Implement Vectors in python.

1 files changed, 355 insertions, 0 deletions

diff --git a/libdimension-python/Vector.c b/libdimension-python/Vector.c
new file mode 100644
index 0000000..ca7d4e1
--- /dev/null
+++ b/libdimension-python/Vector.c
@@ -0,0 +1,355 @@
+/*************************************************************************
+ * Copyright (C) 2009-2011 Tavian Barnes <tavianator@tavianator.com>     *
+ *                                                                       *
+ * This file is part of The Dimension Python Module.                     *
+ *                                                                       *
+ * The Dimension Python Module is free software; you can redistribute it *
+ * and/ or modify it under the terms of the GNU Lesser General Public    *
+ * License as published by the Free Software Foundation; either version  *
+ * 3 of the License, or (at your option) any later version.              *
+ *                                                                       *
+ * The Dimension Python Module is distributed in the hope that it will   *
+ * be useful, but WITHOUT ANY WARRANTY; without even the implied         *
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See *
+ * the GNU Lesser General Public License for more details.               *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+typedef struct dmnsn_py_Vector {
+  PyObject_HEAD
+  dmnsn_vector v;
+} dmnsn_py_Vector;
+
+static PyTypeObject dmnsn_py_VectorType;
+
+static int
+dmnsn_py_Vector_init(dmnsn_py_Vector *self, PyObject *args, PyObject *kwds)
+{
+  static char *kwlist[] = { "x", "y", "z", NULL };
+
+  if (!PyArg_ParseTupleAndKeywords(args, kwds, "ddd", kwlist,
+                                   &self->v.x, &self->v.y, &self->v.z))
+    return -1;
+
+  return 0;
+}
+
+static PyObject *
+dmnsn_py_Vector_repr(dmnsn_py_Vector *self)
+{
+  PyObject *x = PyFloat_FromDouble(self->v.x);
+  PyObject *y = PyFloat_FromDouble(self->v.y);
+  PyObject *z = PyFloat_FromDouble(self->v.z);
+
+  if (!x || !y || !x) {
+    Py_XDECREF(z);
+    Py_XDECREF(y);
+    Py_XDECREF(x);
+    return NULL;
+  }
+
+  PyObject *repr = PyUnicode_FromFormat("dimension.Vector(%R, %R, %R)",
+                                        x, y, z);
+  Py_DECREF(z);
+  Py_DECREF(y);
+  Py_DECREF(x);
+  return repr;
+}
+
+static PyObject *
+dmnsn_py_Vector_str(dmnsn_py_Vector *self)
+{
+  PyObject *x = PyFloat_FromDouble(self->v.x);
+  PyObject *y = PyFloat_FromDouble(self->v.y);
+  PyObject *z = PyFloat_FromDouble(self->v.z);
+
+  if (!x || !y || !x) {
+    Py_XDECREF(z);
+    Py_XDECREF(y);
+    Py_XDECREF(x);
+    return NULL;
+  }
+
+  PyObject *repr = PyUnicode_FromFormat("<%S, %S, %S>", x, y, z);
+  Py_DECREF(z);
+  Py_DECREF(y);
+  Py_DECREF(x);
+  return repr;
+}
+
+static PyObject *
+dmnsn_py_Vector_richcompare(PyObject *lhs, PyObject *rhs, int op)
+{
+  if (!PyObject_TypeCheck(lhs, &dmnsn_py_VectorType)) {
+    PyErr_SetString(PyExc_TypeError,
+                    "Vectors can only be compared with Vectors");
+    return NULL;
+  }
+  if (!PyObject_TypeCheck(lhs, &dmnsn_py_VectorType)) {
+    PyErr_SetString(PyExc_TypeError,
+                    "Vectors can only be compared with Vectors");
+    return NULL;
+  }
+
+  dmnsn_py_Vector *vlhs = (dmnsn_py_Vector *)lhs;
+  dmnsn_py_Vector *vrhs = (dmnsn_py_Vector *)rhs;
+
+  bool equal =
+    dmnsn_vector_norm(dmnsn_vector_sub(vlhs->v, vrhs->v)) < dmnsn_epsilon;
