# autoTiling 8 bit with multiple terrain types (open)

#### jorex

##### Member
I'm sure it's something dumb and easy but I have been racking my brain for days over this. essentially, these lines of code return a boolean that gets multiplied and returns an index to be converted into an image_index and helping me autotile while running my game. problem is that it only works when there is one terrain type so I put checks in that if the boolean returns true that it would take the id of the nearby tiles and check if they are the same terrain type(blockType) and if they aren't then I'd set the boolean to negative. I figured that would work but it seems to completely throw off the math and I'm not sure why that is.

size = sprite_width;

//Directional Check, including corners, returns Boolean
north_tile = place_meeting(x,y-size,obj_stamp);
south_tile = place_meeting(x,y+size,obj_stamp);
west_tile = place_meeting(x-size,y,obj_stamp);
east_tile = place_meeting(x+size,y,obj_stamp);
north_west_tile = place_meeting(x-size,y-size,obj_stamp) && west_tile && north_tile;
north_east_tile = place_meeting(x+size,y-size,obj_stamp) && north_tile && east_tile;
south_west_tile = place_meeting(x-size,y+size,obj_stamp) && south_tile && west_tile;
south_east_tile = place_meeting(x+size,y+size,obj_stamp) && south_tile && east_tile;

if (north_tile = 1)
{
north_tileid = instance_position(x,y-size,obj_stamp);
if (north_tileid != noone)
{
if (blockType != north_tileid.blockType)
{
north_tile = false;
north_tileid = 0;
}
}
}
if (south_tile = 1)
{
south_tileid = instance_position(x,y+size,obj_stamp);
if (south_tileid != noone)
{
if (blockType != south_tileid.blockType)
{
south_tile = false;
south_tileid = 0;
}
}
}
if (west_tile = 1)
{
west_tileid = instance_position(x-size,y,obj_stamp);
if (west_tileid != noone)
{
if (blockType != west_tileid.blockType)
{
west_tile = false;
west_tileid = 0;
}
}
}
if (east_tile = 1)
{
east_tileid = instance_position(x+size,y,obj_stamp);
if (east_tileid != noone)
{
if (blockType != east_tileid.blockType)
{
east_tile = false;
east_tileid = 0;
}
}
}
if (north_west_tile = 1)
{
north_west_tileid = instance_position(x-size,y-size,obj_stamp);
if (north_west_tileid != noone)
{
if (blockType != north_west_tileid.blockType)
{
north_west_tile = false && north_tile && west_tile;
north_west_tileid = 0;
}
}
}
if (north_east_tile = 1)
{
north_east_tileid = instance_position(x+size,y-size,obj_stamp);
if (north_east_tileid != noone)
{
if (blockType != north_east_tileid.blockType)
{
north_east_tile = false && north_tile && east_tile;
north_east_tileid = 0;
}
}
}
if (south_west_tile = 1)
{
south_west_tileid = instance_position(x-size,y+size,obj_stamp);
if (south_west_tileid != noone)
{
if (blockType != south_west_tileid.blockType)
{
south_west_tile = false && south_tile && west_tile;
south_west_tileid = 0;
}
}
}
if (south_east_tile = 1)
{
south_east_tileid = instance_position(x+size,y+size,obj_stamp);
if (south_east_tileid != noone)
{
if (blockType != south_east_tileid.blockType)
{
south_east_tile = false && south_tile && east_tile;
south_east_tileid = 0;
}
}
}

//8 bit Bitmasking calculation using Directional check booleans values
index = north_west_tile + 2*north_tile + 4*north_east_tile + 8*west_tile + 16*east_tile + 32*south_west_tile + 64*south_tile + 128*south_east_tile;

// tile image_index
// "254": 45, "90": 22, "22": 7,
//"0": 47, "10": 3, "2": 1, "94": 24,
//"120": 29, "11": 4, "208": 34, "107": 28,
//"82": 19, "216": 37, "86": 20, "223": 41,
//"214": 36, "104": 26,
//"222": 40, "74": 16, "18": 6, "8": 2,
//"248": 42, "255": 46, "127": 33, "123": 31,
//"66": 14, "16": 5, "219": 39, "75": 17, "80": 18,
//"122": 30, "30": 11, "126": 32, "31": 12,
//"250": 43, "88": 21, "64": 13, "95": 25,
//"251": 44, "91": 23, "24": 8, "27": 10, "218": 38,
//"72": 15, "106": 27, "26": 9, "210": 35

if (index = 254)
{
image_index = 45;
}
if (index = 90)
{
image_index = 22;
}
if (index = 22)
{
image_index = 7;
}
if (index = 0)
{
image_index = 47;
}
if (index = 10)
{
image_index = 3;
}
if (index = 2)
{
image_index = 1;
}
if (index = 94)
{
image_index = 24;
}
if (index = 120)
{
image_index = 29;
}
if (index = 11)
{
image_index = 4;
}
if (index = 208)
{
image_index = 34;
}
if (index = 107)
{
image_index = 28;
}
if (index = 82)
{
image_index = 19;
}
if (index = 216)
{
image_index = 37;
}
if (index = 86)
{
image_index = 20;
}
if (index = 223)
{
image_index = 41;
}
if (index = 214)
{
image_index = 36;
}
if (index = 104)
{
image_index = 26;
}
if (index = 222)
{
image_index = 40;
}
if (index = 74)
{
image_index = 16;
}
if (index = 18)
{
image_index = 6;
}
if (index = 8)
{
image_index = 2;
}
if (index = 248)
{
image_index = 42;
}
if (index = 255)
{
image_index = 46;
}
if (index = 127)
{
image_index = 33;
}
if (index = 123)
{
image_index = 31;
}
if (index = 66)
{
image_index = 14;
}
if (index = 16)
{
image_index = 5;
}
if (index = 219)
{
image_index = 39;
}
if (index = 75)
{
image_index = 17;
}
if (index = 80)
{
image_index = 18;
}
if (index = 122)
{
image_index = 30;
}
if (index = 30)
{
image_index = 11;
}
if (index = 126)
{
image_index = 32;
}
if (index = 31)
{
image_index = 12;
}
if (index = 250)
{
image_index = 43;
}
if (index = 88)
{
image_index = 21;
}
if (index = 64)
{
image_index = 13;
}
if (index = 95)
{
image_index = 25;
}
if (index = 251)
{
image_index = 44;
}
if (index = 91)
{
image_index = 23;
}
if (index = 24)
{
image_index = 8;
}
if (index = 27)
{
image_index = 10;
}
if (index = 218)
{
image_index = 38;
}
if (index = 72)
{
image_index = 15;
}
if (index = 106)
{
image_index = 27;
}
if (index = 26)
{
image_index = 9;
}
if (index = 210)
{
image_index = 35;
}

#### Nidoking

##### Member
Two things I would do, at a minimum: Turn the giant collection of ifs into a switch block, and organize them in any way. Numeric order of the inputs is my recommendation. Then you can see things like missing cases that might cause you problems.

The next thing I would do is throw out the switch statement and put all of those image_index values into an array, and make sure you've filled all 256 possible slots. Then you can turn the whole switch into one array access.

Also, I just spotted this: `south_east_tile = false && south_tile && east_tile; ` That's a lot of work to say south_east_tile = false;