Fire Effects

[Xeda112358]

For all you BASIC programmers looking for a really neat effect to play with, here is something for you. This small assembly program (208 bytes) will let you set your screen or pictures on fire! As an example, you can check out my avatar (the screenies below). The program can be downloaded here.

My avatar (there are some particle effects included, too):


Have fun!

[rankinc]

Logical question ... How did you do this and what magic do I need to unlock in order to do this in different forms?

[Xeda112358]

It is actually pretty simple: You shift each pixel up and give it a 1/x chance of dying (that program uses 1/8 ). If you are using a color screen, you can have it go in several levels (cycling through color). You can assign red=4, darkorange=3, orange=2, yellow=1, black=0. If the pixel is not black, give it a 1/4 chance of decrementing to the next color. Magical, yes? I think I showed you my particle engine before, too, right?

EDIT: Also, after each frame, I OR the picture back onto the screen so that it keeps burning. If you are doing white fire, you will want to do the opposite of OR which in Z80 assembly is cpl \ and (hl) (invert the bytes from the picture and then use AND logic on the screen data).