Basic properties and rules for drawing set of elements

Set of elements are stretchable and non-stretchable. Stretchable sets are those for which the termination sign is set, containing stretchable elements («Line» or «Space»). The end sign is intended to indicate the element of the set with which the contour should end. Any element of the set can be chosen as a end sign. For example, for drawing of a simple dashed line, you need to create a sequence of characters: «Line», «Space». If you specify the «Line» element as an end sign, then the open contour will begin and end with the dash: «Line», «Space», ... «Line». If you specify the «Space» element as an end sign, then the open contour will begin with a dash and end with a space: «Line», «Space», ... «Space». If the end sign is not selected, or the set does not have a «Line» or «Space» element, then the set of elements does not stretch. In this case, the contour can end with any element of the set.

Rules for drawing a set of elements:

1.        The initial contour is divided into relatively straight sections. Each section is drawn separately. If the total length of vector elements is 0, then the contour is not divided into sections; the factor of stretching (compression) of the elements is calculated for the entire contour. This makes it possible to approximate the correspondence of the lengths of the «Line» type elements to the nominal values.

2.        When drawing a non-stretchable set of elements, the contour is sequentially (in the order of description) filled with elements in accordance with the length of each element of the set. If last element of a contour is a «Vector sign» or «TrueType» sign, then if there is no space to draw the element onto its full length, the sign is not drawn. If the last element of a contour is a «Line« or «Space«, then its length is usually shorter than the nominal size.

3.        When drawing a stretchable set of elements, the stretch factor of the set elements is calculated for each section. «Vector sign» and «TrueType» sign elements do not stretch. Only «Line» and «Space» elements are stretched if there are no elements of the «Line» type). The stretch factor tends to range from 75 to 150 percent of the nominal size of the stretched elements. Example: if the line length is set to 2 mm, then when drawing a contour in different areas it can have a length from 1.5 to 3 mm. The longer the section, the closer the line sizes are to nominal - usually from 1.8 to 2.2 mm.

4.        If the first element of the stretched set line is a «Line» or «Space», and the first element of the set is the end sign, then each section of the contour begins and ends with half the length of the first element. In other cases, each section of the contour (stretchable set of elements) begins with a full-size initial element and ends with a full-size end sign.

Recommendations for creating a set of elements and examples