State Polling

Frame-based polling for keyboard input More...

Functions
kbd_state_t *	kbd_get_state (maple_device_t *device)
	Retrieves the keyboard state from a maple device.

Detailed Description

Frame-based polling for keyboard input

One method of checking for key input is to simply poll kbd_state_t::matrix for the desired key states each frame.

First, lets grab a pointer to the kbd_state_t:

kbd_state_t *kbd = kbd_get_state(device);

Then let's "move" every frame an arrow key is held down:

if(kbd->matrix[KBD_KEY_LEFT] == KEY_STATE_PRESSED)
    printf("Moving left!\n");
if(kbd->matrix[KBD_KEY_RIGHT] == KEY_STATE_PRESSED)
    printf("Moving right!\n");
if(kbd->matrix[KBD_KEY_UP] == KEY_STATE_PRESSED)
    printf("Moving up!\n");
if(kbd->matrix[KBD_KEY_DOWN] == KEY_STATE_PRESSED)
    printf("Moving down!\n");

Finally, let's charge an "attack" incrementing the charge for each frame that the key is held and resetting when the key is released:

if(kbd->matrix[KBD_KEY_SPACE] == KEY_STATE_PRESSED)
    charge++;
if(kbd->matrix[KBD_KEY_SPACE] == KEY_STATE_WAS_PRESSED) {
    printf("Releasing a charged attack of %i!\n", charge);
    charge = 0;
}

Function Documentation

kbd_get_state()

kbd_state_t * kbd_get_state

(

maple_device_t *

device

)

Retrieves the keyboard state from a maple device.

Accessor method for safely retrieving a kbd_state_t from a maple_device_t of a MAPLE_FUNC_KEYBOARD type. This function also checks for whether the given device is actually a keyboard and for whether it is currently valid.

Parameters

device

Handle corresponding to a MAPLE_FUNC_KEYBOARD device.

Return values

kbd_state_t*	A pointer to the internal keyboard state on success.
NULL	On failure.