CA fluid simulation

CelularAutomataFluidSimulation.cpp

// part of the code useful for a stochastic fluid dynamics simulation based on a triangle grid of celular automata

typedef unsigned uint;


struct Dot {
	bool current, next;

	uint nextCounters; // number of potential particles which want to occupy this place
};

//bool unevenLineInZDirection = ((x) % 2) ^ ((y) % 2);

const uint NUMBER_OF_NEIGHBORS = 8;

Dot *searchDotWithIndexWhichIsNotNextOccupied(Dot *neighbors[NUMBER_OF_NEIGHBORS], uint usedNeighbors, uint index) {
	uint currentIndex = 0;

	for( uint i = 0; i < usedNeighbors; i++ ) {
		if( !neighbors[i]->next ) {
			if( currentIndex == index ) {
				return neighbors[i];
			}

			currentIndex++;
		}
	}

	// TODO< throw something >
	return (Dot*)0;
}

uint countUnoccupiedNeighbors(Dot *neighbors[NUMBER_OF_NEIGHBORS], uint usedNeighbors) {
	uint neightborOccupiedCounter = 0;

	for( uint i = 0; i < usedNeighbors; i++ ) {
		if( !neighbors[i]->next ) {
			neightborOccupiedCounter++;
		}
	}

	return neightborOccupiedCounter;
}

void moveToNeighborByRandom(Dot *currentDot, Dot *neighbors[NUMBER_OF_NEIGHBORS], uint usedNeighbors, uint rng) {
	if( !currentDot->current ) {
		return;
	}

	uint neightborOccupiedCounter = countUnoccupiedNeighbors(neighbors, usedNeighbors);

	if( neightborOccupiedCounter == usedNeighbors ) {
		// if all neighbors are occupied we can't move it to a enightbor node
	}
	else {
		// choose another dot and move the current dot to it
		uint destinationIndex = rng % neightborOccupiedCounter;
		Dot *notOccupiedDestination = searchDotWithIndexWhichIsNotNextOccupied(neighbors, usedNeighbors, destinationIndex);
		
		notOccupiedDestination->nextCounters++;
		currentDot->next = false;
		
	}
}