lesson1.txt

#color 0xffc3e1fe
#coord 305 17
#title The Subframe Lessons
#title 101: Preliminaries

#font 7px
#color 0xfffbfbbb
#coord 37 46
#section 1.1 What is an Update?

An update is an action that a particle performs every frame.

For example:
- CONV(METL) converts adjacent particles to METL.
- BTRY SPRKs conductors.
- SPRK'ed METL passes its SPRK to adjacent METL.

#section 1.2 Particle IDs

Every frame, particles are updated in order, starting from particle #1,
then particle #2, and so on. This number is called the particle's ID.

Every particle is assigned a unique ID upon creation and
does not change its ID throughout the simulation.

#section 1.3 Solid SPRK

Normally, METL can only stay SPRK'ed for a few frames before
entering a "reset" phase. This creates a flickering effect.

A solid SPRK is a SPRK that does not flicker.

Here, CONV(METL) converts the SPRK'ed METL into METL.
Then, BTRY SPRKs it.

Both happen in the same frame, before the particles are rendered.
Thus, you will always see the METL SPRK'ed.

Here, the BTRY's ID comes before the CONV's.
The METL is SPRK'ed, then converted back to METL each frame.

Thus, you will always see the METL not SPRK'ed.

#font 5px
#color 0xffbefcc4
#coord 410 48
#section Activity #1.1

Mouseover this INSL.

You should see #1227 here.

If not, press 'D'.
(This opens the 'Debug HUD')

This means that the INSL's ID is 1227.

It will be updated after particle #1226
but before particle #1228.

#section Activity #1.2

Press '~' to open the Lua console.
(You can close it by
pressing '~' again.)


Type


and press ENTER.

Now mouseover the CONV(METL)
and press SHIFT-F.

This updates all particles up to the
particle under your mouse.

Here, only particles up to the CONV(METL)
are updated; the BTRY is not updated.

So you should see the METL not SPRK'ed.

This "subframe debugging mode" is useful
for debugging and reverse engineering.

Press 'F' to complete the rest of
the particle updates in the frame.