gistfile1.java

// Of course there are better ways to abstract this process for many styles/sizes. 
// Here is just a brief example without any abstraction.


////// 1. Use PixmapPacker for tight bin packing.. we can adjust spacing/size
PixmapPacker atlas = new PixmapPacker(512, 512, Format.RGBA8888, 2, false);

//generate regular fonts
//prefix string doesn't really matter as long as its unique
TTFGenerator ttf = new TTFGenerator(Gdx.files.internal("data/Roboto-Regular.ttf"));
FreeTypeBitmapFontData d_reg16 = ttf.generateData(16, TTFGenerator.DEFAULT_CHARS, false, atlas, "16_");
FreeTypeBitmapFontData d_reg18 = ttf.generateData(18, TTFGenerator.DEFAULT_CHARS, false, atlas, "18_");  	
ttf.dispose();

//generate bold fonts
ttf = new TTFGenerator(Gdx.files.internal("data/Roboto-Bold.ttf"));
FreeTypeBitmapFontData d_bold16 = ttf.generateData(16, TTFGenerator.DEFAULT_CHARS, false, atlas, "bold_16_");
FreeTypeBitmapFontData d_bold18 = ttf.generateData(18, TTFGenerator.DEFAULT_CHARS, false, atlas, "bold_18_");
ttf.dispose();


////// 2. Upload pixel data to GPU		
//get first page... this only works with 1 page so far
Page p = atlas.getPages().get(0);

//generate texture from pixmap packer
Texture tex = new Texture(p.getPixmap(), p.getPixmap().getFormat(), false);
tex.setFilter(TextureFilter.Nearest, TextureFilter.Nearest);

//dispose pixmap packer
atlas.dispose();

//texture region for our data
TextureRegion region = new TextureRegion(tex);

d_reg16.region = region;
d_reg18.region = region;
d_bold16.region = region;
d_bold18.region = region;

////// 3. Create fonts
BitmapFont reg16 = new BitmapFont(d_reg16, region, false);
BitmapFont reg18 = new BitmapFont(d_reg18, region, false);

BitmapFont bold16 = new BitmapFont(d_bold16, region, false);
BitmapFont bold18 = new BitmapFont(d_bold18, region, false);

TTFGenerator.java

package mdesl.line2dx.test;

/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.files.FileHandle;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Pixmap.Format;
import com.badlogic.gdx.graphics.Texture.TextureFilter;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.g2d.BitmapFont.BitmapFontData;
import com.badlogic.gdx.graphics.g2d.BitmapFont.Glyph;
import com.badlogic.gdx.graphics.g2d.PixmapPacker;
import com.badlogic.gdx.graphics.g2d.TextureAtlas;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.graphics.g2d.freetype.FreeType;
import com.badlogic.gdx.graphics.g2d.freetype.FreeType.Bitmap;
import com.badlogic.gdx.graphics.g2d.freetype.FreeType.Face;
import com.badlogic.gdx.graphics.g2d.freetype.FreeType.GlyphMetrics;
import com.badlogic.gdx.graphics.g2d.freetype.FreeType.GlyphSlot;
import com.badlogic.gdx.graphics.g2d.freetype.FreeType.Library;
import com.badlogic.gdx.graphics.g2d.freetype.FreeType.SizeMetrics;
import com.badlogic.gdx.graphics.g2d.freetype.FreeTypeFontGenerator;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.utils.Disposable;
import com.badlogic.gdx.utils.GdxRuntimeException;

