Game Programming (User Input) 2017. Spring

The Keyboard The Keyboard Most widely available input device The main input device for PC-based games Also available for mobile phones, some consoles, and palm devices Disadvantages Not very well suited for games Impractical for small children User Input : No broad standards are available

The Keyboard Keyboard read methods Synchronous routine Wait until a key is pressed and then report it to the application Not well suited for real gameplay Ex) type information such as the character name in a RPG Asynchronous routine Return immediately after being called, and give the application information about which keys were pressed Two different routines A single-key asynchronous call Test the state of individual keys A whole keyboard check Retrieve the whole keyboard state in a single call Less overhead, more efficient

The Keyboard Asynchronous routine A single-key asynchronous call Win32 API (table 5.1) How to check whether the key is pressed How to test for the key combination Short GetAsyncKeyState(int keycode); If ( GetAsynKeyState(VK_LSHIFT) ) { // whatever } If ( GetAsynKeyState(VK_LSHIFT) && GetAsynKeyState(VK_RETRUN) ) { // whatever } Each key test requires a system call, which can be troublesome for those systems checking a lot of different keys

The Keyboard Asynchronous routine A whole keyboard check How to check whether the key is pressed a simple array lookup Bool GetKeyboardState(PBYTE *lpKeyState); If ( keyState[VK_RSHIFT] ) { // right shift was pressed } This mode does not immediately check the keys when you perform the test  Undesirable side effects might occur (the array will contain “old” key values)

The Keyboard Keyboard with DirectInput A single call can retrieve the state of the whole keyboard Provide fast asynchronous access to key states Encapsulates keyboards, joystick, mice and any other input Setting up a keyboard DirectInput Create the DirectInput object Create the keyboard device Set the data format for reading it Set the cooperative level you will use with the OS Read data as needed

The Keyboard DirectInput Declaration : 1. Create the DirectInput object LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pKeyboard; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->CreateDevice( GUID_SysKeyboard, &g_pKeyboard, NULL); hr = g_pKeyboard->SetDataFormat( &c_dfDIKeyboard); hr = g_pKeyboard->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); hr = g_pKeyboard->Acquire(); DirectInput object ready for use : 1 parameter: send the instance handle to the application that is creating the DirectInput object 2 parameter: pass the current DirectInput version number 3 parameter: pass the unique interface identifier for the object we are requesting (can use other parameters to define ANSI or Unicode versions of the interface) 4 parameter: pass the pointer so we can receive the already initialized object 5 parameter: perform Component Object Model (COM) aggregation

The Keyboard DirectInput Declaration : 2. Create the keyboard device LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pKeyboard; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->CreateDevice( GUID_SysKeyboard, &g_pKeyboard, NULL); hr = g_pKeyboard->SetDataFormat( &c_dfDIKeyboard); hr = g_pKeyboard->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); hr = g_pKeyboard->Acquire(); Request a device from the DirectInput object 1 parameter : Receive Global Unique Identifier (GUID) for the desired device GUIDs for the different devices (128-bit structures)  GUID_SysKeyboard: default system keyboard  GUID_SysMouse: default system mouse 2 parameter : the pointer to the newly created device 3 parameter : reserved for aggregation

The Keyboard DirectInput Declaration : 3. Set the data format for reading it LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pKeyboard; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->CreateDevice( GUID_SysKeyboard, &g_pKeyboard, NULL); hr = g_pKeyboard->SetDataFormat( &c_dfDIKeyboard); hr = g_pKeyboard->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); hr = g_pKeyboard->Acquire(); Tell the keyboard how we want to exchange data 1 parameter : c_dfDIKeyboard  the full keyboard stored in an array of 256 bytes

The Keyboard DirectInput Declaration : 4. Set the cooperative level you will use with the OS LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pKeyboard; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->CreateDevice( GUID_SysKeyboard, &g_pKeyboard, NULL); hr = g_pKeyboard->SetDataFormat( &c_dfDIKeyboard); hr = g_pKeyboard->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); hr = g_pKeyboard->Acquire(); Tell DirectInput about the cooperative level 1 parameter : pass the window handle 2 parameter : the OR of a series of flags that control the cooperative level

