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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <gset.h>
define XCEN 0.5
define YCEN 0.52
define EDGE1 0.1
define EDGE2 0.93
# PL_MAP_VIEWPORT -- set device viewport for contour and hafton plots. If not
# specified by user, a default viewport centered on the device is used.
#
# The value of "extreme" (ext) axes ratios changed from 1/4 to 1/16
# (ShJ 6-10-88)
procedure pl_map_viewport (gp, ncols, nlines, ux1, ux2, uy1, uy2, fill, perim)
pointer gp #I pointer to graphics descriptor
int ncols, nlines #I size of image area, after block reduction
real ux1, ux2, uy1, uy2 #I NDC coordinates of requested viewort
bool fill #I fill viewport (vs preserve aspect ratio)
bool perim #I draw perimeter
real xcen, ycen
real ncolsr, nlinesr, ratio, aspect_ratio
real x1, x2, y1, y2, ext, xdis, ydis
data ext /0.0625/
bool fp_equalr()
real ggetr()
begin
ncolsr = real (ncols)
nlinesr = real (nlines)
if (fp_equalr (ux1, 0.0) && fp_equalr (ux2, 0.0) &&
fp_equalr (uy1, 0.0) && fp_equalr (uy2, 0.0)) {
if (fill && !perim) {
x1 = 0.0; x2 = 1.0
y1 = 0.0; y2 = 1.0
xcen = 0.5; ycen = 0.5
} else {
x1 = EDGE1; x2 = EDGE2
y1 = EDGE1; y2 = EDGE2
xcen = XCEN; ycen = YCEN
}
# Calculate optimum viewport, as in NCAR's conrec, hafton.
if (!fill) {
ratio = min (ncolsr, nlinesr) / max (ncolsr, nlinesr)
if (ratio >= ext) {
if (ncols > nlines)
y2 = (y2 - y1) * nlinesr / ncolsr + y1
else
x2 = (x2 - x1) * ncolsr / nlinesr + x1
}
}
xdis = x2 - x1
ydis = y2 - y1
# So far, the viewport has been calculated so that equal numbers of
# image pixels map to equal distances in NDC space, regardless of
# the aspect ratio of the device. If the parameter "fill" has been
# set to no, the user wants to compensate for a non-unity aspect
# ratio and make equal numbers of image pixels map to into the same
# physical distance on the device, not the same NDC distance.
if (!fill) {
aspect_ratio = ggetr (gp, "ar")
if (fp_equalr (aspect_ratio, 0.0))
aspect_ratio = 1.0
if (aspect_ratio < 1.0)
# Landscape
xdis = xdis * aspect_ratio
else if (aspect_ratio > 1.0)
# Portrait
ydis = ydis / aspect_ratio
}
ux1 = xcen - (xdis / 2.0)
ux2 = xcen + (xdis / 2.0)
uy1 = ycen - (ydis / 2.0)
uy2 = ycen + (ydis / 2.0)
}
# Set window and viewport for WCS 1
call gseti (gp, G_WCS, 1)
call gsview (gp, ux1, ux2, uy1, uy2)
call gswind (gp, 1.0, ncolsr, 1.0, nlinesr)
call set (ux1, ux2, uy1, uy2, 1.0, ncolsr, 1.0, nlinesr, 1)
end
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