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1016 lines
22 KiB
1016 lines
22 KiB
/////////////////////////////////////////////////////////////////////////// |
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// |
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// Copyright (c) 2002-2012, Industrial Light & Magic, a division of Lucas |
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// Digital Ltd. LLC |
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// |
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// All rights reserved. |
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// |
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// Redistribution and use in source and binary forms, with or without |
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// modification, are permitted provided that the following conditions are |
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// met: |
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// * Redistributions of source code must retain the above copyright |
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// notice, this list of conditions and the following disclaimer. |
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// * Redistributions in binary form must reproduce the above |
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// copyright notice, this list of conditions and the following disclaimer |
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// in the documentation and/or other materials provided with the |
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// distribution. |
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// * Neither the name of Industrial Light & Magic nor the names of |
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// its contributors may be used to endorse or promote products derived |
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// from this software without specific prior written permission. |
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// |
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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// |
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/////////////////////////////////////////////////////////////////////////// |
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#ifndef INCLUDED_IMATHBOXALGO_H |
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#define INCLUDED_IMATHBOXALGO_H |
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//--------------------------------------------------------------------------- |
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// |
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// This file contains algorithms applied to or in conjunction |
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// with bounding boxes (Imath::Box). These algorithms require |
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// more headers to compile. The assumption made is that these |
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// functions are called much less often than the basic box |
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// functions or these functions require more support classes. |
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// |
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// Contains: |
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// |
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// T clip<T>(const T& in, const Box<T>& box) |
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// |
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// Vec3<T> closestPointOnBox(const Vec3<T>&, const Box<Vec3<T>>& ) |
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// |
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// Vec3<T> closestPointInBox(const Vec3<T>&, const Box<Vec3<T>>& ) |
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// |
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// Box< Vec3<S> > transform(const Box<Vec3<S>>&, const Matrix44<T>&) |
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// Box< Vec3<S> > affineTransform(const Box<Vec3<S>>&, const Matrix44<T>&) |
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// |
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// void transform(const Box<Vec3<S>>&, const Matrix44<T>&, Box<V3ec3<S>>&) |
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// void affineTransform(const Box<Vec3<S>>&, |
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// const Matrix44<T>&, |
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// Box<V3ec3<S>>&) |
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// |
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// bool findEntryAndExitPoints(const Line<T> &line, |
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// const Box< Vec3<T> > &box, |
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// Vec3<T> &enterPoint, |
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// Vec3<T> &exitPoint) |
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// |
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// bool intersects(const Box<Vec3<T>> &box, |
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// const Line3<T> &ray, |
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// Vec3<T> intersectionPoint) |
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// |
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// bool intersects(const Box<Vec3<T>> &box, const Line3<T> &ray) |
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// |
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//--------------------------------------------------------------------------- |
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#include "ImathBox.h" |
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#include "ImathMatrix.h" |
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#include "ImathLineAlgo.h" |
