Vector font

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A vector font is a font whose character representations are not described by set or unset points within a rectangular dot matrix ( bitmap font ), but by a (possibly broken) line, represented by a list of the coordinates of the start and end points of the individual lines within a virtual dot matrix (whereby one of the corner points of this dot matrix is ​​usually assumed as the origin of coordinates). Since curved lines and filled areas can also be described using lines with the aid of additional attributes, all forms of characters can in principle be described using vector fonts.

Vector fonts can be displayed on a vector graphics screen or another vector graphics output device, or after rasterization using suitable methods on a raster graphics screen or raster printer.

In contrast to bitmap fonts, vector fonts can be scaled as required, i. That is, it can be enlarged as desired without any loss of quality. However, if the resolution of the output device falls below a certain limit, display problems arise because there are no longer enough pixels for the display. This problem can be delayed with the help of hints that are additionally inserted into the font file.

There are two types of vector fonts: With stroke fonts, the lines and their thicknesses are defined, with outline fonts the outlines are described.

Stroke font

The stroke-based vector fonts ( stroke font , stroke-based font ) were used early on in pen plotters . Since the memory requirement is smaller compared to the outline fonts, the stroke fonts are z. B. used for the description of Chinese characters . With very small resolutions, however, the legibility decreases, with very large resolutions, the proportions are no longer correct. METAFONT is a description language for the line-based vector fonts.

Outline font

With outline fonts, the contours are described mathematically. The most popular formats are OpenType , TrueType and Type 1 PostScript .

literature

  • Tom McReynolds, David Blythe: Advanced Graphics Programming Using OpenGL , Verlag Elsevier, 2005, ISBN 0-08-047572-8 , pages 523-525 [1]