python: make ArrayView properly convertible from Python array.

Also fix element sizes that aren't 1.

src/python/corrade/containers.cpp

@@ -24,6 +24,7 @@
 */
 
 #include <pybind11/pybind11.h>
+#include <pybind11/numpy.h> /* so ArrayView is convertible from python array */
 #include <Corrade/Containers/Array.h>
 #include <Corrade/Utility/FormatStl.h>
 
@@ -70,15 +71,13 @@ template<class T> void arrayView(py::class_<PyArrayView<T>>& c) {
         .def(py::init([](py::buffer buffer) {
             py::buffer_info info = buffer.request(!std::is_const<T>::value);
 
-            // TODO: test for items that are not 1 byte size
-
             if(info.ndim != 1)
                 throw py::buffer_error{Utility::formatString("expected one dimension but got {}", info.ndim)};
-            if(info.strides[0] != 1)
-                throw py::buffer_error{Utility::formatString("expected stride of 1 but got {}", info.strides[0])};
+            if(info.strides[0] != info.itemsize)
+                throw py::buffer_error{Utility::formatString("expected stride of {} but got {}", info.itemsize, info.strides[0])};
 
             // TODO: need to take buffer.obj, not buffer!
-            return PyArrayView<T>{{static_cast<T*>(info.ptr), std::size_t(info.shape[0])}, buffer};
+            return PyArrayView<T>{{static_cast<T*>(info.ptr), std::size_t(info.shape[0]*info.itemsize)}, buffer};
         }), "Construct from a buffer")
         .def_buffer([](const PyArrayView<T>& self) -> py::buffer_info {
             return py::buffer_info{

src/python/corrade/test/test_containers.py

@@ -23,6 +23,7 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
+import array
 import sys
 import unittest
 
@@ -72,6 +73,12 @@ class ArrayView(unittest.TestCase):
         self.assertEqual(b[4], '!')
         self.assertEqual(bytes(b), b'hell!')
 
+    def test_init_array(self):
+        a = array.array('f', [1.0, 4.5, 7.9])
+        b = containers.ArrayView(a)
+        self.assertIs(b.obj, a)
+        self.assertEqual(len(b), 3*4)
+
     def test_init_buffer_unexpected_dimensions(self):
         a = memoryview(b'123456').cast('b', shape=[2, 3])
         self.assertEqual(bytes(a), b'123456')

src/python/magnum/test/test_gl_gl.py

@@ -23,6 +23,7 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
+import array
 import sys
 import unittest
 
@@ -47,6 +48,10 @@ class Buffer(GLTestCase):
         a = gl.Buffer()
         a.set_data(b'hello', gl.BufferUsage.STATIC_DRAW)
 
+    def test_set_data_array(self):
+        a = gl.Buffer()
+        a.set_data(array.array('f', [0.5, 1.2]))
+
 class DefaultFramebuffer(GLTestCase):
     def test(self):
         # Using it should not crash, leak or cause double-free issues