Tag Archives: リサージュ

Font & Figure Creator!

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Those of you who own, or are building, an Oscilloclock may have realized how tedious it is to create a new character or drawing. My little Casper (October, Seasonal Treats post) required a grueling 5 hours to get him looking good!

Casper - as drawn by my son (L) and then the Oscilloclock (R)

Casper – as drawn by my son (L) and then the Oscilloclock (R)

The current method – Painful

I have another blog post series in progress describing the theory behind Circle Graphics figure display, so I won’t elaborate on details, but the current process of getting a figure from paper to screen is very much manual:

  1. Roughly sketch out your figure on graph paper.
  2. Split out your lines and curves into blanked circle and line segments.
  3. For each segment, roughly ascertain the circle’s radius (width and height) and centre coordinates.
  4. Type the numbers into the code file, in PIC assembly language syntax.
  5. Build the code and Program the PIC.
Easy?

NO.The figure looks NOTHING like you expect. The size is wrong. The edges don’t meet up. The curvature is out. The thing is upside down. All of the above!

  • Repeat steps 3, 4, 5 for several hours. Drink coffee. Redraw and repeat for yet another few hours.
    …
    …
  • Finally – Celebrate the birth of a new figure!

The Easier Way

The new Oscilloclock Figure Creator utility allows you to easily create and modify font characters, graphic images, and sprites – interactively.

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Circle Graphics – Lissajous figures

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By the time you read this post, you must have seen the term “Circle Graphics” in a thousand places across the site.

In fact, “Circle Graphics” is not an official term – I just use it to describe how shapes are drawn on these clocks:

Everything you see on this screen is made up of CIRCLES! Blank out part of a circle and you get an arc. Squish an arc and you get a line. This clock simply draws circles, lines, and arcs of different sizes at various points around the screen. It does it quickly. And it does it very, very well!

The effect of using circles is beautiful – shapes are smooth and precise, with no jagged edges or pixelation.

Beautiful circles with no jagged edges

Making “perfect” circles

I carry on as if it were some incredible new concept or discovery, like the Higgs boson. But in fact, the analog technique of constructing perfect circles, ovals, and lines on a CRT is very, very old. These figures are really part of a class of shapes called Lissajous Figures.

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