pouët.net

.sS - A LINK BETWEEN WORLDS - Ss.

a SYNC production

256 byte intro for SOMMARHACK 2021

v1.1

It's easy to output graphics to the
screen when size-coding, as long as
you use built in TOS primitives.

But where's the fun in that.

The font used for this intro is a
BlueSTar creation, and is exactly
the same as used in {Closure} and in
our Audio Sculpture v1.5 cracktro.

The text is 30 characters long. The
characters used from the font are
7 lines high. This means the graphics
alone uses 210 of the allowed 256
bytes. The code needed to output to
the screen and to set up palette and
interrupts would need another 58 bytes
(highly highly optimized).

210+58 is 12 bytes over the limit.

We did not want to change the idea.
We did not want to change the text.

The intro thus contains an extremely
optimized packer, with some similarity
to lz77. The depacker takes 26 bytes.

The packed graphics uses 164 bytes
instead of the original 210. 58 plus
164 plus 26 is only 248 bytes, the
missing 8 are needed to handle where
to depack to.

In a 256 byte intro sizecoding compo
saving 10% on the graphics including
the size of the depacker is a big win.

And that's the technical challenge
motivating the release of this intro.
Now go download what we link to :)

/Troed of SYNC


v1.1 released two days after the compo
fixes a TOS 2.06 depacking corruption
- thanks goes out to ggn