rename Vec2 -> Vec

This commit is contained in:
faiface 2016-11-19 14:06:52 +01:00
parent 0974069426
commit 966f31a68e
1 changed files with 19 additions and 19 deletions

38
vec.go
View File

@ -6,10 +6,10 @@ import (
"math/cmplx" "math/cmplx"
) )
// Vec2 is a 2d vector type. It is unusually implemented as complex128 for convenience. Since Go // Vec is a 2d vector type. It is unusually implemented as complex128 for convenience. Since Go does
// does not allow operator overloading, implementing vector as a struct leads to a bunch of methods // not allow operator overloading, implementing vector as a struct leads to a bunch of methods for
// for addition, subtraction and multiplication of vectors. With complex128, much of this // addition, subtraction and multiplication of vectors. With complex128, much of this functionality
// functionality is given through operators. // is given through operators.
// //
// Create vectors with the V constructor: // Create vectors with the V constructor:
// //
@ -30,59 +30,59 @@ import (
// fmt.Println("this won't happend") // fmt.Println("this won't happend")
// } // }
// x := u.Unit().Dot(v.Unit()) // x := u.Unit().Dot(v.Unit())
type Vec2 complex128 type Vec complex128
// V returns a new 2d vector with the given coordinates. // V returns a new 2d vector with the given coordinates.
func V(x, y float64) Vec2 { func V(x, y float64) Vec {
return Vec2(complex(x, y)) return Vec(complex(x, y))
} }
// String returns the string representation of a vector u as "Vec2(x, y)". // String returns the string representation of a vector u as "Vec(x, y)".
func (u Vec2) String() string { func (u Vec) String() string {
return fmt.Sprintf("Vec2(%v, %v)", u.X(), u.Y()) return fmt.Sprintf("Vec(%v, %v)", u.X(), u.Y())
} }
// X returns the x coordinate of a vector u. // X returns the x coordinate of a vector u.
func (u Vec2) X() float64 { func (u Vec) X() float64 {
return real(u) return real(u)
} }
// Y returns the y coordinate of a vector u. // Y returns the y coordinate of a vector u.
func (u Vec2) Y() float64 { func (u Vec) Y() float64 {
return imag(u) return imag(u)
} }
// Len returns the length of a vector u. // Len returns the length of a vector u.
func (u Vec2) Len() float64 { func (u Vec) Len() float64 {
return cmplx.Abs(complex128(u)) return cmplx.Abs(complex128(u))
} }
// Angle returns the angle between a vector u and the x-axis. The result is in the range [-Pi, Pi]. // Angle returns the angle between a vector u and the x-axis. The result is in the range [-Pi, Pi].
func (u Vec2) Angle() float64 { func (u Vec) Angle() float64 {
return cmplx.Phase(complex128(u)) return cmplx.Phase(complex128(u))
} }
// Unit returns a vector of length 1 with the same angle as u. // Unit returns a vector of length 1 with the same angle as u.
func (u Vec2) Unit() Vec2 { func (u Vec) Unit() Vec {
return u / V(u.Len(), 0) return u / V(u.Len(), 0)
} }
// Scaled returns a vector u multiplied by k. // Scaled returns a vector u multiplied by k.
func (u Vec2) Scaled(k float64) Vec2 { func (u Vec) Scaled(k float64) Vec {
return u * V(k, 0) return u * V(k, 0)
} }
// Rotated returns a vector u rotated by the given angle in radians. // Rotated returns a vector u rotated by the given angle in radians.
func (u Vec2) Rotated(angle float64) Vec2 { func (u Vec) Rotated(angle float64) Vec {
return u * V(math.Cos(angle), math.Sin(angle)) return u * V(math.Cos(angle), math.Sin(angle))
} }
// Dot returns the dot product of vectors u and v. // Dot returns the dot product of vectors u and v.
func (u Vec2) Dot(v Vec2) float64 { func (u Vec) Dot(v Vec) float64 {
return u.X()*v.X() + u.Y()*v.Y() return u.X()*v.X() + u.Y()*v.Y()
} }
// Cross return the cross product of vectors u and v. // Cross return the cross product of vectors u and v.
func (u Vec2) Cross(v Vec2) float64 { func (u Vec) Cross(v Vec) float64 {
return u.X()*v.Y() - v.X()*u.Y() return u.X()*v.Y() - v.X()*u.Y()
} }