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#include "ImathPlane.h" |
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#include "ImathNamespace.h" |
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IMATH_INTERNAL_NAMESPACE_HEADER_ENTER |
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template <class T> |
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inline T |
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clip (const T &p, const Box<T> &box) |
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{ |
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// |
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// Clip the coordinates of a point, p, against a box. |
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// The result, q, is the closest point to p that is inside the box. |
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// |
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T q; |
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for (int i = 0; i < int (box.min.dimensions()); i++) |
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{ |
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if (p[i] < box.min[i]) |
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q[i] = box.min[i]; |
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else if (p[i] > box.max[i]) |
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q[i] = box.max[i]; |
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else |
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q[i] = p[i]; |
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} |
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return q; |
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} |
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template <class T> |
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inline T |
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closestPointInBox (const T &p, const Box<T> &box) |
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{ |
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return clip (p, box); |
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} |
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template <class T> |
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Vec3<T> |
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closestPointOnBox (const Vec3<T> &p, const Box< Vec3<T> > &box) |
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{ |
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// |
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// Find the point, q, on the surface of |
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// the box, that is closest to point p. |
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// |
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// If the box is empty, return p. |
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// |
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if (box.isEmpty()) |
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return p; |
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Vec3<T> q = closestPointInBox (p, box); |
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if (q == p) |
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{ |
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Vec3<T> d1 = p - box.min; |
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Vec3<T> d2 = box.max - p; |
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Vec3<T> d ((d1.x < d2.x)? d1.x: d2.x, |
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(d1.y < d2.y)? d1.y: d2.y, |
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(d1.z < d2.z)? d1.z: d2.z); |
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if (d.x < d.y && d.x < d.z) |
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{ |
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q.x = (d1.x < d2.x)? box.min.x: box.max.x; |
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} |
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else if (d.y < d.z) |
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{ |
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q.y = (d1.y < d2.y)? box.min.y: box.max.y; |
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} |
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else |
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{ |
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q.z = (d1.z < d2.z)? box.min.z: box.max.z; |
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} |
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} |
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return q; |
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} |
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template <class S, class T> |
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Box< Vec3<S> > |
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transform (const Box< Vec3<S> > &box, const Matrix44<T> &m) |
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{ |
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// |
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// Transform a 3D box by a matrix, and compute a new box that |
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// tightly encloses the transformed box. |
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// |
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// If m is an affine transform, then we use James Arvo's fast |
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// method as described in "Graphics Gems", Academic Press, 1990, |
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// pp. 548-550. |
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// |
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// |
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// A transformed empty box is still empty, and a transformed infinite box |
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// is still infinite |
