6.2  bitmap%

A bitmap% object is a pixel-based image, either monochrome or color.

Sometimes, a bitmap object creation fails in a low-level manner. In that case, the ok? method returns #f, and the bitmap cannot be supplied to methods that consume or operate on bitmaps (otherwise, an exn:application:mismatch exception is raised).

• (make-object bitmap% bits width height) -> bitmap% object
     bits : string
     width : exact integer in [1, 10000]
     height : exact integer in [1, 10000]

  Creates a monochrome bitmap from an array of bit values, where each character in bits specifies eight bits, and padding bits are added so that each bitmap line starts on a character boundary. A 1 bit value indicates black, and 0 indicates white. If width times height is larger than 8 times the length of bits, an exn:application:mismatch exception is raised.

  
  

• (make-object bitmap% width height monochrome?) -> bitmap% object
     width : exact integer in [1, 10000]
     height : exact integer in [1, 10000]
     monochrome? = #f : boolean

  Creates a new bitmap. If monochrome? is #f, the bitmap matches the display depth of the screen. The initial content of the bitmap is undefined.

  
  

• (make-object bitmap% name kind) -> bitmap% object
     name : string
     kind = 'unknown : symbol in '(unknown gif jpeg xbm xpm bmp pict)

  Creates a bitmap from a file, where kind specifies the kind of image file. See load-file for details.

  
  

Methods
    get-depth
    get-height
    get-width
    is-color?
    load-file
    ok?
    save-file