function getAnyGamepad() {
	// buttons
	for (var i = 0; i < MAPPING_BUTTONS.length; i++) {
		var key = MAPPING_BUTTONS[i];
		ANY_GAMEPADS.btnp[key] = btnp[key] || GAMEPADS[0].btnp[key] || GAMEPADS[1].btnp[key] || GAMEPADS[2].btnp[key] || GAMEPADS[3].btnp[key];
		ANY_GAMEPADS.btnr[key] = btnr[key] || GAMEPADS[0].btnr[key] || GAMEPADS[1].btnr[key] || GAMEPADS[2].btnr[key] || GAMEPADS[3].btnr[key];
		ANY_GAMEPADS.btn[key]  = btn[key]  || GAMEPADS[0].btn[key]  || GAMEPADS[1].btn[key]  || GAMEPADS[2].btn[key]  || GAMEPADS[3].btn[key];
	}

	// forbid up and left or up and down to be set at the same time
	if (ANY_GAMEPADS.btn.up    && ANY_GAMEPADS.btn.down) ANY_GAMEPADS.btn.down = false;
	if (ANY_GAMEPADS.btn.right && ANY_GAMEPADS.btn.left) ANY_GAMEPADS.btn.left = false;

	// TODO: axes and triggers

	return ANY_GAMEPADS;
}
Merge gamepad's left analog stick state (x, y axis) with Dpad.

@param {number} deadzone - stick minimum value before considering it as pressed