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// |
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if (box.isEmpty() || box.isInfinite()) |
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return box; |
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// |
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// If the last column of m is (0 0 0 1) then m is an affine |
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// transform, and we use the fast Graphics Gems trick. |
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// |
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if (m[0][3] == 0 && m[1][3] == 0 && m[2][3] == 0 && m[3][3] == 1) |
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{ |
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Box< Vec3<S> > newBox; |
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for (int i = 0; i < 3; i++) |
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{ |
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newBox.min[i] = newBox.max[i] = (S) m[3][i]; |
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for (int j = 0; j < 3; j++) |
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{ |
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S a, b; |
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a = (S) m[j][i] * box.min[j]; |
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b = (S) m[j][i] * box.max[j]; |
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if (a < b) |
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{ |
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newBox.min[i] += a; |
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newBox.max[i] += b; |
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} |
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else |
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{ |
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newBox.min[i] += b; |
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newBox.max[i] += a; |
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} |
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} |
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} |
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return newBox; |
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} |
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// |
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// M is a projection matrix. Do things the naive way: |
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// Transform the eight corners of the box, and find an |
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// axis-parallel box that encloses the transformed corners. |
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// |
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Vec3<S> points[8]; |
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points[0][0] = points[1][0] = points[2][0] = points[3][0] = box.min[0]; |
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points[4][0] = points[5][0] = points[6][0] = points[7][0] = box.max[0]; |
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points[0][1] = points[1][1] = points[4][1] = points[5][1] = box.min[1]; |
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points[2][1] = points[3][1] = points[6][1] = points[7][1] = box.max[1]; |
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points[0][2] = points[2][2] = points[4][2] = points[6][2] = box.min[2]; |
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points[1][2] = points[3][2] = points[5][2] = points[7][2] = box.max[2]; |
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Box< Vec3<S> > newBox; |
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for (int i = 0; i < 8; i++) |
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newBox.extendBy (points[i] * m); |
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return newBox; |
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} |
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template <class S, class T> |
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void |
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transform (const Box< Vec3<S> > &box, |
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const Matrix44<T> &m, |
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Box< Vec3<S> > &result) |
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{ |
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// |
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// Transform a 3D box by a matrix, and compute a new box that |
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// tightly encloses the transformed box. |
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// |
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// If m is an affine transform, then we use James Arvo's fast |
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// method as described in "Graphics Gems", Academic Press, 1990, |
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// pp. 548-550. |
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// |
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// |
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// A transformed empty box is still empty, and a transformed infinite |
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// box is still infinite |
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// |
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if (box.isEmpty() || box.isInfinite()) |
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{ |
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return; |
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} |
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// |
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// If the last column of m is (0 0 0 1) then m is an affine |
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// transform, and we use the fast Graphics Gems trick. |
