forked from bartvdbraak/blender
add mathutils function to intersect 2 circles. Converted to C from a python script by Alex Fraser.
This commit is contained in:
parent
9b2c0f03dd
commit
f44b7868c5
@ -251,6 +251,86 @@ static PyObject *M_Geometry_intersect_line_line(PyObject *UNUSED(self), PyObject
|
||||
}
|
||||
}
|
||||
|
||||
/* Line-Line intersection using algorithm from mathworld.wolfram.com */
|
||||
|
||||
PyDoc_STRVAR(M_Geometry_intersect_sphere_sphere_2d_doc,
|
||||
".. function:: intersect_sphere_sphere_2d(p_a, radius_a, p_b, radius_b)\n"
|
||||
"\n"
|
||||
" Returns 2 points on between intersecting circles.\n"
|
||||
"\n"
|
||||
" :arg p_a: Center of the first circle\n"
|
||||
" :type p_a: :class:`mathutils.Vector`\n"
|
||||
" :arg radius_a: Radius of the first circle\n"
|
||||
" :type radius_a: float\n"
|
||||
" :arg p_b: Center of the second circle\n"
|
||||
" :type p_b: :class:`mathutils.Vector`\n"
|
||||
" :arg radius_b: Radius of the second circle\n"
|
||||
" :type radius_b: float\n"
|
||||
" :rtype: tuple of :class:`mathutils.Vector`'s or None when there is no intersection\n"
|
||||
);
|
||||
static PyObject *M_Geometry_intersect_sphere_sphere_2d(PyObject *UNUSED(self), PyObject *args)
|
||||
{
|
||||
PyObject *ret;
|
||||
VectorObject *vec_a, *vec_b;
|
||||
float *v_a, *v_b;
|
||||
float rad_a, rad_b;
|
||||
float v_ab[2];
|
||||
float dist;
|
||||
|
||||
if (!PyArg_ParseTuple(args, "O!fO!f:intersect_sphere_sphere_2d",
|
||||
&vector_Type, &vec_a, &rad_a,
|
||||
&vector_Type, &vec_b, &rad_b))
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if (BaseMath_ReadCallback(vec_a) == -1 ||
|
||||
BaseMath_ReadCallback(vec_b) == -1)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
ret = PyTuple_New(2);
|
||||
|
||||
v_a = vec_a->vec;
|
||||
v_b = vec_b->vec;
|
||||
|
||||
sub_v2_v2v2(v_ab, v_b, v_a);
|
||||
dist = len_v2(v_ab);
|
||||
|
||||
if (/* out of range */
|
||||
(dist > rad_a + rad_b) ||
|
||||
/* fully-contained in the other */
|
||||
(dist < abs(rad_a - rad_b)) ||
|
||||
/* co-incident */
|
||||
(dist < FLT_EPSILON))
|
||||
{
|
||||
/* out of range */
|
||||
PyTuple_SET_ITEM(ret, 0, Py_None); Py_INCREF(Py_None);
|
||||
PyTuple_SET_ITEM(ret, 1, Py_None); Py_INCREF(Py_None);
|
||||
}
|
||||
else {
|
||||
const float dist_delta = ((rad_a * rad_a) - (rad_b * rad_b) + (dist * dist)) / (2.0f * dist);
|
||||
const float h = powf(fabsf((rad_a * rad_a) - (dist_delta * dist_delta)), 0.5f);
|
||||
float i_cent[2];
|
||||
float i1[2], i2[2];
|
||||
|
||||
i_cent[0] = v_a[0] + ((v_ab[0] * dist_delta) / dist);
|
||||
i_cent[1] = v_a[1] + ((v_ab[1] * dist_delta) / dist);
|
||||
|
||||
i1[0] = i_cent[0] + h * v_ab[1] / dist;
|
||||
i1[1] = i_cent[1] - h * v_ab[0] / dist;
|
||||
|
||||
i2[0] = i_cent[0] - h * v_ab[1] / dist;
|
||||
i2[1] = i_cent[1] + h * v_ab[0] / dist;
|
||||
|
||||
PyTuple_SET_ITEM(ret, 0, Vector_CreatePyObject(i1, 2, Py_NEW, NULL));
|
||||
PyTuple_SET_ITEM(ret, 1, Vector_CreatePyObject(i2, 2, Py_NEW, NULL));
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
PyDoc_STRVAR(M_Geometry_normal_doc,
|
||||
".. function:: normal(v1, v2, v3, v4=None)\n"
|
||||
"\n"
|
||||
@ -1376,6 +1456,7 @@ static PyMethodDef M_Geometry_methods[] = {
|
||||
{"intersect_line_sphere", (PyCFunction) M_Geometry_intersect_line_sphere, METH_VARARGS, M_Geometry_intersect_line_sphere_doc},
|
||||
{"intersect_line_sphere_2d", (PyCFunction) M_Geometry_intersect_line_sphere_2d, METH_VARARGS, M_Geometry_intersect_line_sphere_2d_doc},
|
||||
{"distance_point_to_plane", (PyCFunction) M_Geometry_distance_point_to_plane, METH_VARARGS, M_Geometry_distance_point_to_plane_doc},
|
||||
{"intersect_sphere_sphere_2d", (PyCFunction) M_Geometry_intersect_sphere_sphere_2d, METH_VARARGS, M_Geometry_intersect_sphere_sphere_2d_doc},
|
||||
{"area_tri", (PyCFunction) M_Geometry_area_tri, METH_VARARGS, M_Geometry_area_tri_doc},
|
||||
{"normal", (PyCFunction) M_Geometry_normal, METH_VARARGS, M_Geometry_normal_doc},
|
||||
{"barycentric_transform", (PyCFunction) M_Geometry_barycentric_transform, METH_VARARGS, M_Geometry_barycentric_transform_doc},
|
||||
|
Loading…
Reference in New Issue
Block a user