+
+  PyObject *result;
+  switch (op) {
+  case Py_EQ:
+    result = equal ? Py_True : Py_False;
+    break;
+  case Py_NE:
+    result = !equal ? Py_True : Py_False;
+    break;
+  default:
+    result = Py_NotImplemented;
+    break;
+  }
+
+  Py_INCREF(result);
+  return result;
+}
+
+static PyObject *
+dmnsn_py_Vector_add(PyObject *lhs, PyObject *rhs)
+{
+  if (!PyObject_TypeCheck(lhs, &dmnsn_py_VectorType)
+      || !PyObject_TypeCheck(rhs, &dmnsn_py_VectorType))
+  {
+    PyErr_SetString(PyExc_TypeError,
+                    "Vectors can only be added to Vectors");
+    return NULL;
+  }
+
+  dmnsn_py_Vector *ret = PyObject_New(dmnsn_py_Vector, &dmnsn_py_VectorType);
+  if (ret) {
+    dmnsn_py_Vector *vlhs = (dmnsn_py_Vector *)lhs;
+    dmnsn_py_Vector *vrhs = (dmnsn_py_Vector *)rhs;
+    ret->v = dmnsn_vector_add(vlhs->v, vrhs->v);
+  }
+  return (PyObject *)ret;
+}
+
+static PyObject *
+dmnsn_py_Vector_sub(PyObject *lhs, PyObject *rhs)
+{
+  if (!PyObject_TypeCheck(lhs, &dmnsn_py_VectorType)
+      || !PyObject_TypeCheck(rhs, &dmnsn_py_VectorType))
+  {
+    PyErr_SetString(PyExc_TypeError,
+                    "Vectors can only be subtracted from Vectors");
+    return NULL;
+  }
+
+  dmnsn_py_Vector *ret = PyObject_New(dmnsn_py_Vector, &dmnsn_py_VectorType);
+  if (ret) {
+    dmnsn_py_Vector *vlhs = (dmnsn_py_Vector *)lhs;
+    dmnsn_py_Vector *vrhs = (dmnsn_py_Vector *)rhs;
+    ret->v = dmnsn_vector_sub(vlhs->v, vrhs->v);
+  }
+  return (PyObject *)ret;
+}
+
+static PyObject *
+dmnsn_py_Vector_mul(PyObject *lhs, PyObject *rhs)
+{
+  dmnsn_py_Vector *vec;
+  double dbl;
+
+  if (PyObject_TypeCheck(lhs, &dmnsn_py_VectorType)) {
+    vec = (dmnsn_py_Vector *)lhs;
+    dbl = PyFloat_AsDouble(rhs);
+    if (PyErr_Occurred())
+      return NULL;
+  } else {
+    vec = (dmnsn_py_Vector *)rhs;
+    dbl = PyFloat_AsDouble(lhs);
+    if (PyErr_Occurred())
+      return NULL;
+  }
+
+  dmnsn_py_Vector *ret = PyObject_New(dmnsn_py_Vector, &dmnsn_py_VectorType);
+  if (ret) {
+    ret->v = dmnsn_vector_mul(dbl, vec->v);
+  }
+  return (PyObject *)ret;
+}
+
+static PyObject *
+dmnsn_py_Vector_div(PyObject *lhs, PyObject *rhs)
+{
+  if (!PyObject_TypeCheck(lhs, &dmnsn_py_VectorType)) {
+    PyErr_SetString(PyExc_TypeError,
+                    "Vectors can only be divided by scalars");
+    return NULL;
+  }
+
+  double drhs = PyFloat_AsDouble(rhs);
+  if (PyErr_Occurred())
+    return NULL;
+
+  dmnsn_py_Vector *ret = PyObject_New(dmnsn_py_Vector, &dmnsn_py_VectorType);
+  if (ret) {
+    dmnsn_py_Vector *vlhs = (dmnsn_py_Vector *)lhs;
+    ret->v = dmnsn_vector_div(vlhs->v, drhs);
+  }
+  return (PyObject *)ret;
+}
+
+static int
+dmnsn_py_Vector_bool(PyObject *obj)
+{
+  dmnsn_py_Vector *vec = (dmnsn_py_Vector *)obj;
+  return dmnsn_vector_norm(vec->v) >= dmnsn_epsilon;
+}
+
+static PyObject *
+dmnsn_py_Vector_positive(PyObject *rhs)
+{
+  Py_INCREF(rhs);
+  return rhs;
+}
+
+static PyObject *
+dmnsn_py_Vector_negative(PyObject *rhs)
+{
+  dmnsn_py_Vector *ret = PyObject_New(dmnsn_py_Vector, &dmnsn_py_VectorType);
+  if (ret) {
+    dmnsn_py_Vector *vrhs = (dmnsn_py_Vector *)rhs;
+    ret->v = dmnsn_vector_negate(vrhs->v);
+  }
+  return (PyObject *)ret;
+}
+
+static PyObject *
+dmnsn_py_Vector_cross(PyObject *self, PyObject *args)
+{
+  dmnsn_py_Vector *lhs, *rhs;
+  if (!PyArg_ParseTuple(args, "O!O!",
+                        &dmnsn_py_VectorType, &lhs,
+                        &dmnsn_py_VectorType, &rhs))
