From 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 Mon Sep 17 00:00:00 2001
From: Joe Hunkeler <jhunkeler@gmail.com>
Date: Tue, 11 Aug 2015 16:51:37 -0400
Subject: Repatch (from linux) of OSX IRAF

---
 sys/gio/cursor/gtrbackup.x | 74 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 sys/gio/cursor/gtrbackup.x

(limited to 'sys/gio/cursor/gtrbackup.x')

diff --git a/sys/gio/cursor/gtrbackup.x b/sys/gio/cursor/gtrbackup.x
new file mode 100644
index 00000000..9ab13c0b
--- /dev/null
+++ b/sys/gio/cursor/gtrbackup.x
@@ -0,0 +1,74 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<gset.h>
+include	<gio.h>
+include	<gki.h>
+include	"gtr.h"
+
+# GTR_BACKUP -- Backup one drawing instruction in the frame buffer.  Erase
+# the graphics if possible.  The effects of this function may be undone by
+# the UNDO operator.
+
+procedure gtr_backup (stream)
+
+int	stream				# graphics stream
+
+int	opcode
+pointer	tr, op, bp, sp, ap
+pointer	gtr_init()
+errchk	gtr_init
+include	"gtr.com"
+
+begin
+	call smark (sp)
+	call salloc (ap, LEN_PL, TY_STRUCT)
+
+	tr = gtr_init (stream)
+
+	# Scan backward to the beginning of the last drawing instruction in the
+	# frame buffer.
+
+	op = TR_OP(tr)
+	bp = TR_FRAMEBUF(tr)
+	if (op <= bp) {
+	    call sfree (sp)
+	    return
+	}
+
+	repeat {
+	    op = op - 1
+	    while (Mems[op] != BOI)
+		if (op <= bp) {
+		    TR_OP(tr) = bp
+		    TR_IP(tr) = bp
+		    call sfree (sp)
+		    return
+		} else
+		    op = op - 1
+	    opcode = Mems[op+GKI_HDR_OPCODE-1]
+	} until (opcode >= GKI_POLYLINE && opcode <= GKI_PUTCELLARRAY)
+
+	# Redraw the last instruction to erase it (device permitting).
+	if (opcode == GKI_POLYLINE) {
+	    PL_LTYPE(ap) = GL_CLEAR
+	    PL_WIDTH(ap) = 1.0
+	    PL_COLOR(ap) = 1
+	    call gki_plset (stream, ap)
+
+	    if (wstranset == YES)
+		call gtr_wstran (Mems[op])
+	    else
+		call gki_write (stream, Mems[op])
+
+	    PL_LTYPE(ap) = GL_SOLID
+	    call gki_plset (stream, ap)
+	    call gki_fflush (stream)
+	}
+
+	# Return the space in the buffer.
+	TR_LASTOP(tr) = TR_OP(tr)
+	TR_OP(tr) = op
+	TR_IP(tr) = min (op, TR_IP(tr))
+
+	call sfree (sp)
+end
-- 
cgit