Color Fonts Overview

Fontisan supports multiple color font formats for modern typography.

Supported Formats

Format	Tables	Description
COLR/CPAL	COLR, CPAL	Layered vector glyphs
sbix	sbix	Bitmap images (Apple)
CBDT/CBLC	CBDT, CBLC	Bitmap images (Google)
SVG	SVG	SVG embedded in font

COLR/CPAL

COLR/CPAL uses layered vector glyphs with palette-based coloring.

Advantages

• Scalable — Vectors scale to any size
• Small file size — Efficient compression
• Variable support — Works with variable fonts
• Wide support — Modern browsers and apps

Structure

COLR table:
- Glyph layers (which glyphs make up each color glyph)
- Layer order (back to front)

CPAL table:
- Color palettes (sets of colors)
- Color values (RGBA for each palette entry)

sbix

sbix stores bitmap images at multiple resolutions (Apple format).

Advantages

• Photo-realistic — Any image quality
• Multiple sizes — Different bitmaps for different sizes

Structure

sbix table:
- Strikes (image sets at different sizes)
- Per-glyph images (PNG, JPG, etc.)

CBDT/CBLC

CBDT/CBLC stores bitmap images (Google/Android format).

Advantages

• Android support — Primary Android bitmap format
• Multiple sizes — Different bitmaps per ppem

Structure

CBLC table:
- Location data (where each bitmap is)
- Size information

CBDT table:
- Bitmap data (actual images)

SVG Color Fonts

SVG fonts embed complete SVG documents.

Advantages

• Full SVG features — Gradients, effects, etc.
• Standalone — No external resources

Limitations

• Large file size — XML overhead
• Limited support — Not all browsers

Guides

• COLR/CPAL — Vector layered color fonts
• Bitmaps — sbix and CBDT/CBLC
• SVG Color — SVG-based color fonts

Quick Start

Check for Color Tables

font = Fontisan::FontLoader.load('font.ttf')

if font.tables['COLR']
  puts "COLR/CPAL color font"
end

if font.tables['sbix']
  puts "sbix bitmap font"
end

if font.tables['CBDT']
  puts "CBDT/CBLC bitmap font"
end

if font.tables['SVG']
  puts "SVG color font"
end

Get Color Information

colr = font.tables['COLR']
cpal = font.tables['CPAL']

if colr && cpal
  # Get base glyphs (color emoji)
  colr.base_glyphs.each do |glyph_id|
    puts "Base glyph: #{glyph_id}"
    puts "  Layers: #{colr.layers_for(glyph_id).length}"

    colr.layers_for(glyph_id).each do |layer|
      color = cpal.color(layer[:palette_index])
      puts "    Layer #{layer[:glyph_id]}: #{color}"
    end
  end
end