stm32-conway-update.cpp

stm32-conway-update.cpp

void Conway64::update()
{
	// From my book Python Playground
	// https://www.nostarch.com/pythonplayground

	// copy grid since we require 8 neighbors for calculation
    // and we go line by line
	BitBuf88 _newGrid = _grid;
	uint8_t N = 8;
	// compute 8-neighbour sum
	// using toroidal boundary conditions - x and y wrap around
	// so that the simulaton takes place on a toroidal surface.
	for(int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			int total = 0;
			// count
			if(_grid.get(i, (uint8_t)(j-1)%N))
				total++;
			if(_grid.get(i, (j+1)%N))
				total++;
			if(_grid.get((uint8_t)(i-1)%N, j))
				total++;
			if(_grid.get((i+1)%N, j))
				total++;
			if(_grid.get((uint8_t)(i-1)%N, (uint8_t)(j-1)%N))
				total++;
			if(_grid.get((uint8_t)(i-1)%N, (j+1)%N))
				total++;
			if(_grid.get((i+1)%N, (uint8_t)(j-1)%N))
				total++;
			if(_grid.get((i+1)%N, (j+1)%N))
				total++;

			// apply Conway's rules
			if (_grid.get(i, j)) {
				if ((total < 2) || (total > 3)) {
					_newGrid.clr(i, j);
				}
			}
			else {
				if (total == 3) {
					_newGrid.set(i, j);
				}
			}
		}
	}

	// render
	_max7219->setBuffer(_newGrid);

	// update data
	_grid = _newGrid;
}