Remove third_party/golang.org/x/mobile as it is no longer used with Go 1.5.

third_party/go/src/golang.org/x/mobile/f32/mat4.go

-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package f32
-
-import "fmt"
-
-// A Mat4 is a 4x4 matrix of float32 values.
-// Elements are indexed first by row then column, i.e. m[row][column].
-type Mat4 [4]Vec4
-
-func (m Mat4) String() string {
-        return fmt.Sprintf(`Mat4[% 0.3f, % 0.3f, % 0.3f, % 0.3f,
-     % 0.3f, % 0.3f, % 0.3f, % 0.3f,
-     % 0.3f, % 0.3f, % 0.3f, % 0.3f,
-     % 0.3f, % 0.3f, % 0.3f, % 0.3f]`,
-                m[0][0], m[0][1], m[0][2], m[0][3],
-                m[1][0], m[1][1], m[1][2], m[1][3],
-                m[2][0], m[2][1], m[2][2], m[2][3],
-                m[3][0], m[3][1], m[3][2], m[3][3])
-}
-
-func (m *Mat4) Identity() {
-        *m = Mat4{
-                {1, 0, 0, 0},
-                {0, 1, 0, 0},
-                {0, 0, 1, 0},
-                {0, 0, 0, 1},
-        }
-}
-
-func (m *Mat4) Eq(n *Mat4, epsilon float32) bool {
-        for i := range m {
-                for j := range m[i] {
-                        diff := m[i][j] - n[i][j]
-                        if diff < -epsilon || +epsilon < diff {
-                                return false
-                        }
-                }
-        }
-        return true
-}
-
-// Mul stores a × b in m.
-func (m *Mat4) Mul(a, b *Mat4) {
-        // Store the result in local variables, in case m == a || m == b.
-        m00 := a[0][0]*b[0][0] + a[0][1]*b[1][0] + a[0][2]*b[2][0] + a[0][3]*b[3][0]
-        m01 := a[0][0]*b[0][1] + a[0][1]*b[1][1] + a[0][2]*b[2][1] + a[0][3]*b[3][1]
-        m02 := a[0][0]*b[0][2] + a[0][1]*b[1][2] + a[0][2]*b[2][2] + a[0][3]*b[3][2]
-        m03 := a[0][0]*b[0][3] + a[0][1]*b[1][3] + a[0][2]*b[2][3] + a[0][3]*b[3][3]
-        m10 := a[1][0]*b[0][0] + a[1][1]*b[1][0] + a[1][2]*b[2][0] + a[1][3]*b[3][0]
-        m11 := a[1][0]*b[0][1] + a[1][1]*b[1][1] + a[1][2]*b[2][1] + a[1][3]*b[3][1]
-        m12 := a[1][0]*b[0][2] + a[1][1]*b[1][2] + a[1][2]*b[2][2] + a[1][3]*b[3][2]
-        m13 := a[1][0]*b[0][3] + a[1][1]*b[1][3] + a[1][2]*b[2][3] + a[1][3]*b[3][3]
-        m20 := a[2][0]*b[0][0] + a[2][1]*b[1][0] + a[2][2]*b[2][0] + a[2][3]*b[3][0]
-        m21 := a[2][0]*b[0][1] + a[2][1]*b[1][1] + a[2][2]*b[2][1] + a[2][3]*b[3][1]
-        m22 := a[2][0]*b[0][2] + a[2][1]*b[1][2] + a[2][2]*b[2][2] + a[2][3]*b[3][2]
-        m23 := a[2][0]*b[0][3] + a[2][1]*b[1][3] + a[2][2]*b[2][3] + a[2][3]*b[3][3]
-        m30 := a[3][0]*b[0][0] + a[3][1]*b[1][0] + a[3][2]*b[2][0] + a[3][3]*b[3][0]
-        m31 := a[3][0]*b[0][1] + a[3][1]*b[1][1] + a[3][2]*b[2][1] + a[3][3]*b[3][1]
-        m32 := a[3][0]*b[0][2] + a[3][1]*b[1][2] + a[3][2]*b[2][2] + a[3][3]*b[3][2]
-        m33 := a[3][0]*b[0][3] + a[3][1]*b[1][3] + a[3][2]*b[2][3] + a[3][3]*b[3][3]
-        m[0][0] = m00
-        m[0][1] = m01
-        m[0][2] = m02
-        m[0][3] = m03
-        m[1][0] = m10
-        m[1][1] = m11
-        m[1][2] = m12
-        m[1][3] = m13
-        m[2][0] = m20
-        m[2][1] = m21
-        m[2][2] = m22
-        m[2][3] = m23
-        m[3][0] = m30
-        m[3][1] = m31
-        m[3][2] = m32
-        m[3][3] = m33
-}
-
-// Perspective sets m to be the GL perspective matrix.
