Code for Tile Collisions

I Spillerens Create Event:
tilemap = layer_tilemap_get_id("CollisionMap")

I Step event:
var bbox_side

// Horizontal tile colission check
if (hsp > 0) bbox_side = bbox_right else bbox_side = bbox_left
if  (tilemap_get_at_pixel(tilemap, bbox_side + hsp, bbox_top + 1) != 0) ||
    (tilemap_get_at_pixel(tilemap, bbox_side + hsp, bbox_bottom - 1) != 0) ||
    (tilemap_get_at_pixel(tilemap, bbox_side + hsp, y) != 0) {
    if (hsp > 0) x = x - x % 128 + 127 - (bbox_right - x)
    else x = x - x % 128 - (bbox_left - x)
    hsp = 0
}
x += hsp

// Vertical tile colission check
vsp += grav;
if (vsp > 0) bbox_side = bbox_bottom else bbox_side = bbox_top
if  (tilemap_get_at_pixel(tilemap, bbox_left + 1, bbox_side + vsp) != 0) ||
    (tilemap_get_at_pixel(tilemap, bbox_right - 1, bbox_side + vsp) != 0) ||
    (tilemap_get_at_pixel(tilemap, x, bbox_side + vsp) != 0) {
    if (vsp > 0) y =  y - y % 128 + 127 - (bbox_bottom - y)
    else y = y - y % 128 - (bbox_top - y)
    vsp = 0
}
y += vsp