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// |
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if (m[0][3] == 0 && m[1][3] == 0 && m[2][3] == 0 && m[3][3] == 1) |
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{ |
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for (int i = 0; i < 3; i++) |
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{ |
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result.min[i] = result.max[i] = (S) m[3][i]; |
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for (int j = 0; j < 3; j++) |
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{ |
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S a, b; |
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a = (S) m[j][i] * box.min[j]; |
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b = (S) m[j][i] * box.max[j]; |
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if (a < b) |
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{ |
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result.min[i] += a; |
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result.max[i] += b; |
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} |
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else |
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{ |
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result.min[i] += b; |
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result.max[i] += a; |
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} |
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} |
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} |
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return; |
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} |
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// |
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// M is a projection matrix. Do things the naive way: |
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// Transform the eight corners of the box, and find an |
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// axis-parallel box that encloses the transformed corners. |
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// |
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Vec3<S> points[8]; |
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points[0][0] = points[1][0] = points[2][0] = points[3][0] = box.min[0]; |
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points[4][0] = points[5][0] = points[6][0] = points[7][0] = box.max[0]; |
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points[0][1] = points[1][1] = points[4][1] = points[5][1] = box.min[1]; |
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points[2][1] = points[3][1] = points[6][1] = points[7][1] = box.max[1]; |
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points[0][2] = points[2][2] = points[4][2] = points[6][2] = box.min[2]; |
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points[1][2] = points[3][2] = points[5][2] = points[7][2] = box.max[2]; |
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for (int i = 0; i < 8; i++) |
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result.extendBy (points[i] * m); |
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} |
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template <class S, class T> |
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Box< Vec3<S> > |
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affineTransform (const Box< Vec3<S> > &box, const Matrix44<T> &m) |
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{ |
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// |
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// Transform a 3D box by a matrix whose rightmost column |
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// is (0 0 0 1), and compute a new box that tightly encloses |
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// the transformed box. |
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// |
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// As in the transform() function, above, we use James Arvo's |
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// fast method. |
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// |
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if (box.isEmpty() || box.isInfinite()) |
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{ |
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// |
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// A transformed empty or infinite box is still empty or infinite |
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// |
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return box; |
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} |
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Box< Vec3<S> > newBox; |
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for (int i = 0; i < 3; i++) |
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{ |
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newBox.min[i] = newBox.max[i] = (S) m[3][i]; |
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for (int j = 0; j < 3; j++) |
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{ |
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S a, b; |
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a = (S) m[j][i] * box.min[j]; |
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b = (S) m[j][i] * box.max[j]; |
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if (a < b) |
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{ |
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newBox.min[i] += a; |
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newBox.max[i] += b; |
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} |
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else |
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{ |
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newBox.min[i] += b; |
