Controller support for VrShell

chrome/browser/android/vr_shell/vr_controller.h

Index: chrome/browser/android/vr_shell/vr_controller.h
diff --git a/chrome/browser/android/vr_shell/vr_controller.h b/chrome/browser/android/vr_shell/vr_controller.h
new file mode 100644
index 0000000000000000000000000000000000000000..e2f95556a29dfdacaa85d749cd0137fe3f98acb1
--- /dev/null
+++ b/chrome/browser/android/vr_shell/vr_controller.h
@@ -0,0 +1,149 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_ANDROID_VR_SHELL_VR_CONTROLLER_H_
+#define CHROME_BROWSER_ANDROID_VR_SHELL_VR_CONTROLLER_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/task_runner_util.h"
+#include "chrome/browser/android/vr_shell/vr_gesture.h"
+#include "content/public/browser/android/content_view_core.h"
+#include "third_party/gvr-android-sdk/src/ndk-beta/include/vr/gvr/capi/include/gvr.h"
+#include "third_party/gvr-android-sdk/src/ndk-beta/include/vr/gvr/capi/include/gvr_controller.h"
+#include "third_party/gvr-android-sdk/src/ndk-beta/include/vr/gvr/capi/include/gvr_types.h"
+
+namespace vr_shell {
+
+class VrController {
+ public:
+  // Controller API entry point.
+  explicit VrController(gvr_context* gvr_context);
+  ~VrController();
+
+  // Must be called when the Activity gets OnResume().
+  void OnResume();
+
+  // Must be called when the Activity gets OnPause().
+  void OnPause();
+
+  // Must be called when the GL renderer gets OnSurfaceCreated().
+  void Initialize(gvr_context* gvr_context);
+
+  // Must be called when the GL renderer gets OnDrawFrame().
+  void UpdateState();
+  VrGesture DetectGesture();
+
+  bool IsTouching();
+
+  float TouchPosX();
+
+  float TouchPosY();
+
+  const gvr::Quatf Orientation();
+
+  bool IsTouchDown();
+
+  bool IsTouchUp();
+
+  bool ButtonUp(const int32_t button);
+  bool ButtonDown(const int32_t button);
+
+  bool IsConnected();
+
+ private:
+  enum gesture_detector_state {

[bshe, 2016/09/22 23:16:49]

nit: use CamelCase

[asimjour, 2016/09/23 16:58:20]

Done.

+    WAITING,   // waiting for user to touch down
+    TOUCHING,  // touching the touch pad but not scrolling
+    SCROLLING  // scrolling on the touch pad
+  };
+
+  struct TouchPoint {
+    gvr::Vec2f position;
+    int64_t timestamp;

[tdresser, 2016/09/23 13:48:19]

Can we store time in a base::TimeTicks (throughout the patch)? We've had lots of
issues with mixing timebases elsewhere.

[asimjour, 2016/09/23 16:58:21]

Would it be fine if we switch to TimeTicks in another CL? There are some
concerns about the controller events that we need to talk + I think vr_shell
also uses the same timestamp and we can fix controller/vr_shell in the same
patch. 

[tdresser, 2016/09/23 17:45:17]

SGTM - maybe add a TODO?

+  };
+
+  struct TouchInfo {
+    TouchPoint touch_point;
+    bool touch_up;
+    bool touch_down;
+    bool is_touching;

[tdresser, 2016/09/23 13:48:19]

Should this be an enum instead of a bunch of bools? It looks like this could
hold an invalid state.

[asimjour, 2016/09/23 16:58:20]

I rather to keep it as is to be consistence with gesture detection.

[tdresser, 2016/09/23 17:45:17]

Ideally I think we'd change it in both places, but this is fine for now.

+  };
+
+  struct ButtonInfo {
+    gvr_controller_button button;

[bshe, 2016/09/22 23:16:49]

prefer gvr::ControllerButton

[asimjour, 2016/09/23 16:58:21]

Done.

+    bool button_up;
+    bool button_down;
+    bool button_state;
+    int64_t timestamp;
+  };
+
+  void UpdateGestureFromTouchInfo();
+
+  bool GetButtonLongPressFromButtonInfo();
+
+  // Handle the waiting state.
+  void HandleWaitingState();
+
+  // Handle the detecting state.
+  void HandleDetectingState();
+
+  // Handle the scrolling state.
+  void HandleScrollingState();
+  void Update(const gvr_controller_state* controller_state);
+  void Update(bool touch_up,
+              bool touch_down,
+              bool is_touching,
+              const gvr::Vec2f position,
+              int64_t timestamp);
+
+  // Returns true if the touch position is with in the slop of the initial touch

[bshe, 2016/09/22 23:16:49]

nit: within

[asimjour, 2016/09/23 16:58:20]

Done.

+  // point,

[tdresser, 2016/09/23 13:48:19]

nit: remove newline.

[asimjour, 2016/09/23 16:58:21]

Done.

+  // false otherwise.
+  bool InSlop(const gvr::Vec2f touch_position);
+
+  void Reset();
+
+  size_t GetGestureListSize() { return gesture_list_.size(); }
+
+  const VrGesture* GetGesturePtr(const size_t index);
+
+  // Update gesture parameters,
+  void UpdateGesture(VrGesture* gesture);
+
+  // If the user is touching the touch pad and the touch point is different from
+  // before, update the touch point and return true. Otherwise, return false.
+  bool UpdateCurrentTouchpoint();
+
+  // State of gesture detector.
+  gesture_detector_state state_;
+
+  std::unique_ptr<gvr::ControllerApi> controller_api_;
+
+  // The last controller state (updated once per frame).
+  gvr::ControllerState controller_state_;
+
+  float last_qx_;
+  float last_qz_;

[tdresser, 2016/09/23 13:48:19]

Can we use a Vector2dF?

[asimjour, 2016/09/23 16:58:20]

removed last_qz_

+  bool pinch_started_;
+  bool zoom_in_progress_ = false;
+
+  std::vector<VrGesture> gesture_list_;
+  std::unique_ptr<TouchInfo> touch_info_;
+
+  // A pointer storing the touch point from previous frame.
+  std::unique_ptr<TouchPoint> prev_touch_point_;
+
+  // A pointer storing the touch point from current frame.
+  std::unique_ptr<TouchPoint> cur_touch_point_;
+
+  // Initial touch point.
+  std::unique_ptr<TouchPoint> init_touch_point_;
+
+  // Overall velocity
+  gvr::Vec2f overall_velocity_;

[bshe, 2016/09/22 23:16:49]

nit: DISALLOW_COPY_AND_ASSIGN

[tdresser, 2016/09/23 13:48:19]

I'm out of the loop on VR things. Why don't we use Vector2dF here?

[asimjour, 2016/09/23 16:58:20]

Done.

[asimjour, 2016/09/23 16:58:21]

Done.

+};
+
+}  // namespace vr_shell
+
+#endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_CONTROLLER_H_