Glyph Blaster

WIP C++11 Port

Justifications.

• Standard smart pointers that will make the memory management of resources less error prone.
• can drop dependency on uthash and utlist, and use standard collections
• lamdas provide a better mechanism for rendering hooks then c function ptrs.
• all of my personal projects are in C++, C linkage is not important to me.
• shared lib version of library is also not important to me.
• Interop with other languages is not important to me.

Design questions

Should Context be a singleton? YES. simplifies things, i can sort this out later if necessary.

Architecture Diagram

The Context holds a weak collection of all gyphs ever created. Each Text object holds a collection of glyphs it is activly using.

Features

• Pluggable render function, to integrate into existing engines.
• Uses HarfBuzz for glyph shaping for ligatures & arabic languages.
• FreeType is used for rasterization, after shaping.
• Manages glyph bitmaps in a tightly packed set of OpenGL textures.
• utf8 support
• rtl language support (arabic & hebrew)

Dependencies

• FreeType2
• HarfBuzz-0.9 (optional)

Implementation Notes

• When cache is full, glyphs will use a fallback texture, which is 1/2 alpha.
• When glyph is not present in the font, the replacement character is used. �
• Bidi text is not supported, it makes word-wrapping a pain.
• I still don't know how slow a full repack is. Benchmark it.
• I'm not sure if the interface is very good.
  • Text's are not mutable, they must be destroyed and re-created.
  • No metrics available.
  • The metrics should be good enough to perform custom word-wrapping, bidi, underline & html styles at a higher level.

TODO:

Dependency Build Tasks

• Bundle harf-buzz, to make building easier

Implementation Tasks

• Split MakeGlyphQuadRuns into two parts.
  • Build metrics/do word wrapping.
  • Build quads from metrics.
• Group quads that share the same texture into a single mesh.
• Add metrics function to text.
• Add ability to set pen position.
• Test support of LCD subpixel decimated RGB using shader and GL_COLOR_MASK
• Enable sRGB aware blending, during rendering. (if available) provide a sample renderer
• Justify-Vertical: top, center, bottom
• Justify: Scale to fit
• currently two fonts with different pt sizes will have two copies of the same FreeType font. resources should be shared.
• add glyph bitmap-padding option, necessary for scaled or non-screen aligned text.
• Currently mipmapping on glyph texture is disabled.
• bidi
• Better SDL test prog.
• Add pluggable texture creation & subload functions, for Direct3D renderers.