8.3 Drawing Points, Lines, Rectangles, and Arcs

• A single point or multiple points

• A single line or multiple lines

• A single rectangle or multiple rectangles

• A single arc or multiple arcs

Some of the functions described in the following sections use these structures:

typedef struct {
	short x1, y1, x2, y2;
} XSegment;

typedef struct {
	short x, y;
} XPoint;

typedef struct {
	short x, y;
	unsigned short width, height;
} XRectangle;

typedef struct {
	short x, y;
	unsigned short width, height;
	short angle1, angle2;             /* Degrees * 64 */
} XArc;

All x and y members are signed integers. The width and height members are 16-bit unsigned integers. You should be careful not to generate coordinates and sizes out of the 16-bit ranges, because the protocol only has 16-bit fields for these values.

Next: Drawing Single and Multiple Points