title	tags	created	published
Vector	note vector math	2023-08-29T11:59:28Z	true

2D

Angle

atan2(y, x)

Cross

x * y2 - y * x2

Distance

(a - b).Length()

Dot

x * x2 + y * y2

From angle

x = cos(angle)
y = sin(angle)

Length

sqrt(x * x + y * y)

Normalize

length := x * x + y * y

if length == 0 {
	return
}

length = sqrt(length)
x /= length
y /= length

3D

Cross

( y * z2 - z * y2,
  z * x2 - x * z2,
  x * y2 - y * x2 )

Distance

(a - b).Length()

Dot

x * x2 + y * y2 + z * z2

Length

sqrt(x * x + y * y + z * z)

Normalize

length := x * x + y * y + z * z

if length == 0 {
	return
}

length = sqrt(length)
x /= length
y /= length
z /= length