1 files changed, 54 insertions, 0 deletions
diff --git a/sys/gio/sgikern/sgiclear.x b/sys/gio/sgikern/sgiclear.x
new file mode 100644
index 00000000..f2a63d29
--- /dev/null
+++ b/sys/gio/sgikern/sgiclear.x
@@ -0,0 +1,54 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<mach.h>
+include	"sgi.h"
+
+# SGI_CLEAR -- Advance a frame on the plotter.  All attribute packets are
+# initialized to their default values.  Redundant calls or calls immediately
+# after a workstation open (before anything has been drawn) are ignored.
+
+procedure sgi_clear (dummy)
+
+int	dummy			# not used at present
+
+int	sgk_open()
+errchk	sgk_open
+include	"sgi.com"
+
+begin
+	# This is a no-op if nothing has been drawn.
+	if (g_kt == NULL || g_ndraw == 0)
+	    return
+
+	# Start a new frame.  This is done either by issuing the frame advance
+	# instruction or by starting a new metafile.  Close the output file and 
+	# start a new metafile if the maximum frame count has been reached.
+	# This disposes of the metafile to the system, causing the actual
+	# plots to be drawn.  Open a new metafile ready to receive next frame.
+
+	g_nframes = g_nframes + 1
+	if (g_nframes >= g_maxframes) {
+
+	    # Does this device require a frame advance at end of metafile?
+	    if (SGI_ENDFRAME(g_kt) == YES)
+		call sgk_frame (g_out)
+
+	    g_nframes = 0
+	    call sgk_close (g_out)
+	    g_out = sgk_open (Memc[SGI_DEVNAME(g_kt)], g_tty)
+
+	    # Does this device require a frame advance at beginning of metafile?
+	    if (SGI_STARTFRAME(g_kt) == YES)
+		call sgk_frame (g_out)
+
+	} else {
+	    # Merely output frame instruction to start a new frame in the same
+	    # metafile.
+
+	    call sgk_frame (g_out)
+	}
+
+	# Init kernel data structures.
+	call sgi_reset()
+	g_ndraw = 0
+end