1 files changed, 144 insertions, 0 deletions
diff --git a/sys/gio/stdgraph/stgdrawch.x b/sys/gio/stdgraph/stgdrawch.x
new file mode 100644
index 00000000..fd317d2b
--- /dev/null
+++ b/sys/gio/stdgraph/stgdrawch.x
@@ -0,0 +1,144 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<math.h>
+include	<gset.h>
+include	<gki.h>
+include	"stdgraph.h"
+include	"font.h"
+
+define	ITALIC_TILT	0.30	# fraction of xsize to tilt italics at top
+define	MAXPTS		40	# max points in a char drawing polyline
+
+
+# STG_DRAWCHAR -- Draw a character of the given size and orientation at the
+# given position.
+
+procedure stg_drawchar (ch, x, y, xsize, ysize, orien, font)
+
+char	ch			# character to be drawn
+int	x, y			# lower left GKI coords of character
+int	xsize, ysize		# width, height of char in GKI units
+int	orien			# orientation of character (0 degrees normal)
+int	font			# desired character font
+
+pointer	pl, tx
+real	px, py, coso, sino, theta
+int	stroke, tab1, tab2, i, pen, mx, my
+int	save_ltype, save_lwidth, save_color
+int	bitupk()
+include	"font.com"
+include	"stdgraph.com"
+
+begin
+	if (ch < CHARACTER_START || ch > CHARACTER_END)
+	    i = '?' - CHARACTER_START + 1
+	else
+	    i = ch  - CHARACTER_START + 1
+
+	# Set the font.
+	if (SG_TXFONT(g_sg) != font) {
+	    call stg_ctrl1 ("TF", font - GT_ROMAN + 1)
+	    SG_TXFONT(g_sg) = font
+	}
+
+	# Since we will be using the polyline generator, set the polyline
+	# linetype to solid and save the current linetype for later restoration.
+
+	pl = SG_PLAP(g_sg)
+	tx = SG_TXAP(g_sg)
+	save_color = PL_COLOR(pl)
+	save_ltype = PL_LTYPE(pl)
+	save_lwidth = PL_WIDTH(pl)
+	PL_COLOR(pl) = TX_COLOR(tx)
+	PL_LTYPE(pl) = GL_SOLID
+	PL_WIDTH(pl) = 1
+
+	tab1 = chridx[i]
+	tab2 = chridx[i+1] - 1
+
+	theta = -DEGTORAD(orien)
+	coso = cos(theta)
+	sino = sin(theta)
+
+	do i = tab1, tab2 {
+	    stroke = chrtab[i]
+	    px  = bitupk (stroke, COORD_X_START,   COORD_X_LEN)
+	    py  = bitupk (stroke, COORD_Y_START,   COORD_Y_LEN)
+	    pen = bitupk (stroke, COORD_PEN_START, COORD_PEN_LEN)
+
+	    # Scale size of character.
+	    px = px / FONT_WIDTH  * xsize
+	    py = py / FONT_HEIGHT * ysize
+
+	    # The italic font is implemented applying a tilt.
+	    if (font == GT_ITALIC)
+		px = px + ((py / ysize) * xsize * ITALIC_TILT)
+
+	    # Rotate and shift.
+	    mx = x + px * coso + py * sino
+	    my = y - px * sino + py * coso
+
+	    # Draw the line segment or move pen.
+	    if (pen == 0)
+		call sgch_move (mx, my)
+	    else
+		call sgch_draw (mx, my)
+	}
+
+	# Flush any remaining points.
+	call sgch_flush()
+
+	# Restore polyline linetype and color.
+	PL_LTYPE(pl) = save_ltype
+	PL_WIDTH(pl) = save_lwidth
+	PL_COLOR(pl) = save_color
+end
+
+
+# SGCH_MOVE -- Start accumulating a new polyline.
+
+procedure sgch_move (mx, my)
+
+int	mx, my
+short	pl[MAXPTS], op
+common	/sgchcm/ pl, op
+
+begin
+	call sgch_flush()
+
+	pl[1] = mx
+	pl[2] = my
+	op = 3
+end
+
+
+# SGCH_DRAW -- Add a point to the polyline.
+
+procedure sgch_draw (mx, my)
+
+int	mx, my
+short	pl[MAXPTS], op
+common	/sgchcm/ pl, op
+
+begin
+	pl[op] = mx
+	pl[op+1] = my
+	op = min (MAXPTS, op + 2)
+end
+
+
+# SGCH_FLUSH -- Flush the polyline to the output device.
+
+procedure sgch_flush()
+
+int	npts
+short	pl[MAXPTS], op
+common	/sgchcm/ pl, op
+
+begin
+	if (op > 2) {
+	    npts = op / 2
+	    call stg_polyline (pl, npts)
+	}
+	op = 1
+end