Class FontTexture

core/src/processing/opengl/FontTexture.java:51–379

All the infrastructure needed for optimized font rendering in OpenGL. Basically, this special class is needed because fonts in Processing are handled by a separate PImage for each glyph. For performance reasons, all these glyphs should be stored in a single OpenGL texture (otherwise, rendering a str

 * @author Andres Colubri
 */
class FontTexture implements PConstants {
  protected PGL pgl;
  protected boolean is3D;

  protected int minSize;
  protected int maxSize;
  protected int offsetX;
  protected int offsetY;
  protected int lineHeight;
  protected Texture[] textures = null;
  protected PImage[] images = null;
  protected int lastTex;
  protected TextureInfo[] glyphTexinfos;
  protected HashMap<PFont.Glyph, TextureInfo> texinfoMap;

  public FontTexture(PGraphicsOpenGL pg, PFont font, boolean is3D) {
    pgl = pg.pgl;
    this.is3D = is3D;

    initTexture(pg, font);
  }


  protected void allocate() {
    // Nothing to do here: the font textures will allocate
    // themselves.
  }


  protected void dispose() {
    for (int i = 0; i < textures.length; i++) {
      textures[i].dispose();
    }
  }


  protected void initTexture(PGraphicsOpenGL pg, PFont font) {
    lastTex = -1;

    int spow = PGL.nextPowerOfTwo(font.getSize());
    minSize = PApplet.min(PGraphicsOpenGL.maxTextureSize,
                          PApplet.max(PGL.MIN_FONT_TEX_SIZE, spow));
    maxSize = PApplet.min(PGraphicsOpenGL.maxTextureSize,
                          PApplet.max(PGL.MAX_FONT_TEX_SIZE, 2 * spow));

    if (maxSize < spow) {
      PGraphics.showWarning("The font size is too large to be properly " +
                            "displayed with OpenGL");
    }

    addTexture(pg);

    offsetX = 0;
    offsetY = 0;
    lineHeight = 0;

    texinfoMap = new HashMap<PFont.Glyph, TextureInfo>();
    glyphTexinfos = new TextureInfo[font.getGlyphCount()];