implement motion controllers and vr drawing with brush preview

src/hmd.h

@@ -10,6 +10,11 @@ struct Controller
         Menu = 0x000000002,
         Grip = 0x000000004,
     };
+    enum class ButtonAxis : uint8_t
+    {
+        Trigger = 1,
+        Pad = 0,
+    };
     enum class Action
     {
         Press,
@@ -18,6 +23,7 @@ struct Controller
     int index = 0;
     bool active = false;
     std::map<uint64_t, bool> buttons;
+    std::map<uint8_t, float> buttons_axis;
     uint64_t buttons_bits{ 0 };
     glm::vec2 axis[5];
     glm::mat4 xform{ 1 };
@@ -46,6 +52,7 @@ struct Vive
     RTT eyes[2];
     vr::IVRSystem* hmd = nullptr;
     vr::IVRCompositor* comp = nullptr;
+    vr::IVRSettings* settings = nullptr;
     glm::vec3 euler{ 0 };
     glm::vec4 background{ .5, .2, .2, 1 };
     float yaw_offset = 0;
@@ -55,18 +62,22 @@ struct Vive
     Controller controllers[32];
     Controller trackers[32];
     bool swap_controllers = false;
+    bool active = false;
     std::string dev_serial{ "0000001" };
     std::string dev_model{ "Vive" };
     std::string dev_tracksys{ "lighthouse" };
     std::string dev_manufacturer{ "HTC" };
     std::function<void(const glm::mat4& proj, const glm::mat4& view, const glm::mat4& pose)> on_draw = nullptr;
     std::function<void(const Controller&, Controller::Button, Controller::Action)> on_button = nullptr;
+    std::function<void(const Controller&, Controller::ButtonAxis, Controller::Action)> on_button_axis = nullptr;
 
     Vive();
     bool Initialize();
     void Terminate();
     void ResetYaw();
+    void Update();
     void Draw();
+    std::string ReadPropString(vr::TrackedDeviceIndex_t nDevice, vr::ETrackedDeviceProperty p);
     bool Valid();
 };