tilemap_set_mask not working?

[KMVegas]

Hey, all. I'm trying to learn bitmasking with tile layers. It's taken me awhile to grasp it, but at this point, it seems pretty straightforward. I followed an old post from 2016 to start setting things up, but I'm having an issue. When I go back and check the tile index after setting a bit, the index comes back NOT ignoring the bit I set. Let's say index is 1, then I set a bit, and suddenly the index is 33. The post from 2016 mentioned a bug but Mike Daily said it was fixed internally and that was over 3 years ago. Is it still broken?

Single object in a room with tiles, from a 4x4 tile set, so possibility of indices 0 - 15.

Thanks for any help!

Create Event

// get the tilemap
tmap=layer_tilemap_get_id("TL_Test");

// set the mask
var _mask = tile_rotate | tile_mirror | tile_flip | 15;

//tilemap_set_mask(tmap, _mask);
tilemap_set_global_mask(_mask);

Step Event

/// @desc Set bit / get index

var _tdata,_tdatanew,_tindex;

#region left click to see tile index

if(mouse_check_button_pressed(mb_left)){

    // get data from clicked tile
    _tdata=tilemap_get_at_pixel(tmap,mouse_x,mouse_y);
   
    // exit on void tile
    if(_tdata==0){
        show_message("Empty space!");
        exit;
    }
   
    // get index in case a property has been changed
    _tindex=tile_get_index(_tdata);
   
    // Show the index
    show_message("Tile index: "+string(_tindex));
   
}#endregion

#region right click to set bit 6

if(mouse_check_button_pressed(mb_right)){

    // get data from clicked tile
    _tdata=tilemap_get_at_pixel(tmap,mouse_x,mouse_y);
   
    // exit on void tile
    if(_tdata==0){
        show_message("Empty space!");
        exit;
    }
   
    // set the sixth bit
    _tdatanew = _tdata | 32;
   
    // show tile data
    show_message("Tile data blob was: "+string(_tdata)
        +", and is now: "+string(_tdatanew));
   
    // place the modified tile
    tilemap_set_at_pixel(tmap,_tdatanew,mouse_x,mouse_y);
   
}#endregion

 

[Nocturne]

Your code seems okay, so I'd suggest filing a bug report with YYG and please supply a link to download an example that shows the issue.