Glyphs

DRAW Reference Manual

Colours and Styles : Line Styles : Glyphs

Glyphs are used in conjunction with user-defined Linestyles to produce special effects, for example: symbols at the ends of lines or symbols drawn at regular intervals along the line.

A set of pre-defined Glyphs is provided, and you can also define your own, which are stored in the database.

Pre-defined Glyphs

25 pre-defined Glyphs are provided.

User-Defined Glyphs

User-defined Glyphs are defined in the database by GLYPH elements which are members of a Glyph Table (GLYTB) element. GLYPHs attributes are:


GLYNO:	A system defined attribute that has a unique value within the Multiple Database (MDB). It is this number that is be used when the Glyph is used in conjunction with a user-defined Linestyle.
REFSIZe:	(Integer) The value that is mapped to the DECSIZ attribute value of the LINEST when the Glyph is used. Thus if a Glyph with REFSIZ 2000 consisting of a circle of diameter 1000 is used in conjunction with a LINEST with DECSIZ 6mm the result is a line with 3mm diameter circles. The database default value is 100.
FUNCtion:	Text attribute for descriptive purposes

Note:

If you intend your glyph to be used as a terminal glyph on a line, the glyph will be placed such that the origin of the glyph will coincide with the end point of the line. For arrow-type glyphs, make sure the origin is at the point of the arrow.

GLYPH elements can own GLYCIR, GLYREC, and GLYOUT elements that represent circles, rectangles, and outlines. In addition to the basic attribute(s) that define their dimensions these glyph-primitive elements can be rotated and offset from the glyph origin, and can be solid-filled.

Element GLYCIRcle has attributes:


GDIAMeter:	(Integer) The diameter of the Circle.
GOFFSet:	(2 Integers) The X & Y offsets of the Circle centre point from the Glyph origin.
GFILLD:	If set TRUE causes the Circle to be solid-filled. By default this is FALSE.

Element GLYRECtangle has attributes:


GXLENgth:	(Integer) The length of the X-side of the Rectangle
GYLENgth:	(Integer) The length of the Y-side of the Rectangle.
GANGLE:	(Degrees) The rotation of the Rectangle about its centre point.
GOFFSet:	(2 Integers) The X & Y offsets of the Rectangle centre point from the Glyph origin.
GFILLD:	If set TRUE causes the Rectangle to be solid-filled. By default this is FALSE.

Element GLYOUTline has attributes:


GDEFINition:	(Integer array). A series of XY coordinates describing the Outline.
GANGLE:	(Degrees) The rotation of the Outline about its origin.
GOFFSet:	(2 Integers) The X & Y offsets of the Outline origin from the Glyph origin.
GFILLD:	If set TRUE causes the Outline to be solid-filled. By default this is FALSE.

A GLYOUT is a series of spans that can be straight lines or circular arcs. They can be continuous or discontinuous. The geometry of these is created using the syntax of the <GDEFIN> graph and stored in the GDEFIN attribute. The syntax is:


GDEFIN -- M/TO -- <int2> --\|-- L/TO -- <int2> --\|-- <int2> -- etc \| \| \| \|-- M/TO - etc \| \| \| \|-- L/TO - etc \| \| \| \|-- ANG/TO - etc \| \| \| `--> \| \| `-- ANG/TO -- <int3> -\|- <int3> - etc \| \|- M/TO - etc \| \|- L/TO - etc \| \|- ANG/TO - etc \| `-->


Where <int2>	represents the input of 2 integers to define the coordinates of the end point of a straight-line span,
<int3>	represents the input of 3 integers defining the angle subtended by a circular arc plus the coordinates of the end point of the arc. A positive angle denotes a counter-clockwise arc, a negative angle denotes a clockwise arc.

The sequence must start with the MTO (MoveTo) keyword followed by two integers, this defines the start point of the Outline. The LTO (LineTo) or ANGTO (AngleTo) keyword must then follow and then two or three integers respectively to define the first span. Having defined a span another similar span can be defined immediately by the input of two or three integers or alternatively the type of span can be changed by a LTO or ANGTO keyword. If a break in the Outline is required the MTO keyword must be used to define the start of a new sequence.

For example, a symbolic flower-head of reference diameter 120 with alternating filled and unfilled petals can be defined as:

NEW GLYPH

REFSIZ 120

NEW GLYOUT

GDEFIN MTO 10 0 LTO 50 -17 ANG 45 50 17 LTO 10 0

NEW GLYOUT COPY GLYOUT 1

GANGLE 45
GFILLD TRUE

NEW GLYOUT COPY GLYOUT 1

GANGLE 90

NEW GLYOUT COPY GLYOUT 1

GANGLE 135
GFILLD TRUE

NEW GLYOUT COPY GLYOUT 1