Text.md

Displaying text

h2d.Text can be used to draw text using precomputed bitmap fonts.

Use text in Heaps

var font : h2d.Font = hxd.res.DefaultFont.get();
var tf = new h2d.Text(font);
tf.text = "Hello World\nHeaps is great!";
tf.textAlign = Center;

// add to any parent, in this case we append to root
s2d.addChild(tf);

For each font family you need a different font file, but you can tint them with code, using textColor.

HtmlText usage

Along with regular Text, there is also an h2d.HtmlText class that allows to use simple html markdown for rich text.

Supported HTML tags and their attributes

• <font>: Alters font parameters for tag contents.
  • face="myFontFace": Sets different font face. See remarks about font loading below.
  • color="#880088": Sets text color. Should be in hexadecimal format.
  • opacity="0.5": Set text opacity. Value should be between 0 and 1.
• <p>: Inserts line-breaks before and after paragraph and allows to control text alignment.
  • align="center": Set text align for tag contents. Valid values are: left, right, center, multiline-center, multiline-right.
• <b>: Alias to <font face="bold">
• <i>: Alias to <font face="italic">
• <br/>: Creates a line-break.
• <img>: Inserts an image.
  • src="myimage.png": Name of the image to load. See remarks about image loading beloew.

Font and image loading

HtmlText does not use Resource Manager to load fonts or images. Loading is performed by setting the callback methods:

// Global callbacks that work for all HtmlText instances.
HtmlText.defaultLoadImage = function( url : String ) : h2d.Tile { return null; }
HtmlText.defaultLoadFont = function( name : String ) : h2d.Font { return null; }
HtmlText.defaultFormatText = function ( text : String ) : String { return text; }
// Per-instance callbacks that allow to customize each instance
// with individual scope.
htmlText.loadImage = function( url : String ) : h2d.Tile { return null; }
htmlText.loadFont = function( name : String ) : h2d.Font { return null; }
htmlText.formatText = function ( text : String ) : String { return text; }

It's up to user how to implement resource loading. Please note, that there is no tile/font caching on HtmlText side. Lastly, formatText allows to modify and/or validate text contents when it's changed.

Font creation

If you want to use custom fonts, other than the Default one, you need to create a .fnt file and put it into your res directory. Heaps automatically converts all supported .fnt files to its own .bfnt format to speed up font loading. Alternatively it is possible to use Signed Distance Field to generate scalable fonts. See Hiero section for details.

Supported formats

• All 3 BMFont formats: XML, Text and Binary. Note: Multiple images per font are not supported.
• FontBuilder: Divo (discouraged to use, as it is less advanced than BMFont)

Convert font to bitmap font using BMfont tool

Download BMFont here: http://www.angelcode.com/products/bmfont/

In the BMFont-tool, use these settings:

• Options → Font settings
  • Add font file (if you want custom font)
  • Font (select your added font or any other)
  • Size (select size in px)
  • Render from TrueType outline (if you want smooth fonts)
• Select chars that you need
• Options → Export settings
  • Bit depth: 32
  • Presets: white text with alpha (black or outline w/ alpha will do as well, but black isn't tintable)
  • Font descriptor: Any
  • Texture: Png
• Options → Save bitmap font as.. (select name wisely, it's problematic to change)
  • Put in your Heaps project under ./res/fonts/myFontName.fnt
• Note: Multi-texture fnt files are not supported, ensure that there is only one font texture per fnt file.

Convert font to bitmap font using Littera

Due to browsers no longer supporting Flash, Littera can be ran only by older browser versions here or trough standalone flash player by running swf file directly. Use following settings:

• Settings in the left column
  • Update a font from your computer with Select Font button
  • Choose size
  • Set the values:
    • Select what glyphs do you want to export.
    • Fill: to get a non-gradient color, remove one of the markers dragging it down from the rectangle.
    • Enable/disable stroke
    • Background color
    • ...
• Export settings in the header
  • Format: Either XML (.fnt) or Text (.fnt)
  • Default values are fine for Heaps
  • Press Export start the downloading process.
  • Unzip the file and put it's content in your Heaps project under ./res/fonts/
• If you renamed the files, don't forget to update reference to font texture in pages section of .fnt file.

Using libgdx Hiero

Hiero can be utilized to generate fonts with extra filters as well as SDF fonts.

• Refer to this instruction to generate SDF fonts: Distance Field Fonts
• Refer to this page for general instruction on Hiero usage: Hiero

Using fontgen tool

Fontgen is a command-line utility to generate fonts including SDF and MSDF formats. It was written specifically for Heaps and ShiroGames. Utility is strictly command-line with config files, please refer to readme file.

Be creative with bitmapfonts

If you add some 'padding' (not 'spacing') in the export options, you can decorate the outputted .png-file in your image-editing software with some colors/effects/gradients. You can bake this inside your bitmap.

Want gradients? Its not simple to add them with image-editing software if cells are uneven. Use the "equalize the cell heights" in the export options. Then all chars have the same height and is a bit easier to add the gradients. Of course, the texture will be a bit bigger in that case, since there is a bit more whitespace.

Using the Font

Once the font is ready, you can use it for your Text:

• initialize the Resource manager
• have a .fnt and the corresponding .png file in your res folder
  • For Divo, .png file should have exactly the same name as .fnt
  • For BMFont, Heaps will try to find texture referenced in .fnt first, and then, if unsuccessful, fallback to same behavior as Divo.
• load it using hxd.Res.fonts.myFont.toFont()
• create an h2d.Text using this font

SDF / MSDF

For SDF fonts you need to load fonts slightly differently.

• Instead of toFont() use toSdfFont(size, channel, alphaCutoff, smoothing)
  • size will represent desired font size.
  • channel tells which texture channel SDF shader should take the information from.
  • alphaCutoff will set the border of a glyph, with 0.5 being default value.
  • smoothing controls the amount of antialiasing applied to glyph borders.
• Set Text.smoothing to true, otherwise SDF won't render properly.