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Diffstat (limited to 'vendor/github.com/golang/geo/s2/matrix3x3.go')
| -rw-r--r-- | vendor/github.com/golang/geo/s2/matrix3x3.go | 127 |
1 files changed, 0 insertions, 127 deletions
diff --git a/vendor/github.com/golang/geo/s2/matrix3x3.go b/vendor/github.com/golang/geo/s2/matrix3x3.go deleted file mode 100644 index 01696fe83..000000000 --- a/vendor/github.com/golang/geo/s2/matrix3x3.go +++ /dev/null @@ -1,127 +0,0 @@ -// Copyright 2015 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 s2 - -import ( - "fmt" - - "github.com/golang/geo/r3" -) - -// matrix3x3 represents a traditional 3x3 matrix of floating point values. -// This is not a full fledged matrix. It only contains the pieces needed -// to satisfy the computations done within the s2 package. -type matrix3x3 [3][3]float64 - -// col returns the given column as a Point. -func (m *matrix3x3) col(col int) Point { - return Point{r3.Vector{m[0][col], m[1][col], m[2][col]}} -} - -// row returns the given row as a Point. -func (m *matrix3x3) row(row int) Point { - return Point{r3.Vector{m[row][0], m[row][1], m[row][2]}} -} - -// setCol sets the specified column to the value in the given Point. -func (m *matrix3x3) setCol(col int, p Point) *matrix3x3 { - m[0][col] = p.X - m[1][col] = p.Y - m[2][col] = p.Z - - return m -} - -// setRow sets the specified row to the value in the given Point. -func (m *matrix3x3) setRow(row int, p Point) *matrix3x3 { - m[row][0] = p.X - m[row][1] = p.Y - m[row][2] = p.Z - - return m -} - -// scale multiplies the matrix by the given value. -func (m *matrix3x3) scale(f float64) *matrix3x3 { - return &matrix3x3{ - [3]float64{f * m[0][0], f * m[0][1], f * m[0][2]}, - [3]float64{f * m[1][0], f * m[1][1], f * m[1][2]}, - [3]float64{f * m[2][0], f * m[2][1], f * m[2][2]}, - } -} - -// mul returns the multiplication of m by the Point p and converts the -// resulting 1x3 matrix into a Point. -func (m *matrix3x3) mul(p Point) Point { - return Point{r3.Vector{ - m[0][0]*p.X + m[0][1]*p.Y + m[0][2]*p.Z, - m[1][0]*p.X + m[1][1]*p.Y + m[1][2]*p.Z, - m[2][0]*p.X + m[2][1]*p.Y + m[2][2]*p.Z, - }} -} - -// det returns the determinant of this matrix. -func (m *matrix3x3) det() float64 { - // | a b c | - // det | d e f | = aei + bfg + cdh - ceg - bdi - afh - // | g h i | - return m[0][0]*m[1][1]*m[2][2] + m[0][1]*m[1][2]*m[2][0] + m[0][2]*m[1][0]*m[2][1] - - m[0][2]*m[1][1]*m[2][0] - m[0][1]*m[1][0]*m[2][2] - m[0][0]*m[1][2]*m[2][1] -} - -// transpose reflects the matrix along its diagonal and returns the result. -func (m *matrix3x3) transpose() *matrix3x3 { - m[0][1], m[1][0] = m[1][0], m[0][1] - m[0][2], m[2][0] = m[2][0], m[0][2] - m[1][2], m[2][1] = m[2][1], m[1][2] - - return m -} - -// String formats the matrix into an easier to read layout. -func (m *matrix3x3) String() string { - return fmt.Sprintf("[ %0.4f %0.4f %0.4f ] [ %0.4f %0.4f %0.4f ] [ %0.4f %0.4f %0.4f ]", - m[0][0], m[0][1], m[0][2], - m[1][0], m[1][1], m[1][2], - m[2][0], m[2][1], m[2][2], - ) -} - -// getFrame returns the orthonormal frame for the given point on the unit sphere. -func getFrame(p Point) matrix3x3 { - // Given the point p on the unit sphere, extend this into a right-handed - // coordinate frame of unit-length column vectors m = (x,y,z). Note that - // the vectors (x,y) are an orthonormal frame for the tangent space at point p, - // while p itself is an orthonormal frame for the normal space at p. - m := matrix3x3{} - m.setCol(2, p) - m.setCol(1, Point{p.Ortho()}) - m.setCol(0, Point{m.col(1).Cross(p.Vector)}) - return m -} - -// toFrame returns the coordinates of the given point with respect to its orthonormal basis m. -// The resulting point q satisfies the identity (m * q == p). -func toFrame(m matrix3x3, p Point) Point { - // The inverse of an orthonormal matrix is its transpose. - return m.transpose().mul(p) -} - -// fromFrame returns the coordinates of the given point in standard axis-aligned basis -// from its orthonormal basis m. -// The resulting point p satisfies the identity (p == m * q). -func fromFrame(m matrix3x3, q Point) Point { - return m.mul(q) -} |