// Create
x = room_width / 2;
y = 3 * room_height / 4;
viewStep = .2;
maxViewStep = 2;
imageIndexStep = 1;
acceleration = .5;
deceleration = .25;

// Step
var h, v;
h = keyboard_check(ord("D")) - keyboard_check(ord("A"));
v = keyboard_check(ord("S")) - keyboard_check(ord("W"));
hspeed = min(max(hspeed + acceleration * h - deceleration * sign(hspeed) * (h == 0), - 4), 4);
vspeed = min(max(vspeed + acceleration * v - deceleration * sign(vspeed) * (v == 0), - 4), 4);
view_angle[0] = min(max(view_angle[0] - viewStep * (h + sign(view_angle[0]) * (h == 0)), - maxViewStep), maxViewStep);
image_angle = (imageIndexStep / viewStep) * view_angle[0];