public void Execute(int index)
{
float2 position = particles[index].position;
int hash = GridHashUtilities.Hash(position, radius);
hashMap.Add(hash, index);
}
public void Execute(int index)
{
float2 forcePressure = 0;
float2 forceViscosity = 0;
WaterParticle2D pi = particles[index];
for (int i = 0; i < cellOffset.Length; i++)
{
float2 position = pi.position + (float2)cellOffset[i] * particleRadius;
int bucketIndex = GridHashUtilities.Hash(position, particleRadius);
NativeMultiHashMapIterator <int> iterator;
bool hasValue = hashMap.TryGetFirstValue(bucketIndex, out int j, out iterator);
while (hasValue)
{
if (index == j)
{
hasValue = hashMap.TryGetNextValue(out j, ref iterator);
continue;
}
WaterParticle2D pj = readOnlyParticles[j]; // particles[j];
float2 diff = pj.position - pi.position;
float distanceSquared = math.lengthsq(diff);
if (distanceSquared < particleRadiusSquared)
{
float distance = math.sqrt(distanceSquared);
float radiusRatio = particleRadius - distance;
float2 normalizedDir = diff / distance;
forcePressure += -normalizedDir * MASS * (pi.pressure + pj.pressure) / (2f * pj.density) * SPIKY_GRAD * radiusRatio * radiusRatio;
forceViscosity += VISC * MASS * (pj.velocity - pi.velocity) / pj.density * VISC_LAP * (particleRadius - distance);
}
hasValue = hashMap.TryGetNextValue(out j, ref iterator);
}
}
float2 forceFravity = GRAVITY * pi.density;
pi.force = forcePressure + forceViscosity + forceFravity;
particles[index] = pi;
}
public void Execute(int index)
{
WaterParticle2D pi = particles[index];
pi.density = 0;
for (int i = 0; i < cellOffset.Length; i++)
{
float2 position = pi.position + (float2)cellOffset[i] * particleRadius;
int bucketIndex = GridHashUtilities.Hash(position, particleRadius);
NativeMultiHashMapIterator <int> iterator;
bool hasValue = hashMap.TryGetFirstValue(bucketIndex, out int j, out iterator);
while (hasValue)
{
WaterParticle2D pj = readOnlyParticles[j]; // particles[j];
float2 diff = pj.position - pi.position;
float distanceSq = math.lengthsq(diff);
if (distanceSq < particleRadiusSquared)
{
float ratio = particleRadius - math.sqrt(distanceSq);
pi.density += MASS * POLY6 * ratio * ratio * ratio;
//float squaredRatio = particleRadiusSquared - distanceSq;
//pi.density += MASS * POLY6 * squaredRatio * squaredRatio * squaredRatio;
}
hasValue = hashMap.TryGetNextValue(out j, ref iterator);
}
}
pi.pressure = GAS_CONST * (pi.density - REST_DENS);
particles[index] = pi;
}
