157 lines
3.3 KiB
Go
157 lines
3.3 KiB
Go
package engine
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import (
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"fmt"
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"image"
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"strconv"
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)
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// Int3 is a an element of int^3.
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type Int3 struct {
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X, Y, Z int
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}
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// Pt3(x, y, z) is shorthand for Int3{x, y, z}.
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func Pt3(x, y, z int) Int3 {
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return Int3{x, y, z}
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}
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// String returns a string representation of p like "(3,4,5)".
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func (p Int3) String() string {
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return "(" + strconv.Itoa(p.X) + "," + strconv.Itoa(p.Y) + "," + strconv.Itoa(p.Z) + ")"
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}
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// XY applies the Z-forgetting projection. (It returns just X and Y.)
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func (p Int3) XY() image.Point {
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return image.Point{p.X, p.Y}
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}
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// Add performs vector addition.
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func (p Int3) Add(q Int3) Int3 {
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return Int3{p.X + q.X, p.Y + q.Y, p.Z + q.Z}
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}
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// Sub performs vector subtraction.
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func (p Int3) Sub(q Int3) Int3 {
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return p.Add(q.Neg())
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}
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// CMul performs componentwise multiplication.
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func (p Int3) CMul(q Int3) Int3 {
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return Int3{p.X * q.X, p.Y * q.Y, p.Z * q.Z}
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}
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// Mul performs scalar multiplication.
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func (p Int3) Mul(k int) Int3 {
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return Int3{p.X * k, p.Y * k, p.Z * k}
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}
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// CDiv performs componentwise division.
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func (p Int3) CDiv(q Int3) Int3 {
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return Int3{p.X / q.X, p.Y / q.Y, p.Z / q.Z}
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}
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// Div performs scalar division by k.
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func (p Int3) Div(k int) Int3 {
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return Int3{p.X / k, p.Y / k, p.Z / k}
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}
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// Neg returns the vector pointing in the opposite direction.
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func (p Int3) Neg() Int3 {
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return Int3{-p.X, -p.Y, -p.Z}
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}
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// Coord returns the components of the vector.
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func (p Int3) Coord() (x, y, z int) {
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return p.X, p.Y, p.Z
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}
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// Sign returns a sign vector.
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func (p Int3) Sign() Int3 {
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return Int3{sign(p.X), sign(p.Y), sign(p.Z)}
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}
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// Dot returns the dot product of the two vectors.
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func (p Int3) Dot(q Int3) int {
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return p.X*q.X + p.Y*q.Y + p.Z*q.Z
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}
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func sign(m int) int {
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if m == 0 {
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return 0
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}
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if m < 0 {
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return -1
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}
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return 1
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}
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func signf(m float64) float64 {
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if m == 0 {
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return 0
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}
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if m < 0 {
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return -1
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}
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return 1
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}
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// Float3 is an element of float64^3.
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type Float3 struct {
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X, Y, Z float64
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}
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// String returns a string representation of p like "(3.0,4.0,5.0)".
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func (p Float3) String() string {
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return fmt.Sprintf("(%f,%f,%f)", p.X, p.Y, p.Z)
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}
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// Add performs vector addition.
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func (p Float3) Add(q Float3) Float3 {
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return Float3{p.X + q.X, p.Y + q.Y, p.Z + q.Z}
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}
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// Sub performs vector subtraction.
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func (p Float3) Sub(q Float3) Float3 {
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return p.Add(q.Neg())
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}
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// CMul performs componentwise multiplication.
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func (p Float3) CMul(q Float3) Float3 {
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return Float3{p.X * q.X, p.Y * q.Y, p.Z * q.Z}
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}
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// Mul performs scalar multiplication.
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func (p Float3) Mul(k float64) Float3 {
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return Float3{p.X * k, p.Y * k, p.Z * k}
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}
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// CDiv performs componentwise division.
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func (p Float3) CDiv(q Float3) Float3 {
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return Float3{p.X / q.X, p.Y / q.Y, p.Z / q.Z}
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}
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// Div performs scalar division by k.
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func (p Float3) Div(k float64) Float3 {
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return Float3{p.X / k, p.Y / k, p.Z / k}
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}
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// Neg returns the vector pointing in the opposite direction.
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func (p Float3) Neg() Float3 {
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return Float3{-p.X, -p.Y, -p.Z}
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}
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// Coord returns the components of the vector.
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func (p Float3) Coord() (x, y, z float64) {
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return p.X, p.Y, p.Z
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}
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// Sign returns a sign vector.
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func (p Float3) Sign() Float3 {
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return Float3{signf(p.X), signf(p.Y), signf(p.Z)}
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}
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// Dot returns the dot product of the two vectors.
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func (p Float3) Dot(q Float3) float64 {
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return p.X*q.X + p.Y*q.Y + p.Z*q.Z
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}
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