kicad/3d-viewer/3d_rendering/3d_render_raytracing/ray.cpp

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/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2015-2017 Mario Luzeiro <mrluzeiro@ua.pt>
* Copyright (C) 1992-2017 KiCad Developers, see AUTHORS.txt for contributors.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/**
* @file ray.cpp
* @brief
*/
#include "ray.h"
#include "../../3d_fastmath.h"
#include <stdio.h>
#include <wx/debug.h>
#include <cmath>
//static unsigned int gs_next_rayID = 0;
void RAY::Init( const SFVEC3F& o, const SFVEC3F& d )
{
m_Origin = o;
m_Dir = d;
m_InvDir = 1.0f / d;
//rayID = gs_next_rayID;
//gs_next_rayID++;
// An Efficient and Robust RayBox Intersection Algorithm
// Amy Williams Steve Barrus R. Keith Morley Peter Shirley
// University of Utah
// http://people.csail.mit.edu/amy/papers/box-jgt.pdf
m_dirIsNeg[0] = m_Dir.x <= 0.0f;
m_dirIsNeg[1] = m_Dir.y <= 0.0f;
m_dirIsNeg[2] = m_Dir.z <= 0.0f;
// ray slope
// "Fast Ray / Axis-Aligned Bounding Box Overlap Tests using Ray Slopes"
// by Martin Eisemann, Thorsten Grosch, Stefan Müller and Marcus Magnor
// Computer Graphics Lab, TU Braunschweig, Germany and
// University of Koblenz-Landau, Germany
// Licence: "This source code is public domain, but please mention us if you use it."
//
// https://github.com/rjw57/mcvoxel/tree/master/third-party/rayslope
// https://github.com/rjw57/mcvoxel/blob/master/third-party/rayslope/ray.cpp
ibyj = m_Dir.x * m_InvDir.y;
jbyi = m_Dir.y * m_InvDir.x;
jbyk = m_Dir.y * m_InvDir.z;
kbyj = m_Dir.z * m_InvDir.y;
ibyk = m_Dir.x * m_InvDir.z;
kbyi = m_Dir.z * m_InvDir.x;
c_xy = m_Origin.y - jbyi * m_Origin.x;
c_xz = m_Origin.z - kbyi * m_Origin.x;
c_yx = m_Origin.x - ibyj * m_Origin.y;
c_yz = m_Origin.z - kbyj * m_Origin.y;
c_zx = m_Origin.x - ibyk * m_Origin.z;
c_zy = m_Origin.y - jbyk * m_Origin.z;
// ray slope classification
if( m_Dir.x < 0 )
{
if( m_Dir.y < 0 )
{
if( m_Dir.z < 0 )
{
m_Classification = MMM;
}
else if( m_Dir.z > 0 ){
m_Classification = MMP;
}
else//( m_Dir.z >= 0 )
{
m_Classification = MMO;
}
}
else//( m_Dir.y >= 0 )
{
if( m_Dir.z < 0 )
{
m_Classification = MPM;
if( m_Dir.y == 0 )
m_Classification = MOM;
}
else//( m_Dir.z >= 0 )
{
if( ( m_Dir.y == 0 ) && ( m_Dir.z == 0 ) )
m_Classification = MOO;
else if( m_Dir.z == 0 )
m_Classification = MPO;
else if( m_Dir.y == 0 )
m_Classification = MOP;
else
m_Classification = MPP;
}
}
}
else//( m_Dir.x >= 0 )
{
if( m_Dir.y < 0 )
{
if( m_Dir.z < 0 )
{
m_Classification = PMM;
if( m_Dir.x == 0 )
m_Classification = OMM;
}
else//( m_Dir.z >= 0 )
{
if( ( m_Dir.x == 0 ) && ( m_Dir.z == 0 ) )
m_Classification = OMO;
else if( m_Dir.z == 0 )
m_Classification = PMO;
else if( m_Dir.x == 0 )
m_Classification = OMP;
else
