fencer/src/input.c

116 lines
2.9 KiB
C

#include "input.h"
#include "debug.h"
#include <stdint.h>
typedef struct InputAction {
const uint8_t* positive;
const uint8_t* negative;
int last;
InputActionDelegate delegate;
} InputAction;
static InputAction* _actions = NULL;
static size_t _actions_len = 0;
static size_t _actions_cap = 0;
static const uint8_t* _keys;
void input_init() {
_actions = malloc(8 * sizeof(InputAction));
if(_actions == NULL) {
LOG_ERROR("Failed to allocate memory for input actions array");
return;
}
_actions_cap = 8;
_keys = SDL_GetKeyboardState(NULL);
}
void input_clean() {
free(_actions);
_actions_len = 0;
_actions_cap = 0;
}
static
void _key_changed_event(SDL_Event evt) {
const uint8_t* keyptr = _keys + evt.key.keysym.scancode;
for(InputAction* action = _actions; action < _actions + _actions_len; ++action) {
if(keyptr == action->positive || keyptr == action->negative) {
int val = *action->positive - *action->negative;
if(val != action->last) {
action->last = val;
action->delegate(val);
}
}
}
}
void input_handle_event(SDL_Event event) {
switch(event.type) {
default:return;
case SDL_KEYDOWN:
case SDL_KEYUP:
_key_changed_event(event);
break;
}
}
static
void _resize_actions_if_needed(size_t needed_amount) {
if(_actions_cap > needed_amount)
return;
size_t next_amount = _actions_cap;
while(next_amount <= needed_amount) {
next_amount *= 2;
}
InputAction* new = realloc(_actions, next_amount);
if(new == NULL) {
LOG_ERROR("Failed to allocate enough space for adding a new input actions");
return;
}
_actions = new;
_actions_cap = next_amount;
}
void input_add_axis_action(SDL_Scancode negative, SDL_Scancode positive, InputActionDelegate delegate) {
_resize_actions_if_needed(_actions_len + 1);
_actions[_actions_len] = (InputAction){
.negative = _keys + negative,
.positive = _keys + positive,
.delegate = delegate
};
++_actions_len;
}
void input_add_key_action(SDL_Scancode key, InputActionDelegate delegate) {
_resize_actions_if_needed(_actions_len + 1);
_actions[_actions_len] = (InputAction) {
.negative = _keys + SDL_SCANCODE_UNKNOWN,
.positive = _keys + key,
.delegate = delegate
};
++_actions_len;
}
static
void _remove_element(InputAction* item) {
InputAction* next = item + 1;
if(next < _actions + _actions_len) {
memmove(item, next, (_actions + _actions_len) - next);
}
--_actions_len;
}
void input_remove_actions(InputActionDelegate delegate) {
for(InputAction* action = _actions; action < _actions + _actions_len; ++action) {
if(action->delegate == delegate) {
_remove_element(action);
}
}
}