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newBox.max[i] += a; |
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} |
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} |
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} |
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return newBox; |
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} |
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template <class S, class T> |
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void |
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affineTransform (const Box< Vec3<S> > &box, |
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const Matrix44<T> &m, |
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Box<Vec3<S> > &result) |
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{ |
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// |
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// Transform a 3D box by a matrix whose rightmost column |
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// is (0 0 0 1), and compute a new box that tightly encloses |
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// the transformed box. |
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// |
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// As in the transform() function, above, we use James Arvo's |
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// fast method. |
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// |
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if (box.isEmpty()) |
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{ |
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// |
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// A transformed empty box is still empty |
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// |
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result.makeEmpty(); |
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return; |
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} |
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if (box.isInfinite()) |
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{ |
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// |
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// A transformed infinite box is still infinite |
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// |
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result.makeInfinite(); |
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return; |
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} |
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for (int i = 0; i < 3; i++) |
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{ |
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result.min[i] = result.max[i] = (S) m[3][i]; |
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for (int j = 0; j < 3; j++) |
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{ |
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S a, b; |
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a = (S) m[j][i] * box.min[j]; |
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b = (S) m[j][i] * box.max[j]; |
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if (a < b) |
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{ |
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result.min[i] += a; |
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result.max[i] += b; |
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} |
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else |
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{ |
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result.min[i] += b; |
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result.max[i] += a; |
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} |
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} |
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} |
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} |
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template <class T> |
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bool |
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findEntryAndExitPoints (const Line3<T> &r, |
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const Box<Vec3<T> > &b, |
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Vec3<T> &entry, |
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Vec3<T> &exit) |
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{ |
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// |
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// Compute the points where a ray, r, enters and exits a box, b: |
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// |
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// findEntryAndExitPoints() returns |
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// |
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// - true if the ray starts inside the box or if the |
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// ray starts outside and intersects the box |
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// |
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// - false otherwise (that is, if the ray does not |
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// intersect the box) |
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// |
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// The entry and exit points are |
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// |
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// - points on two of the faces of the box when |
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// findEntryAndExitPoints() returns true |
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// (The entry end exit points may be on either |
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// side of the ray's origin) |
