1016 lines
24 KiB
C++
1016 lines
24 KiB
C++
///////////////////////////////////////////////////////////////////////////
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//
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// Copyright (c) 2002-2010, 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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namespace Imath {
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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))
|
|
{
|
|
T t1 = d1 / r.dir.x;
|
|
T t2 = d2 / r.dir.x;
|
|
|
|
if (tBackMin > t1)
|
|
{
|
|
tBackMin = t1;
|
|
|
|
exit.x = b.min.x;
|
|
exit.y = clamp (r.pos.y + t1 * r.dir.y, b.min.y, b.max.y);
|
|
exit.z = clamp (r.pos.z + t1 * r.dir.z, b.min.z, b.max.z);
|
|
}
|
|
|
|
if (tFrontMax < t2)
|
|
{
|
|
tFrontMax = t2;
|
|
|
|
entry.x = b.max.x;
|
|
entry.y = clamp (r.pos.y + t2 * r.dir.y, b.min.y, b.max.y);
|
|
entry.z = clamp (r.pos.z + t2 * r.dir.z, b.min.z, b.max.z);
|
|
}
|
|
}
|
|
else 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)
|
|
{
|
|
T d1 = b.max.y - r.pos.y;
|
|
T d2 = b.min.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.max.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.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);
|
|
}
|
|
|
|
|
|
} // namespace Imath
|
|
|
|
#endif
|