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author | 2024-08-02 11:46:41 +0000 | |
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committer | 2024-08-02 12:46:41 +0100 | |
commit | 94e87610c4ce9bbb1c614a61bab29c1422fed11b (patch) | |
tree | 2e06b8ce64212140e796f6077ba841b6cc678501 /vendor/github.com/golang/geo/r3/vector.go | |
parent | [feature] Allow import of following and blocks via CSV (#3150) (diff) | |
download | gotosocial-94e87610c4ce9bbb1c614a61bab29c1422fed11b.tar.xz |
[chore] add back exif-terminator and use only for jpeg,png,webp (#3161)
* add back exif-terminator and use only for jpeg,png,webp
* fix arguments passed to terminateExif()
* pull in latest exif-terminator
* fix test
* update processed img
---------
Co-authored-by: tobi <tobi.smethurst@protonmail.com>
Diffstat (limited to 'vendor/github.com/golang/geo/r3/vector.go')
-rw-r--r-- | vendor/github.com/golang/geo/r3/vector.go | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/vendor/github.com/golang/geo/r3/vector.go b/vendor/github.com/golang/geo/r3/vector.go new file mode 100644 index 000000000..ccda622f4 --- /dev/null +++ b/vendor/github.com/golang/geo/r3/vector.go @@ -0,0 +1,183 @@ +// Copyright 2014 Google Inc. All rights reserved. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package r3 + +import ( + "fmt" + "math" + + "github.com/golang/geo/s1" +) + +// Vector represents a point in ℝ³. +type Vector struct { + X, Y, Z float64 +} + +// ApproxEqual reports whether v and ov are equal within a small epsilon. +func (v Vector) ApproxEqual(ov Vector) bool { + const epsilon = 1e-16 + return math.Abs(v.X-ov.X) < epsilon && math.Abs(v.Y-ov.Y) < epsilon && math.Abs(v.Z-ov.Z) < epsilon +} + +func (v Vector) String() string { return fmt.Sprintf("(%0.24f, %0.24f, %0.24f)", v.X, v.Y, v.Z) } + +// Norm returns the vector's norm. +func (v Vector) Norm() float64 { return math.Sqrt(v.Dot(v)) } + +// Norm2 returns the square of the norm. +func (v Vector) Norm2() float64 { return v.Dot(v) } + +// Normalize returns a unit vector in the same direction as v. +func (v Vector) Normalize() Vector { + n2 := v.Norm2() + if n2 == 0 { + return Vector{0, 0, 0} + } + return v.Mul(1 / math.Sqrt(n2)) +} + +// IsUnit returns whether this vector is of approximately unit length. +func (v Vector) IsUnit() bool { + const epsilon = 5e-14 + return math.Abs(v.Norm2()-1) <= epsilon +} + +// Abs returns the vector with nonnegative components. +func (v Vector) Abs() Vector { return Vector{math.Abs(v.X), math.Abs(v.Y), math.Abs(v.Z)} } + +// Add returns the standard vector sum of v and ov. +func (v Vector) Add(ov Vector) Vector { return Vector{v.X + ov.X, v.Y + ov.Y, v.Z + ov.Z} } + +// Sub returns the standard vector difference of v and ov. +func (v Vector) Sub(ov Vector) Vector { return Vector{v.X - ov.X, v.Y - ov.Y, v.Z - ov.Z} } + +// Mul returns the standard scalar product of v and m. +func (v Vector) Mul(m float64) Vector { return Vector{m * v.X, m * v.Y, m * v.Z} } + +// Dot returns the standard dot product of v and ov. +func (v Vector) Dot(ov Vector) float64 { return v.X*ov.X + v.Y*ov.Y + v.Z*ov.Z } + +// Cross returns the standard cross product of v and ov. +func (v Vector) Cross(ov Vector) Vector { + return Vector{ + v.Y*ov.Z - v.Z*ov.Y, + v.Z*ov.X - v.X*ov.Z, + v.X*ov.Y - v.Y*ov.X, + } +} + +// Distance returns the Euclidean distance between v and ov. +func (v Vector) Distance(ov Vector) float64 { return v.Sub(ov).Norm() } + +// Angle returns the angle between v and ov. +func (v Vector) Angle(ov Vector) s1.Angle { + return s1.Angle(math.Atan2(v.Cross(ov).Norm(), v.Dot(ov))) * s1.Radian +} + +// Axis enumerates the 3 axes of ℝ³. +type Axis int + +// The three axes of ℝ³. +const ( + XAxis Axis = iota + YAxis + ZAxis +) + +// Ortho returns a unit vector that is orthogonal to v. +// Ortho(-v) = -Ortho(v) for all v. +func (v Vector) Ortho() Vector { + ov := Vector{0.012, 0.0053, 0.00457} + switch v.LargestComponent() { + case XAxis: + ov.Z = 1 + case YAxis: + ov.X = 1 + default: + ov.Y = 1 + } + return v.Cross(ov).Normalize() +} + +// LargestComponent returns the axis that represents the largest component in this vector. +func (v Vector) LargestComponent() Axis { + t := v.Abs() + + if t.X > t.Y { + if t.X > t.Z { + return XAxis + } + return ZAxis + } + if t.Y > t.Z { + return YAxis + } + return ZAxis +} + +// SmallestComponent returns the axis that represents the smallest component in this vector. +func (v Vector) SmallestComponent() Axis { + t := v.Abs() + + if t.X < t.Y { + if t.X < t.Z { + return XAxis + } + return ZAxis + } + if t.Y < t.Z { + return YAxis + } + return ZAxis +} + +// Cmp compares v and ov lexicographically and returns: +// +// -1 if v < ov +// 0 if v == ov +// +1 if v > ov +// +// This method is based on C++'s std::lexicographical_compare. Two entities +// are compared element by element with the given operator. The first mismatch +// defines which is less (or greater) than the other. If both have equivalent +// values they are lexicographically equal. +func (v Vector) Cmp(ov Vector) int { + if v.X < ov.X { + return -1 + } + if v.X > ov.X { + return 1 + } + + // First elements were the same, try the next. + if v.Y < ov.Y { + return -1 + } + if v.Y > ov.Y { + return 1 + } + + // Second elements were the same return the final compare. + if v.Z < ov.Z { + return -1 + } + if v.Z > ov.Z { + return 1 + } + + // Both are equal + return 0 +} |