Class: Quartz::Bitmap

Inherits:
Object
  • Object
show all
Defined in:
lib/rubyquartz/bitmap.rb

Instance Method Summary collapse

Constructor Details

#initialize(width, height, colorspace, options = {}) ⇒ Bitmap

Returns a new instance of Bitmap.



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# File 'lib/rubyquartz/bitmap.rb', line 28

def initialize(width, height, colorspace, options={})
  raise "Width must be an integer" if width.to_i != width
  raise "Height must be an integer" if height.to_i != height
  
  super()
  
  bits_per_channel = options[:bits_per_channel] || 8
  alpha = options[:alpha] || Bitmap::ALPHA_PREMULTIPLIED_FIRST
  float_pixels = options[:float_pixels] || false
  byte_order = options[:byte_order] || Bitmap::BYTE_ORDER_DEFAULT
  
  bytes_per_row = options[:bytes_per_row]
  if bytes_per_row.nil?
    case alpha
    when Bitmap::ALPHA_NONE
      component_count = colorspace.component_count
    when Bitmap::ALPHA_ONLY
      component_count = 1
    else
      component_count = colorspace.component_count + 1
    end
    
    if float_pixels
      bytes_per_component = 4
    else
      bytes_per_component = 1
    end
    
    bytes_per_row = width * component_count * bytes_per_component
  end
  
  _initialize(width, height, bits_per_channel, bytes_per_row, alpha, float_pixels, byte_order)
end