/** Generates {@link BitmapFont} and {@link BitmapFontData} instances from TrueType font files.</p>
 * 
 * Usage example:
 * 
 * <pre>
 * FreeTypeFontGenerator gen = new FreeTypeFontGenerator(Gdx.files.internal(&quot;myfont.ttf&quot;));
 * BitmapFont font = gen.generateFont(16);
 * gen.dispose();
 * </pre>
 * 
 * The generator has to be disposed once it is no longer used. The returned {@link BitmapFont} instances are managed by the user
 * and have to be disposed as usual.
 * 
 * @author mzechner */
public class TTFGenerator implements Disposable {
  public static final String DEFAULT_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890\"!`?'.,;:()[]{}<>|/@\\^$-%+=#_&~*\u0080\u0081\u0082\u0083\u0084\u0085\u0086\u0087\u0088\u0089\u008A\u008B\u008C\u008D\u008E\u008F\u0090\u0091\u0092\u0093\u0094\u0095\u0096\u0097\u0098\u0099\u009A\u009B\u009C\u009D\u009E\u009F\u00A0\u00A1\u00A2\u00A3\u00A4\u00A5\u00A6\u00A7\u00A8\u00A9\u00AA\u00AB\u00AC\u00AD\u00AE\u00AF\u00B0\u00B1\u00B2\u00B3\u00B4\u00B5\u00B6\u00B7\u00B8\u00B9\u00BA\u00BB\u00BC\u00BD\u00BE\u00BF\u00C0\u00C1\u00C2\u00C3\u00C4\u00C5\u00C6\u00C7\u00C8\u00C9\u00CA\u00CB\u00CC\u00CD\u00CE\u00CF\u00D0\u00D1\u00D2\u00D3\u00D4\u00D5\u00D6\u00D7\u00D8\u00D9\u00DA\u00DB\u00DC\u00DD\u00DE\u00DF\u00E0\u00E1\u00E2\u00E3\u00E4\u00E5\u00E6\u00E7\u00E8\u00E9\u00EA\u00EB\u00EC\u00ED\u00EE\u00EF\u00F0\u00F1\u00F2\u00F3\u00F4\u00F5\u00F6\u00F7\u00F8\u00F9\u00FA\u00FB\u00FC\u00FD\u00FE\u00FF";
	final Library library;
	final Face face;

	/** Creates a new generator from the given TrueType font file. Throws a {@link GdxRuntimeException} in case loading did not
	 * succeed.
	 * @param font the {@link FileHandle} to the TrueType font file */
	public TTFGenerator (FileHandle font) {
		library = FreeType.initFreeType();
		if (library == null) throw new GdxRuntimeException("Couldn't initialize FreeType");
		face = FreeType.newFace(library, font, 0);
		if (face == null) throw new GdxRuntimeException("Couldn't create face for font '" + font + "'");
		if (!FreeType.setPixelSizes(face, 0, 15)) throw new GdxRuntimeException("Couldn't set size for font '" + font + "'");
	}

	/** Generates a new {@link BitmapFont}, containing glyphs for the given characters. The size is expressed in pixels. Throws a
	 * GdxRuntimeException in case the font could not be generated. Using big sizes might cause such an exception. All characters
	 * need to fit onto a single texture.
	 * @param size the size in pixels
	 * @param characters the characters the font should contain
	 * @param flip whether to flip the font horizontally, see {@link BitmapFont#BitmapFont(FileHandle, TextureRegion, boolean)} */
	public BitmapFont generateFont (int size, String characters, boolean flip) {
		FreeTypeBitmapFontData data = generateData(size, characters, flip, null, null);
		BitmapFont font = new BitmapFont(data, data.getTextureRegion(), false);
		font.setOwnsTexture(true);
		return font;
	}

	/** Generates a new {@link BitmapFont}. The size is expressed in pixels. Throws a GdxRuntimeException in case the font could not
	 * be generated. Using big sizes might cause such an exception. All characters need to fit onto a single texture.
	 * 
	 * @param size the size of the font in pixels */
	public BitmapFont generateFont (int size) {
		return generateFont(size, DEFAULT_CHARS, false);
	}
	
	/** Uses ascender and descender of font to calculate real height that makes
	 *  all glyphs to fit in given pixel size. Source:
	 *  http://nothings.org/stb/stb_truetype.h / stbtt_ScaleForPixelHeight
	 */
	public int scaleForPixelHeight(int size) {
		if (!FreeType.setPixelSizes(face, 0, size)) throw new GdxRuntimeException("Couldn't set size for font");
		SizeMetrics fontMetrics = face.getSize().getMetrics();
		int ascent = FreeType.toInt(fontMetrics.getAscender());
		int descent = FreeType.toInt(fontMetrics.getDescender());
		return size * size / (ascent - descent);
	}
	
	public class GlyphAndBitmap {
		public Glyph glyph;
		public Bitmap bitmap;
	}
	
	/** Returns null if glyph was not found. If there is nothing to render,
	 * for example with various space characters, then bitmap is null.
	 * */
	public GlyphAndBitmap generateGlyphAndBitmap(int c, int size, boolean flip) {
		if (!FreeType.setPixelSizes(face, 0, size)) throw new GdxRuntimeException("Couldn't set size for font");