The Keyboard DirectInput Declaration : 5. Read data as needed LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pKeyboard; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->CreateDevice( GUID_SysKeyboard, &g_pKeyboard, NULL); hr = g_pKeyboard->SetDataFormat( &c_dfDIKeyboard); hr = g_pKeyboard->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); hr = g_pKeyboard->Acquire(); Acquire the keyboard  Can begin querying its state

The Keyboard DirectInput Reading the keyboard Query a specific key The most significant bit is activated If the key is currently pressed DirectInput Reading the keyboard Query a specific key Releasing the keyboard BYTE diks[256]; // DirectInput keyboard state buffer ZeroMemory( diks, sizeof(diks) ); hr = g_pKeyboard->GetDeviceState( sizeof(diks), diks ); If ( FAILED(hr) ) { hr = g_pKeyboard->Acquire(); while ( hr == DIERR_INPUTLOST || hr == DIEER_OTHERAPPHASPRIO) } Bool return_pressed = ( buffer[DIK_RETURN] & 0x80 ) ! = 0); If ( g_pKeyboard ) g_pKeyboard->Unacquire(); SAFE_RELEASE( g_pKeyboard ); SAFE_RELEASE( g_pDI );

Mouse The Mouse Not only generate button or key press, but 2D positions as well The operation of the mouse Transmitting positional information Sending button press and release message

Mouse DirectInput declaration LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pMouse; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->CreateDevice( GUID_SysMouse, &g_pMouse, NULL); hr = g_pMouse->SetDataFormat( &c_dfDIMouse); hr = g_pMouse->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); hr = g_pMouse->Acquire();

Mouse DirectInput Reading from the mouse DIMOUSESTATE dims; // DirectInput mouse state structure ZeroMemory( &dims, sizeof(dims) ); hr = g_pMouse->GetDeviceState( sizeof(DIMOUSESTATE), &dims ); If ( FAILED(hr) ) { hr = g_pMouse->Acquire(); while ( hr == DIERR_INPUTLOST || hr == DIEER_OTHERAPPHASPRIO || hr == DIEER_NOTACTIVATED) }

Mouse DirectInput Access the mouse attributes Typedef struct DIMOUSESTATE { LONG lX, lY, lZ; BYTE rgbButtons[4]; } DIMOUSESTATE, *LPDIMOUSESTATE DirectInput Access the mouse attributes Button 0: left mouse button Button 1: right mouse button Button 2: middle button Relative pointing device Return the displacement from the last one Release the mouse Int MouseX=dims.lX; Int MouseY=dims.lY; bool lbutton = ( dims.rgbButtons[0] & 0x80 ) ! = 0); Buttons are pressed if the high-order bit is set If ( g_pMouse ) g_pMouse->Unacquire(); SAFE_RELEASE( g_pMouse ); SAFE_RELEASE( g_pDI );

Mouselook Mouselook The classic mouselook used in many first person shooters The keys to change our position X and Z values The mouse to reorient our viewpoint A yaw and pitch angle (Ref] Camera) Mapping Mouse: Mouselook Left arrow: Strafe left Right arrow: Strafe right Up arrow: Move forward Down arrow: Move back

Mouselook Implementation // strafe and fwd by -1, 0, or 1 int strafe = (buffer[DIK_RIGHT] & 0x80) != 0) – (buffer[DIK_LEFT] & 0x80) != 0) ; int fwd = (buffer[DIK_UP] & 0x80) != 0) – (buffer[DIK_DOWN] & 0x80) != 0) ; // elapsed : elapsed time factor  ensure device-independent performance pos.x += fwd*FWDSPEED*elapsed*cos(yaw) + strafe*STRAFESPEED*elapsed*cos(yaw+3.1416/2); pos.z += fwd*FWDSPEED*elapsed*sin(yaw) + strafe*STRAFESPEED*elapsed*sin(yaw+3.1416/2); yaw += YAWSPEED*elapsed*dims.lX; pitch += PITCHSPEED*elapsed*dims.lY; // lookat: spherical mapping using the pitch and yaw point campos( pos.x, pos.y, pos.z ); point camlookat( pos.x+cos(yaw)*cos(pitch), pos.y+sin(pitch), pos.z+sin(yaw)*cos(pitch) );

