diff options
Diffstat (limited to 'pkg/xtools/ranges/rgwindow.x')
| -rw-r--r-- | pkg/xtools/ranges/rgwindow.x | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/pkg/xtools/ranges/rgwindow.x b/pkg/xtools/ranges/rgwindow.x new file mode 100644 index 00000000..fe495362 --- /dev/null +++ b/pkg/xtools/ranges/rgwindow.x @@ -0,0 +1,43 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include <pkg/rg.h> + +# RG_WINDOW -- Intersect a set of ordered and merged ranges with a window. + +pointer procedure rg_window (rg, rmin, rmax) + +pointer rg # Ranges +int rmin, rmax # Window + +pointer rgout # Pointer to windowed ranges + +int i, j + +begin + if (rg == NULL) + call error (0, "Range descriptor undefined") + + # Allocate the range points array. + + call malloc (rgout, LEN_RG + 2 * max (1, RG_NRGS(rg)), TY_STRUCT) + + # Set the windowed ranges. + + j = 0 + do i = 1, RG_NRGS(rg) { + if ((rmin <= RG_X2(rg, i)) && (rmax >= RG_X1(rg, i))) { + j = j + 1 + RG_X1(rgout, j) = max (rmin, RG_X1(rg, i)) + RG_X2(rgout, j) = min (rmax, RG_X2(rg, i)) + } + } + + call realloc (rgout, LEN_RG + 2 * max (1, j), TY_STRUCT) + RG_NRGS(rgout) = j + RG_NPTS(rgout) = 0 + do i = 1, RG_NRGS(rgout) + RG_NPTS(rgout) = RG_NPTS(rgout) + + abs (RG_X1(rgout, i) - RG_X2(rgout, i)) + 1 + + return (rgout) +end |