Red: Rotating Images: feedback requested

[Michael J. Lew]

Richmond Mathewson was >Having some problems with rotation...

I don't know anything much about rotating images, but if the project 
is just a clock then why not move a graphic around rather than rotate 
an image? I'm sure you could recalculate the points of even a quite 
complex graphic in very little time. The code below is from a clock 
that I built when first learning to use Revolution. It seems to work 
OK and you can get the trigonometric transformations from it.

on oneTick
   global gClockRunning
   if gClockRunning then send "oneTick" to me in 500 milliseconds
   set the tickMessageID of me to the result
   --seconds
   put the secondHandLength of group "clock" into L
   put the clockTime of group "clock" + 1 into currentTime
   put the long time into theTime
   convert theTime to dateItems
   put item 6 of theTime into mySec
   add item 5 of theTime*60 to mySec
   add item 4 of theTime*3600 to mySec
   put -pi/2 +mySec*2*pi/60 into theta
   put round(L*sin(theta)) into y
   put round(L*cos(theta)) into x
   put the loc of graphic "spindle" into myPoint
   add x to item 1 of myPoint
   add y to item 2 of myPoint
   put the loc of graphic "spindle"  & return & myPoint into handPoints
   set the points of graphic "secondHand" to handPoints
   --minutes (do only every 6 seconds)
   if currentTime mod 6 = 0 then
     put the minuteHandLength of group "clock" into L
     put -pi/2 +mySec*2*pi/3600 into theta
     put round(L*sin(theta)) into y
     put round(L*cos(theta)) into x
     put the loc of graphic "spindle" into myPoint
     add x to item 1 of myPoint
     add y to item 2 of myPoint
     put the loc of graphic "spindle"  & return & myPoint into handPoints
     set the points of graphic "minuteHand" to handPoints
   end if
   --hours (do only every 60 seconds)
   if currentTime mod 60 = 0 then
     put the hourHandLength of group "clock" into L
     put -pi/2 +mySec*2*pi/(12*60*60) into theta
     put round(L*sin(theta)) into y
     put round(L*cos(theta)) into x
     put the loc of graphic "spindle" into myPoint
     add x to item 1 of myPoint
     add y to item 2 of myPoint
     put the loc of graphic "spindle"  & return & myPoint into handPoints
     set the points of graphic "hourHand" to handPoints
   end if
end oneTick

Regards,
-- 
Michael J. Lew

Senior Lecturer
Department of Pharmacology
The University of Melbourne
Parkville 3010
Victoria
Australia

Phone +613 8344 8304

**
New email address: michaell at unimelb.edu.au
**