Step 2: Defining the Action Map

Next, each game action should be assigned to at least one virtual control or device object. These controls are defined as action-mapping constants, and they are defined by genre and subgenre. In the case of the ActionMapper Sample, the best choice is the Space Combat subgenre of the flight games genre. This subgenre makes the following constants available.

Priority 1 Controls

DIAXIS_SPACESIM_LATERAL
DIAXIS_SPACESIM_MOVE
DIAXIS_SPACESIM_THROTTLE
DIBUTTON_SPACESIM_FIRE
DIBUTTON_SPACESIM_MENU
DIBUTTON_SPACESIM_TARGET
DIBUTTON_SPACESIM_WEAPONS

Priority 2 Controls

DIAXIS_SPACESIM_CLIMB
DIAXIS_SPACESIM_ROTATE
DIBUTTON_SPACESIM_BACKWARD_LINK
DIBUTTON_SPACESIM_DEVICE DIBUTTON_SPACESIM_DISPLAY
DIBUTTON_SPACESIM_FASTER_LINK
DIBUTTON_SPACESIM_FIRESECONDARY
DIBUTTON_SPACESIM_FORWARD_LINK
DIBUTTON_SPACESIM_GEAR
DIBUTTON_SPACESIM_GLANCE_DOWN_LINK
DIBUTTON_SPACESIM_GLANCE_LEFT_LINK
DIBUTTON_SPACESIM_GLANCE_RIGHT_LINK
DIBUTTON_SPACESIM_GLANCE_UP_LINK
DIBUTTON_SPACESIM_LEFT_LINK DIBUTTON_SPACESIM_LOWER
DIBUTTON_SPACESIM_PAUSE DIBUTTON_SPACESIM_RAISE
DIBUTTON_SPACESIM_RIGHT_LINK
DIBUTTON_SPACESIM_SLOWER_LINK
DIBUTTON_SPACESIM_TURN_LEFT_LINK
DIBUTTON_SPACESIM_TURN_RIGHT_LINK
DIBUTTON_SPACESIM_VIEW
DIHATSWITCH_SPACESIM_GLANCE

Priority 1 controls are those controls that, at the minimum, should be mapped to a device object if possible. Priority 2 controls are less critical to basic game operation and may be mapped as needed.

Game actions are assigned to action-mapping constant controls in an array of DIACTION types. Each DIACTION type contains at least one game action, its associated action-mapping constant, any necessary flags, and a friendly name for the action. The remaining DIACTION members are not used at this point. The following code sample shows the array of DIACTION types defined in the ActionMapper Sample. Note that CInputMapper is a class used and defined by the ActionMapper sample to contain many of the standard action-mapping procedures. In this case it uses its own AddAction function to add each new DIACTION type to an array of them contained in a DIACTIONFORMAT type.

Dim m_mapper As New CInputMapper

With m_mapper
.AddAction INPUT_LEFTRIGHT_AXIS, DIAXIS_SPACESIM_LATERAL, 0, "Turn"
.AddAction INPUT_UPDOWN_AXIS, DIAXIS_SPACESIM_MOVE, 0, "Move"
.AddAction INPUT_FIREWEAPONS, DIBUTTON_SPACESIM_FIRE, 0, "Shoot"
.AddAction INPUT_ENABLESHIELD, DIBUTTON_SPACESIM_GEAR, 0, "Shield"
.AddAction INPUT_DISPLAYGAMEMENU,DIBUTTON_SPACESIM_DISPLAY,0,"Display"
.AddAction INPUT_QUITGAME, DIBUTTON_SPACESIM_MENU, 0, "Quit Game"

' Keyboard input mappings
.AddAction INPUT_FORWARDTHRUST, DIKEYBOARD_UP, 0, "Forward thrust"
.AddAction INPUT_REVERSETHRUST, DIKEYBOARD_DOWN, 0, "Reverse thrust"
.AddAction INPUT_FIREWEAPONS, DIKEYBOARD_F, 0, "Fire weapons"
.AddAction INPUT_ENABLESHIELD, DIKEYBOARD_S, 0, "Enable shields"
.AddAction INPUT_DISPLAYGAMEMENU, DIKEYBOARD_D, 0, "Display game menu"
.AddAction INPUT_QUITGAME, DIKEYBOARD_ESCAPE, 0, "Quit game"
.AddAction INPUT_TURNRIGHT, DIKEYBOARD_RIGHT, 0, "Right Turn"
.AddAction INPUT_TURNLEFT, DIKEYBOARD_LEFT, 0, "Left Turn"

' Mouse input mappings
.AddAction INPUT_LEFTRIGHT_AXIS, DIMOUSE_XAXIS, 0, "Turn"
.AddAction INPUT_UPDOWN_AXIS, DIMOUSE_YAXIS, 0, "Move"
.AddAction INPUT_FIREWEAPONS, DIMOUSE_BUTTON0, 0, "Fire weapons"
.AddAction INPUT_ENABLESHIELD, DIMOUSE_BUTTON1, 0, "Enable shields"
End With

The DIACTIONFORMAT type containing the array of DIACTION types will be used to find a device that can best be used with it. This is shown in Step 3: Mapping Actions to Devices.