# tpic specials commands

The origin of the position of each graphical element is the page position maintained by TeX. The direction to the right is the positive direction of the X axis. The downward direction is the positive direction of the Y axis. The coordinates are represented by integers in milli-inch (0.254 mm) units.
An angle is measured in radian units clockwise from the positive direction of the X axis and has a value from 0 to "2 times pi". By the command for drawing arcs, with setting the starting angle to zero and the final angle to "2 times pi" or more, a full circle or an ellipse can be drawn.
\special{pn s}% The line width is set to s milli-inches.
\special{pa x y}% The point (x, y) is added to the path.
\special{fp}% The path defined previously is drawn with the current line width. If shading is set and the path is closed, the interior of the path is painted. The number of points in the path is reset to zero.
\special{ip}% This is similar to \special{fp}, but the path is not drawn. If specified, there is shading.
\special{da f}% This is similar to \special{fp}, but the path is drawn with dashed line. f is a real number that specifies the length of each dash in inches (cf. tpic specials extensions).
\special{dt f}% This is similar to \special{fp}, but the path is drawn with a dotted line. f is a real number that specifies the gap between dots in inches.
\special{sp d}% This is similar to \special{fp}, but the path is drawn with spline curves. d is a real number that specifies the type of curve.
- If d = 0 or is omitted, solid lines are drawn.
- If d > 0, dashed lines are drawn. d is the length of a dash.
- If d < 0, dotted lines are drawn. -d is the gap between each dot.
\special{ar x y u v s e}% draws an arc centered on (x, y). s is the starting angle. e is the final angle. These real numbers are in radian units.
For a complete circle or ellipse, u and v represent the x and y radii, respectively. Otherwise, u=v, and an arc is drawn from s to e. If specified, there is shading.
\special{ia x y u v s e}% is similar to \special{ar x y u v s e}, but does not draw the arc. If specified, there is shading.
\special{sh s}%specifies shading. The interior of the closed figure (three or more pa's followed by fp or ip, or ar or ia) defined after this command is painted.
s is a real number between zero and one. Zero means paint over in white. Anything below the figure, including text, is complete erased. A value other than zero means gray. Anything below the figure is not erased but is painted gray.
The default is 0.5 and is gray. One means black. If s is not specified, the value 0.5 is used. Only the interior of a figure is shaded. The boundary lines are independent on this specification and have the current line width.
\special{wh}% Same as \special{sh 0}.
\special{bk}% Same as \special{sh 1}.