sim

type Animator struct {

	//frames for rendering
	Frames []image.Image

	// as refernce to simulation variables
	Simulation *Simulation
	// contains filtered or unexported fields
}

type Cell struct {
	Particles []Particle

	// Bounds of Cell
	LowerLeft  Vec2
	UpperRight Vec2

	// Minimum Bounding Sphere
	BCenter Vec2
	BRadius float64

	// Children
	Lower *Cell
	Upper *Cell
}

type Kernel struct {
	F           func(q float64) float64
	FPrefactor  float64
	DF          func(q float64) float64
	DFPrefactor float64
}

type Orientation int

type Param struct {
	Title    string
	Subtitle string
	Name     string
}

type Particle struct {
	Pos Vec2
	Vel Vec2
	Rho float64 // Density
	C   float64 // Speed of sound
	E   float64 // Specific internal energy

	// Temporary values filled by Simulation
	EDot  float64 // specific internal energy change de/dt
	VDot  Vec2    // Acceleration
	EPred float64 // Predicted internal energy
	VPred Vec2    // Predicted Velicty

	// TODO: move this out of particles so we have smaller particle size! -> cache locality
	// @Speed might be bad because we have a big particle size now
	// should rather keep it seperate to prevent cache misses?
	// for now we just naively implement it like this
	// 32*(8+8)  = 512 bytes
	NearestNeighbours [NN_SIZE]*Particle
	NNDists           [NN_SIZE]float64
	NNPos             [NN_SIZE]Vec2 // keep track of position,  we need to know because of periodic b.c.

	// visualisation trick for depth rendering
	Z int
}

type ParticleSource interface {
	Spawn(t float64) []Particle
}

type Reflection struct {
	Offset     Vec2
	FromOrigin bool
}

type Simulation struct {
	Config SphConfig

	Root        *Cell // Tree structure for keeping track of spatial cells of particles
	Particles   []Particle
	CurrentStep int

	IsBusy sync.Mutex
}

type SphConfig struct {
	NSteps       int
	DeltaTHalf   float64
	Gamma        float64
	ParticleMass float64
	Acceleration Vec2

	Kernel Kernel

	HorPeriodicity  [2]float64 // -math.MaxFloat64, math.MaxFloat64 is open
	VertPeriodicity [2]float64 // -math.MaxFloat64, math.MaxFloat64 is open

	Reflections []Reflection
	Sources     []ParticleSource
	Start       []ParticleSource

	Viewport [2]Vec2 // upperleft and lower right
}

type Token struct {
	Type    TokenType
	AsStr   string
	AsInt   int64
	AsFloat float64
	AsVec2  Vec2

	// if it's a parameter
	Name string

	// info for error reporting
	Line  int
	Row   int
	Fname *string
}

type TokenType int

type Tokenizer struct {
	// contains filtered or unexported fields
}

type UniformRectSpawner struct {
	UpperLeft  Vec2
	LowerRight Vec2
	NParticles int
}

type Vec2 struct {
	X, Y float64
}

type Vec2i struct {
	X, Y int
}