Open Source Computer Vision Library https://opencv.org/
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///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
// Digital Ltd. LLC
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Industrial Light & Magic nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
///////////////////////////////////////////////////////////////////////////
#ifndef INCLUDED_IMATHBOXALGO_H
#define INCLUDED_IMATHBOXALGO_H
//---------------------------------------------------------------------------
//
// This file contains algorithms applied to or in conjunction
// with bounding boxes (Imath::Box). These algorithms require
// more headers to compile. The assumption made is that these
// functions are called much less often than the basic box
// functions or these functions require more support classes.
//
// Contains:
//
// T clip<T>(const T& in, const Box<T>& box)
//
// Vec3<T> closestPointOnBox(const Vec3<T>&, const Box<Vec3<T>>& )
//
// Vec3<T> closestPointInBox(const Vec3<T>&, const Box<Vec3<T>>& )
//
// void transform(Box<Vec3<T>>&, const Matrix44<T>&)
//
// bool findEntryAndExitPoints(const Line<T> &line,
// const Box< Vec3<T> > &box,
// Vec3<T> &enterPoint,
// Vec3<T> &exitPoint)
//
// bool intersects(const Box<Vec3<T>> &box,
// const Line3<T> &line,
// Vec3<T> result)
//
// bool intersects(const Box<Vec3<T>> &box, const Line3<T> &line)
//
//---------------------------------------------------------------------------
#include "ImathBox.h"
#include "ImathMatrix.h"
#include "ImathLineAlgo.h"
#include "ImathPlane.h"
namespace Imath {
template <class T>
inline T clip(const T& in, const Box<T>& box)
{
//
// Clip a point so that it lies inside the given bbox
//
T out;
for (int i=0; i<(int)box.min.dimensions(); i++)
{
if (in[i] < box.min[i]) out[i] = box.min[i];
else if (in[i] > box.max[i]) out[i] = box.max[i];
else out[i] = in[i];
}
return out;
}
//
// Return p if p is inside the box.
//
template <class T>
Vec3<T>
closestPointInBox(const Vec3<T>& p, const Box< Vec3<T> >& box )
{
Imath::V3f b;
if (p.x < box.min.x)
b.x = box.min.x;
else if (p.x > box.max.x)
b.x = box.max.x;
else
b.x = p.x;
if (p.y < box.min.y)
b.y = box.min.y;
else if (p.y > box.max.y)
b.y = box.max.y;
else
b.y = p.y;
if (p.z < box.min.z)
b.z = box.min.z;
else if (p.z > box.max.z)
b.z = box.max.z;
else
b.z = p.z;
return b;
}
template <class T>
Vec3<T> closestPointOnBox(const Vec3<T>& pt, const Box< Vec3<T> >& box )
{
//
// This sucker is specialized to work with a Vec3f and a box
// made of Vec3fs.
//
Vec3<T> result;
// trivial cases first
if (box.isEmpty())
return pt;
else if (pt == box.center())
{
// middle of z side
result[0] = (box.max[0] + box.min[0])/2.0;
result[1] = (box.max[1] + box.min[1])/2.0;
result[2] = box.max[2];
}
else
{
// Find the closest point on a unit box (from -1 to 1),
// then scale up.
// Find the vector from center to the point, then scale
// to a unit box.
Vec3<T> vec = pt - box.center();
T sizeX = box.max[0]-box.min[0];
T sizeY = box.max[1]-box.min[1];
T sizeZ = box.max[2]-box.min[2];
T halfX = sizeX/2.0;
T halfY = sizeY/2.0;
T halfZ = sizeZ/2.0;
if (halfX > 0.0)
vec[0] /= halfX;
if (halfY > 0.0)
vec[1] /= halfY;
if (halfZ > 0.0)
vec[2] /= halfZ;
// Side to snap side that has greatest magnitude in the vector.
Vec3<T> mag;
mag[0] = fabs(vec[0]);
mag[1] = fabs(vec[1]);
mag[2] = fabs(vec[2]);
result = mag;
// Check if beyond corners
if (result[0] > 1.0)
result[0] = 1.0;
if (result[1] > 1.0)
result[1] = 1.0;
if (result[2] > 1.0)
result[2] = 1.0;
// snap to appropriate side
if ((mag[0] > mag[1]) && (mag[0] > mag[2]))
{
result[0] = 1.0;
}
else if ((mag[1] > mag[0]) && (mag[1] > mag[2]))
{
result[1] = 1.0;
}
else if ((mag[2] > mag[0]) && (mag[2] > mag[1]))
{
result[2] = 1.0;
}
else if ((mag[0] == mag[1]) && (mag[0] == mag[2]))
{
// corner
result = Vec3<T>(1,1,1);
}
else if (mag[0] == mag[1])
{
// edge parallel with z
result[0] = 1.0;
result[1] = 1.0;
}
else if (mag[0] == mag[2])
{
// edge parallel with y
result[0] = 1.0;
result[2] = 1.0;
}
else if (mag[1] == mag[2])
{
// edge parallel with x
result[1] = 1.0;
result[2] = 1.0;
}
// Now make everything point the right way
for (int i=0; i < 3; i++)
{
if (vec[i] < 0.0)
result[i] = -result[i];
}
// scale back up and move to center
result[0] *= halfX;
result[1] *= halfY;
result[2] *= halfZ;
result += box.center();
}
return result;
}
template <class S, class T>
Box< Vec3<S> >
transform(const Box< Vec3<S> >& box, const Matrix44<T>& m)
{
// Transforms Box3f by matrix, enlarging Box3f to contain result.