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// |
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// - undefined when findEntryAndExitPoints() |
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// returns false |
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// |
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if (b.isEmpty()) |
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{ |
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// |
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// No ray intersects an empty box |
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// |
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return false; |
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} |
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// |
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// The following description assumes that the ray's origin is outside |
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// the box, but the code below works even if the origin is inside the |
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// box: |
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// |
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// Between one and three "frontfacing" sides of the box are oriented |
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// towards the ray's origin, and between one and three "backfacing" |
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// sides are oriented away from the ray's origin. |
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// We intersect the ray with the planes that contain the sides of the |
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// box, and compare the distances between the ray's origin and the |
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// ray-plane intersections. The ray intersects the box if the most |
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// distant frontfacing intersection is nearer than the nearest |
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// backfacing intersection. If the ray does intersect the box, then |
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// the most distant frontfacing ray-plane intersection is the entry |
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// point and the nearest backfacing ray-plane intersection is the |
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// exit point. |
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// |
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const T TMAX = limits<T>::max(); |
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T tFrontMax = -TMAX; |
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T tBackMin = TMAX; |
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// |
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// Minimum and maximum X sides. |
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// |
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if (r.dir.x >= 0) |
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{ |
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T d1 = b.max.x - r.pos.x; |
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T d2 = b.min.x - r.pos.x; |
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if (r.dir.x > 1 || |
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(abs (d1) < TMAX * r.dir.x && |
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abs (d2) < TMAX * r.dir.x)) |
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{ |
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T t1 = d1 / r.dir.x; |
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T t2 = d2 / r.dir.x; |
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if (tBackMin > t1) |
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{ |
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tBackMin = t1; |
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exit.x = b.max.x; |
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exit.y = clamp (r.pos.y + t1 * r.dir.y, b.min.y, b.max.y); |
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exit.z = clamp (r.pos.z + t1 * r.dir.z, b.min.z, b.max.z); |
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} |
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if (tFrontMax < t2) |
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{ |
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tFrontMax = t2; |
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entry.x = b.min.x; |
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entry.y = clamp (r.pos.y + t2 * r.dir.y, b.min.y, b.max.y); |
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entry.z = clamp (r.pos.z + t2 * r.dir.z, b.min.z, b.max.z); |
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} |
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} |
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else if (r.pos.x < b.min.x || r.pos.x > b.max.x) |
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{ |
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return false; |
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} |
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} |
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else // r.dir.x < 0 |
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{ |
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T d1 = b.min.x - r.pos.x; |
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T d2 = b.max.x - r.pos.x; |
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if (r.dir.x < -1 || |
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(abs (d1) < -TMAX * r.dir.x && |
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abs (d2) < -TMAX * r.dir.x)) |
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{ |
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T t1 = d1 / r.dir.x; |
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T t2 = d2 / r.dir.x; |
