Module: ChunkyPNG::Canvas::Operations

Included in:
ChunkyPNG::Canvas
Defined in:
lib/chunky_png/canvas/operations.rb

Instance Method Summary collapse

Instance Method Details

#compose(new_foreground, dx = 0, dy = 0) ⇒ Object 



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# File 'lib/chunky_png/canvas/operations.rb', line 4

def compose(new_foreground, dx = 0, dy = 0)
  check_size_constraints!(new_foreground, dx, dy)

  for y in 0...new_foreground.height do
    for x in 0...new_foreground.width do
      self[x+dx, y+dy] = ChunkyPNG::Color.compose(new_foreground[x, y], self[x+dx, y+dy])
    end
  end
  self
end

#crop(x, y, crop_width, crop_height) ⇒ Object 



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# File 'lib/chunky_png/canvas/operations.rb', line 24

def crop(x, y, crop_width, crop_height)
  new_pixels = []
  for cy in 0...crop_height do
    new_pixels += pixels.slice((cy + y) * width + x, crop_width)
  end
  ChunkyPNG::Canvas.new(crop_width, crop_height, new_pixels)
end

#replace(other, offset_x = 0, offset_y = 0) ⇒ Object 



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# File 'lib/chunky_png/canvas/operations.rb', line 15

def replace(other, offset_x = 0, offset_y = 0)
  check_size_constraints!(other, offset_x, offset_y)

  for y in 0...other.height do
    pixels[(y + offset_y) * width + offset_x, other.width] = other.pixels[y * other.width, other.width]
  end
  self
end