Performance optimization
Contents
Introduction
Gamebuino is a video game console which has limited hardware (8-bits CPU running at 16Mhz and 2KB of RAM...). It's far enough if you want to program Pong or Tetris, but if you plan to do some advanced games with multiplayer and artificial intelligence, you will probably have to optimize your game for it to run fast enough and fit in the chip's memory.
Most of the optimization work is done at high level, by using smart algorithms. But sometimes it's not enough, and to go further you have to get into more system-specific programming to gain speed and memory usage.
General optimization
Premature optimization
Don't optimize something that doesn't need to be. First write a clean code, something easy to read and maintain. Then, only if you actually need performance improvement, benchmark your code to know what is most time consuming and likely to be optimized. Don't try to guess what should be optimized, because you'll be wrong most of the time, and you'll spend time optimizing something that isn't the bottleneck.
Don't be smart
"You should think REALLY, REALLY hard about sacrificing code clarity for the sake of speed or space." westfw on Arduino forum
Other tips & tricks
System specific optimization
Minimum variables size
Gamebuino runs on an atmega328 microcontroller, which is a 8-bits platform. So if you use 8-bits variables, it will run (a lot) faster and consume (far) less memory (both ROM and RAM) than if you use 16 or 32 bit integers, or even 32 bit floats, which are very, very heavy and slow.
| Type | Values | Size |
|---|---|---|
| byte | 0..255 | 8 |
| char | -127..128 | 8 |
| int | -127..128 | 16 |
| unsigned int | 0..65,535 | 16 |
| int | −32,768..32,767 | 16 |
Loops
SPI
I2C / TWI
Clock frequency
Assembly language
Other tips & tricks
References
For further information, you can read the following :
