com.badlogic.gdx.tools.hiero.unicodefont.UnicodeFont.java Source code

Java tutorial

Introduction

Here is the source code for com.badlogic.gdx.tools.hiero.unicodefont.UnicodeFont.java

Source

/*******************************************************************************
 * 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.
 ******************************************************************************/

package com.badlogic.gdx.tools.hiero.unicodefont;

import java.awt.Font;
import java.awt.FontFormatException;
import java.awt.FontMetrics;
import java.awt.Rectangle;
import java.awt.font.GlyphVector;
import java.awt.font.TextAttribute;
import java.io.IOException;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.lwjgl.opengl.GL11;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.tools.hiero.unicodefont.effects.Effect;
import com.badlogic.gdx.utils.GdxRuntimeException;

// BOZO - Look at actual pixels to determine glyph size, current size sometimes selects blank pixels (eg Calibri, 45, 'o').

/** A bitmap font that can display unicode glyphs from a TrueTypeFont.
 * 
 * For efficiency, glyphs are packed on to textures. Glyphs can be loaded to the textures on the fly, when they are first needed
 * for display. However, it is best to load the glyphs that are known to be needed at startup.
 * @author Nathan Sweet */
public class UnicodeFont {
    static private final int DISPLAY_LIST_CACHE_SIZE = 200;
    static private final int MAX_GLYPH_CODE = 0x10FFFF;
    static private final int PAGE_SIZE = 512;
    static private final int PAGES = MAX_GLYPH_CODE / PAGE_SIZE;

    private Font font;
    private FontMetrics metrics;
    private String ttfFileRef;
    private int ascent, descent, leading, spaceWidth;
    private final Glyph[][] glyphs = new Glyph[PAGES][];
    private final List glyphPages = new ArrayList();
    private final List queuedGlyphs = new ArrayList(256);
    private final List effects = new ArrayList();
    private int paddingTop, paddingLeft, paddingBottom, paddingRight, paddingAdvanceX, paddingAdvanceY;
    private Glyph missingGlyph;
    private int glyphPageWidth = 512, glyphPageHeight = 512;
    private final DisplayList emptyDisplayList = new DisplayList();
    private boolean nativeRendering;

    private int baseDisplayListID = -1;
    int eldestDisplayListID;
    private final LinkedHashMap displayLists = new LinkedHashMap(DISPLAY_LIST_CACHE_SIZE, 1, true) {
        protected boolean removeEldestEntry(Entry eldest) {
            DisplayList displayList = (DisplayList) eldest.getValue();
            if (displayList != null)
                eldestDisplayListID = displayList.id;
            return size() > DISPLAY_LIST_CACHE_SIZE;
        }
    };

    /** @param ttfFileRef The file system or classpath location of the TrueTypeFont file.
     * @param hieroFileRef The file system or classpath location of the Hiero settings file. */
    public UnicodeFont(String ttfFileRef, String hieroFileRef) {
        this(ttfFileRef, new HieroSettings(hieroFileRef));
    }

    /** @param ttfFileRef The file system or classpath location of the TrueTypeFont file. */
    public UnicodeFont(String ttfFileRef, HieroSettings settings) {
        this.ttfFileRef = ttfFileRef;
        Font font = createFont(ttfFileRef);
        initializeFont(font, settings.getFontSize(), settings.isBold(), settings.isItalic());
        loadSettings(settings);
    }

    /** @param ttfFileRef The file system or classpath location of the TrueTypeFont file. */
    public UnicodeFont(String ttfFileRef, int size, boolean bold, boolean italic) {
        this.ttfFileRef = ttfFileRef;
        initializeFont(createFont(ttfFileRef), size, bold, italic);
    }

    /** Creates a new UnicodeFont.
     * @param hieroFileRef The file system or classpath location of the Hiero settings file. */
    public UnicodeFont(Font font, String hieroFileRef) {
        this(font, new HieroSettings(hieroFileRef));
    }

    /** Creates a new UnicodeFont. */
    public UnicodeFont(Font font, HieroSettings settings) {
        initializeFont(font, settings.getFontSize(), settings.isBold(), settings.isItalic());
        loadSettings(settings);
    }

    /** Creates a new UnicodeFont. */
    public UnicodeFont(Font font) {
        initializeFont(font, font.getSize(), font.isBold(), font.isItalic());
    }

