Class LineTracer
addVertex
,
followed by a call to flush()
.
Where possible, sub-sequences of the point sequence
are aggregated in supplied work
arrays and plotted using Graphics2D.draw(Shape)
.
This is superior to the more obvious strategy of calling
Graphics.drawLine
for every pair of points.
It is probably faster, it can work with non-integer coordinates,
I think the line joining is better,
and it is necessary to get the dashing right for dashed strokes,
otherwise the dash starts anew for each edge.
However, this is only possible for runs of points of the same colour;
line segments of different colours have to be drawn separately,
which means that lines of varying colour may look worse than
single colour ones (poorer sub-pixel positioning, nastier line joins,
incorrect dash phase).
This class does some other useful things like avoid attempts to plot lines which are extremely long or which are known to be outside the clip.
- Since:
- 12 Jun 2013
- Author:
- Mark Taylor
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Constructor Summary
ConstructorsConstructorDescriptionLineTracer
(Graphics g, Rectangle bounds, Stroke stroke, boolean antialias, int nwork, boolean isPixel) Constructor. -
Method Summary
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Constructor Details
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LineTracer
public LineTracer(Graphics g, Rectangle bounds, Stroke stroke, boolean antialias, int nwork, boolean isPixel) Constructor. Thenwork
parameter determines the number of points aggregated into a single plotting call. There may be visual anomalies everynwork
points, so it should not be too small, but arrays of this size are allocated, so it should not be too large either.- Parameters:
g
- the base graphics contextbounds
- bounds beyond which lines should not be drawnstroke
- line strokeantialias
- whether lines are to be antialiasednwork
- workspace array sizeisPixel
- if true, the graphics context is considered to be pixellised, allowing some optimisations to be made that should not be visible
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Method Details
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addVertex
Adds a point to the sequence to be plotted. A null value for thecolor
argument results in a break in the line.- Parameters:
dx
- graphics X coordinatedy
- graphics Y coordinatecolor
- line colour at point
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flush
public void flush()Ensures that all points have been drawn. Since points are plotted in bursts for reasons of aesthetics and efficiency, this must be called after alladdVertex(double, double, java.awt.Color)
calls to ensure that the drawing has actually been done.
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