--- a/src/system_sdl.c	Fri Apr 01 21:51:46 2016 -0700
+++ b/src/system_sdl.c	Sun Apr 03 00:33:54 2016 -0700
@@ -1,6 +1,7 @@
 #include <SDL.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include "controller.h"
 
 
 static SDL_Window   *window;
@@ -69,9 +70,12 @@
 	return buffer_size;
 }
 
+static int num_controllers;
+static SDL_GameController **game_controllers;
+
 int system_init(int width, int height, int desired_sample_rate)
 {
-	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0) {
+	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_GAMECONTROLLER) < 0) {
 		fprintf(stderr, "Failed to init SDL: %s\n", SDL_GetError());
 		return 0;
 	}
@@ -116,6 +120,18 @@
 	atexit(close_audio);
 	SDL_PauseAudio(0);
 	
+	num_controllers = SDL_NumJoysticks();
+	game_controllers = calloc(num_controllers, sizeof(*game_controllers));
+	
+	for (int i = 0; i < num_controllers; i++)
+	{
+		if (!SDL_IsGameController(i)) {
+			printf("Joystick %d: %s is not recognized as a controller by SDL2\n", i, SDL_JoystickNameForIndex(i));
+			continue;
+		}
+		game_controllers[i] = SDL_GameControllerOpen(i);
+	}
+	
 	return 1;
 	
 error:
@@ -142,6 +158,36 @@
 	SDL_RenderPresent(renderer);
 }
 
+//SDL2 provides this, but only in 2.0.4+
+SDL_GameController *controller_by_id(SDL_JoystickID which)
+{
+	for (int i = 0; i < num_controllers; i++)
+	{
+		if (!game_controllers[i]) {
+			continue;
+		}
+		if (SDL_JoystickInstanceID(SDL_GameControllerGetJoystick(game_controllers[i])) == which) {
+			return game_controllers[i];
+		}
+	}
+	return NULL;
+}
+
+const uint16_t mapping[SDL_CONTROLLER_BUTTON_MAX] = {
+	[SDL_CONTROLLER_BUTTON_LEFTSHOULDER]  = 0x001,
+	[SDL_CONTROLLER_BUTTON_Y]             = 0x002,
+	[SDL_CONTROLLER_BUTTON_X]             = 0x004,
+	[SDL_CONTROLLER_BUTTON_RIGHTSHOULDER] = 0x008,
+	[SDL_CONTROLLER_BUTTON_B]             = 0x010,
+	[SDL_CONTROLLER_BUTTON_A]             = 0x020,
+	[SDL_CONTROLLER_BUTTON_BACK]          = 0x040,
+	[SDL_CONTROLLER_BUTTON_START]         = 0x080,
+	[SDL_CONTROLLER_BUTTON_DPAD_RIGHT]    = 0x100,
+	[SDL_CONTROLLER_BUTTON_DPAD_LEFT]     = 0x200,
+	[SDL_CONTROLLER_BUTTON_DPAD_DOWN]     = 0x400,
+	[SDL_CONTROLLER_BUTTON_DPAD_UP]       = 0x800,
+};
+
 void system_poll_events()
 {
 	SDL_Event event;
@@ -152,6 +198,14 @@
 		case SDL_QUIT:
 			exit(0);
 			break;
+		case SDL_CONTROLLERBUTTONDOWN:
+			controller_pressed(event.cbutton.which, mapping[event.cbutton.button]);
+			break;
+		case SDL_CONTROLLERBUTTONUP:
+			controller_released(event.cbutton.which, mapping[event.cbutton.button]);
+			break;
+		//TODO: Keyboard input
+		//TODO: Controller hotplug
 		}
 	}
 }