel

createThickStrokeKit

public static StrokeKit createThickStrokeKit(int nthick)

Returns a stroke kit for drawing a thick line.

Parameters:

nthick - line thickness, >=0

Returns:

thick stroke