class Iup::Image

Image made from greyscale values. The colors are defined in a table, and their indices used when defining the image pixel-map.

Example

The following image is built from 3 colors: the pixmap gives their placement in the 11x11 image, and the constructor uses a block to specify the color for each of the 3 values. When displayed, the image presents a red X on a yellow background.

 pixmap_x = [
  1,2,3,3,3,3,3,3,3,2,1, 
  2,1,2,3,3,3,3,3,2,1,2, 
  3,2,1,2,3,3,3,2,1,2,3, 
  3,3,2,1,2,3,2,1,2,3,3, 
  3,3,3,2,1,2,1,2,3,3,3, 
  3,3,3,3,2,1,2,3,3,3,3, 
  3,3,3,2,1,2,1,2,3,3,3, 
  3,3,2,1,2,3,2,1,2,3,3, 
  3,2,1,2,3,3,3,2,1,2,3, 
  2,1,2,3,3,3,3,3,2,1,2, 
  1,2,3,3,3,3,3,3,3,2,1
]

img = Iup::Image.new(11, 11, pixmap_x) do |i|
 i.color(1, '0 1 0')
 i.color(2, '255 0 0')
 i.color(3, '255 255 0')
end

Public Class Methods

new (width, height, pixels) { |self| ... }

Source

# File lib/wrapped/image.rb, line 112
def initialize(width, height, pixels)
  @handle = IupLib.IupImage(width, height, IupLib.pointer_from_chars(pixels))

  # run any provided block on instance, to set up further attributes
  yield self if block_given?
end

Constructor creates an image from raw pixels, using 1-value per pixel. If a block is given, the new instance is yielded to it.

width - width of image in pixels
height - height of image in pixels
pixels - an array of pixel values, each value being a color index

Public Instance Methods

color(index) # retrieves

color(index, value) # sets

Source

# File lib/wrapped/image.rb, line 126
def color(index, value=nil)
  IupLib.IupSetAttribute(@handle, index.to_s, value)
end

Access color at given index.

index - integer of color found in pixel map
value - ‘r g b’ representation of color