m_Classification = PMP;
}
}
else//( m_Dir.y >= 0 )
{
if( m_Dir.z < 0 )
{
if( ( m_Dir.x == 0 ) && ( m_Dir.y == 0 ) )
m_Classification = OOM;
else if( m_Dir.x == 0 )
m_Classification = OPM;
else if( m_Dir.y == 0 )
m_Classification = POM;
else
m_Classification = PPM;
}
else//( m_Dir.z > 0 )
{
if( m_Dir.x == 0 )
{
if( m_Dir.y == 0 )
m_Classification = OOP;
else if( m_Dir.z == 0 )
m_Classification = OPO;
else
m_Classification = OPP;
}
else
{
if( ( m_Dir.y == 0 ) && ( m_Dir.z == 0 ) )
m_Classification = POO;
else if( m_Dir.y == 0 )
m_Classification = POP;
else if( m_Dir.z == 0 )
m_Classification = PPO;
else
m_Classification = PPP;
}
}
}
}
}
bool IntersectSegment( const SFVEC2F &aStartA, const SFVEC2F &aEnd_minus_startA,
const SFVEC2F &aStartB, const SFVEC2F &aEnd_minus_startB )
{
float rxs = aEnd_minus_startA.x *
aEnd_minus_startB.y - aEnd_minus_startA.y *
aEnd_minus_startB.x;
if( std::abs( rxs ) > glm::epsilon<float>() )
{
float inv_rxs = 1.0f / rxs;
SFVEC2F pq = aStartB - aStartA;
float t = (pq.x * aEnd_minus_startB.y - pq.y * aEnd_minus_startB.x) * inv_rxs;
if( (t < 0.0f) || (t > 1.0f) )
return false;
float u = (pq.x * aEnd_minus_startA.y - pq.y * aEnd_minus_startA.x) * inv_rxs;
if( (u < 0.0f) || (u > 1.0f) )
return false;
return true;
}
return false;
}
// !TODO: not tested
bool RAY::IntersectSphere( const SFVEC3F &aCenter, float aRadius, float &aOutT0, float &aOutT1 ) const
{
/*
// Ray-sphere intersection: algebraic
SFVEC3F CO = m_Origin - aCenter;
float a = glm::dot( m_Dir, m_Dir );
float b = 2.0f * glm::dot( CO, m_Dir );
float c = glm::dot( CO, CO ) - aRadius*aRadius;
float discriminant = b * b - 4.0f * a * c;
if( discriminant < 0.0f )
return false;
aOutT0 = (-b - sqrtf(discriminant)) / (2.0f * a);
aOutT1 = (-b + sqrtf(discriminant)) / (2.0f * a);
if( aOutT0 > aOutT1 )
{
float temp = aOutT0;
aOutT0 = aOutT1;
aOutT1 = temp;
}
return true;
*/
// Ray-sphere intersection: geometric
SFVEC3F OC = aCenter - m_Origin;
float p_dot_d = glm::dot( OC, m_Dir );
if( p_dot_d < 0.0f )
return 0.0f;
float p_dot_p = glm::dot( OC, OC );
float discriminant = p_dot_p - p_dot_d * p_dot_d;
if( discriminant > aRadius*aRadius )
return false;
discriminant = sqrtf( aRadius*aRadius - discriminant );
aOutT0 = p_dot_d - discriminant;
aOutT1 = p_dot_d + discriminant;
if( aOutT0 > aOutT1 )
{
float temp = aOutT0;
aOutT0 = aOutT1;
aOutT1 = temp;
}
return true;
}
RAYSEG2D::RAYSEG2D( const SFVEC2F& s, const SFVEC2F& e )
{
m_Start = s;
m_End = e;
m_End_minus_start = e - s;
m_Length = glm::length( m_End_minus_start );
m_Dir = glm::normalize( m_End_minus_start );
m_InvDir = (1.0f / m_Dir);
if( fabs(m_Dir.x) < FLT_EPSILON )
m_InvDir.x = NextFloatDown(FLT_MAX);
if( fabs(m_Dir.y) < FLT_EPSILON )
m_InvDir.y = NextFloatDown(FLT_MAX);
