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include <gset.h>
include <fset.h>
# APGSCUR -- Read the x and y coordinates of an object from a file and move
# the cursor to those coordinates.
int procedure apgscur (sl, gd, xcur, ycur, prev_num, req_num, num)
int sl # coordinate file descriptor
pointer gd # pointer to graphics stream
real xcur, ycur # x cur and y cur
int prev_num # previous number
int req_num # requested number
int num # list number
int stdin, nskip, ncount
pointer sp, fname
int fscan(), nscan(), strncmp()
errchk greactivate, gdeactivate, gscur
begin
if (sl == NULL)
return (EOF)
call smark (sp)
call salloc (fname, SZ_FNAME, TY_CHAR)
# Find the number of objects to be skipped.
call fstats (sl, F_FILENAME, Memc[fname], SZ_FNAME)
if (strncmp ("STDIN", Memc[fname], 5) == 0) {
stdin = YES
nskip = 1
} else {
stdin = NO
if (req_num <= prev_num) {
call seek (sl, BOF)
nskip = req_num
} else
nskip = req_num - prev_num
}
# Initialize.
ncount = 0
num = prev_num
# Read the coordinates and write the cursor.
repeat {
# Print the prompt if file is STDIN.
if (stdin == YES) {
call printf ("Type object x and y coordinates: ")
call flush (STDOUT)
}
# Fetch the coordinates.
if (fscan (sl) != EOF) {
call gargr (xcur)
call gargr (ycur)
if (nscan () == 2) {
ncount = ncount + 1
num = num + 1
}
} else
ncount = EOF
# Move the cursor.
if (gd != NULL && (ncount == nskip || ncount == EOF)) {
iferr {
call greactivate (gd, 0)
call gscur (gd, xcur, ycur)
call gdeactivate (gd, 0)
} then
;
}
} until (ncount == EOF || ncount == nskip)
call sfree (sp)
if (ncount == EOF) {
return (EOF)
} else if (nskip == req_num) {
num = ncount
return (ncount)
} else {
return (num)
}
end
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