Planet Demo - Player Step Event Code

if (!isInAir && oInputSystem.wasJumpPressed) {
    isInAir = true;
    verticalSpeed -= JUMP_INITIAL_VERTICAL_SPEED;
    audio_play_sound(sndJump, 1, false);
}

verticalSpeed += MY_GRAVITY;

var fallDirection = point_direction(x, y, oPlanet.x, oPlanet.y);

var isWalking = false;

if (oInputSystem.isLeftPressed) {
    isFacingRight = false;
    isWalking = true;
    x += lengthdir_x(HORIZONTAL_SPEED_MAGNITUDE, fallDirection - 90);
    y += lengthdir_y(HORIZONTAL_SPEED_MAGNITUDE, fallDirection - 90);
}

if (oInputSystem.isRightPressed) {
    isFacingRight = true;
    isWalking = true;
    x += lengthdir_x(HORIZONTAL_SPEED_MAGNITUDE, fallDirection + 90);
    y += lengthdir_y(HORIZONTAL_SPEED_MAGNITUDE, fallDirection + 90);
}

if (!isInAir && isWalking) {
    sprite_index = sPlayerWalking;
} else if (isInAir && verticalSpeed <= 0) {
    sprite_index = sPlayerJumping;
} else if (isInAir && verticalSpeed > 0) {
    sprite_index = sPlayerFalling;
} else {
    sprite_index = sPlayerStanding;
}

image_angle = fallDirection + 90;
if (isFacingRight) {
    image_xscale = 1;
} else {
    image_xscale = -1;
}

var newDeltaXFromFalling = lengthdir_x(verticalSpeed, fallDirection);
var newDeltaYFromFalling = lengthdir_y(verticalSpeed, fallDirection);
var newX = x + newDeltaXFromFalling;
var newY = y + newDeltaYFromFalling;
if (place_meeting(newX, newY, oPlanet)) {
    while (!place_meeting(x, y, oPlanet)) {
        x += lengthdir_x(0.5, fallDirection);
        y += lengthdir_y(0.5, fallDirection);
    }

    verticalSpeed = 0;
    isInAir = false;
} else {
    x = newX;
    y = newY;
}