6.3  bitmap-dc%

Implements: dc<%>

A bitmap-dc% object allows drawing directly into a bitmap. A bitmap% object must be supplied at initialization or installed into a bitmap DC using set-bitmap before any other method of the DC is called, except get-text-extent, get-char-height, or get-char-width. If any other bitmap-dc% method is called before a bitmap is selected, the method call is ignored.

Drawing to a bitmap-dc% with a color bitmap is guaranteed to produce the same result as drawing into a canvas% instance (with appropriate clipping and offsets). Thus, a bitmap-dc% can be used for offscreen staging of canvas content.

• (new bitmap-dc% (bitmap _)) -> bitmap-dc% object
     bitmap : bitmap% object or #f

  Creates a new memory DC. If bitmap is not #f, it is installed into the DC so that drawing commands on the DC draw to bitmap. Otherwise, no bitmap is installed into the DC and set-bitmap must be called before any other method of the DC is called.

  
  

Methods
    get-argb-pixels
    get-bitmap
    get-pixel
    set-argb-pixels
    set-bitmap
    set-pixel

All Methods
    clear from dc<%>
    draw-arc from dc<%>
    draw-bitmap from dc<%>
    draw-bitmap-section from dc<%>
    draw-ellipse from dc<%>
    draw-line from dc<%>
    draw-lines from dc<%>
    draw-point from dc<%>
    draw-polygon from dc<%>
    draw-rectangle from dc<%>
    draw-rounded-rectangle from dc<%>
    draw-spline from dc<%>
    draw-text from dc<%>
    end-doc from dc<%>
    end-page from dc<%>
    get-argb-pixels from bitmap-dc%
    get-background from dc<%>
    get-bitmap from bitmap-dc%
    get-brush from dc<%>
    get-char-height from dc<%>
    get-char-width from dc<%>
    get-clipping-region from dc<%>
    get-font from dc<%>
    get-gl-context from dc<%>
    get-origin from dc<%>
    get-pen from dc<%>
    get-pixel from bitmap-dc%
    get-scale from dc<%>
    get-size from dc<%>
    get-text-background from dc<%>
    get-text-extent from dc<%>
    get-text-foreground from dc<%>
    get-text-mode from dc<%>
    ok? from dc<%>
    set-argb-pixels from bitmap-dc%
    set-background from dc<%>
    set-bitmap from bitmap-dc%
    set-brush from dc<%>
    set-clipping-rect from dc<%>
    set-clipping-region from dc<%>
    set-font from dc<%>
    set-origin from dc<%>
    set-pen from dc<%>
    set-pixel from bitmap-dc%
    set-scale from dc<%>
    set-text-background from dc<%>
    set-text-foreground from dc<%>
    set-text-mode from dc<%>
    start-doc from dc<%>
    start-page from dc<%>
    try-color from dc<%>