1. 1 Interaction Devices CIS 487/587 Bruce R. Maxim UM-Dearborn

2. 2 User Communication Keyboard remains the users primary input device Most GUI systems expect pointing devices as well –Light pen –Touch screen –Mouse –Trackball –Joystick –Graphics tablet –Touch pad –Foot controls –Gloves –Eye movement detectors

3. 3 Pointing Device Tasks Selection Positioning objects Orienting objects on screen Path tracing Quantify Text entry/editing (not easily done)

4. 4 Comparison Keyboard –Fast control, require memorization and recall Mouse –Best choice for pointing to objects in arbitrary positions, can be as fast as pointing with a finger Joystick –Poor cursor control devices, actually slower than mouse (only use where they are game realistic)

5. 5 Direct-Input 1.Create main DirectInput interface using CreateIDirectIntput8( ) 2.(optional) Query for device GUIDs for all devices (mouse, keyboard, joystick) 3.Create each device using CreateDevice( ) please note: GUID_SysKeyboard and GUID_SysMouse are built in 4.Set cooperation level for each device using SetCooperativeLevel( ) 5.Set data format for each device using SetDatFormat( )

6. 6 Direct-Input 6.Set properties of each device using IDirectIntputDevice8::SetProperty( ) 7.Acquire each device using IDirectIntputDevice8::Acquire( ) 8.(optional) Poll devices using IDirectIntputDevice8::Poll( ) 9.Read device using IDirectIntputDevice8::GetStateDevice( )

7. 7 Input DirectX can request input in two ways –Immediate input (default) –Buffered input LaMothe only uses immediate input DirectX can cut Windows out of the message loop altogether, so be careful when you set each device cooperation level

8. 8 LaMothe Example

9. 9 Keyboard Global Declarations #include // directX includes #include #include "T3DLIB1.H" // directinput globals LPDIRECTINPUT8 lpdi = NULL; // dinput object LPDIRECTINPUTDEVICE8 lpdikey = NULL; // dinput keyboard LPDIRECTINPUTDEVICE8 lpdimouse = NULL; // dinput mouse LPDIRECTINPUTDEVICE8 lpdijoy = NULL; // dinput joystick GUID joystickGUID; // guid for main joystick char joyname[80]; // name of joystick // these contain the target records for all di input packets UCHAR keyboard_state[256]; // contains keyboard state table DIMOUSESTATE mouse_state; // contains state of mouse DIJOYSTATE joy_state; // contains state of joystick

10. 10 Game_Init( ) // initialize directdraw DDraw_Init(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP); // first create the direct input object if (DirectInput8Create(main_instance,DIRECTINPUT_VERSION, IID_IDirectInput8, (void **)&lpdi,NULL)!=DI_OK) return(0); // create a keyboard device ////////////////////////////////// if (lpdi->CreateDevice(GUID_SysKeyboard, &lpdikey, NULL)!=DI_OK) return(0); // set cooperation level if (lpdikey->SetCooperativeLevel(main_window_handle, DISCL_NONEXCLUSIVE | DISCL_BACKGROUND)!=DI_OK) return(0); // set data format if (lpdikey->SetDataFormat(&c_dfDIKeyboard)!=DI_OK) return(0); // acquire the keyboard if (lpdikey->Acquire()!=DI_OK) return(0);

11. 11 Game_Shutdown( ) // kill the reactor Destroy_Bitmap(&reactor); // kill skelaton Destroy_BOB(&skelaton); // release keyboard lpdikey->Unacquire(); lpdikey->Release(); lpdi->Release(); // shutdonw directdraw DDraw_Shutdown();

12. 12 Game_Main( ) // get player input // get the keyboard data lpdikey->GetDeviceState(256, (LPVOID)keyboard_state); // reset motion flag player_moving = 0; // test direction of motion if (keyboard_state[DIK_RIGHT] && keyboard_state[DIK_UP]) { // move skelaton skelaton.x += 2; skelaton.y -= 2; dx=2; dy =- 2; // set motion flag player_moving = 1; // check animation needs to change if (skelaton.curr_animation != SKELATON_NEAST) Set_Animation_BOB(&skelaton,SKELATON_NEAST); } // end if …

13. 13 Mouse Detects changes in X, y position (Mickeys) Specifies absolute position Can specify velcoity range Good for selecting objects, moving objects, or changing head position (view) Hard to center if used as joystick replacement Has small number of buttons (2 or 3

14. 14 LaMothe Example

15. 15 Mouse Global Declarations #define BUTTON_SPRAY 0 // defines for each button #define BUTTON_PENCIL 1 #define BUTTON_ERASE 2 #define BUTTON_EXIT 3 // directinput globals LPDIRECTINPUT8 lpdi = NULL; // dinput object LPDIRECTINPUTDEVICE8 lpdikey = NULL; // dinput keyboard LPDIRECTINPUTDEVICE8 lpdimouse = NULL; // dinput mouse LPDIRECTINPUTDEVICE8 lpdijoy = NULL; // dinput joystick GUID joystickGUID; // guid for main joystick char joyname[80]; // name of joystick // these contain the target records for all di input packets UCHAR keyboard_state[256]; // contains keyboard state table DIMOUSESTATE mouse_state; // contains state of mouse DIJOYSTATE joy_state; // contains state of joystick

