FireworksXY
Just in time for the fireworks season, here’s a (slightly) revised version of the Fireworks simulation I wrote a couple of years ago. This revised sketch Fireworks sketch should scale to different XY matrix sizes more easily.
The code is here: https://gist.github.com/kriegsman/68929cbd1d6de4535b20 (and is still not terribly-well commented as these things go, but it’s a good starting point). It should be relatively portable; let us know what you get it running on … maybe post a video!
Enjoy, and have a happy, exciting, and safe (safety third!) 4th of July weekend!
http://www.youtube.com/watch?v=v4_nrWii6tY
Love it , I can 't stop staring at my matrix lol , great coding Mark.
Thanks for sharing! I can’t wait to try it on my 32x32 matrix! I hope to try it out tonight and post video.
Not sure if I’d mentioned this in the past, but the ‘Fireworks Simulator’ on STEAM at http://store.steampowered.com/app/323780/ could also provide some inspiration.
Most of this code is two years old; I feel I could do better if I started from scratch, but it makes me happy to share this around even as is. There are newer and fancier simulations (thanks for the specific links!) and I encourage everyone to experiment, and share their results!
Awesome-sauce!
If you have a matrix with serpentine layout, replace method XY with this one (same author):
CRGB& XY( byte x, byte y) {
uint16_t i;
x -= PIXEL_X_OFFSET;
y -= PIXEL_Y_OFFSET;
if( x > PIXEL_WIDTH || y > PIXEL_HEIGHT) {
return overrun;
}
if( kMatrixSerpentineLayout == false) {
i = (y * PIXEL_WIDTH) + x;
}
if( kMatrixSerpentineLayout == true) {
if( y & 0x01) {
// Odd rows run backwards
uint8_t reverseX = (PIXEL_WIDTH - 1) - x;
i = (y * PIXEL_WIDTH) + reverseX;
} else {
// Even rows run forwards
i = (y * PIXEL_WIDTH) + x;
}
}
return leds[i];
}
I wonder how well it would work on a 16x5 matrix 
Try removing the initial pixel offset subtraction. I’m not sure, what that is for. But it was in the original code.
Garett: there is one easy way to find out! 
Garrett: THAT a great idea! Hrm. I’d want to rethink it a bit but I suspect the answer is YES.
Also, I may have to tweak the code to handle more than 256 pixels. I have this habit of using the narrowest data types I need (ESPECIALLY on AVR), which is often just a byte. Just a habit born of long hours of optimizing code, I guess. Then I go to scale up, and oops-- need to upgrade to uint16_t!
I just adapted it for a 32x32 SmartMatrix: https://gist.github.com/jasoncoon/0cccc5ba7ab108c0a373
It needs some more tweaking. It’s a bit ‘jerky’, and some shells go off the top of the screen and wrap to the bottom. But it still looks great! Thanks again!
P.S. I only found one byte that I had to change to a uint16_t.
@Jason_Coon : maybe take a look at the groundlaunch method and reduce the “25” down to 20 or 15 and see if that helps with the escaped shells.
And I see that “dark blue sky twinkle” uint16_t there- I just updated the original. Thanks!
Looking over this two-year-old code, I bet if I wrote it from scratch today it’d be half as long. You know that feeling? And in open-source software, one tends to be a little more self-conscious than usual about that. But for now, I’ll just say Thanks, me-from-two-years-ago. It’s not bad.
@Thomas_Runge It now works on my 8x8 (homemade) Serpentine layout if I replace:
if( x > PIXEL_WIDTH || y > PIXEL_HEIGHT)
with:
if( x >= PIXEL_WIDTH || y >= PIXEL_HEIGHT)
Thanks for this!
@Thomas_Runge when I try and compile it says kMatrixSerpentineLayout was not declared? do I need to #DEFINE it? and if so how would I go about doing that? I have a 8x39 vertical zigzag matrix I would like to try this on, But when I try to edit the variables to make it work everything turns out a little funny?
@Aren_Hibbing Sure, just #define if you have serpentine layout or not. Reference: https://github.com/FastLED/FastLED/blob/master/examples/XYMatrix/XYMatrix.ino