m_DOT_End_minus_start = glm::dot( m_End_minus_start, m_End_minus_start );
}
bool RAYSEG2D::IntersectSegment( const SFVEC2F &aStart,
const SFVEC2F &aEnd_minus_start,
float *aOutT ) const
{
float rxs = m_End_minus_start.x *
aEnd_minus_start.y - m_End_minus_start.y *
aEnd_minus_start.x;
if( std::abs( rxs ) > glm::epsilon<float>() )
{
const float inv_rxs = 1.0f / rxs;
const SFVEC2F pq = aStart - m_Start;
const float t = (pq.x * aEnd_minus_start.y - pq.y * aEnd_minus_start.x) * inv_rxs;
if( (t < 0.0f) || (t > 1.0f) )
return false;
float u = (pq.x * m_End_minus_start.y - pq.y * m_End_minus_start.x) * inv_rxs;
if( (u < 0.0f) || (u > 1.0f) )
return false;
*aOutT = t;
return true;
}
return false;
}
// http://geomalgorithms.com/a02-_lines.html
float RAYSEG2D::DistanceToPointSquared( const SFVEC2F &aPoint ) const
{
SFVEC2F p = aPoint - m_Start;
const float c1 = glm::dot( p, m_End_minus_start );
if( c1 < FLT_EPSILON )
return glm::dot( p, p );
if( m_DOT_End_minus_start <= c1 )
p = aPoint - m_End;
else
{
const float b = c1 / m_DOT_End_minus_start;
const SFVEC2F pb = m_Start + m_End_minus_start * b;
p = aPoint - pb;
}
return glm::dot( p, p );
}
bool RAYSEG2D::IntersectCircle( const SFVEC2F &aCenter,
float aRadius,
float *aOutT0,
float *aOutT1,
SFVEC2F *aOutNormalT0,
SFVEC2F *aOutNormalT1 ) const
{
// This code used directly from Steve Marschner's CS667 framework
// http://cs665pd.googlecode.com/svn/trunk/photon/sphere.cpp
// Compute some factors used in computation
const float qx = m_Start.x - aCenter.x;
const float qy = m_Start.y - aCenter.y;
const float qd = qx * m_Dir.x + qy * m_Dir.y;
const float qq = qx * qx + qy * qy;
// solving the quadratic equation for t at the pts of intersection
// dd*t^2 + (2*qd)*t + (qq-r^2) = 0
const float discriminantsqr = (qd * qd - (qq - aRadius * aRadius));
// If the discriminant is less than zero, there is no intersection
if( discriminantsqr < FLT_EPSILON )
return false;
// Otherwise check and make sure that the intersections occur on the ray (t
// > 0) and return the closer one
const float discriminant = std::sqrt( discriminantsqr );
const float t1 = (-qd - discriminant);
const float t2 = (-qd + discriminant);
if( (( t1 < 0.0f ) || ( t1 > m_Length ) ) &&
(( t2 < 0.0f ) || ( t2 > m_Length ) ) )
return false;// Neither intersection was in the ray's half line.
// Convert the intersection to a normalized
*aOutT0 = t1 / m_Length;
*aOutT1 = t2 / m_Length;
SFVEC2F hitPointT1 = at( t1 );
SFVEC2F hitPointT2 = at( t2 );
*aOutNormalT0 = (hitPointT1 - aCenter) / aRadius;
*aOutNormalT1 = (hitPointT2 - aCenter) / aRadius;
return true;
}
void RAY::debug() const
{
printf("O(%f, %f, %f) D(%f, %f, %f)\n", m_Origin.x, m_Origin.y, m_Origin.z,
m_Dir.x, m_Dir.y, m_Dir.z );
}