    /** Creates a new UnicodeFont. */
    public UnicodeFont(Font font, int size, boolean bold, boolean italic) {
        initializeFont(font, size, bold, italic);
    }

    private void initializeFont(Font baseFont, int size, boolean bold, boolean italic) {
        Map attributes = baseFont.getAttributes();
        attributes.put(TextAttribute.SIZE, new Float(size));
        attributes.put(TextAttribute.WEIGHT, bold ? TextAttribute.WEIGHT_BOLD : TextAttribute.WEIGHT_REGULAR);
        attributes.put(TextAttribute.POSTURE,
                italic ? TextAttribute.POSTURE_OBLIQUE : TextAttribute.POSTURE_REGULAR);
        try {
            attributes.put(TextAttribute.class.getDeclaredField("KERNING").get(null),
                    TextAttribute.class.getDeclaredField("KERNING_ON").get(null));
        } catch (Throwable ignored) {
        }
        font = baseFont.deriveFont(attributes);

        metrics = GlyphPage.scratchGraphics.getFontMetrics(font);
        ascent = metrics.getAscent();
        descent = metrics.getDescent();
        leading = metrics.getLeading();

        // Determine width of space glyph (getGlyphPixelBounds gives a width of zero).
        char[] chars = " ".toCharArray();
        GlyphVector vector = font.layoutGlyphVector(GlyphPage.renderContext, chars, 0, chars.length,
                Font.LAYOUT_LEFT_TO_RIGHT);
        spaceWidth = vector.getGlyphLogicalBounds(0).getBounds().width;
    }

    private void loadSettings(HieroSettings settings) {
        paddingTop = settings.getPaddingTop();
        paddingLeft = settings.getPaddingLeft();
        paddingBottom = settings.getPaddingBottom();
        paddingRight = settings.getPaddingRight();
        paddingAdvanceX = settings.getPaddingAdvanceX();
        paddingAdvanceY = settings.getPaddingAdvanceY();
        glyphPageWidth = settings.getGlyphPageWidth();
        glyphPageHeight = settings.getGlyphPageHeight();
        effects.addAll(settings.getEffects());
    }

    /** Queues the glyphs in the specified codepoint range (inclusive) to be loaded. Note that the glyphs are not actually loaded
     * until {@link #loadGlyphs()} is called.
     * 
     * Some characters like combining marks and non-spacing marks can only be rendered with the context of other glyphs. In this
     * case, use {@link #addGlyphs(String)}. */
    public void addGlyphs(int startCodePoint, int endCodePoint) {
        for (int codePoint = startCodePoint; codePoint <= endCodePoint; codePoint++)
            addGlyphs(new String(Character.toChars(codePoint)));
    }

    /** Queues the glyphs in the specified text to be loaded. Note that the glyphs are not actually loaded until
     * {@link #loadGlyphs()} is called. */
    public void addGlyphs(String text) {
        if (text == null)
            throw new IllegalArgumentException("text cannot be null.");

        char[] chars = text.toCharArray();
        GlyphVector vector = font.layoutGlyphVector(GlyphPage.renderContext, chars, 0, chars.length,
                Font.LAYOUT_LEFT_TO_RIGHT);
        for (int i = 0, n = vector.getNumGlyphs(); i < n; i++) {
            int codePoint = text.codePointAt(vector.getGlyphCharIndex(i));
            Rectangle bounds = getGlyphBounds(vector, i, codePoint);
            getGlyph(vector.getGlyphCode(i), codePoint, bounds, vector, i);
        }
    }

    /** Queues the glyphs in the ASCII character set (codepoints 32 through 255) to be loaded. Note that the glyphs are not actually
     * loaded until {@link #loadGlyphs()} is called. */
    public void addAsciiGlyphs() {
        addGlyphs(32, 255);
    }

    /** Queues the glyphs in the NEHE character set (codepoints 32 through 128) to be loaded. Note that the glyphs are not actually
     * loaded until {@link #loadGlyphs()} is called. */
    public void addNeheGlyphs() {
        addGlyphs(32, 32 + 96);
    }

    /** Loads all queued glyphs to the backing textures. Glyphs that are typically displayed together should be added and loaded at
     * the same time so that they are stored on the same backing texture. This reduces the number of backing texture binds required
     * to draw glyphs. */
    public boolean loadGlyphs() {
        return loadGlyphs(-1);
    }

