zzz/README.md

kb

Single-header permissively-licensed libraries for C/C++.

Libraries

• kb_text_shape.h: Unicode text segmentation and OpenType shaping

kb_text_shape.h

kb_text_shape.h provides:

• ICU-like text segmentation (i.e. breaking Unicode text by direction, line, script, word and grapheme).
• Harfbuzz-like text shaping for OpenType fonts, which means it is capable of handling complex script layout and ligatures, among other things.
• Font coverage checking: know if a font can display a given string.

It does not handle rasterization. It does not handle paragraph layout. It does not handle selection and loading of system fonts. It will only help you know which glyphs to display where on a single, infinitely-long line, using the fonts you have provided!

(See https://www.newroadoldway.com/text1.html for an explanation of the different steps of text processing.)

For an in-depth usage example, check out refpad.

// Yours to provide:
void DrawGlyph(kbts_u16 GlyphId, kbts_s32 GlyphOffsetX, kbts_s32 GlyphOffsetY, kbts_s32 GlyphAdvanceX, kbts_s32 GlyphAdvanceY,
               kbts_direction ParagraphDirection, kbts_direction RunDirection, kbts_script Script, kbts_font *Font);
void NextLine(void);
void *CreateRenderFont(const char *FontPath);

void HandleText(kbts_shape_context *Context, const char *Text, kbts_language Language)
{
  kbts_ShapeBegin(Context, KBTS_DIRECTION_DONT_KNOW, Language);
  kbts_ShapeUtf8(Context, Text, (int)strlen(Text), KBTS_USER_ID_GENERATION_MODE_CODEPOINT_INDEX);
  kbts_ShapeEnd(Context);

  kbts_run Run;
  while(kbts_ShapeRun(Context, &Run))
  {
    if(Run.Flags & KBTS_BREAK_FLAG_LINE_HARD)
    {
      NextLine();
    }

    kbts_glyph *Glyph;
    while(kbts_GlyphIteratorNext(&Run.Glyphs, &Glyph))
    {
      DrawGlyph(Glyph->Id, Glyph->OffsetX, Glyph->OffsetY, Glyph->AdvanceX, Glyph->AdvanceY,
                Run.ParagraphDirection, Run.Direction, Run.Script, Run.Font);
    }
  }
}

void Example(void)
{
  kbts_shape_context *Context = kbts_CreateShapeContext(0, 0);
  kbts_font *FontA = kbts_ShapePushFontFromFile(Context, "NotoSansMyanmar-Regular.ttf", 0);
  kbts_font *FontB = kbts_ShapePushFontFromFile(Context, "NotoSansArabic-Regular.ttf", 0);

  FontA->UserData = CreateRenderFont("NotoSansMyanmar-Regular.ttf");
  FontB->UserData = CreateRenderFont("NotoSansArabic-Regular.ttf");

  HandleText(Context, (const char *)u8"یکအမည်မရှိیک", KBTS_LANGUAGE_ARABIC);
}