		SizeMetrics fontMetrics = face.getSize().getMetrics();
		int baseline = FreeType.toInt(fontMetrics.getAscender());

		// Check if character exists in this font.
		// 0 means 'undefined character code'
		if (FreeType.getCharIndex(face, c) == 0) {
			return null;
		}

		// Try to load character
		if (!FreeType.loadChar(face, c, FreeType.FT_LOAD_DEFAULT)) {
			throw new GdxRuntimeException("Unable to load character!");
		}

		GlyphSlot slot = face.getGlyph();
		
		// Try to render to bitmap
		Bitmap bitmap;
		if (!FreeType.renderGlyph(slot, FreeType.FT_RENDER_MODE_LIGHT)) {
			bitmap = null;
		} else {
			bitmap = slot.getBitmap();
		}

		GlyphMetrics metrics = slot.getMetrics();

		Glyph glyph = new Glyph();
		if (bitmap != null) {
			glyph.width = bitmap.getWidth();
			glyph.height = bitmap.getRows();
		} else {
			glyph.width = 0;
			glyph.height = 0;
		}
		glyph.xoffset = slot.getBitmapLeft();
		glyph.yoffset = flip ? -slot.getBitmapTop() + baseline : -(glyph.height - slot.getBitmapTop()) - baseline;
		glyph.xadvance = FreeType.toInt(metrics.getHoriAdvance());
		glyph.srcX = 0;
		glyph.srcY = 0;

		GlyphAndBitmap result = new GlyphAndBitmap();
		result.glyph = glyph;
		result.bitmap = bitmap;
		return result;
	}

	/** Generates a new {@link BitmapFontData} instance, expert usage only. Throws a GdxRuntimeException in case something went
	 * wrong.
	 * @param size the size in pixels */
	public FreeTypeBitmapFontData generateData (int size) {
		return generateData(size, DEFAULT_CHARS, false, null, null);
	}
	
	public static int count;

	/** Generates a new {@link BitmapFontData} instance, expert usage only. Throws a GdxRuntimeException in case something went
	 * wrong.
	 * 
	 * @param size the size in pixels
	 * @param characters the characters the font should contain
	 * @param flip whether to flip the font horizontally, see {@link BitmapFont#BitmapFont(FileHandle, TextureRegion, boolean)} */
	public FreeTypeBitmapFontData generateData (int size, String characters, boolean flip, PixmapPacker atlas, String packPrefix) {
		FreeTypeBitmapFontData data = new FreeTypeBitmapFontData();
		if (!FreeType.setPixelSizes(face, 0, size)) throw new GdxRuntimeException("Couldn't set size for font");

		// set general font data
		SizeMetrics fontMetrics = face.getSize().getMetrics();
		data.flipped = flip;
		data.ascent = FreeType.toInt(fontMetrics.getAscender());
		data.descent = FreeType.toInt(fontMetrics.getDescender());
		data.lineHeight = FreeType.toInt(fontMetrics.getHeight());
		float baseLine = data.ascent;

		// determine space width and set glyph
		if (FreeType.loadChar(face, ' ', FreeType.FT_LOAD_DEFAULT)) {
			data.spaceWidth = FreeType.toInt(face.getGlyph().getMetrics().getHoriAdvance());
		} else {
			data.spaceWidth = face.getMaxAdvanceWidth(); // FIXME possibly very wrong :)
		}
		Glyph spaceGlyph = new Glyph();
		spaceGlyph.xadvance = (int)data.spaceWidth;
		data.setGlyph(' ', spaceGlyph);

		// determine x-height
		for (char xChar : BitmapFont.xChars) {
			if (!FreeType.loadChar(face, xChar, FreeType.FT_LOAD_DEFAULT)) continue;
			data.xHeight = FreeType.toInt(face.getGlyph().getMetrics().getHeight());
			break;
		}
		if (data.xHeight == 0) throw new GdxRuntimeException("No x-height character found in font");
		for (char capChar : BitmapFont.capChars) {
			if (!FreeType.loadChar(face, capChar, FreeType.FT_LOAD_DEFAULT)) continue;
			data.capHeight = FreeType.toInt(face.getGlyph().getMetrics().getHeight());
			break;
		}