Joysticks Joystick Introduced in the 1970s as a way to represent positional data Controlling a joystick LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pJoystick; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->EnumDevice( DI8DEVCLASS_GAMECTRL, EnumJoysticksCallback, NULL, DIEDFL_ATTACHEDONLY); hr = g_pJoystick->SetDataFormat( &c_dfDIJoystick); hr = g_pJoystick->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); g_pJoystick->EnumObjects(EnumObjectsCallback, (VOID*)hwnd, DIDFT_ALL);

Joysticks Controlling a joystick LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pJoystick; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->EnumDevice( DI8DEVCLASS_GAMECTRL, // game pads and joystick EnumJoysticksCallback, NULL, DIEDFL_ATTACHEDONLY); hr = g_pJoystick->SetDataFormat( &c_dfDIJoystick); hr = g_pJoystick->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); g_pJoystick->EnumObjects(EnumObjectsCallback, (VOID*)hwnd, DIDFT_ALL); Ask DirectInput to enumerate any joystick it is detecting: 1 parameter: tells DirectInput which kind of device we want to detect (keyboard  DI8DEVCLASS_KEYBOARD, mouse  DI8DEVCLASS_POINTER) 2 parameter: a callback that will get triggered once for each detected joystick 3 parameter: user-defined parameter to be passed to the callback 4 parameter: the enumeration flags (DIEDFL_ATTACHEDONLY  only detect devices that are properly attached and installed DIEDFL_FORCEFEEDBACK  restrict the enumeration to force feedback)

Joysticks Controlling a joystick LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pJoystick; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->EnumDevice( DI8DEVCLASS_GAMECTRL, // game pads and joystick EnumJoysticksCallback, NULL, DIEDFL_ATTACHEDONLY); hr = g_pJoystick->SetDataFormat( &c_dfDIJoystick); hr = g_pJoystick->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); g_pJoystick->EnumObjects(EnumObjectsCallback, (VOID*)hwnd, DIDFT_ALL); BOOL CALLBACK EnumJoysticksCallback(const DIDEVICEINSTANCE * pdidInstance, VOID* pContext ) { HRESULT hr= g_pDI->createdevice( pdidInstance->guidInstance, &g_pJoystick, NULL); if (FAILED(hr)) return DIENUM_CONTINUE; return DIENUM_STOP; }

Joysticks Controlling a joystick LPDIRECTINPUT8 g_pDI=NULL; LPDIRECTINPUTDEVICE g_pJoystick; HRESULT hr; hr = DirectInput8Create( GetModuleHandle (NULL), DIRECTINPUT_VERSION, IID_IDirectInput8, (VOID**) &g_pDI, NULL ); hr = g_pDI->EnumDevice( DI8DEVCLASS_GAMECTRL, // game pads and joystick EnumJoysticksCallback, NULL, DIEDFL_ATTACHEDONLY); hr = g_pJoystick->SetDataFormat( &c_dfDIJoystick); hr = g_pJoystick->SetCooperativeLevel( hwnd, DISCL_FOREGROUND | DISCL_EXCLUSIVE); g_pJoystick->EnumObjects(EnumObjectsCallback, (VOID*)hwnd, DIDFT_ALL); Set the data format and cooperative level

Joysticks Controlling a joystick g_pJoystick->EnumObjects(EnumObjectsCallback, (VOID*)hwnd, DIDFT_ALL); Set the output range for the joystick (Ex: -1…1 , -100…100 ) 1 parameter: Need to a callback that request the objects associated with the joystick (Objects  axes, buttons, POVs, and so on) BOOL CALLBACK EnumObjectsCallback(const DIDEVICEINSTANCE * pdidInstance, VOID* pContext ) { HWND hDlg =(HWND)pContext; if (pdidoi->dwType & DIDFT_AXIS) { DIPROPRANGE diprg; diprg.diph.dwSize = sizeof(DIPROPRANGE); diprg.diph.dwHeaderSize= sizeof(DIPROHEADER); diprg.diph.dwHow = DIPH_BYID; diprg.diph.dwObj = pdidoi->dwType; diprg.diph.lMin = -100; diprg.diph.lMax = 100; if (FAILED(g_pJoystick->SetProperty(DIPROP_RANGE, &diprg.diph))) return DIENUM_STOP; }