    /** Loads up to the specified number of queued glyphs to the backing textures. This is typically called from the game loop to
     * load glyphs on the fly that were requested for display but have not yet been loaded. */
    public boolean loadGlyphs(int maxGlyphsToLoad) {
        if (queuedGlyphs.isEmpty())
            return false;

        if (effects.isEmpty())
            throw new IllegalStateException(
                    "The UnicodeFont must have at least one effect before any glyphs can be loaded.");

        for (Iterator iter = queuedGlyphs.iterator(); iter.hasNext();) {
            Glyph glyph = (Glyph) iter.next();
            int codePoint = glyph.getCodePoint();

            // Don't load an image for a glyph with nothing to display.
            if (glyph.getWidth() == 0 || codePoint == ' ') {
                iter.remove();
                continue;
            }

            // Only load the first missing glyph.
            if (glyph.isMissing()) {
                if (missingGlyph != null) {
                    if (glyph != missingGlyph)
                        iter.remove();
                    continue;
                }
                missingGlyph = glyph;
            }
        }

        Collections.sort(queuedGlyphs, heightComparator);

        // Add to existing pages.
        for (Iterator iter = glyphPages.iterator(); iter.hasNext();) {
            GlyphPage glyphPage = (GlyphPage) iter.next();
            maxGlyphsToLoad -= glyphPage.loadGlyphs(queuedGlyphs, maxGlyphsToLoad);
            if (maxGlyphsToLoad == 0 || queuedGlyphs.isEmpty())
                return true;
        }

        // Add to new pages.
        while (!queuedGlyphs.isEmpty()) {
            GlyphPage glyphPage = new GlyphPage(this, glyphPageWidth, glyphPageHeight);
            glyphPages.add(glyphPage);
            maxGlyphsToLoad -= glyphPage.loadGlyphs(queuedGlyphs, maxGlyphsToLoad);
            if (maxGlyphsToLoad == 0)
                return true;
        }

        return true;
    }

    /** Clears all loaded and queued glyphs. */
    public void clearGlyphs() {
        for (int i = 0; i < PAGES; i++)
            glyphs[i] = null;

        for (Iterator iter = glyphPages.iterator(); iter.hasNext();) {
            GlyphPage page = (GlyphPage) iter.next();
            page.getTexture().dispose();
        }
        glyphPages.clear();

        if (baseDisplayListID != -1) {
            GL11.glDeleteLists(baseDisplayListID, displayLists.size());
            baseDisplayListID = -1;
        }

        queuedGlyphs.clear();
        missingGlyph = null;
    }

    /** Releases all resources used by this UnicodeFont. This method should be called when this UnicodeFont instance is no longer
     * needed. */
    public void destroy() {
        // The destroy() method is just to provide a consistent API for releasing resources.
        clearGlyphs();
    }

    /** Identical to {@link #drawString(float, float, String, Color, int, int)} but returns a DisplayList which provides access to
     * the width and height of the text drawn. */
    public void drawDisplayList(float x, float y, String text, Color color, int startIndex, int endIndex) {
        if (text == null)
            throw new IllegalArgumentException("text cannot be null.");
        if (text.length() == 0)
            return;
        if (color == null)
            throw new IllegalArgumentException("color cannot be null.");

        x -= paddingLeft;
        y -= paddingTop;

        String displayListKey = text.substring(startIndex, endIndex);

        GL11.glColor4f(color.r, color.g, color.b, color.a);

        GL11.glTranslatef(x, y, 0);

        char[] chars = text.substring(0, endIndex).toCharArray();
        GlyphVector vector = font.layoutGlyphVector(GlyphPage.renderContext, chars, 0, chars.length,
                Font.LAYOUT_LEFT_TO_RIGHT);

        int maxWidth = 0, totalHeight = 0, lines = 0;
        int extraX = 0, extraY = ascent;
        boolean startNewLine = false;
        Texture lastBind = null;
        int offsetX = 0;
        for (int glyphIndex = 0, n = vector.getNumGlyphs(); glyphIndex < n; glyphIndex++) {
            int charIndex = vector.getGlyphCharIndex(glyphIndex);
            if (charIndex < startIndex)
                continue;
            if (charIndex > endIndex)
                break;

            int codePoint = text.codePointAt(charIndex);

