;+
; suncirc.pro
;
; PURPOSE	Draw a 1.0 Rsun circle on an image.
;
; SYNTAX	suncirc, fits_image_file
;
; AUTHOR	Andrew L. Stanger   HAO/NCAR   30 Oct 2000
;		23 Jan 2001: set xcen/ycen to array center if < 0.
;		12 Apr 2001: Use dispmin & dispmax for intensity scaling.
;		12 Apr 2001: Draw circle centered at array center.
;-

PRO suncirc, fits_file

lct, '/home/stanger/color/chip1.lut'
xcen = -1
ycen = -1
dispmin = 0
dispmax = 0

img = readfits (fits_file, hdu)

telescop = fxpar (hdu, 'TELESCOP')
xdim     = fxpar (hdu, 'NAXIS1')
ydim     = fxpar (hdu, 'NAXIS2')
xcen     = fxpar (hdu, 'CRPIX1',   count=xcencnt)
ycen     = fxpar (hdu, 'CRPIX2',   count=ycencnt)
pixrs    = fxpar (hdu, 'CRRADIUS', count=pixrscnt)
roll     = fxpar (hdu, 'CROTA1')
dispmin  = fxpar (hdu, 'DISPMIN')
dispmax  = fxpar (hdu, 'DISPMAX')

telescop = STRUPCASE (STRTRIM (telescop, 2))
if (telescop EQ 'PSPT') then	$
begin
    xcen = fxpar (hdu, 'CENTER_X', count=xcencnt)
    ycen = fxpar (hdu, 'CENTER_Y', count=ycencnt)
    xrad = fxpar (hdu, 'XRADIUS',  count=pixrscnt)
    yrad = fxpar (hdu, 'YRADIUS',  count=pixrscnt)
    pixrs = (xrad + yrad) / 2.0			; Average.
end

if (xcencnt NE 1)  then xcen  = -1.0
if (ycencnt NE 1)  then ycen  = -1.0
if (pixrscnt NE 1) then pixrs = -1.0

print, 'xcen/ycen: ', xcen, ycen

print, 'dispmin/dispmax: ', dispmin, dispmax
imin = min (img, max=imax)
print, 'imin/imax: ', imin, imax
if (dispmin EQ dispmax) then	$
begin
    tmin = imin
    tmax = imax
end				$
else				$
begin
    tmin = dispmin
    tmax = dispmax
end
print, 'tmin/tmax: ', tmin, tmax

xc = (xdim - 1) * 0.5
yc = (ydim - 1) * 0.5

IF (xcen LT 0.0) THEN xcen = (xdim - 1) / 2.0
IF (ycen LT 0.0) THEN ycen = (ydim - 1) / 2.0
print, 'xcen/ycen: ', xcen, ycen

sizimg = size (img)

WHILE (sizimg [1] GT 1000 OR sizimg [2] GT 1000) DO	$
    BEGIN
    img = rebin (img, xdim/2, ydim/2)
    xdim = xdim / 2
    ydim = ydim / 2
    xcen = xcen / 2.0
    ycen = ycen / 2.0
    xc = xc * 0.5
    yc = yc * 0.5
    pixrs = pixrs / 2.0
    sizimg = size (img)
    END
print, 'xc/yc: ', xc, yc, '  pixrs: ', pixrs

window, xsize=xdim, ysize=ydim
tv, bytscl (img, min=tmin, max=tmax, top=249)

radius = 1.0

FOR it = 0, 361, 1 DO	$
    BEGIN
    theta = FLOAT (it)
    ierr = rcoord (radius, theta, x, y, 1, roll, xc, yc, pixrs)
    ix = FIX (x + 0.5)
    iy = FIX (y + 0.5)
    IF (it EQ 0) THEN plots, ix, iy, /device, color=251		$
    ELSE plots, ix, iy, /device, color=251, /continue
    END

;FOR it = 0, 361, 1 DO	$
;    BEGIN
;    theta = FLOAT (it)
;    ierr = rcoord (radius, theta, x, y, 1, roll, xcen, ycen, pixrs)
;    ix = FIX (x + 0.5)
;    iy = FIX (y + 0.5)
;    IF (it EQ 0) THEN plots, ix, iy, /device, color=253		$
;    ELSE plots, ix, iy, /device, color=253, /continue
;    END

END