		// determine cap height
		if (data.capHeight == 1) throw new GdxRuntimeException("No cap character found in font");
		data.ascent = data.ascent - data.capHeight;
		data.down = -data.lineHeight;
		if (flip) {
			data.ascent = -data.ascent;
			data.down = -data.down;
		}

		// generate the glyphs
		int maxGlyphHeight = (int)Math.ceil(data.lineHeight);
		int pageWidth = MathUtils.nextPowerOfTwo((int)Math.sqrt(maxGlyphHeight * maxGlyphHeight * characters.length()));
		
		boolean ownsAtlas = false;
		if (atlas==null) {
			ownsAtlas = true;
			atlas = new PixmapPacker(pageWidth, pageWidth, Format.RGBA8888, 2, false);
		}
		packPrefix = packPrefix!=null ? packPrefix : "";
		for (int i = 0; i < characters.length(); i++) {
			char c = characters.charAt(i);
			if (!FreeType.loadChar(face, c, FreeType.FT_LOAD_DEFAULT)) {
				Gdx.app.log("FreeTypeFontGenerator", "Couldn't load char '" + c + "'");
				continue;
			}
			if (!FreeType.renderGlyph(face.getGlyph(), FreeType.FT_RENDER_MODE_NORMAL)) {
				Gdx.app.log("FreeTypeFontGenerator", "Couldn't render char '" + c + "'");
				continue;
			}
			GlyphSlot slot = face.getGlyph();
			GlyphMetrics metrics = slot.getMetrics();
			Bitmap bitmap = slot.getBitmap();
			Pixmap pixmap = bitmap.getPixmap(Format.RGBA8888);
			Rectangle rect = atlas.pack(packPrefix + c, pixmap);
			count++;
			Glyph glyph = new Glyph();
			glyph.width = pixmap.getWidth();
			glyph.height = pixmap.getHeight();
			glyph.xoffset = slot.getBitmapLeft();
			glyph.yoffset = flip ? -slot.getBitmapTop() + (int)baseLine : -(glyph.height - slot.getBitmapTop()) - (int)baseLine;
			glyph.xadvance = FreeType.toInt(metrics.getHoriAdvance());
			glyph.srcX = (int)rect.x;
			glyph.srcY = (int)rect.y;
			data.setGlyph(c, glyph);
			pixmap.dispose();
		}

		// generate kerning
		for (int i = 0; i < characters.length(); i++) {
			for (int j = 0; j < characters.length(); j++) {
				char firstChar = characters.charAt(i);
				Glyph first = data.getGlyph(firstChar);
				if (first == null) continue;
				char secondChar = characters.charAt(j);
				Glyph second = data.getGlyph(secondChar);
				if (second == null) continue;
				int kerning = FreeType.getKerning(face, FreeType.getCharIndex(face, firstChar),
					FreeType.getCharIndex(face, secondChar), 0);
				if (kerning == 0) continue;
				first.setKerning(secondChar, FreeType.toInt(kerning));
			}
		}
		if (ownsAtlas) {
			TextureAtlas textureAtlas = atlas.generateTextureAtlas(TextureFilter.Nearest, TextureFilter.Nearest, false);
			data.region = new TextureRegion(textureAtlas.getRegions().get(0).getTexture());
		}
		
		return data;
	}

	/** Cleans up all resources of the generator. Call this if you no longer use the generator. */
	@Override
	public void dispose () {
		FreeType.doneFace(face);
		FreeType.doneFreeType(library);
	}

	/** {@link BitmapFontData} used for fonts generated via the {@link FreeTypeFontGenerator}. The texture storing the glyphs is
	 * held in memory, thus the {@link #getImagePath()} and {@link #getFontFile()} methods will return null.
	 * 
	 * @author mzechner */
	public static class FreeTypeBitmapFontData extends BitmapFontData {
		public TextureRegion region;
		
		public TextureRegion getTextureRegion () {
			return region;
		}
	}
}