mirror of
https://github.com/unidoc/unipdf.git
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86 lines
1.5 KiB
Go
86 lines
1.5 KiB
Go
/*
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* This file is subject to the terms and conditions defined in
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* file 'LICENSE.md', which is part of this source code package.
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*/
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package draw
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import "math"
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type Vector struct {
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Dx float64
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Dy float64
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}
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func NewVector(dx, dy float64) Vector {
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v := Vector{}
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v.Dx = dx
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v.Dy = dy
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return v
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}
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func NewVectorBetween(a Point, b Point) Vector {
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v := Vector{}
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v.Dx = b.X - a.X
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v.Dy = b.Y - a.Y
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return v
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}
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func NewVectorPolar(length float64, theta float64) Vector {
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v := Vector{}
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v.Dx = length * math.Cos(theta)
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v.Dy = length * math.Sin(theta)
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return v
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}
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func (v Vector) Add(other Vector) Vector {
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v.Dx += other.Dx
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v.Dy += other.Dy
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return v
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}
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func (v Vector) Rotate(phi float64) Vector {
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mag := v.Magnitude()
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angle := v.GetPolarAngle()
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return NewVectorPolar(mag, angle+phi)
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}
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// Flip changes the sign of the vector: -vector.
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func (this Vector) Flip() Vector {
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mag := this.Magnitude()
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theta := this.GetPolarAngle()
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this.Dx = mag * math.Cos(theta+math.Pi)
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this.Dy = mag * math.Sin(theta+math.Pi)
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return this
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}
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func (v Vector) FlipY() Vector {
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v.Dy = -v.Dy
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return v
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}
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func (v Vector) FlipX() Vector {
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v.Dx = -v.Dx
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return v
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}
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func (this Vector) Scale(factor float64) Vector {
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mag := this.Magnitude()
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theta := this.GetPolarAngle()
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this.Dx = factor * mag * math.Cos(theta)
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this.Dy = factor * mag * math.Sin(theta)
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return this
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}
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func (this Vector) Magnitude() float64 {
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return math.Sqrt(math.Pow(this.Dx, 2.0) + math.Pow(this.Dy, 2.0))
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}
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func (this Vector) GetPolarAngle() float64 {
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return math.Atan2(this.Dy, this.Dx)
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}
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