Module: Skrift::Color::CPAL

Defined in:
lib/skrift/color/cpal.rb

Overview

Parses a CPAL table’s first palette into an array of [r, g, b, a] (0..255). CPAL stores colours as BGRA; we normalise to RGBA. Returns nil if the font has no CPAL table.

Class Method Summary collapse

Class Method Details

.parse(font) ⇒ Object 



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# File 'lib/skrift/color/cpal.rb', line 11

def parse(font)
  off = font.tables["CPAL"]
  return nil unless off

  num_entries = font.getu16(off + 2)
  records_off = off + font.getu32(off + 8)
  first_index = font.getu16(off + 12) # colorRecordIndices[0]

  num_entries.times.map do |i|
    rec = records_off + (first_index + i) * 4
    b = font.getu8(rec)
    g = font.getu8(rec + 1)
    r = font.getu8(rec + 2)
    a = font.getu8(rec + 3)
    [r, g, b, a]
  end
end