[MIT-Scheme-users] Trouble drawing immediately after making a graphics device on the X window system

[Ty Lewis]

Hello,

I am just having some trouble with the graphics functionality on X. I have a simple program line.scm:

(define device (make-graphics-device 'x))

(graphics-draw-line device 0 0 5 5)

; No line is drawn

When I try to load this program in the REPL with (load "line.scm"), I get an empty screen, no line is drawn. If, however, I add short sleep or wait for a key input right after the device is made, then the line appears:

(define device (make-graphics-device 'x))

(sleep-current-thread 100)

(graphics-draw-line device 0 0 5 5)

; Line is drawn

Is this a known issue by chance? Are there any better workarounds? Again this is on X11 and with Scheme release 9.2.

Regards,

Ty