LineRenderer.java
/* ========================================================================
* PlantUML : a free UML diagram generator
* ========================================================================
*
* (C) Copyright 2009-2024, Arnaud Roques
*
* Project Info: https://plantuml.com
*
* If you like this project or if you find it useful, you can support us at:
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*
* This file is part of PlantUML.
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* PlantUML is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* PlantUML distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
* License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
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* Original Author: David Fyfe
*
*/
package net.sourceforge.plantuml.chart;
import java.util.ArrayList;
import java.util.List;
import net.sourceforge.plantuml.klimt.UPath;
import net.sourceforge.plantuml.klimt.UStroke;
import net.sourceforge.plantuml.klimt.UTranslate;
import net.sourceforge.plantuml.klimt.color.HColor;
import net.sourceforge.plantuml.klimt.color.HColors;
import net.sourceforge.plantuml.klimt.drawing.UGraphic;
import net.sourceforge.plantuml.klimt.geom.NaturalSpline;
import net.sourceforge.plantuml.klimt.geom.XCubicCurve2D;
import net.sourceforge.plantuml.klimt.geom.XPoint2D;
import net.sourceforge.plantuml.klimt.shape.ULine;
import net.sourceforge.plantuml.style.ISkinParam;
public class LineRenderer {
private final ISkinParam skinParam;
private final double plotWidth;
private final double plotHeight;
private final int categoryCount;
private final ChartAxis axis;
private final ChartAxis xAxis;
public LineRenderer(ISkinParam skinParam, double plotWidth, double plotHeight, int categoryCount,
ChartAxis axis, ChartAxis xAxis) {
this.skinParam = skinParam;
this.plotWidth = plotWidth;
this.plotHeight = plotHeight;
this.categoryCount = categoryCount;
this.axis = axis;
this.xAxis = xAxis;
}
public void draw(UGraphic ug, ChartSeries series, HColor color) {
if (categoryCount == 0 && !series.hasExplicitXValues())
return;
if (series.isInterpolate()) {
final List<XCubicCurve2D> curves = NaturalSpline.through(points(series));
if (curves.isEmpty() == false) {
final UPath curve = UPath.none();
curve.moveTo(curves.get(0).getP1());
for (XCubicCurve2D bezier : curves)
curve.cubicTo(bezier.ctrlx1, bezier.ctrly1, bezier.ctrlx2, bezier.ctrly2, bezier.x2, bezier.y2);
ug.apply(color).apply(UStroke.withThickness(2.0)).apply(HColors.none().bg()).draw(curve);
return;
}
}
// A missing value is skipped: the values on both sides of it are joined by one segment
if (series.isConnect()) {
final List<XPoint2D> points = points(series);
for (int i = 0; i < points.size() - 1; i++) {
final XPoint2D p1 = points.get(i);
final XPoint2D p2 = points.get(i + 1);
final ULine line = new ULine(p2.x - p1.x, p2.y - p1.y);
ug.apply(color).apply(UStroke.withThickness(2.0)).apply(UTranslate.dx(p1.x).compose(UTranslate.dy(p1.y))).draw(line);
}
return;
}
final List<Double> values = series.getValues();
if (series.hasExplicitXValues()) {
// Coordinate-pair mode: use explicit x-values
final List<Double> xValues = series.getXValues();
// Safety check
if (xAxis == null) {
System.err.println("ERROR: xAxis is null in coordinate-pair mode!");
return;
}
// Draw line segments
for (int i = 0; i < values.size() - 1; i++) {
// A missing value (spread over an h-axis range, see ChartDiagram) leaves a gap
if (values.get(i) == null || values.get(i + 1) == null)
continue;
final double xVal1 = xValues.get(i);
final double yVal1 = values.get(i);
final double xVal2 = xValues.get(i + 1);
final double yVal2 = values.get(i + 1);
final double x1 = xAxis.valueToPixel(xVal1, 0, plotWidth);
final double y1 = plotHeight - (yVal1 - axis.getMin()) / (axis.getMax() - axis.getMin()) * plotHeight;
final double x2 = xAxis.valueToPixel(xVal2, 0, plotWidth);
final double y2 = plotHeight - (yVal2 - axis.getMin()) / (axis.getMax() - axis.getMin()) * plotHeight;
final ULine line = new ULine(x2 - x1, y2 - y1);
ug.apply(color).apply(UStroke.withThickness(2.0)).apply(UTranslate.dx(x1).compose(UTranslate.dy(y1))).draw(line);
}
} else {
// Index-based mode: use category positioning
final double categoryWidth = plotWidth / categoryCount;
// Draw line segments
for (int i = 0; i < Math.min(values.size() - 1, categoryCount - 1); i++) {
// No segment touches a missing value, so the line has a gap there
if (values.get(i) == null || values.get(i + 1) == null)
continue;
final double value1 = values.get(i);
final double value2 = values.get(i + 1);
final double x1 = (i + 0.5) * categoryWidth;
final double y1 = plotHeight - (value1 - axis.getMin()) / (axis.getMax() - axis.getMin()) * plotHeight;
final double x2 = (i + 1.5) * categoryWidth;
final double y2 = plotHeight - (value2 - axis.getMin()) / (axis.getMax() - axis.getMin()) * plotHeight;
final ULine line = new ULine(x2 - x1, y2 - y1);
ug.apply(color).apply(UStroke.withThickness(2.0)).apply(UTranslate.dx(x1).compose(UTranslate.dy(y1))).draw(line);
}
}
}
// The points of the series in pixels, leaving out missing values
private List<XPoint2D> points(ChartSeries series) {
final List<XPoint2D> result = new ArrayList<>();
final List<Double> values = series.getValues();
final double range = axis.getMax() - axis.getMin();
if (series.hasExplicitXValues()) {
if (xAxis == null)
return result;
final List<Double> xValues = series.getXValues();
for (int i = 0; i < values.size(); i++)
if (values.get(i) != null)
result.add(new XPoint2D(xAxis.valueToPixel(xValues.get(i), 0, plotWidth),
plotHeight - (values.get(i) - axis.getMin()) / range * plotHeight));
} else {
final double categoryWidth = plotWidth / categoryCount;
for (int i = 0; i < Math.min(values.size(), categoryCount); i++)
if (values.get(i) != null)
result.add(new XPoint2D((i + 0.5) * categoryWidth,
plotHeight - (values.get(i) - axis.getMin()) / range * plotHeight));
}
return result;
}
}