BPY: move bpy and mathutils to C++

Also see #103343.

Pull Request: https://projects.blender.org/blender/blender/pulls/110299

source/blender/python/mathutils/mathutils_interpolate.cc

@@ -0,0 +1,111 @@
+/* SPDX-FileCopyrightText: 2023 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup pymathutils
+ */
+
+#include <Python.h>
+
+#include "mathutils.h"
+#include "mathutils_interpolate.h"
+
+#include "BLI_math.h"
+#include "BLI_utildefines.h"
+
+#ifndef MATH_STANDALONE /* define when building outside blender */
+#  include "MEM_guardedalloc.h"
+#endif
+
+/*-------------------------DOC STRINGS ---------------------------*/
+PyDoc_STRVAR(M_Interpolate_doc, "The Blender interpolate module");
+
+/* ---------------------------------WEIGHT CALCULATION ----------------------- */
+
+#ifndef MATH_STANDALONE
+
+PyDoc_STRVAR(M_Interpolate_poly_3d_calc_doc,
+             ".. function:: poly_3d_calc(veclist, pt)\n"
+             "\n"
+             "   Calculate barycentric weights for a point on a polygon.\n"
+             "\n"
+             "   :arg veclist: list of vectors\n"
+             "   :arg pt: point"
+             "   :rtype: list of per-vector weights\n");
+static PyObject *M_Interpolate_poly_3d_calc(PyObject * /*self*/, PyObject *args)
+{
+  float fp[3];
+  float(*vecs)[3];
+  Py_ssize_t len;
+
+  PyObject *point, *veclist, *ret;
+  int i;
+
+  if (!PyArg_ParseTuple(args, "OO:poly_3d_calc", &veclist, &point)) {
+    return nullptr;
+  }
+
+  if (mathutils_array_parse(
+          fp, 2, 3 | MU_ARRAY_ZERO, point, "pt must be a 2-3 dimensional vector") == -1)
+  {
+    return nullptr;
+  }
+
+  len = mathutils_array_parse_alloc_v(((float **)&vecs), 3, veclist, __func__);
+  if (len == -1) {
+    return nullptr;
+  }
+
+  if (len) {
+    float *weights = static_cast<float *>(MEM_mallocN(sizeof(float) * len, __func__));
+
+    interp_weights_poly_v3(weights, vecs, len, fp);
+
+    ret = PyList_New(len);
+    for (i = 0; i < len; i++) {
+      PyList_SET_ITEM(ret, i, PyFloat_FromDouble(weights[i]));
+    }
+
+    MEM_freeN(weights);
+
+    PyMem_Free(vecs);
+  }
+  else {
+    ret = PyList_New(0);
+  }
+
+  return ret;
+}
+
+#endif /* MATH_STANDALONE */
+
+static PyMethodDef M_Interpolate_methods[] = {
+#ifndef MATH_STANDALONE
+    {"poly_3d_calc",
+     (PyCFunction)M_Interpolate_poly_3d_calc,
+     METH_VARARGS,
+     M_Interpolate_poly_3d_calc_doc},
+#endif
+    {nullptr, nullptr, 0, nullptr},
+};
+
+static PyModuleDef M_Interpolate_module_def = {
+    /*m_base*/ PyModuleDef_HEAD_INIT,
+    /*m_name*/ "mathutils.interpolate",
+    /*m_doc*/ M_Interpolate_doc,
+    /*m_size*/ 0,
+    /*m_methods*/ M_Interpolate_methods,
+    /*m_slots*/ nullptr,
+    /*m_traverse*/ nullptr,
+    /*m_clear*/ nullptr,
+    /*m_free*/ nullptr,
+};
+
+/*----------------------------MODULE INIT-------------------------*/
+
+PyMODINIT_FUNC PyInit_mathutils_interpolate(void)
+{
+  PyObject *submodule = PyModule_Create(&M_Interpolate_module_def);
+  return submodule;
+}