public Particle(ParticlePropertyGroup properties, SKRect rect, Random rnd)
{
Position = properties.Spawn.SpawnPosition.CurrentValue switch
{
SpawnPosition.TopEdge => new SKPoint(rnd.RandomBetween(0, rect.Width), 0),
SpawnPosition.RightEdge => new SKPoint(rect.Width, rnd.RandomBetween(0, rect.Height)),
SpawnPosition.BottomEdge => new SKPoint(rnd.RandomBetween(0, rect.Width), rect.Height),
SpawnPosition.LeftEdge => new SKPoint(0, rnd.RandomBetween(0, rect.Height)),
SpawnPosition.Custom => new SKPoint(rect.Width * properties.Spawn.SpawnPositionPercent.CurrentValue.X,
rect.Height * properties.Spawn.SpawnPositionPercent.CurrentValue.Y),
_ => new SKPoint(rnd.RandomBetween(0, rect.Width), rnd.RandomBetween(0, rect.Height)),
};
Velocity = new SKPoint(
properties.Spawn.InitialXVelocityRange.CurrentValue.GetRandomValue(),
properties.Spawn.InitialYVelocityRange.CurrentValue.GetRandomValue()
);
Radius = properties.Spawn.SizeRange.CurrentValue.GetRandomValue();
Lifetime = 0;
MaxLifetime = properties.Spawn.MaxLifetimeRange.CurrentValue.GetRandomValue();
}
public void Update(ParticlePropertyGroup properties, double deltaTime)
{
if (deltaTime < 0)
{
return;//TODO
}
Lifetime += deltaTime;
Velocity = new SKPoint(
Velocity.X + (float)(properties.Physics.Acceleration.CurrentValue.X * deltaTime),
Velocity.Y + (float)(properties.Physics.Acceleration.CurrentValue.Y * deltaTime)
);
Velocity = new SKPoint(
Velocity.X * (float)Math.Pow(1 - properties.Physics.Drag.CurrentValue.X, deltaTime),
Velocity.Y * (float)Math.Pow(1 - properties.Physics.Drag.CurrentValue.Y, deltaTime)
);
Position = new SKPoint(
Position.X + Velocity.X,
Position.Y + Velocity.Y
);
Radius += (float)(properties.Physics.DeltaSize.CurrentValue * deltaTime);
}