WHIP format

Draw Contour Set

Purpose

The Draw Contour Set function draws a set of complex polygonal shaded regions.

Syntax

Opcode format	Opcode [ASCII] (Hex)	Operand Format	Comments
Extended ASCII	(ContourSet	<ws><I_CS-count>[<ws><I_P-counti>]⁺<ws><I_xl>,<I_yl>[<ws><I_xj>,<I_yj>]⁺	Absolute coordinates.
Single-byte, binary operand	[k] (71)	<B_CS-count>[<US_CS-Ecount>][<B_P-counti>[US_P-Ecounti>]]⁺<L_x1><L_y1>[<L_xj><L_yj>]⁺	Relative coordinates.
	[Ctrl-k] (11)	<B_CS-count>[<US_CS-Ecount>][<B_P-counti>[US_P-Ecounti>]]⁺<S_x1><S_y1>[<S_xj><S_yj>]⁺	Relative coordinates.

CS-count This is the number of contours in the contour set and it must be greater than zero. However, in the binary operand form, a value of zero for CS-count indicates that an extended count (CS-Ecount) will follow (as an unsigned short).

CS-Ecount When CS-count is zero, a 2-byte extended count follows allowing for values from 256 through 65,791 which are encoded as an integer (0 to 65,535).

P-count_i The number of points in the i^th contour. Must be 2 or greater. In the binary operand form, a value of zero for P-count indicates that an extended count (P-Ecount) will follow

P-Ecount When P-count is zero, a 2-byte extended count follows allowing for values from 256 through 65,791 which are encoded as an integer (0 to 65,535).

X₁,Y₁ The first point (in logical coordinates) in the first contour.

X_j,Y_j The j^th point (in logical coordinates) in the n^th contour.

Notes

Figure 1 shows a contour set example, representing the letter "A", that could be used for transmitting text in an outline font format. In the figure, CS-count=2, P-count₁=8 and P-count₂=3.

Figure 1. Contour set

Implementation in WHIP! Versions

Toolkit Function	TBD	Partial	Full	Revised in
Draw Contour Set	-	-	2.0	-