pro rotate_surf,data,colmap=colmap

shades=5^byte(data)
sortsh=shades(sort(shades))
colourfac=1

axv=50
azv=30
device,decomposed=0
xbox=[0.3,0.5]
ybox=[0.88,0.95]
xline1=mean(xbox)

if keyword_set(colmap) then ctab=colmap else ctab=4
loadct,ctab,bottom=min(data)



while 1 do begin
shadscale=50*(1+data/max(data))
SHADE_SURF, data, AX = axv, az = azv,shades=byte(shadscale)*colourfac

xyouts,0.1,0.93,strcompress("AZ: "+string(fix(axv))+" ZA:"+string(fix(azv))),/norm
xyouts,0.9,0.93,"Left button to rotate",alignment=1,/norm
xyouts,0.9,0.91,"Middle button to change colour scale",alignment=1,/norm
xyouts,0.9,0.89,"Right Button to Quit",alignment=1,/norm
cursor,x0,y0,/down,/norm
cursor,x1,y1,/up,/norm


if !mouse.button eq 1 then begin

azrot=180*(x1-x0)
axrot=180*(y0-y1)
axv=(axv+axrot) mod 360
azv=(azv+azrot) mod 360
endif

if !mouse.button eq 2 then begin
colourfac=abs(colourfac*(y1/y0)) mod 500
endif

if !mouse.button eq 4 then return
endwhile
end