-- Game of life routine macro, before nested 'if' and 'while' were implemented. Made in August 2020.

local script = [[

; String-substitute frame and rState counters with more helpful names.
alias xx               fa
alias yy               fb
alias neighbors        fc
alias this_cell        fd


*    game_of_life
    
    ; Sets up the actor: finds the zone shape and copies dimensions to data table.
    init_zone_info
    
    goLabel g_loop
    
    
    ; Idle loop. Wait 1/4th of a second, then execute one GoL cycle.
    .g_loop
64  noop

    ; The entry-point for executing a cycle.
    .g_exec
    set xx = get_zone_x
    set yy = get_zone_y
    goLabel g_count_neighbors

    ; Count this cell's neighbors.
    .g_count_neighbors
    set neighbors = 0
    
    ; Top-left
    set xx - 1
    set yy - 1
    position_self & set this_cell = resting_cell
    if this_cell == get_cell_on set neighbors + 1
    
    ; Top
    set xx + 1
    position_self & set this_cell = resting_cell
    if this_cell == get_cell_on set neighbors + 1
    
    ; Top-right
    set xx + 1
    position_self & set this_cell = resting_cell
    if this_cell == get_cell_on set neighbors + 1
    
    ; Left
    set yy + 1
    set xx - 2
    
    position_self & set this_cell = resting_cell
    if this_cell == get_cell_on set neighbors + 1
    
    ; Right (skip the middle)
    set xx + 2
    position_self & set this_cell = resting_cell
    if this_cell == get_cell_on set neighbors + 1
    
    ; Bottom-left
    set yy + 1
    set xx - 2
    
    position_self & set this_cell = resting_cell
    if this_cell == get_cell_on set neighbors + 1
    
    ; Bottom
    set xx + 1
    position_self & set this_cell = resting_cell
    if this_cell == get_cell_on set neighbors + 1

    ; Bottom-right
    set xx + 1
    position_self & set this_cell = resting_cell
    if this_cell == get_cell_on set neighbors + 1

    ; Return to center
    set xx - 1
    set yy - 1
    
    ; Write neighbor count to an array in the owning actor.
    set_neighbor_count
    
    ; Go to the next cell
    set xx + 1
    if xx >= get_zone_xw goLabel g_new_row
    goLabel g_count_neighbors
    
    .g_new_row
    set xx = get_zone_x
    set yy + 1
    if yy >= get_zone_yh goLabel g_count_done
    goLabel g_count_neighbors
    
    
    .g_count_done
    set xx = get_zone_x
    set yy = get_zone_y
    goLabel g_update
    
    ; Start updating the cells based on neighbor information stored in the owning actor
    .g_update
1   noop                                                  ; Idle for one tick to make the update roll out gradually
    position_self & set this_cell = resting_cell          ; Position actor based on xx and yy counters. Get tile value from resting spot.
    get_neighbor_count                                    ; Read in the neighbor count for this cell coordinate.
    if this_cell == get_cell_on goLabel g_update_live
    goLabel g_update_dead
    
    .g_update_live
    if neighbors < 2 goLabel setDead
    if neighbors > 3 goLabel setDead
    goLabel g_update_continue
    
    .g_update_dead
    if neighbors == 3 goLabel setLive
    goLabel g_update_continue
    
    .setDead
    set resting_cell = get_cell_off
    goLabel g_update_continue
    
    .setLive
    set resting_cell = get_cell_on
    goLabel g_update_continue
    
    .g_update_continue
    set xx + 1
    if xx >= get_zone_xw goLabel g_update_new_row
    goLabel g_update
    
    .g_update_new_row
    set xx = get_zone_x
    set yy + 1
    if yy >= get_zone_yh goLabel g_loop        ; Done execution, go back to idling.
    goLabel g_update
]]