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include <gset.h>
# Default viewport edges.
define EDGE1 0.1
define EDGE2 0.9
define EDGE3 0.12
define EDGE4 0.85
#---------------------------------------------------------------------------
.help sp_map_viewport Sep92 source
.ih
NAME
sp_map_viewport -- set device viewport for contour plots.
.endhelp
#---------------------------------------------------------------------------
procedure sp_map_viewport (gp, ncols, nlines, ux1, ux2, uy1, uy2, pre, perim)
pointer gp # I: pointer to graphics descriptor
real ncols, nlines # I: size of image area, after block reduction
real ux1, ux2, uy1, uy2 # I: NDC coordinates of requested viewort
bool pre # I: Preserve aspect ratio.
bool perim # I: draw perimeter
real xcen, ycen, x, y
real aspect_ratio
real x1, x2, y1, y2, ext, xdis, ydis
data ext /0.0625/
real ggetr()
begin
# Determine the standard window sizes.
if (!pre && !perim) {
x1 = 0.0; x2 = 1.0
y1 = 0.0; y2 = 1.0
} else {
x1 = EDGE1; x2 = EDGE2
y1 = EDGE3; y2 = EDGE4
}
# If any values were specified, then replace them here.
if( !IS_INDEFR( ux1 ) )
x1 = ux1
if( !IS_INDEFR( ux2 ) )
x2 = ux2
if( !IS_INDEFR( uy1 ) )
y1 = uy1
if( !IS_INDEFR( uy2 ) )
y2 = uy2
xdis = x2 - x1
ydis = y2 - y1
xcen = ( x2 + x1 ) / 2.
ycen = ( y2 + y1 ) / 2.
# 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 preserving aspect ratio,
# modify viewport to correctly display the contour aspect.
if (pre) {
aspect_ratio = ggetr (gp, "ar")
if (aspect_ratio == 0.0) {
x = ggetr (gp, "xr")
y = ggetr (gp, "yr")
if ( x != 0.0 && y != 0.0)
aspect_ratio = y / x
else
aspect_ratio = 1.0
}
aspect_ratio = nlines / ncols / aspect_ratio
x = ydis / aspect_ratio
y = ydis
if ( x > xdis) {
y = aspect_ratio * xdis
x = xdis
}
xdis = x
ydis = y
}
# All set.
ux1 = xcen - (xdis / 2.0)
ux2 = xcen + (xdis / 2.0)
uy1 = ycen - (ydis / 2.0)
uy2 = ycen + (ydis / 2.0)
call gsview (gp, ux1, ux2, uy1, uy2)
call gswind (gp, 1.0, ncols, 1.0, nlines)
end
#---------------------------------------------------------------------------
# End of sp_map_viewport
#---------------------------------------------------------------------------
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