plot: fix disc and circle operations

Discs and circles were drawn on screen directly and later erased by
offscreen buffer.
This change puts them in line with other operations, which draw to
offscreen first and to screen when necessary

1 files changed, 23 insertions, 0 deletions

diff --git a/sys/src/cmd/plot/libplot/machdep.c b/sys/src/cmd/plot/libplot/machdep.c
index 64a2d7f91..191de27fc 100644
--- a/sys/src/cmd/plot/libplot/machdep.c
+++ b/sys/src/cmd/plot/libplot/machdep.c
@@ -34,6 +34,29 @@ m_clrwin(int x0, int y0, int x1, int y1, int c)
 	if(offscreen != screen && !buffer)
 		draw(screen, xlr(Rect(x0, y0, x1+1, y1+1)), getcolor(c), nil, ZP);
 }
+
+/*
+ * Draw circle at point p with radius rad in color c
+ */
+void
+m_circ(Point p, int rad, int c)
+{
+	ellipse(offscreen, p, rad, rad, 0, getcolor(c), ZP);
+	if (offscreen != screen && !buffer)
+		ellipse(screen, p, rad, rad, 0, getcolor(c), ZP);
+}
+
+/*
+ * Draw disc (filled circle) at point p with radius rad in color c
+ */
+void
+m_disc(Point p, int rad, int c)
+{
+	fillellipse(offscreen, p, rad, rad, getcolor(c), ZP);
+	if (offscreen != screen && !buffer)
+		fillellipse(screen, p, rad, rad, getcolor(c), ZP);
+}
+
 /*
  * Draw text between pointers p and q with first character centered at x, y.
  * Use color c.  Centered if cen is non-zero, right-justified if right is non-zero.