py: Re-implement controls geneneration

The Python bindings controls generation was not very good. It only
covered the enums and they were in the main namespace.

This adds the controls somewhat similarly to the C++ side. We will have
e.g.:

libcamera.controls.Brightness
libcamera.controls.AeMeteringModeEnum.CentreWeighted

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/py/libcamera/gen-py-controls.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 # SPDX-License-Identifier: GPL-2.0-or-later
 #
-# Generate Python bindings enums for controls from YAML
+# Generate Python bindings controls from YAML
 
 import argparse
 import string
@@ -27,18 +27,22 @@ def generate_py(controls):
     for ctrl in controls:
         name, ctrl = ctrl.popitem()
 
+        if ctrl.get('draft'):
+            ns = 'libcamera::controls::draft::'
+            container = 'draft'
+        else:
+            ns = 'libcamera::controls::'
+            container = 'controls'
+
+        out += f'\t{container}.def_readonly_static("{name}", static_cast<const libcamera::ControlId *>(&{ns}{name}));\n\n'
+
         enum = ctrl.get('enum')
         if not enum:
             continue
 
-        if ctrl.get('draft'):
-            ns = 'libcamera::controls::draft::'
-        else:
-            ns = 'libcamera::controls::'
-
         cpp_enum = name + 'Enum'
 
-        out += '\tpy::enum_<{}{}>(m, \"{}\")\n'.format(ns, cpp_enum, name)
+        out += '\tpy::enum_<{}{}>({}, \"{}\")\n'.format(ns, cpp_enum, container, cpp_enum)
 
         if name == 'LensShadingMapMode':
             prefix = 'LensShadingMapMode'
@@ -54,9 +58,9 @@ def generate_py(controls):
 
             out += '\t\t.value(\"{}\", {}{})\n'.format(py_enum, ns, cpp_enum)
 
-        out += '\t;\n'
+        out += '\t;\n\n'
 
-    return {'enums': out}
+    return {'controls': out}
 
 
 def fill_template(template, data):

src/py/libcamera/meson.build

@@ -18,17 +18,21 @@ pycamera_sources = files([
     'py_main.cpp',
 ])
 
-gen_py_control_enums_input_files = files([
+# Generate controls
+
+gen_py_controls_input_files = files([
     '../../libcamera/control_ids.yaml',
-    'py_control_enums_generated.cpp.in',
+    'py_controls_generated.cpp.in',
 ])
 
-gen_py_control_enums = files('gen-py-control-enums.py')
+gen_py_controls = files('gen-py-controls.py')
 
 pycamera_sources += custom_target('py_gen_controls',
-                                  input : gen_py_control_enums_input_files,
-                                  output : ['py_control_enums_generated.cpp'],
-                                  command : [gen_py_control_enums, '-o', '@OUTPUT@', '@INPUT@'])
+                                  input : gen_py_controls_input_files,
+                                  output : ['py_controls_generated.cpp'],
+                                  command : [gen_py_controls, '-o', '@OUTPUT@', '@INPUT@'])
+
+# Generate formats
 
 gen_py_formats_input_files = files([
     '../../libcamera/formats.yaml',

src/py/libcamera/py_controls_generated.cpp.in

@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
  *
- * Python bindings - Auto-generated control enums
+ * Python bindings - Auto-generated controls
  *
  * This file is auto-generated. Do not edit.
  */
@@ -13,7 +13,18 @@
 
 namespace py = pybind11;
 
-void init_py_control_enums_generated(py::module& m)
+class PyControls
 {
-${enums}
+};
+
+class PyDraftControls
+{
+};
+
+void init_py_controls_generated(py::module& m)
+{
+	auto controls = py::class_<PyControls>(m, "controls");
+	auto draft = py::class_<PyDraftControls>(controls, "draft");
+
+${controls}
 }

src/py/libcamera/py_main.cpp

@@ -131,14 +131,14 @@ static void handleRequestCompleted(Request *req)
 }
 
 void init_py_enums(py::module &m);
-void init_py_control_enums_generated(py::module &m);
+void init_py_controls_generated(py::module &m);
 void init_py_formats_generated(py::module &m);
 void init_py_geometry(py::module &m);
 
 PYBIND11_MODULE(_libcamera, m)
 {
 	init_py_enums(m);
-	init_py_control_enums_generated(m);
+	init_py_controls_generated(m);
 	init_py_geometry(m);
 
 	/* Forward declarations */