This is a morphic application for Squeak 3.7 and Squeak 3.8. It can be used to explore the contents of OpenType™ font files.
To open the Font File Viewer, evaluate this statement:
You obtain this window:
At the top left corner of this window, you see a button with title file:. To open a font file, you left-click this button. You obtain a menu of font file names (with extensions *.ttf and *.ttc) and select a file. (When you press that button the first time, you will be asked for the location of the fonts on your computer. The font directory is stored in class variable FontDirectory of class MorphicTTFReader. To change that setting, right-click on the file: button.)
As soon as a *.ttf file is read, a resumee of the most important font properties is displayed. Also displayed is the font name (in the drop down list on the left) and a list of selectable information items.
For a *.ttc file that contains more than one font, no font name is displayed; you have to select one.
Most OpenType fonts contain two different glyph mappings: One for the Apple and one for Unicode BMP. To explore a font, you have to select one glyph mapping. You do this with the drop down list on the right.
As soon as you have choosen a glyph mapping, additional information items become selectable.
You may wish to see a summary of the tables in the font file. The summary gives the table names, the table sizes and a short explanation.
When you explore a font, you want to see its glyphs. The explore the glyphs, you select
When you select one of these options, the glyph selection morph is displayed. It contains one line of 16 selectable boxes and two grid boxes with 256 small boxes each. The line is used to select the Unicode plane (most fonts support only plane 0, the BMP). The upper box is used to the select the heigh-value byte of an Unicode codepoint and the lower box is used to select the low-value byte of an codepoint. With three selections, you can select every single codepoint. Note that grayed boxes are not selectable.
When it is selected, the glyph table displays one page of glyphs as soon as you have selected a plane and a page. Glyph that are displayed in blue have serveral display forms.
When you select a low-value byte, the selected glyph is shown with red box. On the following image, the codepoint x76F4 is selected. It contains a CJK ideograph for which the font Arial Unicode MS provides serveral display forms.
To see the display forms, you switch to the glyph view. It shows one enlarged glyph in its center and a list of selectable variants on the right. The selected variant is drawn with a red border. On the following image, the default form of the glyph is selected, for Arial Unicode MS this is the japanese variant. The other variants are for Korean and for traditional Chinese.
Arial Unicode MS is a hinted font. You can press the hint button to see the hints. Hints are instructions for a virtual machine, the font renderer.
The OpenType font file specification, a joint effort
of Apple and Microsoft, can be found here:
A different presentation of the OpenType specification,
this time from Apple:
Two shareware fonts, Code2000 and Code2001, both
the admireable work of James Kass:
The font Code2000 offers the most complete support for the Unicode BMP plane, the font Code2001 contains glyphs for other planes.