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I'm getting back into Pico programming and wanted to do some demoscene effects to warm me up like simple sinewave text. Have trouble with math behind it though.

I want to do first as simple bopping up/down sprite that uses sine behind it. I want to be able to control its amplitude (defined as y offset in pixels from the baseline) and frequency (speed). For now I have formula that goes somewhere like:

basey+Sin(upoffset+(t*speed))

where upoffset is mentioned amplitude control defined as max possible deviation from baseline, whether positive or negative, t is time elapsed since start (needed so it will actually bop instead of staying in place) and speed is, well, speed.

Unfortunately speed is somewhat coupled with amp control so when I try to increase speed at which things go, it gets too high/low and vice versa - changing amplitude changes speed at which things go.

Any help? This is best I could come up with and at the rate I'm pulling my hair right now, I estimate to go blind in 36 minutes, 43 seconds and 234 milliseconds.

No need for sample code, the formula will do.

P#19516 2016-03-31 18:19 ( Edited 2016-04-01 09:15)

it seems your upoffset should be outside of the sin :
basey + sin(tspeed)upoffset

P#19517 2016-03-31 19:15 ( Edited 2016-03-31 23:15)

Hm, okay, will test it out. Thanks, man.

P#19527 2016-04-01 05:02 ( Edited 2016-04-01 09:02)

Works great! Thanks again!

P#19528 2016-04-01 05:15 ( Edited 2016-04-01 09:15)

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