make menus controllable with joystick

In most menus, keyboard commands are synthesized
from controller buttons, leveraging the existing
axis-to-button translation.

Menu controls are currently fixed:
- button 0 (A) is confirm (Enter)
- button 1 (B) is cancel (Esc)
- button 2 (X) is switch (Space)
- button 3 (Y) is delete (Delete)
- axes 0 and 1 (main analog pad) maps to cursor keys
- all hats (D-pads) map to cursor keys

Title screens and credits can be confirmed
with any joystick button or axis motion too.

common/arch/sdl/joy.cpp

@@ -14,6 +14,7 @@
 #include <tuple>
 #include <type_traits>
 #include "joy.h"
+#include "key.h"
 #include "dxxerror.h"
 #include "timer.h"
 #include "console.h"
@@ -466,5 +467,48 @@ int apply_deadzone(int value, int deadzone)
 		return 0;
 }
 
+bool joy_translate_menu_key(const d_event &event) {
+	if (event.type != EVENT_JOYSTICK_BUTTON_DOWN)
+		return false;
+#if DXX_MAX_BUTTONS_PER_JOYSTICK || DXX_MAX_HATS_PER_JOYSTICK || DXX_MAX_AXES_PER_JOYSTICK
+	// Find out which button has been pressed by decoding the button
+	// description text. This might not be the ideal way to do things,
+	// but we currently don't have data structures that allow us to do
+	// such a mapping in a saner way, so we'll take what we can get.
+	auto &e = static_cast<const d_event_joystickbutton &>(event);
+	Assert((e.button >= 0) && (e.button < joybutton_text.size()));
+	const char* name = &joybutton_text[e.button][0];
+	Assert((name[0] == 'J') && name[1] && (name[2] == ' '));
+	name = &name[3];  // skip 'Jx ' prefix
+	int key = 0;
+	if      (!strcmp(name, "B1"))  { key = KEY_ENTER; }
+	else if (!strcmp(name, "B2"))  { key = KEY_ESC; }
+	else if (!strcmp(name, "B3"))  { key = KEY_SPACEBAR; }
+	else if (!strcmp(name, "B4"))  { key = KEY_DELETE; }
+	else if (!strcmp(name, "+A1")) { key = KEY_LEFT; }
+	else if (!strcmp(name, "-A1")) { key = KEY_RIGHT; }
+	else if (!strcmp(name, "+A2")) { key = KEY_UP; }
+	else if (!strcmp(name, "-A2")) { key = KEY_DOWN; }
+	else if (name[0] == 'H')
+	{	// handle 'Hxx' / hat motion
+		Assert(name[1]);
+		switch (name[2])
+		{
+			case 0201: key = KEY_LEFT; break;
+			case 0177: key = KEY_RIGHT; break;
+			case 0202: key = KEY_UP; break;
+			case 0200: key = KEY_DOWN; break;
+			default: break;
+		}
+	}
+	if (key)
+	{
+		event_keycommand_send(key);
+		return true;
+	}
+	return false;
+#endif
+}
+
 }
 #endif

common/arch/sdl/key.cpp

@@ -587,6 +587,11 @@ void key_flush()
 		restore_sticky_key(keystate, key);
 }
 
+void event_keycommand_send(int key) {
+	const d_event_keycommand event{EVENT_KEY_COMMAND, unsigned(key)};
+	event_send(event);
+}
+
 int event_key_get(const d_event &event)
 {
 	auto &e = static_cast<const d_event_keycommand &>(event);

common/include/joy.h

@@ -36,6 +36,7 @@ extern void joy_init();
 extern void joy_close();
 const d_event_joystick_axis_value &event_joystick_get_axis(const d_event &event);
 extern void joy_flush();
+extern bool joy_translate_menu_key(const d_event &event);
 extern int event_joystick_get_button(const d_event &event);
 extern int apply_deadzone(int value, int deadzone);
 

common/include/key.h

@@ -61,6 +61,7 @@ extern fix64 keyd_time_when_last_pressed;
 extern std::array<unsigned char, KEY_BUFFER_SIZE> unicode_frame_buffer;
 
 extern void key_flush();    // Clears the 256 char buffer
+extern void event_keycommand_send(int key); // synthesize a key command event from a keycode
 extern int event_key_get(const d_event &event);	// Get the keycode from the EVENT_KEY_COMMAND event
 extern int event_key_get_raw(const d_event &event);	// same as above but without mod states
 unsigned char key_ascii();

similar/main/credits.cpp

@@ -115,6 +115,9 @@ static window_event_result credits_handler(window *, const d_event &event, credi
 			}
 			break;
 
+		case EVENT_JOYSTICK_BUTTON_DOWN:
+			return window_event_result::close;
+
 		case EVENT_IDLE:
 			if (cr->done>NUM_LINES)
 			{

similar/main/kconfig.cpp

@@ -655,6 +655,9 @@ static window_event_result kconfig_key_command(window *, const d_event &event, k
 namespace dsx {
 static window_event_result kconfig_handler(window *wind,const d_event &event, kc_menu *menu)
 {
+	if (!menu->changing && joy_translate_menu_key(event))
+		return window_event_result::handled;
+
 	switch (event.type)
 	{
 		case EVENT_WINDOW_ACTIVATED:

similar/main/newmenu.cpp

@@ -1491,6 +1491,9 @@ static window_event_result newmenu_draw(window *wind, newmenu *menu)
 
 static window_event_result newmenu_handler(window *wind,const d_event &event, newmenu *menu)
 {
+	if (joy_translate_menu_key(event))
+		return window_event_result::handled;
+
 	if (menu->subfunction)
 	{
 		int rval = (*menu->subfunction)(menu, event, menu->userdata);
@@ -2110,6 +2113,9 @@ static window_event_result listbox_handler(window *wind,const d_event &event, li
 			return rval;		// event handled
 	}
 
+	if (joy_translate_menu_key(event))
+		return window_event_result::handled;
+
 	switch (event.type)
 	{
 		case EVENT_WINDOW_ACTIVATED:

similar/main/scores.cpp

@@ -406,6 +406,9 @@ static window_event_result scores_handler(window *wind,const d_event &event, sco
 			}
 			break;
 
+		case EVENT_JOYSTICK_BUTTON_DOWN:
+			return window_event_result::close;
+
 		case EVENT_IDLE:
 			timer_delay2(50);
 			break;

similar/main/titles.cpp

@@ -141,6 +141,13 @@ static window_event_result title_handler(window *, const d_event &event, title_s
 				}
 			return result;
 
+		case EVENT_JOYSTICK_BUTTON_DOWN:
+			if (ts->allow_keys)
+			{
+				return window_event_result::close;
+			}
+			break;
+
 		case EVENT_IDLE:
 			timer_delay2(50);
 
@@ -1529,6 +1536,24 @@ static window_event_result briefing_handler(window *, const d_event &event, brie
 			}
 			break;
 
+		case EVENT_JOYSTICK_BUTTON_DOWN:
+			// using joy_translate_menu_key doesn't work here for unclear
+			// reasons, so we build a reasonable facsimile right here
+			if (event_joystick_get_button(event) == 1)
+				return window_event_result::close;
+			if (br->new_screen)
+			{
+				if (!new_briefing_screen(br, 0))
+				{
+					return window_event_result::close;
+				}
+			}
+			else if (br->new_page)
+				init_new_page(br);
+			else
+				br->delay_count = 0;
+			return window_event_result::handled;
+
 		case EVENT_KEY_COMMAND:
 		{
 			int key = event_key_get(event);