ddmyx/objects/oInput/Step_0.gml

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

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