Joysticks Reading from the joystick hr = g_pMouse->Poll(); If ( FAILED(hr) ) { hr = g_pJoystick->Acquire(); while ( hr == DIERR_INPUTLOST || hr == DIEER_OTHERAPPHASPRIO) return S_OK; } DIJOYSTATE js; hr = g_pJoystick->GetDeviceState ( sizeof (DIJOYSTATE), &js)); typedef struct DIJOYSTATE { LONG lX, lY, lZ; LONG lRx, lRy, lRz; LONG rglSlider[2]; DWORD rgdwPOV[4]; BYTE rgbButtons[32]; } DIJOYSTATE, *LPDIJOYSTATE

Joysticks POV (point of view) switch

Joysticks Response Curve How analog joysticks map the controller position to a continuous range of values Left, Still, Right ?? Response Curve without(left) and with(right) dead zone

Joysticks Analog controller Return a value in a continuous range Need a response curve Types of Response Curve

Hardware Abstraction Platforms that support a variety of input controllers Ex) Standard controller, aircraft-style-joystick, snowboards, dance pads, fishing rod Coding for such a platform Choose to use only one of the existing controllers Ex) strategy games (with a PC mouse) Let the user choose the input method Ex) Action games Hardware Abstraction Coding the game with a “virtual” controller Controllers that conform to that abstract profile via inheritance

Hardware Abstraction Action mapping Allows your device to return not specific state values but game-oriented values Assign device events to game events Device independence Ex) “advance left”  joystick(a movement on the X-axis) DIACTION g_adiaActionMap[ ] = { // Joystick input mappings { WALK, DIAXIS_FIGHTINGH_LATERAL, 0, ACTION_NAMES [WALK], }, { JUMP, DIBUTTON_FIGHTINGH_JUMP, 0, ACTION_NAMES [JUMP], }, // Keyboard input mappings { WALK_LEFT, DIKEYBOARD_LEFT, 0, ACTION_NAMES [WALK_LEFT], }, { WALK_RIGHT, DIKEYBOARD_RIGHT, 0, ACTION_NAMES [WALK_RIGHT], }, { JUMP, DIKEYBOARD_J, 0, ACTION_NAMES [JUMP], }, { QUIT, DIKEYBOARD_Q, DIA_APPFIXED, ACTION_NAMES [QUIT], }, // Mouse input mappings { WALK, DIMOUSE_XAXIS, 0, ACTION_NAMES [WALK], }, { JUMP, DIMOUSE_BUTTON0, 0, ACTION_NAMES [JUMP], }, }; enum GAME_ACTIONS { WALK, WALK_LEFT, WALK_RIGHT, JUMP, QUIT };

Force Feedback Force Feedback Force Feedback H/W simulates vibration by incorporating one or more motors Programming force feedback devices (platform dependent) Create or describe the desired effect (Ex. Force Editor) How it affects the controller’s position, and strength, and so on The effect must be loaded to the input API Reproduce the effect at runtime MS’s Force Editor

Types of game controllers Game Pad (= joypad) the most common kind of game controller Gamepads generally feature a set of action buttons handled with the right thumb and a direction controller(D-pad) handled with the left shoulder buttons placed along the edges of the pad, centrally placed start, select, and mode buttons, and an internal motor to provide force feedback.

Types of game controllers Paddle A paddle is a controller that features a round wheel and one or more fire buttons The wheel is typically used to control movement of the player or of an object along one axis of the video screen Trackball A trackball is basically an upside-down mouse that is manipulated with the palm of one's hand

Types of game controllers Arcade style Joystick It features a shaft that has a ball or drop-shaped handle, and one or more buttons for in game actions Steering wheel The steering wheel, essentially a larger version of a paddle, is used for racing simulators Pedals Pedals may be used for driving simulations or flight simulations

Types of game controllers Touch screen A touch screen is an input device that allows the user to interact with the computer by touching the display screen Motion sensing It uses accelerometers to detect its approximate orientation and acceleration and an image sensor[1] so it can be used as a pointing device Microsoft has also released the Kinect, similar to Sony's Eyetoy, both of which use cameras to detect the player's motions and translate them into inputs for the game.

Types of game controllers Light gun A light gun is a peripheral used to "shoot" targets on a screen Dance pad a flat electronic game controller used for input in dance games Balance Board contains multiple pressure sensors that are used to measure the user's center of balance

Types of game controllers Others Rhythm games controller guitars, drums, turntablism or maracas Fishing rod Microphone Mind-controlled headset VR System VR Gadgets