Class FontGlyphReader

1	/*
2	* Copyright (c) 2016 Vivid Solutions.
3	*
4	* All rights reserved. This program and the accompanying materials
5	* are made available under the terms of the Eclipse Public License 2.0
6	* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
7	* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
8	* and the Eclipse Distribution License is available at
9	*
10	* http://www.eclipse.org/org/documents/edl-v10.php.
11	*/
12
13	package org.locationtech.jts.awt;
14
15	import java.awt.Font;
16	import java.awt.font.FontRenderContext;
17	import java.awt.font.GlyphVector;
18	import java.util.ArrayList;
19	import java.util.List;
20
21	import org.locationtech.jts.geom.Geometry;
22	import org.locationtech.jts.geom.GeometryFactory;
23	import org.locationtech.jts.geom.Polygonal;
24	import org.locationtech.jts.geom.util.AffineTransformation;
25
26	/**
27	* Provides methods to read {@link Font} glyphs for strings
28	* into {@link Polygonal} geometry.
29	* <p>
30	* It is suggested to use larger point sizes to render fonts glyphs,
31	* to reduce the effects of scale-dependent hints.
32	* The result geometry is in the base coordinate system of the font.
33	* The geometry can be further transformed as necessary using
34	* {@link AffineTransformation}s.
35	*
36	* @author Martin Davis
37	*
38	*/
39	public class FontGlyphReader
40	{
41	/**
42	* The font name of the Java logical font Serif.
43	*/
44	public static final String FONT_SERIF = "Serif";
45
46	/**
47	* The font name of the Java logical font SansSerif.
48	* <p>
49	* DEPRECATED - use FONT_SANSSERIF
50	*/
51	public static final String FONT_SANSERIF = "SansSerif";
52
53
54	/**
55	* The font name of the Java logical font SansSerif.
56	*/
57	public static final String FONT_SANSSERIF = "SansSerif";
58
59	/**
60	* The font name of the Java logical font Monospaced.
61	*/
62
63	public static final String FONT_MONOSPACED = "Monospaced";
64
65	// a flatness factor empirically determined to provide good results
66	private static final double FLATNESS_FACTOR = 400;
67
68	private FontGlyphReader() {}
69
70	/**
71	* Converts text rendered in the given font and pointsize to a {@link Geometry}
72	* using a standard flatness factor.
73	*
74	* @param text the text to render
75	* @param fontName the name of the font
76	* @param pointSize the pointSize to render at
77	* @param geomFact the geometryFactory to use to create the result
78	* @return a polygonal geometry representing the rendered text
79	*/
80	public static Geometry read(String text, String fontName, int pointSize, GeometryFactory geomFact)
81	{
82	return read(text, new Font(fontName, Font.PLAIN, pointSize), geomFact);
83	}
84
85	/**
86	* Converts text rendered in the given {@link Font} to a {@link Geometry}
87	* using a standard flatness factor.
88	*
89	* @param text the text to render
90	* @param font the font to render with
91	* @param geomFact the geometryFactory to use to create the result
92	* @return a polygonal geometry representing the rendered text
93	*/
94	public static Geometry read(String text, Font font, GeometryFactory geomFact)
95	{
96	double flatness = font.getSize() / FLATNESS_FACTOR;
97	return read(text, font, flatness, geomFact);
98	}
99
100	/**
101	* Converts text rendered in the given {@link Font} to a {@link Geometry}
102	*
103	* @param text the text to render
104	* @param font the font to render with
105	* @param flatness the flatness factor to use
106	* @param geomFact the geometryFactory to use to create the result
107	* @return a polygonal geometry representing the rendered text
108	*/
109	public static Geometry read(String text, Font font, double flatness, GeometryFactory geomFact)
110	{
111	char[] chs = text.toCharArray();
112	FontRenderContext fontContext = new FontRenderContext(null, false, true);
113	GlyphVector gv = font.createGlyphVector(fontContext, chs);
114	List polys = new ArrayList();
115	for (int i = 0; i < gv.getNumGlyphs(); i++) {
116	Geometry geom = ShapeReader.read(gv.getGlyphOutline(i), flatness, geomFact);
117	for (int j = 0; j < geom.getNumGeometries(); j++) {
118	polys.add(geom.getGeometryN(j));
119	}
120	}
121	return geomFact.buildGeometry(polys);
122	}
123
124	}
125