Quickstart

The algorithm is designed for 2.5 dimensional games where obstacles are mapped to rectangular cells. Your smallest collidable object will occupy one cell. Movement is 4-directional for quick implementation but is easily converted to n-directional by expanding on moveStack_neighbours(). The purpose of this format is to allow us to respect the orthogonal (graphic) representation of the game while facilitating movement and dynamic pathfinding on different planes.

With get_moveStack(), we can assign a stack of waypoints to a given instance. We only need to figure out:

• When we want to read in the next waypoint
• How we're getting to the x and y stored in that waypoint

Once we're ready to read in a waypoint, simply pop the moveStack assigned to a given instance:

• waypoint = ds_stack_pop(moveStack)

Then access the x and y keys:

• xNext = waypoint[? moveX]
• yNext = waypoint[? moveY]

get_moveStack()

Initializes the pathfinding algorithm and assigns a stack of waypoints to a given instance.

Arguments:

• col (int)

  • The relative starting column of the instance we're moving. col = 0 would mean starting in the leftmost column of our moving grid. We can use get_grid(instance.x) to quickly get a relative column.

• row (int)

  • The relative starting row of the instance we're moving. row = 0 would mean starting in the topmost row of our moving grid. We can use get_grid(instance.y) to quickly get a relative row.

• colGoto (int)

  • The relative row of the distination. colGoto = 0 would be the leftmost column considered by the pathfinder. We can use get_grid(x) from this library to convert any x to a relative column. For example, we can easily assign a column with the mouse simply using get_grid(mouse_x) to figure out the relative column for us.

• rowGoto (int)

  • The relative row of the distination. rowGoto = 0 would be the topmost row considered by the pathfinder. We can use get_grid(y) from this library to convert any y to a relative row. For example, we can easily assign a row for following another instance simply using get_grid(ally.y) to figure out the relative row for us.

• grid (mp_grid)

  • ID of some mp_grid

• grid_originX = absolute x coordinate of origin of the grid

• grid_originY = absolute y coordinate of origin of the grid

  • Allows for dynamic pathfinding and optimizing memory

• grid_cellWidth = width of columns in the grid

• grid_cellHeight = height of rows in the grid