            Rectangle bounds = getGlyphBounds(vector, glyphIndex, codePoint);
            bounds.x += offsetX;
            Glyph glyph = getGlyph(vector.getGlyphCode(glyphIndex), codePoint, bounds, vector, glyphIndex);

            if (startNewLine && codePoint != '\n') {
                extraX = -bounds.x;
                startNewLine = false;
            }

            if (glyph.getTexture() == null && missingGlyph != null && glyph.isMissing())
                glyph = missingGlyph;
            if (glyph.getTexture() != null) {
                // Draw glyph, only binding a new glyph page texture when necessary.
                Texture texture = glyph.getTexture();
                if (lastBind != null && lastBind != texture) {
                    GL11.glEnd();
                    lastBind = null;
                }
                if (lastBind == null) {
                    texture.bind();
                    GL11.glBegin(GL11.GL_QUADS);
                    lastBind = texture;
                }
                int glyphX = bounds.x + extraX;
                int glyphY = bounds.y + extraY;
                GL11.glTexCoord2f(glyph.getU(), glyph.getV());
                GL11.glVertex3f(glyphX, glyphY, 0);
                GL11.glTexCoord2f(glyph.getU(), glyph.getV2());
                GL11.glVertex3f(glyphX, glyphY + glyph.getHeight(), 0);
                GL11.glTexCoord2f(glyph.getU2(), glyph.getV2());
                GL11.glVertex3f(glyphX + glyph.getWidth(), glyphY + glyph.getHeight(), 0);
                GL11.glTexCoord2f(glyph.getU2(), glyph.getV());
                GL11.glVertex3f(glyphX + glyph.getWidth(), glyphY, 0);
            }

            if (glyphIndex > 0)
                extraX += paddingRight + paddingLeft + paddingAdvanceX;
            maxWidth = Math.max(maxWidth, bounds.x + extraX + bounds.width);
            totalHeight = Math.max(totalHeight, ascent + bounds.y + bounds.height);

            if (codePoint == '\n') {
                startNewLine = true; // Mac gives -1 for bounds.x of '\n', so use the bounds.x of the next glyph.
                extraY += getLineHeight();
                lines++;
                totalHeight = 0;
            } else if (nativeRendering)
                offsetX += bounds.width;
        }
        if (lastBind != null)
            GL11.glEnd();

        GL11.glTranslatef(-x, -y, 0);
    }

    public void drawString(float x, float y, String text, Color color, int startIndex, int endIndex) {
        drawDisplayList(x, y, text, color, startIndex, endIndex);
    }

    public void drawString(float x, float y, String text) {
        drawString(x, y, text, Color.WHITE);
    }

    public void drawString(float x, float y, String text, Color col) {
        drawString(x, y, text, col, 0, text.length());
    }

    /** Returns the glyph for the specified codePoint. If the glyph does not exist yet, it is created and queued to be loaded. */
    private Glyph getGlyph(int glyphCode, int codePoint, Rectangle bounds, GlyphVector vector, int index) {
        if (glyphCode < 0 || glyphCode >= MAX_GLYPH_CODE) {
            // GlyphVector#getGlyphCode sometimes returns negative numbers on OS X!?
            return new Glyph(codePoint, bounds, vector, index, this) {
                public boolean isMissing() {
                    return true;
                }
            };
        }
        int pageIndex = glyphCode / PAGE_SIZE;
        int glyphIndex = glyphCode & (PAGE_SIZE - 1);
        Glyph glyph = null;
        Glyph[] page = glyphs[pageIndex];
        if (page != null) {
            glyph = page[glyphIndex];
            if (glyph != null)
                return glyph;
        } else
            page = glyphs[pageIndex] = new Glyph[PAGE_SIZE];
        // Add glyph so size information is available and queue it so its image can be loaded later.
        glyph = page[glyphIndex] = new Glyph(codePoint, bounds, vector, index, this);
        queuedGlyphs.add(glyph);
        return glyph;
    }

    private Rectangle getGlyphBounds(GlyphVector vector, int index, int codePoint) {
        Rectangle bounds;
        bounds = vector.getGlyphPixelBounds(index, GlyphPage.renderContext, 0, 0);
        if (nativeRendering) {
            if (bounds.width == 0 || bounds.height == 0)
                bounds = new Rectangle();
            else
                bounds = metrics.getStringBounds("" + (char) codePoint, GlyphPage.scratchGraphics).getBounds();
        }
        if (codePoint == ' ')
            bounds.width = spaceWidth;
        return bounds;
    }

