函数：

void
gdk_draw_arc (GdkDrawable *drawable,
              GdkGC *gc,
              gboolean filled,
              gint x,
              gint y,
              gint width,
              gint height,
              gint angle1,
              gint angle2);

参数：

• drawable
  a GdkDrawable (a GdkWindow or a GdkPixmap).
• gc
  a GdkGC.
• filled
  TRUE if the arc should be filled, producing a ‘pie slice’.
• x
  the x coordinate of the left edge of the bounding rectangle.
• y
  the y coordinate of the top edge of the bounding rectangle.
• width
  the width of the bounding rectangle.
• height
  the height of the bounding rectangle.
• angle1
  the start angle of the arc, relative to the 3 o’clock position, counter-clockwise, in 1/64ths of a degree.
• angle2
  the end angle of the arc, relative to angle1 , in 1/64ths of a degree.

功能：

gdk_draw_arc has been deprecated since version 2.22 and should not be used in newly-written code.

Use cairo_arc() and cairo_fill() or cairo_stroke() instead. Note that arcs just like any drawing operation in Cairo are antialiased unless you call cairo_set_antialias().

Draws an arc or a filled ‘pie slice’. The arc is defined by the bounding rectangle of the entire ellipse, and the start and end angles of the part of the ellipse to be drawn.

小结:

可以画圆、弧线。

来源:
https://developer.gnome.org/gdk2/stable/gdk2-Drawing-Primitives.html#gdk-draw-arc