Difference between revisions of "Font rendering"

Revision as of 04:46, 16 August 2014

µGFX comes with a built-in support of mcufont. The author of the mcufont project provides a re-licensed version of his works to the µGFX projects.

Feature

The µGFX font rendering engine provides the following features:

• unicode
• anti-aliasing
• kerning
• .ttf and .bdf support

For information about cyrillic font support, see Cyrillic.

Fonts

Every font that's available in a .ttf or .bdf format can be displayed through µGFX. However, we added a bunch of fonts in different sizes and versions which should cover most use cases:

• UI1
• UI2
• DejaVu Sans 10 (normal and anti-aliased)
• DejaVu Sans 12 (normal and anti-aliased)
• DejaVu Sans 16 (normal and anti-aliased)
• DjeaVu Sans 24 (normal and anti-aliased)
• DejaVu Sans 32 (normal and anti-aliased)
• DejaVu Sans Bold
• Fixed 5x8
• Fixed 7x14
• Fixed 10x20

Note that each of these fonts has to be enabled in your configuration file.

The UI fonts are created by the µGFX developers to provide a default font. The UI fonts stand under the GFX license and should therefore be used in preference to other fonts if suitable. The other fonts are under their own respective licenses.

Usage

Before you can use a font, you first have to open it by calling gdispOpenFont().

font_t font = gdispOpenFont("DejaVuSans32_aa");

You should call gdispCloseFont() to release any allocated resources if you don't need a font any longer:

gdispCloseFont(font);

After opening a font, the font variable can now be passed to any API call that takes a font parameter. You may read through the API reference to get a list of all font rendering routines.

Adding fonts

The following step-by-step guide will lead you through the process of adding a custom *.ttf font. This guide works for every font, not only ASCII but also cyrillic and any other unicode compatible ones.

1. Acquire a font

First of all, you'll need a font in the *.ttf source. You can find plenty of these using google. Please notice their licenses.

2. Convert the font

The next step is to convert the font into a format that can be understood by the µGFX decoder. This can be done very easily using our online converter. The converter does allow you to set the font size, enable or disable anti-aliasing and also filter for certain glyphs. The latter is very essential to keep the font size low. This table might help to choose the correct glyph range. A click on the button «Get .c file» will offer you a C file to download after certain moments. Please click that button just once. It can take up to a minute to convert a larger font.

3. Implement the font

The generated C file must be added to your build chain (Add it as any other C source).

4. Open the font

You can now open and use this font as any other one. If you're curious about the parameter of gdispOpenFont(), you can either use the full_name or the short_name field that can be found in the struct at the very bottom of the C file (first and second entry). Please note that you need to configure your text editor to operate in UTF-8 mode, when you want to display those fonts successfully.

For a more detailed guide on how to add your own font, see Cyrillic.