    public int getSpaceWidth() {
        return spaceWidth;
    }

    public int getWidth(String text) {
        if (text == null)
            throw new IllegalArgumentException("text cannot be null.");
        if (text.length() == 0)
            return 0;

        char[] chars = text.toCharArray();
        GlyphVector vector = font.layoutGlyphVector(GlyphPage.renderContext, chars, 0, chars.length,
                Font.LAYOUT_LEFT_TO_RIGHT);

        int width = 0;
        int extraX = 0;
        boolean startNewLine = false;
        for (int glyphIndex = 0, n = vector.getNumGlyphs(); glyphIndex < n; glyphIndex++) {
            int charIndex = vector.getGlyphCharIndex(glyphIndex);
            int codePoint = text.codePointAt(charIndex);
            Rectangle bounds = getGlyphBounds(vector, glyphIndex, codePoint);

            if (startNewLine && codePoint != '\n')
                extraX = -bounds.x;

            if (glyphIndex > 0)
                extraX += paddingLeft + paddingRight + paddingAdvanceX;
            width = Math.max(width, bounds.x + extraX + bounds.width);

            if (codePoint == '\n')
                startNewLine = true;
        }

        return width;
    }

    public int getHeight(String text) {
        if (text == null)
            throw new IllegalArgumentException("text cannot be null.");
        if (text.length() == 0)
            return 0;

        char[] chars = text.toCharArray();
        GlyphVector vector = font.layoutGlyphVector(GlyphPage.renderContext, chars, 0, chars.length,
                Font.LAYOUT_LEFT_TO_RIGHT);

        int lines = 0, height = 0;
        for (int i = 0, n = vector.getNumGlyphs(); i < n; i++) {
            int charIndex = vector.getGlyphCharIndex(i);
            int codePoint = text.codePointAt(charIndex);
            if (codePoint == ' ')
                continue;
            Rectangle bounds = getGlyphBounds(vector, i, codePoint);

            height = Math.max(height, ascent + bounds.y + bounds.height);

            if (codePoint == '\n') {
                lines++;
                height = 0;
            }
        }
        return lines * getLineHeight() + height;
    }

    /** Returns the distance from the y drawing location to the top most pixel of the specified text. */
    public int getYOffset(String text) {
        if (text == null)
            throw new IllegalArgumentException("text cannot be null.");

        int index = text.indexOf('\n');
        if (index != -1)
            text = text.substring(0, index);
        char[] chars = text.toCharArray();
        GlyphVector vector = font.layoutGlyphVector(GlyphPage.renderContext, chars, 0, chars.length,
                Font.LAYOUT_LEFT_TO_RIGHT);
        int yOffset = ascent + vector.getPixelBounds(null, 0, 0).y;

        return yOffset;
    }

    /** Returns the TrueTypeFont for this UnicodeFont. */
    public Font getFont() {
        return font;
    }

    /** Returns the padding above a glyph on the GlyphPage to allow for effects to be drawn. */
    public int getPaddingTop() {
        return paddingTop;
    }

    /** Sets the padding above a glyph on the GlyphPage to allow for effects to be drawn. */
    public void setPaddingTop(int paddingTop) {
        this.paddingTop = paddingTop;
    }

    /** Returns the padding to the left of a glyph on the GlyphPage to allow for effects to be drawn. */
    public int getPaddingLeft() {
        return paddingLeft;
    }

    /** Sets the padding to the left of a glyph on the GlyphPage to allow for effects to be drawn. */
    public void setPaddingLeft(int paddingLeft) {
        this.paddingLeft = paddingLeft;
    }

    /** Returns the padding below a glyph on the GlyphPage to allow for effects to be drawn. */
    public int getPaddingBottom() {
        return paddingBottom;
    }

    /** Sets the padding below a glyph on the GlyphPage to allow for effects to be drawn. */
    public void setPaddingBottom(int paddingBottom) {
        this.paddingBottom = paddingBottom;
    }

    /** Returns the padding to the right of a glyph on the GlyphPage to allow for effects to be drawn. */
    public int getPaddingRight() {
        return paddingRight;
    }

    /** Sets the padding to the right of a glyph on the GlyphPage to allow for effects to be drawn. */
    public void setPaddingRight(int paddingRight) {
        this.paddingRight = paddingRight;
    }

    /** Gets the additional amount to offset glyphs on the x axis. */
    public int getPaddingAdvanceX() {
        return paddingAdvanceX;
    }

