ddmyx/objects/oInput/Step_0.gml

_jump_p = kcp("Z") || kcp("K");
_jump_r = kcr("Z") || kcp("K");
_left = kc("A") || kc(vk_left);
_right = kc("D") || kc(vk_right);
_up = kc("W") || kc(vk_up);
_down = kc("S") || kc(vk_down);
_dash = kcp("C") || kcp("L");
_attack = kcp("X") || kcp("J");

if _jump_p
    jump_buffer_timer = jump_buffer_max;
	
if jump_buffer_timer > 0
    jump_buffer_timer--;