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if (tBackMin > t1) |
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{ |
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tBackMin = t1; |
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exit.x = b.min.x; |
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exit.y = clamp (r.pos.y + t1 * r.dir.y, b.min.y, b.max.y); |
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exit.z = clamp (r.pos.z + t1 * r.dir.z, b.min.z, b.max.z); |
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} |
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if (tFrontMax < t2) |
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{ |
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tFrontMax = t2; |
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entry.x = b.max.x; |
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entry.y = clamp (r.pos.y + t2 * r.dir.y, b.min.y, b.max.y); |
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entry.z = clamp (r.pos.z + t2 * r.dir.z, b.min.z, b.max.z); |
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} |
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} |
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else if (r.pos.x < b.min.x || r.pos.x > b.max.x) |
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{ |
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return false; |
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} |
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} |
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// |
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// Minimum and maximum Y sides. |
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// |
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if (r.dir.y >= 0) |
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{ |
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T d1 = b.max.y - r.pos.y; |
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T d2 = b.min.y - r.pos.y; |
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|
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if (r.dir.y > 1 || |
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(abs (d1) < TMAX * r.dir.y && |
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abs (d2) < TMAX * r.dir.y)) |
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{ |
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T t1 = d1 / r.dir.y; |
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T t2 = d2 / r.dir.y; |
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if (tBackMin > t1) |
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{ |
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tBackMin = t1; |
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exit.x = clamp (r.pos.x + t1 * r.dir.x, b.min.x, b.max.x); |
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exit.y = b.max.y; |
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exit.z = clamp (r.pos.z + t1 * r.dir.z, b.min.z, b.max.z); |
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} |
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|
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if (tFrontMax < t2) |
|
{ |
|
tFrontMax = t2; |
|
|
|
entry.x = clamp (r.pos.x + t2 * r.dir.x, b.min.x, b.max.x); |
|
entry.y = b.min.y; |
|
entry.z = clamp (r.pos.z + t2 * r.dir.z, b.min.z, b.max.z); |
|
} |
|
} |
|
else if (r.pos.y < b.min.y || r.pos.y > b.max.y) |
|
{ |
|
return false; |
|
} |
|
} |
|
else // r.dir.y < 0 |
|
{ |
|
T d1 = b.min.y - r.pos.y; |
|
T d2 = b.max.y - r.pos.y; |
|
|
|
if (r.dir.y < -1 || |
|
(abs (d1) < -TMAX * r.dir.y && |
|
abs (d2) < -TMAX * r.dir.y)) |
|
{ |
|
T t1 = d1 / r.dir.y; |
|
T t2 = d2 / r.dir.y; |
|
|
|
if (tBackMin > t1) |
|
{ |
|
tBackMin = t1; |
|
|
|
exit.x = clamp (r.pos.x + t1 * r.dir.x, b.min.x, b.max.x); |
|
exit.y = b.min.y; |
|
exit.z = clamp (r.pos.z + t1 * r.dir.z, b.min.z, b.max.z); |
|
} |
|
|
|
if (tFrontMax < t2) |
|
{ |
|
tFrontMax = t2; |
|
|
|
entry.x = clamp (r.pos.x + t2 * r.dir.x, b.min.x, b.max.x); |
|
entry.y = b.max.y; |
|
entry.z = clamp (r.pos.z + t2 * r.dir.z, b.min.z, b.max.z); |
|
} |
|
} |
|
else if (r.pos.y < b.min.y || r.pos.y > b.max.y) |
|
{ |
|
return false; |
|
} |
|
} |
|
|
|
// |
|
// Minimum and maximum Z sides. |
|
// |
|
|
|
if (r.dir.z >= 0) |
|
{ |
|
T d1 = b.max.z - r.pos.z; |
|
T d2 = b.min.z - r.pos.z; |
|
|
|
if (r.dir.z > 1 || |
|
(abs (d1) < TMAX * r.dir.z && |
|
abs (d2) < TMAX * r.dir.z)) |
|
{ |
|
T t1 = d1 / r.dir.z; |
|
T t2 = d2 / r.dir.z; |
|
|
|
if (tBackMin > t1) |
|
{ |
|
tBackMin = t1; |
|
|
|
exit.x = clamp (r.pos.x + t1 * r.dir.x, b.min.x, b.max.x); |
|
exit.y = clamp (r.pos.y + t1 * r.dir.y, b.min.y, b.max.y); |
|
exit.z = b.max.z; |
|
} |
|
|
|
if (tFrontMax < t2) |
|
{ |
|
tFrontMax = t2; |
|
|
|
entry.x = clamp (r.pos.x + t2 * r.dir.x, b.min.x, b.max.x); |
|
entry.y = clamp (r.pos.y + t2 * r.dir.y, b.min.y, b.max.y); |
|
entry.z = b.min.z; |
|
} |
|
} |
|
else if (r.pos.z < b.min.z || r.pos.z > b.max.z) |
|
{ |
|
return false; |
|
} |
|
} |
|
else // r.dir.z < 0 |
|
{ |
|
T d1 = b.min.z - r.pos.z; |
|
T d2 = b.max.z - r.pos.z; |
|
|
|
if (r.dir.z < -1 || |
|
(abs (d1) < -TMAX * r.dir.z && |
|
abs (d2) < -TMAX * r.dir.z)) |
|
{ |
|
T t1 = d1 / r.dir.z; |
|
T t2 = d2 / r.dir.z; |
|
|
|
if (tBackMin > t1) |
|
{ |
|
tBackMin = t1; |
|
|
|
exit.x = clamp (r.pos.x + t1 * r.dir.x, b.min.x, b.max.x); |
|
exit.y = clamp (r.pos.y + t1 * r.dir.y, b.min.y, b.max.y); |
|
exit.z = b.min.z; |
|
} |
|
|
|
if (tFrontMax < t2) |
|
{ |
|
tFrontMax = t2; |
|
|
|
entry.x = clamp (r.pos.x + t2 * r.dir.x, b.min.x, b.max.x); |
|
entry.y = clamp (r.pos.y + t2 * r.dir.y, b.min.y, b.max.y); |
|
entry.z = b.max.z; |
|
} |
|
} |
|
else if (r.pos.z < b.min.z || r.pos.z > b.max.z) |
|
{ |
|
return false; |
|
} |
|
} |
|
|
|
return tFrontMax <= tBackMin; |
|
} |
|
|
|
|
|
template<class T> |
|
bool |
|
intersects (const Box< Vec3<T> > &b, const Line3<T> &r, Vec3<T> &ip) |
|
{ |
|
// |
|