// Clever method courtesy of Graphics Gems, pp. 548-550
//
// This works for projection matrices as well as simple affine
// transformations. Coordinates of the box are rehomogenized if there
// is a projection matrix
// a transformed empty box is still empty
if (box.isEmpty())
return box;
// If the last column is close enuf to ( 0 0 0 1 ) then we use the
// fast, affine version. The tricky affine method could maybe be
// extended to deal with the projection case as well, but its not
// worth it right now.
if (m[0][3] * m[0][3] + m[1][3] * m[1][3] + m[2][3] * m[2][3]
+ (1.0 - m[3][3]) * (1.0 - m[3][3]) < 0.00001)
{
// Affine version, use the Graphics Gems hack
int i, j;
Box< Vec3<S> > newBox;
for (i = 0; i < 3; i++)
{
newBox.min[i] = newBox.max[i] = (S) m[3][i];
for (j = 0; j < 3; j++)
{
float a, b;
a = (S) m[j][i] * box.min[j];
b = (S) m[j][i] * box.max[j];
if (a < b)
{
newBox.min[i] += a;
newBox.max[i] += b;
}
else
{
newBox.min[i] += b;
newBox.max[i] += a;
}
}
}
return newBox;
}
// This is a projection matrix. Do things the naive way.
Vec3<S> points[8];
/* Set up the eight points at the corners of the extent */
points[0][0] = points[1][0] = points[2][0] = points[3][0] = box.min[0];
points[4][0] = points[5][0] = points[6][0] = points[7][0] = box.max[0];
points[0][1] = points[1][1] = points[4][1] = points[5][1] = box.min[1];
points[2][1] = points[3][1] = points[6][1] = points[7][1] = box.max[1];
points[0][2] = points[2][2] = points[4][2] = points[6][2] = box.min[2];
points[1][2] = points[3][2] = points[5][2] = points[7][2] = box.max[2];
Box< Vec3<S> > newBox;
for (int i = 0; i < 8; i++)
newBox.extendBy(points[i] * m);
return newBox;
}
template <class T>
Box< Vec3<T> >
affineTransform(const Box< Vec3<T> > &bbox, const Matrix44<T> &M)
{
float min0, max0, min1, max1, min2, max2, a, b;
float min0new, max0new, min1new, max1new, min2new, max2new;
min0 = bbox.min[0];
max0 = bbox.max[0];
min1 = bbox.min[1];
max1 = bbox.max[1];
min2 = bbox.min[2];
max2 = bbox.max[2];
min0new = max0new = M[3][0];
a = M[0][0] * min0;
b = M[0][0] * max0;
if (a < b) {
min0new += a;
max0new += b;
} else {
min0new += b;
max0new += a;
}
a = M[1][0] * min1;
b = M[1][0] * max1;
if (a < b) {
min0new += a;
max0new += b;
} else {
min0new += b;
max0new += a;
}
a = M[2][0] * min2;
b = M[2][0] * max2;
if (a < b) {
min0new += a;
max0new += b;
} else {
min0new += b;
max0new += a;
}
min1new = max1new = M[3][1];
a = M[0][1] * min0;
b = M[0][1] * max0;
if (a < b) {
min1new += a;
max1new += b;
} else {
min1new += b;
max1new += a;
}
a = M[1][1] * min1;
b = M[1][1] * max1;
if (a < b) {
min1new += a;
max1new += b;
} else {
min1new += b;
max1new += a;
}
a = M[2][1] * min2;
b = M[2][1] * max2;
if (a < b) {
min1new += a;
max1new += b;
} else {
min1new += b;
max1new += a;
}
min2new = max2new = M[3][2];
a = M[0][2] * min0;
b = M[0][2] * max0;
if (a < b) {
min2new += a;
max2new += b;
} else {
min2new += b;
max2new += a;
}
a = M[1][2] * min1;
b = M[1][2] * max1;
if (a < b) {
min2new += a;
max2new += b;
} else {
min2new += b;
max2new += a;
}
a = M[2][2] * min2;
b = M[2][2] * max2;
if (a < b) {
min2new += a;
max2new += b;
} else {
min2new += b;
max2new += a;
}
Box< Vec3<T> > xbbox;
xbbox.min[0] = min0new;
xbbox.max[0] = max0new;
xbbox.min[1] = min1new;
xbbox.max[1] = max1new;
xbbox.min[2] = min2new;
xbbox.max[2] = max2new;
return xbbox;
}
template <class T>
bool findEntryAndExitPoints(const Line3<T>& line,
const Box<Vec3<T> >& box,
Vec3<T> &enterPoint,
Vec3<T> &exitPoint)
{
if ( box.isEmpty() ) return false;
if ( line.distanceTo(box.center()) > box.size().length()/2. ) return false;
Vec3<T> points[8], inter, bary;
Plane3<T> plane;
int i, v0, v1, v2;
bool front = false, valid, validIntersection = false;
// set up the eight coords of the corners of the box
for(i = 0; i < 8; i++)
{
points[i].setValue( i & 01 ? box.min[0] : box.max[0],
i & 02 ? box.min[1] : box.max[1],
i & 04 ? box.min[2] : box.max[2]);
}
// intersect the 12 triangles.
