Category : OS/2 Files
Archive   : PMGB32.ZIP
Filename : SPIN.PMG

/* Spin the globe with sun position held static */
/* (Note: currently this 'undoes' positions set interactively while running */
/* fixing this is left as an exercise for the reader.) */
'extract viewlat viewlon sunlat sunlon' /* get current */
offlat=sunlat-viewlat /* relative sun latitude */
offlon=sunlon-viewlon /* relative sun longitude */

do forever /* (Use Halt Macro to end) */
'wait +0:05' /* redraw every 5 minutes */
'extract sunlat sunlon' /* get new sun position */
lon=sunlon-offlon /* calculate new view lon */
if lon<-180 then lon=lon+360 /* if wrapped past dateline.. */
else if lon>180 then lon=lon-360 /* .. adjust as needed */
'set viewlon' lon /* new longitude */
lat=sunlat-offlat /* calculate new view lat */
if lat<-90 then lat=-lat-180 /* if wrapped over a pole.. */
else if lat>90 then lat=180-lat /* .. adjust as needed */
'set viewlat' lat /* .. and set */
end