Android: Replace movement buttons with joystick (#7126)

* Android: Replace movement buttons with joystick

Replace movement control buttons (arrows at bottom left screen) with virtual joystick.
Joystick has 8 directions (same as keyboard). Basically, just map it to keyboard input.
Joystick applies only on left 1/3 of screen.
Joystick's position can be fixed by enabling fixed_virtual_joystick setting.
Three new images:
(1) placeholder joystick,
(2) joystick container (background), and
(3) joystick cursor.
Remove unused images: movement control buttons (*_arrow.png).
New data type: touch_gui_joystick_move_id

Joystick's fixed position is spaced one button size from bottom and from left of screen.
Remove unused variable: m_joystick_downlocation

src/gui/touchscreengui.h

@@ -34,11 +34,7 @@ using namespace irr::core;
 using namespace irr::gui;
 
 typedef enum {
-	forward_id = 0,
-	backward_id,
-	left_id,
-	right_id,
-	jump_id,
+	jump_id = 0,
 	crunch_id,
 	after_last_element_id,
 	settings_starter_id,
@@ -51,9 +47,18 @@ typedef enum {
 	range_id,
 	chat_id,
 	inventory_id,
-	drop_id
+	drop_id,
+	forward_id,
+	backward_id,
+	left_id,
+	right_id,
+	joystick_off_id,
+	joystick_bg_id,
+	joystick_center_id
 } touch_gui_button_id;
 
+typedef enum { j_forward = 0, j_backward, j_left, j_right } touch_gui_joystick_move_id;
+
 typedef enum {
 	AHBB_Dir_Top_Bottom,
 	AHBB_Dir_Bottom_Top,
@@ -69,6 +74,7 @@ typedef enum {
 #define RARE_CONTROLS_BAR_Y_OFFSET 4
 
 extern const char **touchgui_button_imagenames;
+extern const char **touchgui_joystick_imagenames;
 
 struct button_info
 {
@@ -91,26 +97,26 @@ public:
 
 	~AutoHideButtonBar();
 
-	/* add button to be shown */
+	// add button to be shown
 	void addButton(touch_gui_button_id id, const wchar_t *caption,
 			const char *btn_image);
 
-	/* detect settings bar button events */
+	// detect settings bar button events
 	bool isButton(const SEvent &event);
 
-	/* handle released hud buttons */
+	// handle released hud buttons
 	bool isReleaseButton(int eventID);
 
-	/* step handler */
+	// step handler
 	void step(float dtime);
 
-	/* deactivate button bar */
+	// deactivate button bar
 	void deactivate();
 
-	/* hide the whole buttonbar */
+	// hide the whole buttonbar
 	void hide();
 
-	/* unhide the buttonbar */
+	// unhide the buttonbar
 	void show();
 
 private:
@@ -124,12 +130,12 @@ private:
 	v2s32 m_upper_left;
 	v2s32 m_lower_right;
 
-	/* show settings bar */
+	// show settings bar
 	bool m_active = false;
 
 	bool m_visible = true;
 
-	/* settings bar timeout */
+	// settings bar timeout
 	float m_timeout = 0.0f;
 	float m_timeout_value = 3.0f;
 	bool m_initialized = false;
@@ -179,14 +185,20 @@ private:
 	IEventReceiver *m_receiver;
 	ISimpleTextureSource *m_texturesource;
 	v2u32 m_screensize;
+	double m_touchscreen_threshold;
 	std::map<int, rect<s32>> m_hud_rects;
 	std::map<int, irr::EKEY_CODE> m_hud_ids;
 	bool m_visible; // is the gui visible
 
-	/* value in degree */
+	// value in degree
 	double m_camera_yaw_change = 0.0;
 	double m_camera_pitch = 0.0;
 
+	// forward, backward, left, right
+	touch_gui_button_id m_joystick_names[4] = {
+			forward_id, backward_id, left_id, right_id};
+	bool m_joystick_status[4] = {false, false, false, false};
+
 	/*!
 	 * A line starting at the camera and pointing towards the
 	 * selected object.
@@ -201,22 +213,33 @@ private:
 	bool m_move_sent_as_mouse_event = false;
 	v2s32 m_move_downlocation = v2s32(-10000, -10000);
 
+	int m_joystick_id = -1;
+	bool m_joystick_has_really_moved = false;
+	bool m_fixed_joystick = false;
+	button_info *m_joystick_btn_off = nullptr;
+	button_info *m_joystick_btn_bg = nullptr;
+	button_info *m_joystick_btn_center = nullptr;
+
 	button_info m_buttons[after_last_element_id];
 
-	/* gui button detection */
+	// gui button detection
 	touch_gui_button_id getButtonID(s32 x, s32 y);
 
-	/* gui button by eventID */
+	// gui button by eventID
 	touch_gui_button_id getButtonID(int eventID);
 
-	/* check if a button has changed */
+	// check if a button has changed
 	void handleChangedButton(const SEvent &event);
 
-	/* initialize a button */
+	// initialize a button
 	void initButton(touch_gui_button_id id, rect<s32> button_rect,
 			std::wstring caption, bool immediate_release,
 			float repeat_delay = BUTTON_REPEAT_DELAY);
 
+	// initialize a joystick button
+	button_info *initJoystickButton(touch_gui_button_id id, rect<s32> button_rect,
+			int texture_id, bool visible = true);
+
 	struct id_status
 	{
 		int id;
@@ -224,28 +247,31 @@ private:
 		int Y;
 	};
 
-	/* vector to store known ids and their initial touch positions*/
+	// vector to store known ids and their initial touch positions
 	std::vector<id_status> m_known_ids;
 
-	/* handle a button event */
+	// handle a button event
 	void handleButtonEvent(touch_gui_button_id bID, int eventID, bool action);
 
-	/* handle pressed hud buttons */
+	// handle pressed hud buttons
 	bool isHUDButton(const SEvent &event);
 
-	/* handle released hud buttons */
+	// handle released hud buttons
 	bool isReleaseHUDButton(int eventID);
 
-	/* handle double taps */
+	// handle double taps
 	bool doubleTapDetection();
 
-	/* handle release event */
+	// handle release event
 	void handleReleaseEvent(int evt_id);
 
-	/* get size of regular gui control button */
+	// apply joystick status
+	void applyJoystickStatus();
+
+	// get size of regular gui control button
 	int getGuiButtonSize();
 
-	/* doubleclick detection variables */
+	// doubleclick detection variables
 	struct key_event
 	{
 		unsigned int down_time;
@@ -253,16 +279,16 @@ private:
 		s32 y;
 	};
 
-	/* array for saving last known position of a pointer */
+	// array for saving last known position of a pointer
 	v2s32 m_pointerpos[MAX_TOUCH_COUNT];
 
-	/* array for doubletap detection */
+	// array for doubletap detection
 	key_event m_key_events[2];
 
-	/* settings bar */
+	// settings bar
 	AutoHideButtonBar m_settingsbar;
 
-	/* rare controls bar */
+	// rare controls bar
 	AutoHideButtonBar m_rarecontrolsbar;
 };
 extern TouchScreenGUI *g_touchscreengui;