+    return NULL;
+
+  dmnsn_py_Vector *ret = PyObject_New(dmnsn_py_Vector, &dmnsn_py_VectorType);
+  if (ret) {
+    ret->v = dmnsn_vector_cross(lhs->v, rhs->v);
+  }
+  return (PyObject *)ret;
+}
+
+static PyObject *
+dmnsn_py_Vector_dot(PyObject *self, PyObject *args)
+{
+  dmnsn_py_Vector *lhs, *rhs;
+  if (!PyArg_ParseTuple(args, "O!O!",
+                        &dmnsn_py_VectorType, &lhs,
+                        &dmnsn_py_VectorType, &rhs))
+    return NULL;
+
+  return PyFloat_FromDouble(dmnsn_vector_dot(lhs->v, rhs->v));
+}
+
+static PyObject *
+dmnsn_py_Vector_proj(PyObject *self, PyObject *args)
+{
+  dmnsn_py_Vector *u, *d;
+  if (!PyArg_ParseTuple(args, "O!O!",
+                        &dmnsn_py_VectorType, &u,
+                        &dmnsn_py_VectorType, &d))
+    return NULL;
+
+  dmnsn_py_Vector *ret = PyObject_New(dmnsn_py_Vector, &dmnsn_py_VectorType);
+  if (ret) {
+    ret->v = dmnsn_vector_proj(u->v, d->v);
+  }
+  return (PyObject *)ret;
+}
+
+static PyNumberMethods dmnsn_py_Vector_as_number = {
+  .nb_add         = dmnsn_py_Vector_add,
+  .nb_subtract    = dmnsn_py_Vector_sub,
+  .nb_multiply    = dmnsn_py_Vector_mul,
+  .nb_true_divide = dmnsn_py_Vector_div,
+  .nb_bool        = dmnsn_py_Vector_bool,
+  .nb_positive    = dmnsn_py_Vector_positive,
+  .nb_negative    = dmnsn_py_Vector_negative,
+};
+
+static PyObject *
+dmnsn_py_Vector_norm(dmnsn_py_Vector *self)
+{
+  return PyFloat_FromDouble(dmnsn_vector_norm(self->v));
+}
+
+static PyObject *
+dmnsn_py_Vector_normalized(dmnsn_py_Vector *self)
+{
+  dmnsn_py_Vector *ret = PyObject_New(dmnsn_py_Vector, &dmnsn_py_VectorType);
+  if (ret) {
+    ret->v = dmnsn_vector_normalized(self->v);
+  }
+  return (PyObject *)ret;
+}
+
+static PyMethodDef dmnsn_py_Vector_methods[] = {
+  { "norm", (PyCFunction)dmnsn_py_Vector_norm, METH_NOARGS,
+    "Return the magnitude of the vector" },
+  { "normalized", (PyCFunction)dmnsn_py_Vector_normalized, METH_NOARGS,
+    "Return the magnitude of the vector" },
+  { NULL }
+};
+
+static PyObject *
+dmnsn_py_Vector_getx(dmnsn_py_Vector *self, void *closure)
+{
+  return PyFloat_FromDouble(self->v.x);
+}
+
+static PyObject *
+dmnsn_py_Vector_gety(dmnsn_py_Vector *self, void *closure)
+{
+  return PyFloat_FromDouble(self->v.y);
+}
+
+static PyObject *
+dmnsn_py_Vector_getz(dmnsn_py_Vector *self, void *closure)
+{
+  return PyFloat_FromDouble(self->v.z);
+}
+
+static PyGetSetDef dmnsn_py_Vector_getsetters[] = {
+  { "x", (getter)dmnsn_py_Vector_getx, NULL, "x coordinate", NULL },
+  { "y", (getter)dmnsn_py_Vector_gety, NULL, "y coordinate", NULL },
+  { "z", (getter)dmnsn_py_Vector_getz, NULL, "z coordinate", NULL },
+  { NULL }
+};
+
+static PyTypeObject dmnsn_py_VectorType = {
+  PyVarObject_HEAD_INIT(NULL, 0)
+  .tp_name = "dimension.Vector",
+  .tp_basicsize = sizeof(dmnsn_py_Vector),
+  .tp_repr = (reprfunc)dmnsn_py_Vector_repr,
+  .tp_str = (reprfunc)dmnsn_py_Vector_str,
+  .tp_as_number = &dmnsn_py_Vector_as_number,
+  .tp_flags = Py_TPFLAGS_DEFAULT,
+  .tp_doc = "Dimension vector",
+  .tp_richcompare = dmnsn_py_Vector_richcompare,
+  .tp_methods = dmnsn_py_Vector_methods,
+  .tp_getset = dmnsn_py_Vector_getsetters,
+  .tp_init = (initproc)dmnsn_py_Vector_init,
+};
+
+static bool
+dmnsn_py_init_VectorType(void)
+{
+  dmnsn_py_VectorType.tp_new = PyType_GenericNew;
+  Py_INCREF(&dmnsn_py_VectorType);
+  return PyType_Ready(&dmnsn_py_VectorType) >= 0;
+}