blender: Explicitly tear down/free c-ray & fix small leak

The destructor for the PyCapsule was never being called, despite me
deleting it in Python, so an explicit teardown function is now expected
to be called.
I don't know if it's specific to my system, but Blender seems to leak
quite a bit of memory, even while using Cycles. I fixed a small leak in
c-ray, but the rest seems to all be in Blender code.

bindings/blender_init.py

@@ -170,13 +170,15 @@ class CrayRender(bpy.types.RenderEngine):
 	bl_label = "c-ray for Blender"
 	bl_use_preview = True
 	bl_use_shading_nodes_custom = False
+	cr_renderer = None
 
 	def __init__(self):
 		print("c-ray initialized")
-		self.cr_renderer = None
 		self.cr_scene = None
 
 	def __del__(self):
+		if self.cr_renderer:
+			self.cr_renderer.close()
 		print("c-ray deleted")
 
 	def sync_scene(self, depsgraph):

bindings/c_ray.py

@@ -384,6 +384,7 @@ def __init__(self, path = None):
 			_lib.load_json(self.obj_ptr, path)
 
 	def close(self):
+		_lib.renderer_destroy(self.obj_ptr)
 		del(self.obj_ptr)
 
 	def stop(self):

bindings/cray_wrap.c

@@ -19,25 +19,26 @@ static PyObject *py_cr_get_git_hash(PyObject *self, PyObject *args) {
 	return PyUnicode_FromString(cr_get_git_hash());
 }
 
-void py_internal_destroy_renderer(PyObject *capsule) {
-	struct cr_renderer *renderer = PyCapsule_GetPointer(capsule, "cray.cr_renderer");
-	cr_destroy_renderer(renderer);
-}
-
 static PyObject *py_cr_new_renderer(PyObject *self, PyObject *args) {
 	(void)self; (void)args;
 	struct cr_renderer *new = cr_new_renderer();
 	if (!new) {
 		PyErr_SetString(PyExc_MemoryError, "Failed to allocate renderer");
 		return NULL;
 	}
-	return PyCapsule_New(new, "cray.cr_renderer", py_internal_destroy_renderer);
+	return PyCapsule_New(new, "cray.cr_renderer", NULL);
 }
 
-// TODO: Not sure if we want to keep this explicit teardown func, or trust the destructor above
-// static PyObject *py_cr_destroy_renderer(PyObject *self, PyObject *args) {
-// 	return NULL;
-// }
+static PyObject *py_cr_destroy_renderer(PyObject *self, PyObject *args) {
+	(void)self;
+	PyObject *r_ext;
+	if (!PyArg_ParseTuple(args, "O", &r_ext)) {
+		return NULL;
+	}
+	struct cr_renderer *r = PyCapsule_GetPointer(r_ext, "cray.cr_renderer");
+	cr_destroy_renderer(r);
+	Py_RETURN_NONE;
+}
 
 static PyObject *py_cr_renderer_set_num_pref(PyObject *self, PyObject *args) {
 	(void)self; (void)args;
@@ -365,6 +366,7 @@ static PyObject *py_cr_mesh_bind_faces(PyObject *self, PyObject *args) {
 
 	struct cr_scene *s = PyCapsule_GetPointer(s_ext, "cray.cr_scene");
 	cr_mesh_bind_faces(s, mesh, faces, face_count);
+	free(faces);
 	Py_RETURN_NONE;
 }
 
@@ -609,6 +611,7 @@ static PyObject *py_debug_dump_state(PyObject *self, PyObject *args) {
 static PyMethodDef cray_methods[] = {
 	{ "get_version", py_cr_get_version, METH_NOARGS, "" },
 	{ "get_git_hash", py_cr_get_git_hash, METH_NOARGS, "" },
+	{ "renderer_destroy", py_cr_destroy_renderer, METH_VARARGS, "" },
 	{ "new_renderer", py_cr_new_renderer, METH_NOARGS, "" },
 	// { "destroy_renderer", py_cr_destroy_renderer, METH_VARARGS, "" },
 	{ "renderer_set_num_pref", py_cr_renderer_set_num_pref, METH_VARARGS, "" },

include/c-ray/c-ray.h

@@ -135,8 +135,6 @@ struct cr_bitmap {
 	size_t height;
 };
 
-// TODO: Maybe redo this to have this update an internal render buffer,
-// and another func to get a ptr to that? No need for awkward free() then
 CR_EXPORT void cr_renderer_render(struct cr_renderer *r);
 CR_EXPORT struct cr_bitmap *cr_renderer_get_result(struct cr_renderer *r);
 

src/lib/renderer/renderer.c

@@ -453,7 +453,7 @@ struct renderer *renderer_new() {
 	r->scene->storage.node_table = newHashtable(compareNodes, &r->scene->storage.node_pool);
 	return r;
 }
-	
+
 void renderer_destroy(struct renderer *r) {
 	if (!r) return;
 	scene_destroy(r->scene);