101 lines
3.2 KiB
C++
101 lines
3.2 KiB
C++
/*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* Copyright 2015-2017 Danny Robson <danny@nerdcruft.net>
|
|
*/
|
|
|
|
#include "ellipse.hpp"
|
|
|
|
#include "ops.hpp"
|
|
#include "aabb.hpp"
|
|
#include "ray.hpp"
|
|
#include "sphere.hpp"
|
|
#include "point.hpp"
|
|
|
|
#include "../matrix.hpp"
|
|
|
|
using util::geom::ellipse;
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
template <size_t S, typename T>
|
|
static bool
|
|
intersects (ellipse<S,T> e, util::point<S,T> p)
|
|
{
|
|
auto mag = (p - e.origin) * (p - e.origin) / (e.radius * e.radius);
|
|
return std::accumulate (mag.begin (), mag.end (), 0) <= 1;
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
template <size_t S, typename T, template <size_t,typename> class A, template <size_t,typename> class B>
|
|
bool
|
|
util::geom::intersects (A<S,T> a, B<S,T> b)
|
|
{
|
|
return ::intersects (a, b);
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
template bool util::geom::intersects (ellipse<2,float>, util::point<2,float>);
|
|
template bool util::geom::intersects (ellipse<3,float>, util::point<3,float>);
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// query a ray-ellipse distance by transforming spaces such that the ellipse is
|
|
// a sphere
|
|
template <>
|
|
float
|
|
util::geom::distance (ray<3,float> r, ellipse<3,float> e)
|
|
{
|
|
// find a transform that puts the ellipse at origin and scales it to a
|
|
// unit sphere.
|
|
auto const from_scaled = util::scale (e.radius) *
|
|
util::look_at (e.origin, {0,0,-1}, e.up);
|
|
auto const to_scaled = inverse (from_scaled);
|
|
|
|
// transform the ray into this new space and query against a unit sphere
|
|
auto const scaled_r = to_scaled * r;
|
|
auto const scaled_d = distance (scaled_r, sphere3f {0, 1.f});
|
|
auto const scaled_p = scaled_r.at (scaled_d);
|
|
|
|
// transform the result back into the original space
|
|
return distance (r.origin, (from_scaled * scaled_p.homog<4> ()).redim<3> ());
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
template <size_t S, typename T>
|
|
static util::geom::aabb<S,T>
|
|
bounds (ellipse<S,T> e)
|
|
{
|
|
return {
|
|
e.origin - e.radius,
|
|
e.origin + e.radius
|
|
};
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
template <size_t S, typename T, template <size_t,typename> class K>
|
|
util::geom::aabb<S,T>
|
|
util::geom::bounds (K<S,T> k)
|
|
{
|
|
return ::bounds (k);
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
template util::geom::aabb<2,float> util::geom::bounds (ellipse<2,float>);
|
|
template util::geom::aabb<3,float> util::geom::bounds (ellipse<3,float>);
|