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455 lines
11 KiB
C++
455 lines
11 KiB
C++
// Filename: boundingSphere.cxx
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// Created by: drose (01Oct99)
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//
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////////////////////////////////////////////////////////////////////
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#include "boundingSphere.h"
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#include "boundingHexahedron.h"
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#include "boundingLine.h"
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#include "config_mathutil.h"
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#include <math.h>
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#include <algorithm>
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TypeHandle BoundingSphere::_type_handle;
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BoundingVolume *BoundingSphere::
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make_copy() const {
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return new BoundingSphere(*this);
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}
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LPoint3f BoundingSphere::
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get_min() const {
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nassertr(!is_empty(), LPoint3f(0.0, 0.0, 0.0));
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nassertr(!is_infinite(), LPoint3f(0.0, 0.0, 0.0));
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return LPoint3f(_center[0] - _radius,
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_center[1] - _radius,
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_center[2] - _radius);
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}
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LPoint3f BoundingSphere::
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get_max() const {
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nassertr(!is_empty(), LPoint3f(0.0, 0.0, 0.0));
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nassertr(!is_infinite(), LPoint3f(0.0, 0.0, 0.0));
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return LPoint3f(_center[0] + _radius,
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_center[1] + _radius,
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_center[2] + _radius);
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}
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LPoint3f BoundingSphere::
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get_approx_center() const {
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nassertr(!is_empty(), LPoint3f(0.0, 0.0, 0.0));
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nassertr(!is_infinite(), LPoint3f(0.0, 0.0, 0.0));
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return get_center();
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}
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void BoundingSphere::
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xform(const LMatrix4f &mat) {
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nassertv(!mat.is_nan());
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if (!is_empty() && !is_infinite()) {
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// First, determine the longest axis of the matrix, in case it
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// contains a non-proportionate scale.
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LVector3f x = mat.get_row3(0);
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LVector3f y = mat.get_row3(1);
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LVector3f z = mat.get_row3(2);
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float xd = dot(x, x);
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float yd = dot(y, y);
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float zd = dot(z, z);
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float scale;
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if (xd < yd) {
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if (yd < zd) {
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scale = sqrtf(zd);
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} else {
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scale = sqrtf(yd);
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}
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} else {
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if (xd < zd) {
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scale = sqrtf(zd);
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} else {
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scale = sqrtf(xd);
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}
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}
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// Transform the center
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_center = _center * mat;
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// And the radius.
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_radius *= scale;
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}
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}
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void BoundingSphere::
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output(ostream &out) const {
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if (is_empty()) {
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out << "bsphere, empty";
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} else if (is_infinite()) {
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out << "bsphere, infinite";
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} else {
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out << "bsphere, c (" << _center << "), r " << _radius;
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}
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}
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bool BoundingSphere::
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extend_other(BoundingVolume *other) const {
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return other->extend_by_sphere(this);
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}
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bool BoundingSphere::
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around_other(BoundingVolume *other,
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const BoundingVolume **first,
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const BoundingVolume **last) const {
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return other->around_spheres(first, last);
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}
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int BoundingSphere::
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contains_other(const BoundingVolume *other) const {
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return other->contains_sphere(this);
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}
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bool BoundingSphere::
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extend_by_point(const LPoint3f &point) {
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nassertr(!point.is_nan(), false);
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if (is_empty()) {
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_center = point;
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_radius = 0.0;
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_flags = 0;
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} else if (!is_infinite()) {
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LVector3f v = point - _center;
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float dist2 = dot(v, v);
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if (dist2 > _radius * _radius) {
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_radius = sqrtf(dist2);
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}
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}
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return true;
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}
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bool BoundingSphere::
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extend_by_sphere(const BoundingSphere *sphere) {
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nassertr(!sphere->is_empty() && !sphere->is_infinite(), false);
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nassertr(!is_infinite(), false);
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if (is_empty()) {
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_center = sphere->_center;
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_radius = sphere->_radius;
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_flags = 0;
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} else {
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float dist = length(sphere->_center - _center);
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_radius = max(_radius, dist + sphere->_radius);
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}
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return true;
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}
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bool BoundingSphere::
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extend_by_hexahedron(const BoundingHexahedron *hexahedron) {
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return extend_by_finite(hexahedron);
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}
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bool BoundingSphere::
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extend_by_finite(const FiniteBoundingVolume *volume) {
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nassertr(!volume->is_empty(), false);
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LVector3f min1 = volume->get_min();
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LVector3f max1 = volume->get_max();
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if (is_empty()) {
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_center = (min1 + max1) * 0.5;
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_radius = length(LVector3f(max1 - _center));
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_flags = 0;
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} else {
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LVector3f v = max1 - _center;
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float dist2 = dot(v, v);
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if (dist2 > _radius * _radius) {
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_radius = sqrtf(dist2);
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}
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}
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return true;
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}
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bool BoundingSphere::
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around_points(const LPoint3f *first, const LPoint3f *last) {
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nassertr(first != last, false);
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// First, get the minmax of all the points to construct a bounding
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// box.
