Add grid coordinates memory allocation to spatialtf_grid

theano/gpuarray/c_code/spatialtf_grid.c

@@ -2,10 +2,11 @@
 
 int spatialtf_grid(cudnnSpatialTransformerDescriptor_t desc,
                    PyGpuArrayObject * theta,
-                   PyGpuArrayObject * num_dimensions,
+                   PyArrayObject * dimensions,
                    PyGpuArrayObject ** grid,
                    cudnnHandle_t _handle)
 {
+    PyGpuContextObject * gpu_ctx = theta->context;
     cudnnDataType_t dt;
     cudnnStatus_t err;
 
@@ -26,12 +27,19 @@ int spatialtf_grid(cudnnSpatialTransformerDescriptor_t desc,
         return -1;
     }
 
-    switch( num_dimensions->ga.typecode )
+    if ( NULL == *grid )
     {
-    case GA_INT:
-        break;
-    default:
-        PyErr_SetString( PyExc_TypeError, "Unsupported data type for the number of dimensions" );
+        npy_int * dimensions_data = (npy_int *)PyArray_DATA( dimensions );
+        const size_t grid_dims[4] = { dimensions_data[0], dimensions_data[1],
+                                      dimensions_data[2], dimensions_data[3] };
+        *grid = pygpu_empty( 4, &(grid_dims[0]), theta->ga.typecode, GA_C_ORDER,
+            gpu_ctx, Py_None );
+        if ( *grid == NULL )
+        {
+            PyErr_Format( PyExc_MemoryError,
+                "Could not allocate memory for grid coordinates" );
+            return 1;
+        }
     }
 
     return 0;