Add bindings for Mechanism2d et al

- Fixes #695

gen/Mechanism2d.yml

@@ -1,9 +1,15 @@
 ---
 
+extra_includes:
+- wpi/sendable/SendableBuilder.h
+
 classes:
   Mechanism2d:
+    ignored_bases:
+    - wpi::SendableHelper<Mechanism2d>
     methods:
       Mechanism2d:
       GetRoot:
+        return_value_policy: reference_internal
       SetBackgroundColor:
       InitSendable:

gen/MechanismLigament2d.yml

@@ -4,6 +4,7 @@ classes:
   MechanismLigament2d:
     methods:
       MechanismLigament2d:
+        ignore: true
       SetColor:
       SetLength:
       GetLength:

gen/MechanismObject2d.yml

@@ -1,11 +1,33 @@
 ---
 
+extra_includes:
+- frc/smartdashboard/MechanismLigament2d.h
+
 classes:
   MechanismObject2d:
+    force_type_casters:
+    - units::degree_t
     attributes:
       m_mutex:
+        ignore: true
     methods:
       GetName:
       Append:
+        ignore: true
       MechanismObject2d:
+        ignore: true
       UpdateEntries:
+
+# keep this in sync with MechanismRoot2d.yml
+inline_code: |
+  cls_MechanismObject2d
+    .def("appendLigament", [](MechanismObject2d *self,
+      std::string_view name, double length, units::degree_t angle,
+      double lineWidth, const frc::Color8Bit& color) {
+        return self->Append<MechanismLigament2d>(name, length, angle, lineWidth, color);
+      },
+      py::arg("name"), py::arg("length"), py::arg("angle"),
+      py::arg("lineWidth") = 6, py::arg("color") = frc::Color8Bit{235, 137, 52},
+      "Append a ligament node",
+      py::return_value_policy::reference_internal)
+    ;

gen/MechanismRoot2d.yml

@@ -1,7 +1,28 @@
 ---
 
+extra_includes:
+- frc/smartdashboard/MechanismLigament2d.h
+
 classes:
   MechanismRoot2d:
+    force_type_casters:
+    - units::degree_t
     methods:
       MechanismRoot2d:
+        ignore: true
       SetPosition:
+
+# keep this in sync with MechanismRoot2d.yml
+inline_code: |
+  cls_MechanismRoot2d
+    .def("getName", [](MechanismRoot2d *self) { return self->GetName(); }, release_gil())
+    .def("appendLigament", [](MechanismRoot2d *self,
+      std::string_view name, double length, units::degree_t angle,
+      double lineWidth, const frc::Color8Bit& color) {
+        return self->Append<MechanismLigament2d>(name, length, angle, lineWidth, color);
+      },
+      py::arg("name"), py::arg("length"), py::arg("angle"),
+      py::arg("lineWidth") = 6, py::arg("color") = frc::Color8Bit{235, 137, 52},
+      release_gil(), "Append a ligament node",
+      py::return_value_policy::reference_internal)
+    ;

pyproject.toml

@@ -176,11 +176,10 @@ VictorSP = "frc/motorcontrol/VictorSP.h"
 Field2d = "frc/smartdashboard/Field2d.h"
 FieldObject2d = "frc/smartdashboard/FieldObject2d.h"
 # ListenerExecutor = "frc/smartdashboard/ListenerExecutor.h"    # internal detail
-# TODO: needs pybind magic
-# Mechanism2d = "frc/smartdashboard/Mechanism2d.h"
-# MechanismLigament2d = "frc/smartdashboard/MechanismLigament2d.h"
-# MechanismObject2d = "frc/smartdashboard/MechanismObject2d.h"
-# MechanismRoot2d = "frc/smartdashboard/MechanismRoot2d.h"
+Mechanism2d = "frc/smartdashboard/Mechanism2d.h"
+MechanismLigament2d = "frc/smartdashboard/MechanismLigament2d.h"
+MechanismObject2d = "frc/smartdashboard/MechanismObject2d.h"
+MechanismRoot2d = "frc/smartdashboard/MechanismRoot2d.h"
 SendableBuilderImpl = "frc/smartdashboard/SendableBuilderImpl.h"
 SendableChooser = "frc/smartdashboard/SendableChooser.h"
 SendableChooserBase = "frc/smartdashboard/SendableChooserBase.h"

tests/test_mechanism2d.py

@@ -0,0 +1,11 @@
+from wpilib import Mechanism2d
+
+
+def test_create_mechanism():
+    m = Mechanism2d(100, 100)
+    r1 = m.getRoot("r1", 10, 10)
+    l1 = r1.appendLigament("l1", 4, 3)
+    l2 = l1.appendLigament("l2", 4, 3)
+    assert l2 is not None
+
+    # TODO... check that they do something?

wpilib/__init__.py

@@ -48,6 +48,10 @@
     Jaguar,
     Joystick,
     LiveWindow,
+    Mechanism2d,
+    MechanismLigament2d,
+    MechanismObject2d,
+    MechanismRoot2d,
     MotorControllerGroup,
     MotorSafety,
     NidecBrushless,
@@ -144,6 +148,10 @@
     "Jaguar",
     "Joystick",
     "LiveWindow",
+    "Mechanism2d",
+    "MechanismLigament2d",
+    "MechanismObject2d",
+    "MechanismRoot2d",
     "MotorControllerGroup",
     "MotorSafety",
     "NidecBrushless",