Page 110	Table of Contents	Index	Page 112
	Chapters
	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 A, B, C, D, E

---

CHAPTER 12. GRAPHICS


12.7.3 Port-specific Drawing Functions

The following port-specific functions are required by the drawing functions in the API. If the
optional arguments to these functions are not supplied, they are defaulted from the medium.

=> port-draw-point* port medium x y &optional ink line-style clipping-region [Generic Function]
Draws a point on the medium medium on the port port. The point is drawn at the position that
results from applying the device transformation to (x;y).

=> port-draw-points* port medium coord-seq &optional ink line-style clipping-region [Generic Function]
Draws a set of points on the medium medium on the port port. coord-seq is a sequence of
coordinate pairs, which are real numbers. It is an error if coord-seq does not contain an even
number of elements. port-draw-points* could be implemented by repeatedly calling port-
draw-point*, but some ports may support faster primitives to do this.

=> port-draw-line* port medium x1 y1 x2 y2 &optional ink line-style clipping-region [Generic Function]
Draws a line on the medium medium on the port port. The device transformation is applied to
(x1;y1) to (x2;y2), and the line is drawn from one transformed endpoint to the other.

=> port-draw-lines* port medium coord-seq &optional ink line-style clipping-region [Generic Function]
Draws a set of disconnected lines on the medium medium on the port port. coord-seq is a
sequence of coordinate pairs, which are real numbers. It is an error if coord-seq does not contain
an even number of elements. port-draw-lines* could be implemented by repeatedly calling
port-draw-line*, but some ports may support faster primitives to do this.

=> port-draw-polygon* port medium coord-seq closed &optional ink line-style clipping-region [Generic Function]
Draws a polygon or polyline on the medium medium on the port port. When line-style is nil,
this draws a filled polygon; otherwise, line-style is the line style to use when drawing a set of
connected lines. coord-seq is a sequence of coordinate pairs, which are real numbers. It is an
error if coord-seq does not contain an even number of elements. The coordinate sequence specifies
the corners of the polygon; the device transformation is applied to each of the coordinates to
produce the corners of the rendered polygon.

When port-draw-polygon* is drawing a set of connected lines, then if closed is true, a closed
polygon is drawn. If closed is false, the polygon will not be closed.

=> port-draw-rectangle* port medium x1 y1 x2 y2 &optional ink line-style clipping-region [Generic Function]

---

Page 110	Table of Contents	Index	Page 112
	Chapters
	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 A, B, C, D, E