// Intersect a ray, r, with a box, b, and compute the intersection |
|
// point, ip: |
|
// |
|
// intersect() returns |
|
// |
|
// - true if the ray starts inside the box or if the |
|
// ray starts outside and intersects the box |
|
// |
|
// - false if the ray starts outside the box and intersects it, |
|
// but the intersection is behind the ray's origin. |
|
// |
|
// - false if the ray starts outside and does not intersect it |
|
// |
|
// The intersection point is |
|
// |
|
// - the ray's origin if the ray starts inside the box |
|
// |
|
// - a point on one of the faces of the box if the ray |
|
// starts outside the box |
|
// |
|
// - undefined when intersect() returns false |
|
// |
|
|
|
if (b.isEmpty()) |
|
{ |
|
// |
|
// No ray intersects an empty box |
|
// |
|
|
|
return false; |
|
} |
|
|
|
if (b.intersects (r.pos)) |
|
{ |
|
// |
|
// The ray starts inside the box |
|
// |
|
|
|
ip = r.pos; |
|
return true; |
|
} |
|
|
|
// |
|
// The ray starts outside the box. Between one and three "frontfacing" |
|
// sides of the box are oriented towards the ray, and between one and |
|
// three "backfacing" sides are oriented away from the ray. |
|
// We intersect the ray with the planes that contain the sides of the |
|
// box, and compare the distances between ray's origin and the ray-plane |
|
// intersections. |
|
// The ray intersects the box if the most distant frontfacing intersection |
|
// is nearer than the nearest backfacing intersection. If the ray does |
|
// intersect the box, then the most distant frontfacing ray-plane |
|
// intersection is the ray-box intersection. |
|
// |
|
|
|
const T TMAX = limits<T>::max(); |
|
|
|
T tFrontMax = -1; |
|
T tBackMin = TMAX; |
|
|
|
// |
|
// Minimum and maximum X sides. |
|
// |
|
|
|
if (r.dir.x > 0) |
|
{ |
|
if (r.pos.x > b.max.x) |
|
return false; |
|
|
|
T d = b.max.x - r.pos.x; |
|
|
|
if (r.dir.x > 1 || d < TMAX * r.dir.x) |
|
{ |
|
T t = d / r.dir.x; |
|
|
|
if (tBackMin > t) |
|
tBackMin = t; |
|
} |
|
|
|
if (r.pos.x <= b.min.x) |
|
{ |
|
T d = b.min.x - r.pos.x; |
|
T t = (r.dir.x > 1 || d < TMAX * r.dir.x)? d / r.dir.x: TMAX; |
|
|
|
if (tFrontMax < t) |
|
{ |
|
tFrontMax = t; |
|
|
|
ip.x = b.min.x; |
|
ip.y = clamp (r.pos.y + t * r.dir.y, b.min.y, b.max.y); |
|
ip.z = clamp (r.pos.z + t * r.dir.z, b.min.z, b.max.z); |
|
} |
|
} |
|
} |
|
else if (r.dir.x < 0) |
|
{ |
|
if (r.pos.x < b.min.x) |
|
return false; |
|
|
|
T d = b.min.x - r.pos.x; |
|
|
|
if (r.dir.x < -1 || d > TMAX * r.dir.x) |
|
{ |
|
T t = d / r.dir.x; |
|
|
|
if (tBackMin > t) |
|
tBackMin = t; |
|
} |
|
|
|
if (r.pos.x >= b.max.x) |
|
{ |
|
T d = b.max.x - r.pos.x; |
|
T t = (r.dir.x < -1 || d > TMAX * r.dir.x)? d / r.dir.x: TMAX; |
|
|
|
if (tFrontMax < t) |
|
{ |
|
tFrontMax = t; |
|
|
|
ip.x = b.max.x; |
|
ip.y = clamp (r.pos.y + t * r.dir.y, b.min.y, b.max.y); |
|
ip.z = clamp (r.pos.z + t * r.dir.z, b.min.z, b.max.z); |
|
} |
|
} |
|
} |
|
else // r.dir.x == 0 |
|
{ |
|
if (r.pos.x < b.min.x || r.pos.x > b.max.x) |
|
return false; |
|
} |
|
|
|
// |
|
// Minimum and maximum Y sides. |
|
// |
|
|
|
if (r.dir.y > 0) |
|
{ |
|
if (r.pos.y > b.max.y) |
|
return false; |
|
|
|
T d = b.max.y - r.pos.y; |
|
|
|
if (r.dir.y > 1 || d < TMAX * r.dir.y) |
|
{ |
|
T t = d / r.dir.y; |
|
|
|
if (tBackMin > t) |
|
tBackMin = t; |
|
} |
|
|
|
if (r.pos.y <= b.min.y) |
|
{ |
|
T d = b.min.y - r.pos.y; |
|
T t = (r.dir.y > 1 || d < TMAX * r.dir.y)? d / r.dir.y: TMAX; |
|
|
|
if (tFrontMax < t) |
|
{ |
|
tFrontMax = t; |
|
|
|
ip.x = clamp (r.pos.x + t * r.dir.x, b.min.x, b.max.x); |
|
ip.y = b.min.y; |
|
ip.z = clamp (r.pos.z + t * r.dir.z, b.min.z, b.max.z); |
|
} |
|
} |
|
} |
|
else if (r.dir.y < 0) |
|
{ |
|
if (r.pos.y < b.min.y) |
|
return false; |
|
|
|
T d = b.min.y - r.pos.y; |
|
|
|
if (r.dir.y < -1 || d > TMAX * r.dir.y) |
|
{ |
|
T t = d / r.dir.y; |
|
|
|
if (tBackMin > t) |
|
tBackMin = t; |
|
} |
|
|
|
if (r.pos.y >= b.max.y) |
|
{ |
|
T d = b.max.y - r.pos.y; |
|
T t = (r.dir.y < -1 || d > TMAX * r.dir.y)? d / r.dir.y: TMAX; |
|
|
|
if (tFrontMax < t) |
|
{ |
|
tFrontMax = t; |
|
|
|
ip.x = clamp (r.pos.x + t * r.dir.x, b.min.x, b.max.x); |
|
ip.y = b.max.y; |
|
ip.z = clamp (r.pos.z + t * r.dir.z, b.min.z, b.max.z); |
|
} |
|
} |
|
} |
|
else // r.dir.y == 0 |
|
{ |
|
if (r.pos.y < b.min.y || r.pos.y > b.max.y) |
|
return false; |
|
} |
|
|
|
// |
|
// Minimum and maximum Z sides. |
|
// |
|
|
|
if (r.dir.z > 0) |
|
{ |
|
if (r.pos.z > b.max.z) |
|
return false; |
|
|
|
T d = b.max.z - r.pos.z; |
|
|
|
if (r.dir.z > 1 || d < TMAX * r.dir.z) |
|
{ |
|
T t = d / r.dir.z; |
|
|
|
if (tBackMin > t) |
|
tBackMin = t; |
|
} |
|
|
|
if (r.pos.z <= b.min.z) |
|
{ |
|
T d = b.min.z - r.pos.z; |
|
T t = (r.dir.z > 1 || d < TMAX * r.dir.z)? d / r.dir.z: TMAX; |
|
|
|
if (tFrontMax < t) |
|
{ |
|
tFrontMax = t; |
|
|
|
ip.x = clamp (r.pos.x + t * r.dir.x, b.min.x, b.max.x); |
|
ip.y = clamp (r.pos.y + t * r.dir.y, b.min.y, b.max.y); |
|
ip.z = b.min.z; |
|
} |
|
} |
|
} |
|
else if (r.dir.z < 0) |
|
{ |
|
if (r.pos.z < b.min.z) |
|
return false; |
|
|
|
T d = b.min.z - r.pos.z; |
|
|
|
if (r.dir.z < -1 || d > TMAX * r.dir.z) |
|
{ |
|
T t = d / r.dir.z; |
|
|
|
if (tBackMin > t) |
|
tBackMin = t; |
|
} |
|
|
|
if (r.pos.z >= b.max.z) |
|
{ |
|
T d = b.max.z - r.pos.z; |
|
T t = (r.dir.z < -1 || d > TMAX * r.dir.z)? d / r.dir.z: TMAX; |
|
|
|
if (tFrontMax < t) |
|
{ |
|
tFrontMax = t; |
|
|
|
ip.x = clamp (r.pos.x + t * r.dir.x, b.min.x, b.max.x); |
|
ip.y = clamp (r.pos.y + t * r.dir.y, b.min.y, b.max.y); |
|
ip.z = b.max.z; |
|
} |
|
} |
|
} |
|
else // r.dir.z == 0 |
|
{ |
|
if (r.pos.z < b.min.z || r.pos.z > b.max.z) |
|
return false; |
|
} |
|
|
|
return tFrontMax <= tBackMin; |
|
} |
|
|
|
|
|
template<class T> |
|
bool |
|
intersects (const Box< Vec3<T> > &box, const Line3<T> &ray) |
|
{ |
|
Vec3<T> ignored; |
|
return intersects (box, ray, ignored); |
|
} |
|
|
|
|
|
IMATH_INTERNAL_NAMESPACE_HEADER_EXIT |
|
|
|
#endif // INCLUDED_IMATHBOXALGO_H
|
|
|