Ren'Py Grid Movement Example

init:
    python:

        # Constants

        MAP_SIZE_X = 4
        MAP_SIZE_Y = 4

        BLOCK_TYPE_WALL     = 0x0
        BLOCK_TYPE_FLOOR    = 0x1
        BLOCK_TYPE_TRAP     = 0x2

        ENTITY_TYPE_HEALTH  = 0x0
        ENTITY_TYPE_KEY     = 0x1
        ENTITY_TYPE_BOMB    = 0x2

        # Map

        mapgrid = [
            [0x1F, 0x1F, 0x1F, 0x1F], # - X
            [0x1F, 0x0F, 0x0F, 0x1F], # The 4x4 block in the middle is a wall
            [0x1F, 0x0F, 0x0F, 0x1F], # If you try and walk here, nothing will happen
            [0x1F, 0x1F, 0x1F, 0x1F]
            # |
            # Y
        ]

        def MapGrid_BlockType(x, y):
            return (mapgrid[x][y] >> 4) & 0xF

        def MapGrid_Entity(x, y):
            return mapgrid[x][y] & 0xF

        # Player

        ply_Name = "Bob"
        ply_PosX = 3
        ply_PosY = 3


label start:

    jump MovementMenu

    return


label MovementMenu:
    menu:
        "Move Forward":
            jump MoveForward

        "Move Backward":
            jump MoveBackward

        "Move Right":
            jump MoveRight

        "Move Left":
            jump MoveLeft


label MoveForward:
    python:
        tmp_x = ply_PosX
        tmp_y = ply_PosY - 1

        if tmp_y > -1:
            block = MapGrid_BlockType(tmp_x, tmp_y)
            entity = MapGrid_Entity(tmp_x, tmp_y)

            if block == BLOCK_TYPE_FLOOR:
                ply_PosY = tmp_y

    jump FinishMove


label MoveBackward:
    python:

        tmp_x = ply_PosX
        tmp_y = ply_PosY + 1

        if tmp_y < MAP_SIZE_X:
            block = MapGrid_BlockType(tmp_x, tmp_y)
            entity = MapGrid_Entity(tmp_x, tmp_y)

            if block == BLOCK_TYPE_FLOOR:
                ply_PosY = tmp_y

    jump FinishMove


label MoveRight:
    python:

        tmp_x = ply_PosX + 1
        tmp_y = ply_PosY

        if tmp_x < MAP_SIZE_X:
            block = MapGrid_BlockType(tmp_x, tmp_y)
            entity = MapGrid_Entity(tmp_x, tmp_y)

            if block == BLOCK_TYPE_FLOOR:
                ply_PosX = tmp_x

    jump FinishMove


label MoveLeft:
    python:

        tmp_x = ply_PosX - 1
        tmp_y = ply_PosY

        if tmp_x > -1:
            block = MapGrid_BlockType(tmp_x, tmp_y)
            entity = MapGrid_Entity(tmp_x, tmp_y)

            if block == BLOCK_TYPE_FLOOR:
                ply_PosX = tmp_x

    jump FinishMove


label FinishMove:

    "You are at grid: X = %(ply_PosX)d Y = %(ply_PosY)d"

    jump MovementMenu