1 files changed, 101 insertions, 0 deletions
diff --git a/sys/gio/gplcache.x b/sys/gio/gplcache.x
new file mode 100644
index 00000000..88201365
--- /dev/null
+++ b/sys/gio/gplcache.x
@@ -0,0 +1,101 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<gki.h>
+include	<gio.h>
+
+# GPL_CACHE -- Cache the transformation parameters for a device in the GADRAW
+# common.  Must be called whenever the current WCS changes.  We need only
+# check that the WCS has not changed because anything more serious than a
+# change current WCS call will cause the cache to be invalidated.
+
+procedure gpl_cache (gp)
+
+pointer	gp			# graphics descriptor
+pointer	w
+real	wx1, wx2, wy1, wy2
+bool	fp_nondegenr()
+real	elogr()
+
+int	wcsord
+data	wcsord /0/
+include	"gpl.com"
+
+begin
+	gp_out = gp
+	wcs = GP_WCS(gp)
+	w = GP_WCSPTR (gp, wcs)
+
+	# The WCS must be fixed to the output device (kernel) when used for
+	# coordinate transformations in metacode output.
+
+	if (GP_WCSSTATE(gp) != FIXED) {
+	    call gactivate (gp, 0)
+	    call gpl_flush()
+	    call gki_setwcs (GP_FD(gp), Memi[GP_WCSPTR(gp,1)],
+		LEN_WCS * MAX_WCS)
+	    GP_WCSSTATE(gp) = FIXED
+	    wcsord = wcsord + 1
+	    GP_WCSORD(gp) = wcsord
+	}
+
+	mx1 = WCS_SX1(w) * GKI_MAXNDC
+	mx2 = WCS_SX2(w) * GKI_MAXNDC
+	my1 = WCS_SY1(w) * GKI_MAXNDC
+	my2 = WCS_SY2(w) * GKI_MAXNDC
+
+	# Compute world -> GKI coordinate transformation.  If log scaling is
+	# indicated but one or both window coords are negative, use ELOG
+	# scaling instead.
+
+	mxorigin = mx1
+	xtran = WCS_XTRAN(w)
+
+	wx1 = WCS_WX1(w)
+	wx2 = WCS_WX2(w)
+
+	# Ensure that the window is nondegenerate.
+	if (fp_nondegenr (wx1, wx2))
+	    ;
+
+	if (xtran == LINEAR) {
+	    wxorigin = wx1
+	    xscale = (mx2 - mx1) / (wx2 - wx1)
+	} else if (xtran == LOG && wx1 > 0 && wx2 > 0) {
+	    wxorigin = log10 (wx1)
+	    xscale = (mx2 - mx1) / (log10(wx2) - wxorigin)
+	} else {
+	    wxorigin = elogr (wx1)
+	    xscale = (mx2 - mx1) / (elogr(wx2) - wxorigin)
+	}
+
+	myorigin = my1
+	ytran = WCS_YTRAN(w)
+
+	wy1 = WCS_WY1(w)
+	wy2 = WCS_WY2(w)
+
+	# Ensure that the window is nondegenerate.
+	if (fp_nondegenr (wy1, wy2))
+	    ;
+
+	if (ytran == LINEAR) {
+	    wyorigin = wy1
+	    yscale = (my2 - my1) / (wy2 - wy1)
+	} else if (ytran == LOG && wy1 > 0 && wy2 > 0) {
+	    wyorigin = log10 (wy1)
+	    yscale = (my2 - my1) / (log10(wy2) - wyorigin)
+	} else {
+	    wyorigin = elogr (wy1)
+	    yscale = (my2 - my1) / (elogr(wy2) - wyorigin)
+	}
+
+	# If clipping is disabled move the clipping viewport out to the
+	# boundary of the device.
+
+	if (and (WCS_FLAGS(w), WF_CLIP) == 0) {
+	    mx1 = 0
+	    mx2 = GKI_MAXNDC
+	    my1 = 0
+	    my2 = GKI_MAXNDC
+	}
+end