Class: String

Inherits:

Object

• Object
• String

Defined in:

lib/glimr/renderer/texture.rb

Instance Method Summary

• #unpremultiply! ⇒ Object

Instance Method Details

#unpremultiply! ⇒ Object

# File 'lib/glimr/renderer/texture.rb', line 246

def unpremultiply!
  if MAC_OS_X
    i = 0
    while i < size
      a = self[i+3]
      a2 = a / 2
      if a > 0
        r = self[i]
        self[i] = (self[i+2] * 255 + a2) / a
        self[i+1] = (self[i+1] * 255 + a2) / a
        self[i+2] = (r * 255 + a2) / a
      end
      i += 4
    end
  else
    i = 0
    while i < size
      r = self[i+1]
      g = self[i+2]
      b = self[i+3]
      a = self[i]
      if a > 0
        self[i] = (r * 255 + a / 2) / a
        self[i+1] = (g * 255 + a / 2) / a
        self[i+2] = (b * 255 + a / 2) / a
      end
      self[i+3] = a
      i += 4
    end
  end
  self
end