Initial SDL game controller integration

src/sdl/Makefile.am

@@ -2,6 +2,6 @@ AM_CFLAGS=-I$(srcdir)/.. @CFLAGS@ @SDL_CFLAGS@
 
 noinst_LIBRARIES = libsdlsopwith.a libsdlsopmain.a
 
-libsdlsopwith_a_SOURCES = video.c pcsound.c timer.c
+libsdlsopwith_a_SOURCES = video.c pcsound.c timer.c controller.c
 libsdlsopmain_a_SOURCES = main.c
 

src/sdl/controller.c

@@ -0,0 +1,110 @@
+//
+// Copyright(C) 2024 Simon Howard
+//
+// You can redistribute and/or modify this program under the terms of the
+// GNU General Public License version 2 as published by the Free Software
+// Foundation, or any later version. This program is distributed WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE.
+//
+//
+// SDL game controller
+//
+
+#include <SDL.h>
+
+#include "sw.h"
+#include "video.h"
+
+int controller_bindings[NUM_KEYS] = {
+	SDL_CONTROLLER_BUTTON_INVALID,        // KEY_UNKNOWN
+	SDL_CONTROLLER_BUTTON_DPAD_DOWN,      // KEY_PULLUP
+	SDL_CONTROLLER_BUTTON_DPAD_UP,        // KEY_PULLDOWN
+	SDL_CONTROLLER_BUTTON_A,              // KEY_FLIP
+	SDL_CONTROLLER_BUTTON_LEFTSHOULDER,   // KEY_BOMB
+	SDL_CONTROLLER_BUTTON_RIGHTSHOULDER,  // KEY_FIRE
+	SDL_CONTROLLER_BUTTON_START,          // KEY_HOME
+	SDL_CONTROLLER_BUTTON_INVALID,        // KEY_MISSILE
+	SDL_CONTROLLER_BUTTON_INVALID,        // KEY_STARBURST
+	SDL_CONTROLLER_BUTTON_Y,              // KEY_ACCEL
+	SDL_CONTROLLER_BUTTON_B,              // KEY_DECEL
+	SDL_CONTROLLER_BUTTON_INVALID,        // KEY_SOUND
+};
+
+static int button_to_key[SDL_CONTROLLER_BUTTON_MAX];
+
+static SDL_GameController *controller = NULL;
+static SDL_JoystickID controller_id;
+
+static void RecalculateButtonMapping(void)
+{
+	int i;
+
+	for (i = 0; i < SDL_CONTROLLER_BUTTON_MAX; i++) {
+		button_to_key[i] = KEY_UNKNOWN;
+	}
+	for (i = 0; i < NUM_KEYS; i++) {
+		int button = controller_bindings[i];
+		if (button != SDL_CONTROLLER_BUTTON_INVALID) {
+			button_to_key[button] = i;
+		}
+	}
+}
+
+void Vid_ControllerButtonDown(SDL_ControllerButtonEvent *event)
+{
+	int gamekey;
+
+	if (controller != NULL && event->which != controller_id) {
+		return;
+	}
+	if (event->button >= SDL_CONTROLLER_BUTTON_MAX) {
+		return;
+	}
+	gamekey = button_to_key[event->button];
+	if (gamekey != KEY_UNKNOWN) {
+		keysdown[gamekey] |= KEYDOWN_GAMEPAD | KEYDOWN_WAS_PRESSED;
+	}
+}
+
+void Vid_ControllerButtonUp(SDL_ControllerButtonEvent *event)
+{
+	int gamekey;
+
+	if (controller != NULL && event->which != controller_id) {
+		return;
+	}
+	if (event->button >= SDL_CONTROLLER_BUTTON_MAX) {
+		return;
+	}
+	gamekey = button_to_key[event->button];
+	if (gamekey != KEY_UNKNOWN) {
+		keysdown[gamekey] &= ~KEYDOWN_GAMEPAD;
+	}
+}
+
+void Vid_ControllerAdded(SDL_ControllerDeviceEvent *event)
+{
+	if (controller != NULL) {
+		return;
+	}
+	controller = SDL_GameControllerOpen(event->which);
+	controller_id = SDL_JoystickInstanceID(
+		SDL_GameControllerGetJoystick(controller));
+}
+
+void Vid_ControllerRemoved(SDL_ControllerDeviceEvent *event)
+{
+	if (controller == NULL || event->which != controller_id) {
+		return;
+	}
+	SDL_GameControllerClose(controller);
+	controller = NULL;
+}
+
+void Vid_ControllerInit(void)
+{
+	SDL_Init(SDL_INIT_JOYSTICK | SDL_INIT_GAMECONTROLLER);
+	// SDL_GameControllerAddMappingsFromFile("gamecontrollerdb.txt");
+	RecalculateButtonMapping();
+}

src/sdl/video.c

@@ -28,6 +28,12 @@
 
 #define INPUT_BUFFER_LEN 32
 
+void Vid_ControllerButtonDown(SDL_ControllerButtonEvent *event);
+void Vid_ControllerButtonUp(SDL_ControllerButtonEvent *event);
+void Vid_ControllerAdded(SDL_ControllerDeviceEvent *event);
+void Vid_ControllerRemoved(SDL_ControllerDeviceEvent *event);
+void Vid_ControllerInit(void);
+
 struct palette {
 	char name[13]; // Up to 12 characters will display correctly on the menu
 	SDL_Color color[4];
@@ -537,6 +543,8 @@ void Vid_Init(void)
 
 	atexit(Vid_Shutdown);
 
+	Vid_ControllerInit();
+
 	SDL_LockSurface(screenbuf);
 }
 
@@ -863,6 +871,22 @@ static void GetEvents(void)
 		case SDL_FINGERMOTION:
 			FingerMove(&event.tfinger);
 			break;
+
+		case SDL_CONTROLLERBUTTONDOWN:
+			Vid_ControllerButtonDown(&event.cbutton);
+			break;
+
+		case SDL_CONTROLLERBUTTONUP:
+			Vid_ControllerButtonUp(&event.cbutton);
+			break;
+
+		case SDL_CONTROLLERDEVICEADDED:
+			Vid_ControllerAdded(&event.cdevice);
+			break;
+
+		case SDL_CONTROLLERDEVICEREMOVED:
+			Vid_ControllerRemoved(&event.cdevice);
+			break;
 		}
 	}
 

src/video.h

@@ -43,6 +43,7 @@ enum gamekey {
 #define KEYDOWN_KEYBOARD     (1 << 0)
 #define KEYDOWN_WAS_PRESSED  (1 << 1)
 #define KEYDOWN_TOUCH        (1 << 2)
+#define KEYDOWN_GAMEPAD      (1 << 3)
 
 extern int keysdown[NUM_KEYS];
 extern int keybindings[NUM_KEYS];