math func to find the intersection(s) between a segment and a sphere for C/python.

from python:
  i1, i2 = mathutils.geometry.intersect_line_sphere(l1, l2, sphere, radius)

1 files changed, 68 insertions, 0 deletions

diff --git a/source/blender/python/generic/mathutils_geometry.c b/source/blender/python/generic/mathutils_geometry.c
index 53c066d1a85..0b98867dcee 100644
--- a/source/blender/python/generic/mathutils_geometry.c
+++ b/source/blender/python/generic/mathutils_geometry.c
@@ -553,6 +553,73 @@ static PyObject *M_Geometry_intersect_line_plane(PyObject *UNUSED(self), PyObjec
 	}
 }
 
+
+PyDoc_STRVAR(M_Geometry_intersect_line_sphere_doc,
+".. function:: intersect_line_sphere(line_a, line_b, sphere_co, sphere_radius)\n"
+"\n"
+"   Takes a lines (as 2 vectors), a sphere as a point and a radius and\n"
+"   returns the intersection\n"
+"\n"
+"   :arg line_a: First point of the first line\n"
+"   :type line_a: :class:`mathutils.Vector`\n"
+"   :arg line_b: Second point of the first line\n"
+"   :type line_b: :class:`mathutils.Vector`\n"
+"   :arg sphere_co: The center of the sphere\n"
+"   :type sphere_co: :class:`mathutils.Vector`\n"
+"   :arg sphere_radius: Radius of the sphere\n"
+"   :type sphere_radius: sphere_radius\n"
+"   :return: The intersection points as a pair of vectors or None when there is no intersection\n"
+"   :rtype: A tuple pair containing :class:`mathutils.Vector` or None\n"
+);
+static PyObject *M_Geometry_intersect_line_sphere(PyObject *UNUSED(self), PyObject* args)
+{
+	PyObject *ret;
+	VectorObject *line_a, *line_b, *sphere_co;
+	float sphere_radius;
+
+	float isect_a[3];
+	float isect_b[3];
+
+	if(!PyArg_ParseTuple(args, "O!O!O!f:intersect_line_sphere",
+	  &vector_Type, &line_a,
+	  &vector_Type, &line_b,
+	  &vector_Type, &sphere_co,
+	  &sphere_radius)
+	) {
+		return NULL;
+	}
+
+	if(		BaseMath_ReadCallback(line_a) == -1 ||
+	        BaseMath_ReadCallback(line_b) == -1 ||
+	        BaseMath_ReadCallback(sphere_co) == -1
+	) {
+		return NULL;
+	}
+
+	if(ELEM3(2, line_a->size, line_b->size, sphere_co->size)) {
+		PyErr_SetString(PyExc_RuntimeError, "geometry.intersect_line_sphere(...) can't use 2D Vectors");
+		return NULL;
+	}
+
+	ret= PyTuple_New(2);
+
+	switch(isect_seg_sphere_v3(line_a->vec, line_b->vec, sphere_co->vec, sphere_radius, isect_a, isect_b)) {
+	case 1:
+		PyTuple_SET_ITEM(ret, 0,  newVectorObject(isect_a, 3, Py_NEW, NULL));
+		PyTuple_SET_ITEM(ret, 1,  Py_None); Py_INCREF(Py_None);
+		break;
+	case 2:
+		PyTuple_SET_ITEM(ret, 0,  newVectorObject(isect_a, 3, Py_NEW, NULL));
+		PyTuple_SET_ITEM(ret, 1,  newVectorObject(isect_b, 3, Py_NEW, NULL));
+		break;
+	default:
+		PyTuple_SET_ITEM(ret, 0,  Py_None); Py_INCREF(Py_None);
+		PyTuple_SET_ITEM(ret, 1,  Py_None); Py_INCREF(Py_None);
+	}
+
+	return ret;
+}
+
 PyDoc_STRVAR(M_Geometry_intersect_point_line_doc,
 ".. function:: intersect_point_line(pt, line_p1, line_p2)\n"
 "\n"
@@ -917,6 +984,7 @@ static PyMethodDef M_Geometry_methods[]= {
 	{"intersect_line_line", (PyCFunction) M_Geometry_intersect_line_line, METH_VARARGS, M_Geometry_intersect_line_line_doc},
 	{"intersect_line_line_2d", (PyCFunction) M_Geometry_intersect_line_line_2d, METH_VARARGS, M_Geometry_intersect_line_line_2d_doc},
 	{"intersect_line_plane", (PyCFunction) M_Geometry_intersect_line_plane, METH_VARARGS, M_Geometry_intersect_line_plane_doc},
+	{"intersect_line_sphere", (PyCFunction) M_Geometry_intersect_line_sphere, METH_VARARGS, M_Geometry_intersect_line_sphere_doc},
 	{"interpolate_bezier", (PyCFunction) M_Geometry_interpolate_bezier, METH_VARARGS, M_Geometry_interpolate_bezier_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},