int BicubicPatch::intersect_bicubic_patch0(const BasicRay &ray, IStack& Depth_Stack, TraceThreadData *Thread)
{
return (bezier_subdivider(ray, &Control_Points, 0.0, 1.0, 0.0, 1.0, 0, Depth_Stack, Thread));
}
static int intersect_bicubic_patch0(RAY *Ray, BICUBIC_PATCH *Shape, ISTACK *Depth_Stack)
{
VECTOR(*Patch)[4][4] = (VECTOR(*)[4][4]) Shape->Control_Points;
return (bezier_subdivider(Ray, Shape, Patch, 0.0, 1.0, 0.0, 1.0, 0, Depth_Stack));
}
int BicubicPatch::bezier_subdivider(const BasicRay &ray, const ControlPoints *Patch, DBL u0, DBL u1, DBL v0, DBL v1, int recursion_depth, IStack& Depth_Stack, TraceThreadData *Thread)
{
int cnt = 0;
DBL ut, vt, radiusSqr;
ControlPoints Lower_Left, Lower_Right;
ControlPoints Upper_Left, Upper_Right;
Vector3d center;
/*
* Make sure the ray passes through a sphere bounding
* the control points of the patch.
*/
bezier_bounding_sphere(Patch, center, &radiusSqr);
if (!spherical_bounds_check(ray, center, radiusSqr))
{
return (0);
}
/*
* If the patch is close to being flat, then just
* perform a ray-plane intersection test.
*/
if (flat_enough(Patch))
return bezier_subpatch_intersect(ray, Patch, u0, u1, v0, v1, Depth_Stack, Thread);
if (recursion_depth >= U_Steps)
{
if (recursion_depth >= V_Steps)
{
return bezier_subpatch_intersect(ray, Patch, u0, u1, v0, v1, Depth_Stack, Thread);
}
else
{
bezier_split_up_down(Patch, &Lower_Left, &Upper_Left);
vt = (v1 + v0) / 2.0;
cnt += bezier_subdivider(ray, &Lower_Left, u0, u1, v0, vt, recursion_depth + 1, Depth_Stack, Thread);
cnt += bezier_subdivider(ray, &Upper_Left, u0, u1, vt, v1, recursion_depth + 1, Depth_Stack, Thread);
}
}
else
{
if (recursion_depth >= V_Steps)
{
bezier_split_left_right(Patch, &Lower_Left, &Lower_Right);
ut = (u1 + u0) / 2.0;
cnt += bezier_subdivider(ray, &Lower_Left, u0, ut, v0, v1, recursion_depth + 1, Depth_Stack, Thread);
cnt += bezier_subdivider(ray, &Lower_Right, ut, u1, v0, v1, recursion_depth + 1, Depth_Stack, Thread);
}
else
{
ut = (u1 + u0) / 2.0;
vt = (v1 + v0) / 2.0;
bezier_split_left_right(Patch, &Lower_Left, &Lower_Right);
bezier_split_up_down(&Lower_Left, &Lower_Left, &Upper_Left) ;
bezier_split_up_down(&Lower_Right, &Lower_Right, &Upper_Right);
cnt += bezier_subdivider(ray, &Lower_Left, u0, ut, v0, vt, recursion_depth + 1, Depth_Stack, Thread);
cnt += bezier_subdivider(ray, &Upper_Left, u0, ut, vt, v1, recursion_depth + 1, Depth_Stack, Thread);
cnt += bezier_subdivider(ray, &Lower_Right, ut, u1, v0, vt, recursion_depth + 1, Depth_Stack, Thread);
cnt += bezier_subdivider(ray, &Upper_Right, ut, u1, vt, v1, recursion_depth + 1, Depth_Stack, Thread);
}
}
return (cnt);
}
static int bezier_subdivider(RAY *Ray, BICUBIC_PATCH *Object, VECTOR (*Patch)[4][4], DBL u0, DBL u1, DBL v0, DBL v1,
int recursion_depth, ISTACK *Depth_Stack)
{
int cnt = 0;
DBL ut, vt, radius;
VECTOR Lower_Left[4][4], Lower_Right[4][4];
VECTOR Upper_Left[4][4], Upper_Right[4][4];
VECTOR center;
/*
* Make sure the ray passes through a sphere bounding
* the control points of the patch.
*/
bezier_bounding_sphere(Patch, center, &radius);
if (!spherical_bounds_check(Ray, center, radius))
{
return (0);
}
/*
* If the patch is close to being flat, then just
* perform a ray-plane intersection test.
*/
if (flat_enough(Object, Patch))
{
return bezier_subpatch_intersect(Ray, Object, Patch, u0, u1, v0, v1, Depth_Stack);
}
if (recursion_depth >= Object->U_Steps)
{
if (recursion_depth >= Object->V_Steps)
{
return bezier_subpatch_intersect(Ray, Object, Patch, u0, u1, v0, v1, Depth_Stack);
}
else
{
bezier_split_up_down(Patch, (VECTOR(*)[4][4])Lower_Left, (VECTOR(*)[4][4])Upper_Left);
vt = (v1 + v0) / 2.0;
cnt += bezier_subdivider(Ray, Object, (VECTOR(*)[4][4])Lower_Left, u0, u1, v0, vt, recursion_depth + 1, Depth_Stack);
cnt += bezier_subdivider(Ray, Object, (VECTOR(*)[4][4])Upper_Left, u0, u1, vt, v1, recursion_depth + 1, Depth_Stack);
}
}
else
{
if (recursion_depth >= Object->V_Steps)
{
bezier_split_left_right(Patch, (VECTOR(*)[4][4])Lower_Left, (VECTOR(*)[4][4])Lower_Right);
ut = (u1 + u0) / 2.0;
cnt += bezier_subdivider(Ray, Object, (VECTOR(*)[4][4])Lower_Left, u0, ut, v0, v1, recursion_depth + 1, Depth_Stack);
cnt += bezier_subdivider(Ray, Object, (VECTOR(*)[4][4])Lower_Right, ut, u1, v0, v1, recursion_depth + 1, Depth_Stack);
}
else
{
ut = (u1 + u0) / 2.0;
vt = (v1 + v0) / 2.0;
bezier_split_left_right(Patch, (VECTOR(*)[4][4])Lower_Left, (VECTOR(*)[4][4])Lower_Right);
bezier_split_up_down((VECTOR(*)[4][4])Lower_Left, (VECTOR(*)[4][4])Lower_Left, (VECTOR(*)[4][4])Upper_Left) ;
bezier_split_up_down((VECTOR(*)[4][4])Lower_Right, (VECTOR(*)[4][4])Lower_Right, (VECTOR(*)[4][4])Upper_Right);
cnt += bezier_subdivider(Ray, Object, (VECTOR(*)[4][4])Lower_Left, u0, ut, v0, vt, recursion_depth + 1, Depth_Stack);
cnt += bezier_subdivider(Ray, Object, (VECTOR(*)[4][4])Upper_Left, u0, ut, vt, v1, recursion_depth + 1, Depth_Stack);
cnt += bezier_subdivider(Ray, Object, (VECTOR(*)[4][4])Lower_Right, ut, u1, v0, vt, recursion_depth + 1, Depth_Stack);
cnt += bezier_subdivider(Ray, Object, (VECTOR(*)[4][4])Upper_Right, ut, u1, vt, v1, recursion_depth + 1, Depth_Stack);
}
}
return (cnt);
}