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const LPoint3f *p = first;
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#ifndef NDEBUG
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// Skip any NaN points.
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int skipped_nan = 0;
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while (p != last && (*p).is_nan()) {
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++p;
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++skipped_nan;
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}
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if (p == last) {
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mathutil_cat.warning()
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<< "BoundingSphere around NaN\n";
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return false;
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}
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#endif
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LPoint3f min_box = *p;
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LPoint3f max_box = *p;
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++p;
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#ifndef NDEBUG
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// Skip more NaN points.
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while (p != last && (*p).is_nan()) {
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++p;
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++skipped_nan;
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}
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#endif
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if (p == last) {
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// Only one point; we have a radius of zero. This is not the same
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// thing as an empty sphere, because our volume contains one
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// point; an empty sphere contains no points.
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_radius = 0.0;
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} else {
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// More than one point; we have a nonzero radius.
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while (p != last) {
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#ifndef NDEBUG
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// Skip more NaN points.
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if ((*p).is_nan()) {
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++skipped_nan;
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} else
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#endif
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{
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min_box.set(min(min_box[0], (*p)[0]),
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min(min_box[1], (*p)[1]),
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min(min_box[2], (*p)[2]));
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max_box.set(max(max_box[0], (*p)[0]),
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max(max_box[1], (*p)[1]),
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max(max_box[2], (*p)[2]));
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}
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++p;
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}
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// Now take the center of the bounding box as the center of the sphere.
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_center = (min_box + max_box) / 2.0;
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// Now walk back through to get the max distance from center.
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float max_dist2 = 0.0;
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for (p = first; p != last; ++p) {
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LVector3f v = (*p) - _center;
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float dist2 = dot(v, v);
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max_dist2 = max(max_dist2, dist2);
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}
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_radius = sqrtf(max_dist2);
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}
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#ifndef NDEBUG
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if (skipped_nan != 0) {
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mathutil_cat.warning()
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<< "BoundingSphere ignored " << skipped_nan << " NaN points of "
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<< (last - first) << " total.\n";
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}
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#endif
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_flags = 0;
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return true;
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}
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bool BoundingSphere::
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around_spheres(const BoundingVolume **first,
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const BoundingVolume **last) {
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return around_finite(first, last);
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}
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bool BoundingSphere::
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around_hexahedrons(const BoundingVolume **first,
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const BoundingVolume **last) {
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return around_finite(first, last);
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}
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bool BoundingSphere::
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around_finite(const BoundingVolume **first,
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const BoundingVolume **last) {
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nassertr(first != last, false);
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// We're given a set of bounding volumes, at least the first one of
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// which is guaranteed to be finite and nonempty. Some others may
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// not be.
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// First, get the minmax of all the points to construct a bounding
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// box.
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const BoundingVolume **p = first;
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nassertr(!(*p)->is_empty() && !(*p)->is_infinite(), false);
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nassertr((*p)->is_of_type(FiniteBoundingVolume::get_class_type()), false);
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const FiniteBoundingVolume *vol = DCAST(FiniteBoundingVolume, *p);
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LPoint3f min_box = vol->get_min();
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LPoint3f max_box = vol->get_max();
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bool any_unknown = false;
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for (++p; p != last; ++p) {
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nassertr(!(*p)->is_infinite(), false);
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if (!(*p)->is_empty() &&
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(*p)->is_of_type(FiniteBoundingVolume::get_class_type())) {
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const FiniteBoundingVolume *vol = DCAST(FiniteBoundingVolume, *p);
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LPoint3f min1 = vol->get_min();
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LPoint3f max1 = vol->get_max();
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min_box.set(min(min_box[0], min1[0]),
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min(min_box[1], min1[1]),
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min(min_box[2], min1[2]));
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max_box.set(max(max_box[0], max1[0]),
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max(max_box[1], max1[1]),
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max(max_box[2], max1[2]));
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if (!(*p)->is_of_type(BoundingSphere::get_class_type())) {
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any_unknown = true;
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}
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}
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}
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// Now take the center of the bounding box as the center of the sphere.
