Purpose
Opcode format | Opcode
[ASCII] (Hex) |
Operand Format | Comments |
Single-byte - ASCII operand | [E] ((45) | [<ws>]<IX>,<IY><ws><IRh>,<IRv> | Absolute coordinates. |
Extended ASCII | (Ellipse | <ws><IX>,<IY><ws><IRh>,<IRv><ws><Istart>,<IEnd><ws><ITilt>[<ws>]) | Absolute coordinates. |
Single-byte - binary operand | [e] ((65) | <LX><LY><ULRh><ULRv><USStart><USEnd><USTilt> | Relative coordinates. |
Rh,Rv The horizontal and vertical radii (in logical coordinates) of the ellipse from the center point, before angle has been applied
Start, End The angles (in 360/65,536ths of a degree) that describe a "pie-slice" of the full ellipse to be rendered; legal values range from 0 to 65,535
Tilt The angle (in 360/65,536ths of a degree) to tilt the aligned ellipse; legal values range from 0 to 65,535
When the "Fill Mode" attribute is active, the Draw Ellipse function renders the interior of an ellipse in a solid color based on the Polygon drawing attributes, which include "Color", and "Visibility".
Some of the ellipse opcodes take Start and End arguments, which allow a portion of the specified ellipse to be rendered. This is shown in figure 1. With "Fill Mode" off, Start and End define an elliptical arc, and with "Fill Mode" on, an elliptical wedge is rendered. The Start and End values are integers that represent 360/65,536ths of a degree. A wedge or arc with the same Start and End points will be rendered as a complete ellipse.
Figure 1. Portion of ellipse rendered by Start and End arguments
When the "Fill Mode" attribute is active, a visually apparent outlining edge of the ellipse is not rendered. The filled Draw Ellipse function may be followed by an additional unfilled Draw Ellipse opcode to render the desired edge on top of the filled region. For an example, see the "Notes" section of the Draw Polyline/Polygon function.