Graphics: Legacy Library
 
1 Basic Commands
2 Position Operations
3 Color Operations
4 Draw, Clear, and Flip Operations
5 World Operations
6 Miscellaneous Operations
7 An Example
8 A More Complicated Example
9 Protecting Graphics Operations
10 Mouse Operations
11 Keyboard Operations
12 Flushing
13 Graphics Library as a Unit
Version: 4.0.2
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8 A More Complicated Example

The use of multiple viewports, viewport descriptors, drawing operations for multiple viewports is as easy as the use of a single viewport:

  (open-graphics)

  (let* (; w1 and w2 are viewports for different windows

         [w1  (open-viewport "viewport 1" 300 300)]

         [w2  (open-viewport "viewport 2" 200 500)]

         ; d1 and d2 draw lines in different viewports

         [d1  (draw-line w1)]

         [d2  (draw-line w2)])

    ; draws a line in viewport labeled “viewport 1”

    (d1 (make-posn 100 5) (make-posn 5 100))

    ; draws a line in viewport labeled “viewport 2”

    (d2 (make-posn 100 100) (make-posn 101 400)))

  

  ; we no longer have access to viewports 1 and 2,

  ; since their descriptors did not escape the let

  (close-graphics)

  ; removes the viewports

 

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