95 lines
2.1 KiB
Go
Executable File
95 lines
2.1 KiB
Go
Executable File
// CookieJar - A contestant's algorithm toolbox
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// Copyright (c) 2013 Peter Szilagyi. All rights reserved.
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//
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// CookieJar is dual licensed: use of this source code is governed by a BSD
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// license that can be found in the LICENSE file. Alternatively, the CookieJar
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// toolbox may be used in accordance with the terms and conditions contained
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// in a signed written agreement between you and the author(s).
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package geometry
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import (
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"math"
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)
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// Two dimensional vector.
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type Vec2 struct {
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X, Y float64
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}
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// Three dimensional vector.
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type Vec3 struct {
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X, Y, Z float64
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}
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// Allocates and returns a new 2D vector.
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func NewVec2(x, y float64) *Vec2 {
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return &Vec2{x, y}
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}
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// Allocates and returns a new 3D vector.
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func NewVec3(x, y, z float64) *Vec3 {
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return &Vec3{x, y, z}
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}
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// Returns the length of x.
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func (x *Vec2) Norm() float64 {
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return math.Sqrt(x.X*x.X + x.Y*x.Y)
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}
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// Returns the length of x.
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func (x *Vec3) Norm() float64 {
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return math.Sqrt(x.X*x.X + x.Y*x.Y + x.Z*x.Z)
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}
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// Sets z to the sum x+y and returns z.
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func (z *Vec2) Add(x, y *Vec2) *Vec2 {
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z.X, z.Y = x.X+y.X, x.Y+y.Y
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return z
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}
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// Sets z to the sum x+y and returns z.
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func (z *Vec3) Add(x, y *Vec3) *Vec3 {
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z.X, z.Y, z.Z = x.X+y.X, x.Y+y.Y, x.Z+y.Z
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return z
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}
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// Sets z to the difference x+y and returns z.
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func (z *Vec2) Sub(x, y *Vec2) *Vec2 {
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z.X, z.Y = x.X-y.X, x.Y-y.Y
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return z
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}
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// Sets z to the difference x+y and returns z.
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func (z *Vec3) Sub(x, y *Vec3) *Vec3 {
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z.X, z.Y, z.Z = x.X-y.X, x.Y-y.Y, x.Z-y.Z
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return z
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}
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// Sets y to x scaled by s and returns y.
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func (y *Vec2) Mul(x *Vec2, s float64) *Vec2 {
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y.X, y.Y = s*x.X, s*x.Y
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return y
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}
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// Sets y to x scaled by s and returns y.
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func (y *Vec3) Mul(x *Vec3, s float64) *Vec3 {
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y.X, y.Y, y.Z = s*x.X, s*x.Y, s*x.Z
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return y
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}
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// Returns the dot product of x and y.
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func (x *Vec2) Dot(y *Vec2) float64 {
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return x.X*y.X + x.Y*y.Y
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}
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// Returns the dot product of x and y.
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func (x *Vec3) Dot(y *Vec3) float64 {
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return x.X*y.X + x.Y*y.Y + x.Z*y.Z
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}
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// Returns the cross product of x and y.
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func (x *Vec2) Cross(y *Vec2) float64 {
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return x.X*y.Y - x.Y*y.X
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}
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