joystick.cpp

#include "joystick.h"
#include <SDL.h>
#include <assert.h>

SDL_Joystick* s_sdlJoy = 0;
Joystick s_joy;

void JOYSTICK_Init()
{
	// Only Xbox360Controller is supported
	if (SDL_NumJoysticks() > 0)
	{
		s_sdlJoy = SDL_JoystickOpen(0);

		printf("Found joystick \"%s\"\n", SDL_JoystickName(0));
		printf("  numAxes = %d\n", SDL_JoystickNumAxes(s_sdlJoy));
		printf("  numButtons = %d\n", SDL_JoystickNumButtons(s_sdlJoy));
		printf("  numBalls = %d\n", SDL_JoystickNumBalls(s_sdlJoy));
		printf("  numHats = %d\n", SDL_JoystickNumHats(s_sdlJoy));
	}
	else
		printf("Joystick not found.\n");
}

void JOYSTICK_Shutdown()
{
	if (s_sdlJoy)
	    SDL_JoystickClose(s_sdlJoy);
}

void JOYSTICK_ClearFlags()
{
	s_joy.buttonPressFlags = 0;
	s_joy.buttonReleaseFlags = 0;
}

// TODO: do a real joystick config.
// maps event to axes
#ifdef DARWIN
static int s_axisMap[] = {
    Joystick::LeftStickX,
    Joystick::LeftStickY,
    Joystick::LeftTrigger,
    Joystick::RightStickX,
    Joystick::RightStickY,
    Joystick::RightTrigger
};
#else
static int s_axisMap[] = {
    Joystick::LeftStickX,
    Joystick::LeftStickY,
    Joystick::LeftTrigger,
    Joystick::RightStickY,
    Joystick::RightStickX,
    Joystick::RightTrigger
};
#endif

void JOYSTICK_UpdateMotion(const SDL_JoyAxisEvent* event)
{
	if (event->which != 0)
		return;

	const float kDeadSpot = 0.2f;

	int i = s_axisMap[event->axis];
	switch (i)
	{
		case Joystick::LeftStickX:
		case Joystick::RightStickX:
			s_joy.axes[i] = event->value / 32768.0f;
			if (fabs(s_joy.axes[i]) < kDeadSpot)
				s_joy.axes[i] = 0.0f;
			break;

		// flip y axis, not sure if this a driver thing or an SDL thing, but I want my +y to mean up.
		case Joystick::LeftStickY:
		case Joystick::RightStickY:
			s_joy.axes[i] = event->value / -32768.0f;
			if (fabs(s_joy.axes[i]) < kDeadSpot)
				s_joy.axes[i] = 0.0f;
			break;

		// I want to map the triggers from 0 to 1
		case Joystick::LeftTrigger:
		case Joystick::RightTrigger:
			s_joy.axes[i] = ((event->value / 32768.0f) * 0.5f) + 0.5f;
			if (s_joy.axes[i] < kDeadSpot)
				s_joy.axes[i] = 0.0f;
			break;
	}
}

unsigned int UpdateButtonFlag(unsigned int orig, unsigned int mask, bool newState)
{
	if (newState)
		return orig | mask;		// set flag
	else
		return orig & ~mask;	// clear flag
}

// TODO: do a real joystick config.
#ifdef DARWIN
static int s_buttonMap[] = {Joystick::DPadDown, Joystick::DPadUp, Joystick::DPadLeft, Joystick::DPadRight,
							Joystick::Start, Joystick::Back, Joystick::LeftStick, Joystick::RightStick,
							Joystick::LeftBumper, Joystick::RightBumper, Joystick::Xbox, Joystick::A,
							Joystick::B, Joystick::X, Joystick::Y};
#else
static int s_buttonMap[] = {Joystick::A, Joystick::B, Joystick::X, Joystick::Y,
							Joystick::LeftBumper, Joystick::RightBumper, Joystick::Back, Joystick::Start,
							Joystick::LeftStick, Joystick::RightStick};
#endif

void JOYSTICK_UpdateButton(const SDL_JoyButtonEvent* event)
{
	if (event->which != 0)
		return;

	int i = s_buttonMap[event->button];

	s_joy.buttonStateFlags = UpdateButtonFlag(s_joy.buttonStateFlags, 1 << i, event->state);

	if (event->state)
		s_joy.buttonPressFlags = UpdateButtonFlag(s_joy.buttonPressFlags, 1 << i, event->state);
	else
		s_joy.buttonReleaseFlags = UpdateButtonFlag(s_joy.buttonReleaseFlags, 1 << i, event->state);
}

Joystick* JOYSTICK_GetJoystick()
{
	return &s_joy;
}