SGA Vorticon Monospace README

If the above heading is incomprehensible to friends and family, congratulations! You have installed SGA Vorticon Monospace successfully.

SGA Vorticon Monospace is a TrueType font based on a vector trace of the font used on Vorticon signage in Commander Keen episodes two and three.

Installation

Archive contents

Punctuation, digits, etc.

Two versions of the sentence end glyph are available, neither of which appear in-game. The first is from an unused tile in EGALATCH.CK3 and is assigned to the Unicode code point U+002E FULL STOP (i.e. the period). The second is from a scanned printout of the complete Standard Galactic Alphabet, it is assigned to the code point U+2022 BULLET. To enter this character:

In the games themselves, the sentence end glyph appears in the lower-right corner of the bounding box of a text fragment, it never appears inline with text. The note at the end of episode five does not use this glyph at all; instead, the line ends after every sentence.

Quotation marks, parentheses, brackets, and curly braces are all based on a sign in episode one that places flourishes around the word "Pogo". These have been assigned to:

In addition, a symmetric version of the glyph is located at U+0022 QUOTATION MARK.

The digits were created from scratch, and were designed to fit with the English text in episode three.

Other punctuation marks in the ISO 8859-1 range map to empty space. Characters outside of this range are undefined and will be replaced with either empty space or a character from another font, depending on the software.

Aspect ratio

The MS-DOS Commander Keen games all run at 320 by 200 pixels. On a standard 4:3 aspect ratio monitor, this means that the pixels themselves will have an aspect ratio of 5:6. This has been compensated for in the font.

Stylistic tweaks

It is assumed that forcing the glyphs into aliased 16 by 16 pixel cells hides features that would be apparent at larger sizes. To add these "hidden" features, the traced outlines have been allowed to deviate – usually by no more than half a pixel – from the source bitmaps. The following summarizes the changes made to the glyphs to improve their appearance.

Three pixel horizonal and vertical stems are not quite the same width after aspect ratio correction. This has been corrected for.

A few objects that were not centered have been centered:

The dots in F and J have been made to be equally sized squares.

The gap in I has been made the same height as the gaps in J.

Based on the episode two/three glyph shape alone, A could be interpreted as having an angular top, but other versions of the glyph seem to indicate a curved top, which is what this font uses.

The two blocks in the S have been made the same size. The C has been similarly adjusted.

Most glyphs have either three pixel horizontal and vertical stems, but the H, I, J, K, and V have four pixel vertical stems that are centered horizontally. Similarly, the F, Q, and Z have four pixel wide dots that are centered horizontally. (While the topmost dot in the W is centered horizontally, the remaining two are not. Consequently, this character is disregarded here.) This font was made under the assumption that these stems and dots have the same width as the other three pixel wide stems, and that they were only made four pixels wide to keep the glyphs balanced.

Source code

Included in the archive are several extra files that can be used to regenerate VortMono.ttf. You will need FontForge, TTIComp, and optionally CacheTT and FastFont for this.

To build the font from scratch, do the following:

SGA Vorticon Monospace was originally designed with cubic splines, but TrueType uses quadratic splines. VortMonoCubic.sfd contains a version of the font with cubic splines, and VortMonoQuadratic.sfd contains a version with quadratic splines. VortMonoQuadratic.sfd can be generated from VortMonoCubic.sfd with Element -> Font Info... -> Layers -> All layers quadratic. Current versions of FontForge will generate identical versions of VortMono1.ttf from both SFD files, but this may change in the future – in particular, the TrueType points may be numbered differently when generated straight from VortMonoCubic.sfd, which would break VortMono.tti.

As of this writing, when FontForge generates a font from VortMonoQuadratic.sfd, it will warn about self-intersecting glyphs C, S, and Z. These warnings can safely be ignored. In actuality, shapes in these glyphs touch at corners, but they do not overlap.

VortMonoCubic.sfd/VortMonoQuadratic.sfd contain hints, but they are not of good quality, so they are not normally used in VortMono.ttf.

VortMono.tti will not compile with current versions of TTIComp. See the note near the beginning of prep() in VortMono.tti for details.

The file tweakvs.c is source code for a program that sets bit 4 in the flags of the 'head' table; this allows TrueType instructions to modify the advance width. It should support most modern C compilers (including GCC), and only requires a standard C library as a prerequisite.

Terms and Conditions

The author hereby dedicates this font and associated source code to the public domain inasmuch as a footnote in a README file has legal standing regarding such matters. Anyone may use this font for any purpose. There is no warranty; use this font at your own risk.

Version history