convince/sway/key_state.c

#include <string.h>
#include <stdbool.h>
#include <ctype.h>

#include "key_state.h"

enum { KEY_STATE_MAX_LENGTH = 64 };

static keycode key_state_array[KEY_STATE_MAX_LENGTH];
static uint8_t key_state_length = 0;

static uint8_t find_key(keycode key)
{
	int i;
	for (i = 0; i < key_state_length; ++i)
	{
		if (key_state_array[i] == key)
		{
			break;
		}
	}
	return i;
}

bool check_key(keycode key)
{
	return find_key(key) < key_state_length;
}

void press_key(keycode key)
{
	// Check if key exists
	if (!check_key(key))
	{
		// Check that we dont exceed buffer length
		if (key_state_length < KEY_STATE_MAX_LENGTH) {
			key_state_array[key_state_length++] = key;
		}
	}
}

void release_key(keycode key)
{
	uint8_t index = find_key(key);
	if (index < key_state_length)
	{
		//shift it over and remove key
		memmove(&key_state_array[index],
				&key_state_array[index + 1],
				sizeof(*key_state_array) * (--key_state_length - index));
	}
}