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_center = (min_box + max_box) * 0.5;
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if (any_unknown) {
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// If we have any volumes in the list that we don't know what to
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// do with, we'll have to make the bounding sphere large enough to
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// enclose the bounding box. Less than ideal, but too bad.
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_radius = length(max_box - _center);
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} else {
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// Otherwise, we do understand all the volumes in the list; make
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// the sphere as tight as we can.
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_radius = 0.0;
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for (p = first; p != last; ++p) {
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if (!(*p)->is_empty()) {
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if ((*p)->is_of_type(BoundingSphere::get_class_type())) {
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const BoundingSphere *sphere = DCAST(BoundingSphere, *p);
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float dist = length(sphere->_center - _center);
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_radius = max(_radius, dist + sphere->_radius);
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} else {
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// Shouldn't get here, unless we missed a type from above.
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mathutil_cat.error()
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<< "Unexpected type in BoundingSphere::around_finite()\n";
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nassertr(false, false);
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}
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}
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}
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}
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_flags = 0;
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return true;
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}
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int BoundingSphere::
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contains_point(const LPoint3f &point) const {
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nassertr(!point.is_nan(), IF_no_intersection);
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if (is_empty()) {
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return IF_no_intersection;
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} else if (is_infinite()) {
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return IF_possible | IF_some | IF_all;
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} else {
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LVector3f v = point - _center;
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float dist2 = dot(v, v);
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return (dist2 <= _radius * _radius) ?
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IF_possible | IF_some | IF_all : IF_no_intersection;
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}
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}
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int BoundingSphere::
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contains_lineseg(const LPoint3f &a, const LPoint3f &b) const {
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nassertr(!a.is_nan() && !b.is_nan(), IF_no_intersection);
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if (a == b) {
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return contains_point(a);
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}
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if (is_empty()) {
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return IF_no_intersection;
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} else if (is_infinite()) {
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return IF_possible | IF_some | IF_all;
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} else {
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LPoint3f from = a;
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LVector3f delta = b - a;
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float t1, t2;
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// Solve the equation for the intersection of a line with a sphere
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// using the quadratic equation.
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float A = dot(delta, delta);
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nassertr(A != 0.0, 0); // Trivial line segment.
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LVector3f fc = from - _center;
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float B = 2.0 * dot(delta, fc);
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float C = dot(fc, fc) - _radius * _radius;
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float radical = B*B - 4.0*A*C;
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if (IS_NEARLY_ZERO(radical)) {
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// Tangent.
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t1 = t2 = -B / (2.0*A);
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return (t1 >= 0.0 && t1 <= 1.0) ?
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IF_possible | IF_some : IF_no_intersection;
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}
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if (radical < 0.0) {
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// No real roots: no intersection with the line.
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return IF_no_intersection;
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}
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float reciprocal_2A = 1.0f/(2.0*A);
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float sqrt_radical = sqrtf(radical);
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t1 = ( -B - sqrt_radical ) * reciprocal_2A;
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t2 = ( -B + sqrt_radical ) * reciprocal_2A;
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if (t1 >= 0.0 && t2 <= 1.0) {
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return IF_possible | IF_some | IF_all;
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} else if (t1 <= 1.0 && t2 >= 0.0) {
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return IF_possible | IF_some;
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} else {
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return IF_no_intersection;
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}
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}
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}
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int BoundingSphere::
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contains_sphere(const BoundingSphere *sphere) const {
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nassertr(!is_empty() && !is_infinite(), 0);
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nassertr(!sphere->is_empty() && !sphere->is_infinite(), 0);
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LVector3f v = sphere->_center - _center;
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float dist2 = dot(v, v);
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if (_radius >= sphere->_radius &&
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dist2 <= (_radius - sphere->_radius) * (_radius - sphere->_radius)) {
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// The other sphere is completely within this sphere.
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return IF_possible | IF_some | IF_all;
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} else if (dist2 > (_radius + sphere->_radius) * (_radius + sphere->_radius)) {
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// The other sphere is completely outside this sphere.
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return IF_no_intersection;
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} else {
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// The other sphere is partially within this sphere.
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return IF_possible | IF_some;
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}
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}
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int BoundingSphere::
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contains_hexahedron(const BoundingHexahedron *hexahedron) const {
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return hexahedron->contains_sphere(this) & ~IF_all;
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}
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int BoundingSphere::
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contains_line(const BoundingLine *line) const {
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return line->contains_sphere(this) & ~IF_all;
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}
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