Introduction to hRasterizer

This page provides information about vector-based bitmap fonts and explains the role of hRasterizer.

Bitmap and vector fonts

Bitmaps describe shapes as arrays of dots (pixels).
Vectors describe shapes as mathematical curves (beziers).

Bitmap font formats such as .fon and .bdf are no longer supported in operating systems.
Vector font formats such as .otf and .ttf are supported in most environments today.

Contemporary ‘bitmap fonts’ are usually produced as vector fonts with a built-in grid – that is, all point coordinates, glyph widths, font metrics, etc. are multiples of a certain value. When such a font is used at its designed size (and multiples thereof), the grid in the font aligns with the pixel grid of the screen to produce the desired bitmaps.

Continuous and discontinous shapes

There are essentially two ways in which a vector-based bitmap font can be drawn:

Continuous shapes have a much smaller point count and are easier to manipulate and transform as a whole.

Discontinuous shapes are built out of several separate contours, making it easier to manipulate individual bits.

Contour and component elements

Discontinuous vector-based glyph shapes can be represented in two ways:

Contour elements are the most direct way to create elements, either by drawing each contour manually or using the Pixel Tool (recommended).

Component elements are references to an ‘element glyph’ in the same layer. Changes to this glyph are propagated automatically to all references in the font.

The role of hRasterizer

hRasterizer converts continuous shapes into discontinuous ones,
using contour- or component-based elements.

The automation provided by the tool makes it possible to use the more convenient continuous shapes while designing, and create discontinuous representations at any point of the design and production process.