    /** Sets the additional amount to offset glyphs on the x axis. This is typically set to a negative number when left or right
     * padding is used so that glyphs are not spaced too far apart. */
    public void setPaddingAdvanceX(int paddingAdvanceX) {
        this.paddingAdvanceX = paddingAdvanceX;
    }

    /** Gets the additional amount to offset a line of text on the y axis. */
    public int getPaddingAdvanceY() {
        return paddingAdvanceY;
    }

    /** Sets the additional amount to offset a line of text on the y axis. This is typically set to a negative number when top or
     * bottom padding is used so that lines of text are not spaced too far apart. */
    public void setPaddingAdvanceY(int paddingAdvanceY) {
        this.paddingAdvanceY = paddingAdvanceY;
    }

    /** Returns the distance from one line of text to the next. This is the sum of the descent, ascent, leading, padding top,
     * padding bottom, and padding advance y. To change the line height, use {@link #setPaddingAdvanceY(int)}. */
    public int getLineHeight() {
        return descent + ascent + leading + paddingTop + paddingBottom + paddingAdvanceY;
    }

    /** Gets the distance from the baseline to the y drawing location. */
    public int getAscent() {
        return ascent;
    }

    /** Gets the distance from the baseline to the bottom of most alphanumeric characters with descenders. */
    public int getDescent() {
        return descent;
    }

    /** Gets the extra distance between the descent of one line of text to the ascent of the next. */
    public int getLeading() {
        return leading;
    }

    /** Returns the width of the backing textures. */
    public int getGlyphPageWidth() {
        return glyphPageWidth;
    }

    /** Sets the width of the backing textures. Default is 512. */
    public void setGlyphPageWidth(int glyphPageWidth) {
        this.glyphPageWidth = glyphPageWidth;
    }

    /** Returns the height of the backing textures. */
    public int getGlyphPageHeight() {
        return glyphPageHeight;
    }

    /** Sets the height of the backing textures. Default is 512. */
    public void setGlyphPageHeight(int glyphPageHeight) {
        this.glyphPageHeight = glyphPageHeight;
    }

    /** Returns the GlyphPages for this UnicodeFont. */
    public List getGlyphPages() {
        return glyphPages;
    }

    /** Returns a list of {@link Effect}s that will be applied to the glyphs. */
    public List getEffects() {
        return effects;
    }

    public void setNativeRendering(boolean nativeRendering) {
        this.nativeRendering = nativeRendering;
    }

    public boolean getNativeRendering() {
        return nativeRendering;
    }

    /** Returns the path to the TTF file for this UnicodeFont, or null. If this UnicodeFont was created without specifying the TTF
     * file, it will try to determine the path using Sun classes. If this fails, null is returned. */
    public String getFontFile() {
        if (ttfFileRef == null) {
            // Worst case if this UnicodeFont was loaded without a ttfFileRef, try to get the font file from Sun's classes.
            try {
                Object font2D = Class.forName("sun.font.FontManager")
                        .getDeclaredMethod("getFont2D", new Class[] { Font.class })
                        .invoke(null, new Object[] { font });
                Field platNameField = Class.forName("sun.font.PhysicalFont").getDeclaredField("platName");
                platNameField.setAccessible(true);
                ttfFileRef = (String) platNameField.get(font2D);
            } catch (Throwable ignored) {
            }
            if (ttfFileRef == null)
                ttfFileRef = "";
        }
        if (ttfFileRef.length() == 0)
            return null;
        return ttfFileRef;
    }

    /** @param ttfFileRef The file system or classpath location of the TrueTypeFont file. */
    static private Font createFont(String ttfFileRef) {
        try {
            return Font.createFont(Font.TRUETYPE_FONT, Gdx.files.absolute(ttfFileRef).read());
        } catch (FontFormatException ex) {
            throw new GdxRuntimeException("Invalid font: " + ttfFileRef, ex);
        } catch (IOException ex) {
            throw new GdxRuntimeException("Error reading font: " + ttfFileRef, ex);
        }
    }

    /** Sorts glyphs by height, tallest first. */
    static private final Comparator heightComparator = new Comparator() {
        public int compare(Object o1, Object o2) {
            return ((Glyph) o1).getHeight() - ((Glyph) o2).getHeight();
        }
    };

    public class DisplayList {
        boolean invalid;
        int id;
        Short yOffset;

        public short width, height;
        public Object userData;

        DisplayList() {
        }
    }
}