SheenFigure
SheenFigure aims to implement the advanced typographic tables of OpenType specification available at https://www.microsoft.com/en-us/Typography/OpenTypeSpecification.aspx along with script specific shaping engines available at https://www.microsoft.com/en-us/Typography/SpecificationsOverview.aspx. Currently, it only supports Arabic script and a subset of GDEF, GSUB and GPOS tables. The support is intended to increase in each newer versions of the library.
Here are some of the advantages of SheenFigure.
- Object based
- Designed to be thread safe
- Lightweight API for interaction
- Clear differentiation of public and private API
- Thoroughly tested
Dependency
SheenFigure only depends on SheenBidi in order to support UTF-8, UTF-16 and UTF-32 string encodings. Other than that, it only uses standard C library headers stddef.h, stdint.h, stdlib.h and string.h.
Configuration
The configuration options are available in Headers/SFConfig.h.
SF_CONFIG_UNITYbuilds the library as a single module and lets the compiler make decisions to inline functions.
Compiling
SheenFigure can be compiled with any C compiler. The best way for compiling is to add all the files in an IDE and hit build. The only thing to consider however is that if SF_CONFIG_UNITY is enabled then only Source/SheenFigure.c should be compiled.
Public API
Here is a glimpse of public API in the form of UML class diagram.
Conformance
Following are the tables implemented by SheenFigure.
OpenType Layout Common Table Formats
| Table | Supported |
|---|---|
| Script List | |
| Feature List | |
| Lookup List | |
| Coverage | |
| Class Definition | |
| Device | |
| Variation Index |
GDEF (Glyph Definition Table)
| Subtable | Supported |
|---|---|
| Glyph Class Definition | |
| Attachment List | |
| Ligature Caret List | |
| Mark Attachment Class Definition | |
| Mark Glyph Sets | |
| Item Variation Store |
GPOS (Glyph Positioning Table)
| Subtable | Format 1 | Format 2 | Format 3 |
|---|---|---|---|
| Single Adjustment | |||
| Pair Adjustment | |||
| Cursive Attachment | |||
| Mark To Base Attachment | |||
| Mark To Ligature Attachment | |||
| Mark To Mark Attachment | |||
| Context Positioning | |||
| Chained Context Positioning | |||
| Extension Positioning |
GSUB (Glyph Substitution Table)
| Subtable | Format 1 | Format 2 | Format 3 |
|---|---|---|---|
| Single | |||
| Multiple | |||
| Alternate | |||
| Ligature | |||
| Context | |||
| Chaining Context | |||
| Extension | |||
| Reverse Chaining Context |