676ea3192f
Former-commit-id:b13cbb7e00[formerly 4909e0dd166e43c22a34d96aa744f51db8a7d6c0] Former-commit-id:3904c4ccf5
103 lines
2.7 KiB
Fortran
103 lines
2.7 KiB
Fortran
SUBROUTINE CCLIP ( npin, xin, yin, ipoint, npout, xout, yout,
|
|
+ more, iret )
|
|
C************************************************************************
|
|
C* CCLIP *
|
|
C* *
|
|
C* This routine will clip points, from a line, that are not visible in *
|
|
C* the bounded area. *
|
|
C* *
|
|
C* CCLIP ( NPIN, XIN, YIN, IPOINT, NPOUT, XOUT, YOUT, MORE, IRET ) *
|
|
C* *
|
|
C* Input parameters: *
|
|
C* NPIN INTEGER Number of input points *
|
|
C* *
|
|
C* Input and output parameters: *
|
|
C* XIN (NPIN) REAL Input X grid points *
|
|
C* YIN (NPIN) REAL Input Y grid points *
|
|
C* IPOINT INTEGER Start point from the input pts *
|
|
C* *
|
|
C* Output parameters: *
|
|
C* NPOUT INTEGER Number of output points *
|
|
C* XOUT (NPOUT) REAL Output X grid points *
|
|
C* YOUT (NPOUT) REAL Output Y grid points *
|
|
C* MORE LOGICAL Flag for more points to process *
|
|
C* IRET INTEGER Return code *
|
|
C* *
|
|
C** *
|
|
C* Log: *
|
|
C* S. Jacobs/NCEP 10/00 Created *
|
|
C* S. Jacobs/NCEP 5/01 Reorder points if the line is closed *
|
|
C************************************************************************
|
|
REAL xin (*), yin (*), xout (*), yout (*)
|
|
LOGICAL more
|
|
C*
|
|
LOGICAL vis (1024), viso (1024)
|
|
C------------------------------------------------------------------------
|
|
iret = 0
|
|
C
|
|
C* Find the visible points for this line.
|
|
C
|
|
CALL GPTVIS ( 'G', npin, xin, yin, vis, ier )
|
|
C
|
|
C* If the line is closed work backward until the first
|
|
C* non visible point. Then reorder the points so that the
|
|
C* first visible point becomes point number 1.
|
|
C
|
|
IF ( ( ipoint .eq. 1 ) .and. vis (1) ) THEN
|
|
C
|
|
IF ( ( xin(1) .eq. xin(npin) ) .and.
|
|
+ ( yin(1) .eq. yin(npin) ) ) THEN
|
|
C
|
|
nn = npin - 1
|
|
C
|
|
DO WHILE ( ( nn .ge. 1 ) .and. vis ( nn ) )
|
|
nn = nn - 1
|
|
END DO
|
|
C
|
|
IF ( nn .gt. 0 ) THEN
|
|
j = nn + 1
|
|
DO i = 1, npin - 1
|
|
IF ( j .gt. npin - 1 ) j = 1
|
|
xout ( i ) = xin ( j )
|
|
yout ( i ) = yin ( j )
|
|
viso ( i ) = vis ( j )
|
|
j = j + 1
|
|
END DO
|
|
xout ( npin ) = xout ( 1 )
|
|
yout ( npin ) = yout ( 1 )
|
|
viso ( npin ) = viso ( 1 )
|
|
C
|
|
DO i = 1, npin
|
|
xin ( i ) = xout ( i )
|
|
yin ( i ) = yout ( i )
|
|
vis ( i ) = viso ( i )
|
|
END DO
|
|
END IF
|
|
C
|
|
END IF
|
|
C
|
|
END IF
|
|
C
|
|
C* Loop through all of the input points, stop at the first point
|
|
C* that is not visible.
|
|
C
|
|
npout = 0
|
|
DO WHILE ( ( ipoint .le. npin ) .and. vis ( ipoint ) )
|
|
npout = npout + 1
|
|
xout (npout) = xin (ipoint)
|
|
yout (npout) = yin (ipoint)
|
|
ipoint = ipoint + 1
|
|
END DO
|
|
C
|
|
C* Find the next visible point.
|
|
C
|
|
DO WHILE ( ( ipoint .le. npin ) .and. .not. vis ( ipoint ) )
|
|
ipoint = ipoint + 1
|
|
END DO
|
|
C
|
|
C* Check for more points to process.
|
|
C
|
|
more = ipoint .le. npin
|
|
C*
|
|
RETURN
|
|
END
|