virtualx-engine/thirdparty/vhacd/src/vhacdRaycastMesh.cpp
Juan Linietsky 5823b5d77d Bundled VHACD library for convex decomposition.
Modified both MeshInstance tools as well as importer to use it instead of QuickHull.
2019-04-10 17:47:28 -03:00

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5.4 KiB
C++

#include "vhacdRaycastMesh.h"
#include <math.h>
#include <assert.h>
namespace RAYCAST_MESH
{
/* a = b - c */
#define vector(a,b,c) \
(a)[0] = (b)[0] - (c)[0]; \
(a)[1] = (b)[1] - (c)[1]; \
(a)[2] = (b)[2] - (c)[2];
#define innerProduct(v,q) \
((v)[0] * (q)[0] + \
(v)[1] * (q)[1] + \
(v)[2] * (q)[2])
#define crossProduct(a,b,c) \
(a)[0] = (b)[1] * (c)[2] - (c)[1] * (b)[2]; \
(a)[1] = (b)[2] * (c)[0] - (c)[2] * (b)[0]; \
(a)[2] = (b)[0] * (c)[1] - (c)[0] * (b)[1];
static inline bool rayIntersectsTriangle(const double *p,const double *d,const double *v0,const double *v1,const double *v2,double &t)
{
double e1[3],e2[3],h[3],s[3],q[3];
double a,f,u,v;
vector(e1,v1,v0);
vector(e2,v2,v0);
crossProduct(h,d,e2);
a = innerProduct(e1,h);
if (a > -0.00001 && a < 0.00001)
return(false);
f = 1/a;
vector(s,p,v0);
u = f * (innerProduct(s,h));
if (u < 0.0 || u > 1.0)
return(false);
crossProduct(q,s,e1);
v = f * innerProduct(d,q);
if (v < 0.0 || u + v > 1.0)
return(false);
// at this stage we can compute t to find out where
// the intersection point is on the line
t = f * innerProduct(e2,q);
if (t > 0) // ray intersection
return(true);
else // this means that there is a line intersection
// but not a ray intersection
return (false);
}
static double getPointDistance(const double *p1, const double *p2)
{
double dx = p1[0] - p2[0];
double dy = p1[1] - p2[1];
double dz = p1[2] - p2[2];
return sqrt(dx*dx + dy*dy + dz*dz);
}
class MyRaycastMesh : public VHACD::RaycastMesh
{
public:
template <class T>
MyRaycastMesh(uint32_t vcount,
const T *vertices,
uint32_t tcount,
const uint32_t *indices)
{
mVcount = vcount;
mVertices = new double[mVcount * 3];
for (uint32_t i = 0; i < mVcount; i++)
{
mVertices[i * 3 + 0] = vertices[0];
mVertices[i * 3 + 1] = vertices[1];
mVertices[i * 3 + 2] = vertices[2];
vertices += 3;
}
mTcount = tcount;
mIndices = new uint32_t[mTcount * 3];
for (uint32_t i = 0; i < mTcount; i++)
{
mIndices[i * 3 + 0] = indices[0];
mIndices[i * 3 + 1] = indices[1];
mIndices[i * 3 + 2] = indices[2];
indices += 3;
}
}
~MyRaycastMesh(void)
{
delete[]mVertices;
delete[]mIndices;
}
virtual void release(void)
{
delete this;
}
virtual bool raycast(const double *from, // The starting point of the raycast
const double *to, // The ending point of the raycast
const double *closestToPoint, // The point to match the nearest hit location (can just be the 'from' location of no specific point)
double *hitLocation, // The point where the ray hit nearest to the 'closestToPoint' location
double *hitDistance) final // The distance the ray traveled to the hit location
{
bool ret = false;
double dir[3];
dir[0] = to[0] - from[0];
dir[1] = to[1] - from[1];
dir[2] = to[2] - from[2];
double distance = sqrt( dir[0]*dir[0] + dir[1]*dir[1]+dir[2]*dir[2] );
if ( distance < 0.0000000001f ) return false;
double recipDistance = 1.0f / distance;
dir[0]*=recipDistance;
dir[1]*=recipDistance;
dir[2]*=recipDistance;
const uint32_t *indices = mIndices;
const double *vertices = mVertices;
double nearestDistance = distance;
for (uint32_t tri=0; tri<mTcount; tri++)
{
uint32_t i1 = indices[tri*3+0];
uint32_t i2 = indices[tri*3+1];
uint32_t i3 = indices[tri*3+2];
const double *p1 = &vertices[i1*3];
const double *p2 = &vertices[i2*3];
const double *p3 = &vertices[i3*3];
double t;
if ( rayIntersectsTriangle(from,dir,p1,p2,p3,t))
{
double hitPos[3];
hitPos[0] = from[0] + dir[0] * t;
hitPos[1] = from[1] + dir[1] * t;
hitPos[2] = from[2] + dir[2] * t;
double pointDistance = getPointDistance(hitPos, closestToPoint);
if (pointDistance < nearestDistance )
{
nearestDistance = pointDistance;
if ( hitLocation )
{
hitLocation[0] = hitPos[0];
hitLocation[1] = hitPos[1];
hitLocation[2] = hitPos[2];
}
if ( hitDistance )
{
*hitDistance = pointDistance;
}
ret = true;
}
}
}
return ret;
}
uint32_t mVcount;
double *mVertices;
uint32_t mTcount;
uint32_t *mIndices;
};
};
using namespace RAYCAST_MESH;
namespace VHACD
{
RaycastMesh * RaycastMesh::createRaycastMesh(uint32_t vcount, // The number of vertices in the source triangle mesh
const double *vertices, // The array of vertex positions in the format x1,y1,z1..x2,y2,z2.. etc.
uint32_t tcount, // The number of triangles in the source triangle mesh
const uint32_t *indices) // The triangle indices in the format of i1,i2,i3 ... i4,i5,i6, ...
{
MyRaycastMesh *m = new MyRaycastMesh(vcount, vertices, tcount, indices);
return static_cast<RaycastMesh *>(m);
}
RaycastMesh * RaycastMesh::createRaycastMesh(uint32_t vcount, // The number of vertices in the source triangle mesh
const float *vertices, // The array of vertex positions in the format x1,y1,z1..x2,y2,z2.. etc.
uint32_t tcount, // The number of triangles in the source triangle mesh
const uint32_t *indices) // The triangle indices in the format of i1,i2,i3 ... i4,i5,i6, ...
{
MyRaycastMesh *m = new MyRaycastMesh(vcount, vertices, tcount, indices);
return static_cast<RaycastMesh *>(m);
}
} // end of VHACD namespace