Independent scroll bar operation

[SWM@SAPSUCKER.SCRC.Symbolics.COM (Scott McKay)]

    Date: Tue, 15 Oct 1991 12:29 EDT
    From: curt@eraserhead.Jpl.Nasa.Gov (Curt Eggemeyer)

Don't you mean to conduct this conversation on CLIM@BBN.COM?

Also, please state exactly what platform you are using.

    ...

I already responded to the stuff elided above.

    Finally, speed has become an issue. There could be a total of 20k presentation
    objects total on my display-pane generated from that loop above.  I have also
    noticed that if I have some complicated presentations with about 200 or more
    atomic drawing operations CLIM takes forever to get it out to the screen?
    If I draw it out not as a presentation it takes seconds, whereas if it is
    a presentation it may take over a minute#(#*&$ even though I told the
    presentation to use :single-box.  How can I avoid this?  One of my possible
    solutions is that I only present what the user can see on the
    display and manually erase and generate presentations?  Any thought on this?

What does "draw not as a presentation" mean?  Do you mean "with output
recording disabled"?  If that is what you mean, then the overhead is
clearly coming from the creation of the presentation output records,
although I don't see how it can take quite so much time.

If you can closely characterize the "200 or more atomic drawing
operations" by a few parameters, then it may be appropriate to define
your own class of output record that knows how to fully draw the whole
figure from the data contained in a single output record.  For example,
here is how a line output record is defined.  Macroexpand these to see
more stuff.  You may need to get more assistance from your appropriate
support organization.

 ;; This defines the DRAW-LINE generic operation
 (define-graphics-operation draw-line (x1 y1 x2 y2)
   :arguments ((point x1 y1 x2 y2))
   :drawing-options :line-cap
   :method-body
     (with-transformed-arguments
       (draw-line-internal stream 0 0 x1 y1 x2 y2
                           (medium-ink stream) (medium-line-style stream))))
 
 ;; This defines the internal methods for output recording
 (define-graphics-internal draw-line-internal (x1 y1 x2 y2 ink line-style)
   :points-to-convert (x1 y1 x2 y2)
   :bounding-rectangle
     (with-half-thickness (lthickness rthickness) line-style
       (fix-rectangle (- (min x1 x2) lthickness) (- (min y1 y2) lthickness)
                      (+ (max x1 x2) rthickness) (+ (max y1 y2) rthickness)))
   :highlighting-test
     ((x y)
      (with-slots (x1 y1 x2 y2 line-style) record
        (point-close-to-line-p x y x1 y1 x2 y2 (line-style-thickness line-style))))
   :highlighting-function
     ((stream state)
      (declare (ignore state))                                  ;for now.
      (multiple-value-bind (xoff yoff)
          (convert-from-relative-to-absolute-coordinates
            stream (output-record-parent record))
        (with-slots (x1 y1 x2 y2 line-style) record
          (outline-line-with-hexagon stream xoff yoff
                                     x1 y1 x2 y2 (line-style-thickness line-style))))))
 
 ;; Here is the CLX code that actually draws the line
 (defmethod draw-line-internal ((stream clx-window) x-offset y-offset
                                start-x start-y end-x end-y ink line-style)
   (fix-points start-x end-x start-y end-y)
   (translate-positions x-offset y-offset start-x start-y end-x end-y)
   (with-slots (window) stream
     (xlib:draw-line window
                     (clx-adjust-ink (clx-decode-ink ink stream) stream line-style)
                     start-x start-y end-x end-y))
   (clx-force-output-if-necessary stream))

Also, note that :SINGLE-BOX T does not affect drawing speed.  It affects
only how sensitivity and highlighting is done.