16. 16 Game_Init( ) // first create the direct input object DirectInput8Create(main_instance,DIRECTINPUT_VERSION,IID_IDirectInput8, (void **)&lpdi,NULL); // create a mouse device ///////////////////////////////////// lpdi->CreateDevice(GUID_SysMouse, &lpdimouse, NULL); // set cooperation level lpdimouse->SetCooperativeLevel(main_window_handle, DISCL_NONEXCLUSIVE | DISCL_BACKGROUND); // set data format lpdimouse->SetDataFormat(&c_dfDIMouse); // acquire the mouse lpdimouse->Acquire();

17. 17 Game_Init( ) // set the global mouse position mouse_x = screen_height/2; mouse_y = screen_height/2; // load the master bitmap in with all the graphics Load_Bitmap_File(&bitmap8bit, "PAINT.BMP"); Set_Palette(bitmap8bit.palette); // make sure all the surfaces are clean before starting DDraw_Fill_Surface(lpddsback, 0); DDraw_Fill_Surface(lpddsprimary, 0); // create the pointer bob Create_BOB(&pointer,mouse_x,mouse_y,32,34,1, BOB_ATTR_VISIBLE | BOB_ATTR_SINGLE_FRAME,DDSCAPS_SYSTEMMEMORY); // load the image for the pointer in Load_Frame_BOB(&pointer,&bitmap8bit,0,0,2,BITMAP_EXTRACT_MODE_CELL);

18. 18 Game_Init( ) // set clipping rectangle to screen extents so mouse cursor // doens't mess up at edges RECT screen_rect = {0,0,screen_width,screen_height}; lpddclipper = DDraw_Attach_Clipper(lpddsback,1,&screen_rect); // hide the mouse ShowCursor(FALSE);

19. 19 Game_Shutdown( ) // first unacquire the mouse lpdimouse->Unacquire(); // now release the mouse lpdimouse->Release(); // release directinput lpdi->Release();

20. 20 Game_Main( ) // move the mouse cursor mouse_x+=(mouse_state.lX); mouse_y+=(mouse_state.lY); // test bounds // first x boundaries if (mouse_x >= screen_width) mouse_x = screen_width-1; else if (mouse_x < 0) mouse_x = 0; // now the y boundaries if (mouse_y >= screen_height) mouse_y= screen_height-1; else if (mouse_y < 0) mouse_y = 0;

21. 21 Game_Main( ) // position the pointer bob to the mouse coords pointer.x = mouse_x - 16; pointer.y = mouse_y - 16; // test what the user is doing with the mouse if ((mouse_x > 3) && (mouse_x < 500-3) && (mouse_y > 3) && (mouse_y < SCREEN_HEIGHT-3)) { // mouse is within canvas region // if left button is down then draw if (mouse_state.rgbButtons[0]) { … };

22. 22 Game Pads Simplified keyboard Buttons have good stimulus/response compatibility Lets you use two hand Good for multiplayer games Can require weird combinations of buttons Dont get to rely on fastest finger (index) Doesnt support variable input

23. 23 Joysticks Lots of devices look like joysticks (digital – 8 positions, analog x,y deflection) Allow variable input plus buttons Great for specifying changes Can be used to specify rate in a direction Not good for specifying absolute positions (need to hold position steady) Not good for many arcade games

24. 24 Using Joysticks & Game Pads 1.Scan for all devices and record GUIDs 2.Create joystick device using one GUID 3.Use interface from step 2 and create another interface (release the first) 4.Set cooperation level 5.Set data format and properties 6.Acquire joystick 7.Read joystick using Poll and GetDevice

25. 25 LaMothe Example

26. 26 Joystick Global Declarations // directinput globals LPDIRECTINPUT8 lpdi = NULL; // dinput object LPDIRECTINPUTDEVICE8 lpdikey = NULL; // dinput keyboard LPDIRECTINPUTDEVICE8 lpdimouse = NULL; // dinput mouse LPDIRECTINPUTDEVICE8 lpdijoy = NULL; // dinput joystick GUID joystickGUID; // guid for main joystick char joyname[80]; // name of joystick // these contain the target records for all di input packets UCHAR keyboard_state[256]; // contains keyboard state table DIMOUSESTATE mouse_state; // contains state of mouse DIJOYSTATE joy_state; // contains state of joystick

27. 27 DI_Enum_Joysticks( ) // this function enumerates the joysticks, but // stops at the first one and returns the // instance guid of it, so we can create it *(GUID*)guid_ptr = lpddi->guidInstance; // copy name into global strcpy(joyname, (char *)lpddi->tszProductName); // stop enumeration after one iteration return(DIENUM_STOP);

