[jokosher-devel] SVG vs. PNG loading on startup

[Laszlo Pandy <laszlok2 gmail com>]

There was some discussion on IRC a little while ago about rendering all
our instrument SVG icons to PNG to improve loading speed, and thus
allowing our collection of instruments to increase without having to add
a splash screen.

I just recently did some profiling and got some real numbers or this.
All number include the entire _cacheInstrumentsGenerator() method;
meaning disk access, etc are included in these times.
Loading 16 instruments with SVG: 2.179 CPU seconds
Loading 16 instruments with PNG: 0.277 CPU seconds

This means that PNG are 7.9 times faster to load, and save almost 2 CPU
seconds at startup (in current SVN with 16 instruments). This number
will obviously get larger as we add instruments.

Also there are memory savings:
for SVG: VM 356.0, RAM 59.9
for PNG: VM 77.4, RAM 21.6

I was thinking that the PNGs could be created using make at install
time, however I created then using Inkscape's command line export
feature and I'm sure not everyone will have Inkscape installed.

The icons should still be developed in SVG format and kept this way in
the Jokosher art module, however unless SVG has some other advantages
that out way this increase in speed, I think we should have only PNGs in
the Instruments/images folder.

Laszlo