-func (m *Mat4) Perspective(fov Radian, aspect, near, far float32) {
-        t := Tan(float32(fov) / 2)
-
-        m[0][0] = 1 / (aspect * t)
-        m[1][1] = 1 / t
-        m[2][2] = -(far + near) / (far - near)
-        m[2][3] = -1
-        m[3][2] = -2 * far * near / (far - near)
-}
-
-// Scale sets m to be a scale followed by p.
-// It is equivalent to
-//      m.Mul(p, &Mat4{
-//              {x, 0, 0, 0},
-//              {0, y, 0, 0},
-//              {0, 0, z, 0},
-//              {0, 0, 0, 1},
-//      }).
-func (m *Mat4) Scale(p *Mat4, x, y, z float32) {
-        m[0][0] = p[0][0] * x
-        m[0][1] = p[0][1] * y
-        m[0][2] = p[0][2] * z
-        m[0][3] = p[0][3]
-        m[1][0] = p[1][0] * x
-        m[1][1] = p[1][1] * y
-        m[1][2] = p[1][2] * z
-        m[1][3] = p[1][3]
-        m[2][0] = p[2][0] * x
-        m[2][1] = p[2][1] * y
-        m[2][2] = p[2][2] * z
-        m[2][3] = p[2][3]
-        m[3][0] = p[3][0] * x
-        m[3][1] = p[3][1] * y
-        m[3][2] = p[3][2] * z
-        m[3][3] = p[3][3]
-}
-
-// Translate sets m to be a translation followed by p.
-// It is equivalent to
-//      m.Mul(p, &Mat4{
-//              {1, 0, 0, x},
-//              {0, 1, 0, y},
-//              {0, 0, 1, z},
-//              {0, 0, 0, 1},
-//      }).
-func (m *Mat4) Translate(p *Mat4, x, y, z float32) {
-        m[0][0] = p[0][0]
-        m[0][1] = p[0][1]
-        m[0][2] = p[0][2]
-        m[0][3] = p[0][0]*x + p[0][1]*y + p[0][2]*z + p[0][3]
-        m[1][0] = p[1][0]
-        m[1][1] = p[1][1]
-        m[1][2] = p[1][2]
-        m[1][3] = p[1][0]*x + p[1][1]*y + p[1][2]*z + p[1][3]
-        m[2][0] = p[2][0]
-        m[2][1] = p[2][1]
-        m[2][2] = p[2][2]
-        m[2][3] = p[2][0]*x + p[2][1]*y + p[2][2]*z + p[2][3]
-        m[3][0] = p[3][0]
-        m[3][1] = p[3][1]
-        m[3][2] = p[3][2]
-        m[3][3] = p[3][0]*x + p[3][1]*y + p[3][2]*z + p[3][3]
-}
-
-// Rotate sets m to a rotation in radians around a specified axis, followed by p.
-// It is equivalent to m.Mul(p, affineRotation).
-func (m *Mat4) Rotate(p *Mat4, angle Radian, axis *Vec3) {
-        a := *axis
-        a.Normalize()
-
-        c, s := Cos(float32(angle)), Sin(float32(angle))
-        d := 1 - c
-
-        m.Mul(p, &Mat4{{
-                c + d*a[0]*a[1],
-                0 + d*a[0]*a[1] + s*a[2],
-                0 + d*a[0]*a[1] - s*a[1],
-                0,
-        }, {
-                0 + d*a[1]*a[0] - s*a[2],
-                c + d*a[1]*a[1],
-                0 + d*a[1]*a[2] + s*a[0],
-                0,
-        }, {
-                0 + d*a[2]*a[0] + s*a[1],
-                0 + d*a[2]*a[1] - s*a[0],
-                c + d*a[2]*a[2],
-                0,
-        }, {
-                0, 0, 0, 1,
-        }})
-}
-
-func (m *Mat4) LookAt(eye, center, up *Vec3) {
-        f, s, u := new(Vec3), new(Vec3), new(Vec3)
-
-        *f = *center
-        f.Sub(f, eye)
-        f.Normalize()
-
-        s.Cross(f, up)
-        s.Normalize()
-        u.Cross(s, f)
-
-        *m = Mat4{
-                {s[0], u[0], -f[0], 0},
-                {s[1], u[1], -f[1], 0},
-                {s[2], u[2], -f[2], 0},
-                {-s.Dot(eye), -u.Dot(eye), +f.Dot(eye), 1},
-        }
-}