for(i = 0; i < 12; i++)
{
switch(i)
{
case 0: v0 = 2; v1 = 1; v2 = 0; break; // +z
case 1: v0 = 2; v1 = 3; v2 = 1; break;
case 2: v0 = 4; v1 = 5; v2 = 6; break; // -z
case 3: v0 = 6; v1 = 5; v2 = 7; break;
case 4: v0 = 0; v1 = 6; v2 = 2; break; // -x
case 5: v0 = 0; v1 = 4; v2 = 6; break;
case 6: v0 = 1; v1 = 3; v2 = 7; break; // +x
case 7: v0 = 1; v1 = 7; v2 = 5; break;
case 8: v0 = 1; v1 = 4; v2 = 0; break; // -y
case 9: v0 = 1; v1 = 5; v2 = 4; break;
case 10: v0 = 2; v1 = 7; v2 = 3; break; // +y
case 11: v0 = 2; v1 = 6; v2 = 7; break;
}
if((valid=intersect (line, points[v0], points[v1], points[v2],
inter, bary, front)) == true)
{
if(front == true)
{
enterPoint = inter;
validIntersection = valid;
}
else
{
exitPoint = inter;
validIntersection = valid;
}
}
}
return validIntersection;
}
template<class T>
bool intersects(const Box< Vec3<T> > &box,
const Line3<T> &line,
Vec3<T> &result)
{
/*
Fast Ray-Box Intersection
by Andrew Woo
from "Graphics Gems", Academic Press, 1990
*/
const int right = 0;
const int left = 1;
const int middle = 2;
const Vec3<T> &minB = box.min;
const Vec3<T> &maxB = box.max;
const Vec3<T> &origin = line.pos;
const Vec3<T> &dir = line.dir;
bool inside = true;
char quadrant[3];
int whichPlane;
float maxT[3];
float candidatePlane[3];
/* Find candidate planes; this loop can be avoided if
rays cast all from the eye(assume perpsective view) */
for (int i=0; i<3; i++)
{
if(origin[i] < minB[i])
{
quadrant[i] = left;
candidatePlane[i] = minB[i];
inside = false;
}
else if (origin[i] > maxB[i])
{
quadrant[i] = right;
candidatePlane[i] = maxB[i];
inside = false;
}
else
{
quadrant[i] = middle;
}
}
/* Ray origin inside bounding box */
if ( inside )
{
result = origin;
return true;
}
/* Calculate T distances to candidate planes */
for (int i = 0; i < 3; i++)
{
if (quadrant[i] != middle && dir[i] !=0.)
{
maxT[i] = (candidatePlane[i]-origin[i]) / dir[i];
}
else
{
maxT[i] = -1.;
}
}
/* Get largest of the maxT's for final choice of intersection */
whichPlane = 0;
for (int i = 1; i < 3; i++)
{
if (maxT[whichPlane] < maxT[i])
{
whichPlane = i;
}
}
/* Check final candidate actually inside box */
if (maxT[whichPlane] < 0.) return false;
for (int i = 0; i < 3; i++)
{
if (whichPlane != i)
{
result[i] = origin[i] + maxT[whichPlane] *dir[i];
if ((quadrant[i] == right && result[i] < minB[i]) ||
(quadrant[i] == left && result[i] > maxB[i]))
{
return false; /* outside box */
}
}
else
{
result[i] = candidatePlane[i];
}
}
return true;
}
template<class T>
bool intersects(const Box< Vec3<T> > &box, const Line3<T> &line)
{
Vec3<T> ignored;
return intersects(box,line,ignored);
}
} // namespace Imath
#endif