28. 28 Game_Init( ) // joystick creation section //////////////////////////////// // first create the direct input object if (DirectInput8Create(main_instance,DIRECTINPUT_VERSION, IID_IDirectInput8, (void **)&lpdi,NULL)!=DI_OK) return(0); // first find the f***ing GUID of your particular joystick lpdi->EnumDevices(DI8DEVCLASS_GAMECTRL, DI_Enum_Joysticks, &joystickGUID, DIEDFL_ATTACHEDONLY); if (lpdi->CreateDevice(joystickGUID, &lpdijoy, NULL)!=DI_OK) return(0); // set cooperation level if (lpdijoy->SetCooperativeLevel(main_window_handle, DISCL_NONEXCLUSIVE | DISCL_BACKGROUND)!=DI_OK) return(0);

29. 29 Game_Init( ) // set data format if (lpdijoy->SetDataFormat(&c_dfDIJoystick)!=DI_OK) return(0); // set the range of the joystick DIPROPRANGE joy_axis_range; // first x axis joy_axis_range.lMin = -24; joy_axis_range.lMax = 24; joy_axis_range.diph.dwSize = sizeof(DIPROPRANGE); joy_axis_range.diph.dwHeaderSize = sizeof(DIPROPHEADER); joy_axis_range.diph.dwObj = DIJOFS_X; joy_axis_range.diph.dwHow = DIPH_BYOFFSET; lpdijoy->SetProperty(DIPROP_RANGE,&joy_axis_range.diph);

30. 30 Game_Init( ) // now y-axis joy_axis_range.lMin = -24; joy_axis_range.lMax = 24; joy_axis_range.diph.dwSize = sizeof(DIPROPRANGE); joy_axis_range.diph.dwHeaderSize = sizeof(DIPROPHEADER); joy_axis_range.diph.dwObj = DIJOFS_Y; joy_axis_range.diph.dwHow = DIPH_BYOFFSET; lpdijoy->SetProperty(DIPROP_RANGE,&joy_axis_range.diph); // and now the dead band (zone where movements are ignored) DIPROPDWORD dead_band; // here's our property word dead_band.diph.dwSize = sizeof(dead_band); dead_band.diph.dwHeaderSize = sizeof(dead_band.diph); dead_band.diph.dwObj = DIJOFS_X; dead_band.diph.dwHow = DIPH_BYOFFSET;

31. 31 Game_Init( ) // 10% will be used on both sides of the range +/- dead_band.dwData = 1000; // finally set the property lpdijoy->SetProperty(DIPROP_DEADZONE,&dead_band.diph); dead_band.diph.dwSize = sizeof(dead_band); dead_band.diph.dwHeaderSize = sizeof(dead_band.diph); dead_band.diph.dwObj = DIJOFS_Y; dead_band.diph.dwHow = DIPH_BYOFFSET; // 10% will be used on both sides of the range +/- dead_band.dwData = 1000; // finally set the property lpdijoy->SetProperty(DIPROP_DEADZONE,&dead_band.diph); // acquire the joystick if (lpdijoy->Acquire()!=DI_OK) return(0);

32. 32 Game_Shutdown( ) // release joystick lpdijoy->Unacquire(); lpdijoy->Release(); lpdi->Release(); // shutdonw directdraw DDraw_Shutdown();

33. 33 Game_Main( ) // get joystick data lpdijoy->Poll(); // this is needed for joysticks only lpdijoy->GetDeviceState(sizeof(DIJOYSTATE), (LPVOID)&joy_state); // lock the back buffer DDraw_Lock_Back_Surface(); // draw the background reactor image Draw_Bitmap(&playfield, back_buffer, back_lpitch, 0); // unlock the back buffer DDraw_Unlock_Back_Surface(); // is the player moving? blaster.x+=joy_state.lX; blaster.y+=joy_state.lY;

34. 34 Game_Main( ) // is player firing? if (joy_state.rgbButtons[0]) Start_Missile(); // display joystick and buttons 0-7 sprintf(buffer,"Joystick Stats: X-Axis=%d, Y-Axis=%d, buttons(%d,%d,%d,%d,%d,%d,%d,%d)", joy_state.lX,joy_state.lY, joy_state.rgbButtons[0], joy_state.rgbButtons[1], joy_state.rgbButtons[2], joy_state.rgbButtons[3], joy_state.rgbButtons[4], joy_state.rgbButtons[5], joy_state.rgbButtons[6], joy_state.rgbButtons[7]); // print out name of joystick sprintf(buffer, "Joystick Name & Vendor: %s",joyname); Draw_Text_GDI(buffer,0,SCREEN_HEIGHT-40,RGB(255,255,50),lpddsback);

35. 35 Force Feedback Gameplay can influence input device by producing some resistive force Requires bi-directional communication between interaction device and computer (e.g. joysticks, steering wheels, yokes, etc.) Examples –Engine-hum (sine-wave) –Machine gun (square-wave vibrations)

36. 36 Force Feedback Lags > 25ms between visual event and feedback are noticable Designers need to anticipate effects of conditions (e.g. wind) and surface texture (e.g. bumps and grit) in planning game play Can be mesmerizing to players (adds to realism) LaMothe has example, cant run on my laptop (my FFB device is not USB)