diff --git a/src/reskit/cli/evaluator.rs b/src/reskit/cli/evaluator.rs
index 5b6f9c9..4d4c39a 100644
--- a/src/reskit/cli/evaluator.rs
+++ b/src/reskit/cli/evaluator.rs
@@ -1,6 +1,6 @@
 use std::{error::Error, fs::File, io::Write, path::Path, collections::HashMap};
 use clap::Parser;
-use crate::reskit::{tileset, soundtrack::{formats::dmf::DmfModule, engines::echo::engine::{EchoFormat, EchoArtifact}}, utility::print_good, level::{converter::get_tiled_tilemap, system::{get_tiles, get_code, get_tilemap, get_collision_map, get_objs, get_sprites}}, easing::get_cubic_bezier};
+use crate::reskit::{tileset, soundtrack::{formats::dmf::DmfModule, engines::echo::engine::{EchoFormat, EchoArtifact}}, utility::print_good, level::{converter::get_tiled_tilemap, system::{get_tiles, get_code, get_metatile_maps, get_collision_map, get_objs, get_sprites}}, easing::get_cubic_bezier};
 use super::settings::{Args, Tools, TileOutputFormat, TileOrder};
 
 pub fn run_command() -> Result<(), Box<dyn Error>> {
@@ -110,7 +110,7 @@ pub fn run_command() -> Result<(), Box<dyn Error>> {
             print_good( "exported palettes.pal" );
 
             let mut nametables_bin = File::create( format!( "{}nametables.map", output_directory ) )?;
-            nametables_bin.write_all( &get_tilemap( &tiled_file )? )?;
+            nametables_bin.write_all( &get_metatile_maps( &tiled_file )? )?;
             print_good( "exported nametables.map" );
 
             let mut nametables_bin = File::create( format!( "{}collision.lvc", output_directory ) )?;
diff --git a/src/reskit/level/converter.rs b/src/reskit/level/converter.rs
index 81eb24e..9ff8f3c 100644
--- a/src/reskit/level/converter.rs
+++ b/src/reskit/level/converter.rs
@@ -1,4 +1,4 @@
-use std::{error::Error, fs::read_to_string, path::Path, borrow::Cow};
+use std::{error::Error, fs::read_to_string, path::Path, borrow::Cow, collections::HashSet};
 use euclid::default::Rect;
 use image::{DynamicImage, GenericImageView};
 use linked_hash_map::LinkedHashMap;
@@ -8,6 +8,7 @@ use crate::reskit::{utility::print_warning, cli::settings::TileOrder};
 #[derive(Debug)]
 pub struct TiledTilemap {
     pub tileset: Vec<TiledTileset>,
+    pub metatiles: Vec<Metatile>,
     pub layers: Vec<Layer>,
     pub objects: Vec<Object>,
     pub collision: Vec<Rect<u16>>,
@@ -15,6 +16,15 @@ pub struct TiledTilemap {
     pub height: usize
 }
 
+#[derive(Debug, PartialEq)]
+pub struct Metatile {
+    pub id: u32,
+    pub source: String,
+    pub width: u16,
+    pub height: u16,
+    pub tiles: Vec<u32>
+}
+
 #[derive(Debug)]
 pub struct Object {
     pub id: String,
@@ -32,7 +42,7 @@ pub struct SpriteMetadata {
 
 #[derive(Debug)]
 pub struct TiledTileset {
-    pub first_gid: usize,
+    pub source: String,
     pub image: DynamicImage,
     pub palettes: Vec<Option<u8>>,
     pub tile_order: TileOrder,
@@ -47,7 +57,7 @@ pub enum SystemPlane {
 
 #[derive(Debug)]
 pub enum Layer {
-    Tile {
+    Metatile {
         system_plane: SystemPlane,
         tiles: Vec<u32>
     }
@@ -95,11 +105,11 @@ fn get_layer( layer: Node, map_width: usize, map_height: usize ) -> Result<Optio
             let tiles: Vec<u32> = data.into_iter().map( | string | Ok( string.trim().parse()? ) ).collect::< Result< Vec<u32>, Box<dyn Error> > >()?;
 
             match layer_type.to_lowercase().as_str() {
-                "a" => Ok( Some( Layer::Tile {
+                "a" => Ok( Some( Layer::Metatile {
                     system_plane: SystemPlane::MdPlaneA,
                     tiles
                 } ) ),
-                "b" => Ok( Some( Layer::Tile {
+                "b" => Ok( Some( Layer::Metatile {
                     system_plane: SystemPlane::MdPlaneB,
                     tiles
                 } ) ),
@@ -118,11 +128,51 @@ fn get_layer( layer: Node, map_width: usize, map_height: usize ) -> Result<Optio
     }
 }
 
-fn get_tiles( tileset: Node, first_gid: usize, working_directory: &str ) -> Result<TiledTileset, Box<dyn Error>> {
-    // Get the image for the tileset
+fn get_tiles( tileset: Node, seen_sources: &mut HashSet<String>, working_directory: &str ) -> Result<Option<TiledTileset>, Box<dyn Error>> {
+    // Get the image for the tileset and its source
     let image = tileset.descendants().find( | node | node.tag_name() == "image".into() ).ok_or( "invalid file: no image object" )?;
-    let image_path = format!( "{}/{}", working_directory, image.attribute( "source" ).ok_or( "invalid file: no source attribute on image" )? );
-    let image = image::open( image_path )?;
+    let source = image.attribute( "source" ).ok_or( "invalid file: no source attribute on image" )?.to_string();
+
+    // If the file path ends in .tmx, it's a metatile definition. We need to hop to the .tmx file in source, then redefine layer
+    // to the single tileset in that metatile .tmx.
+    let full_path = format!( "{}/{}", working_directory, source );
+    let formatted_path = Path::new( &full_path );
+    if let Some( extension ) = formatted_path.extension() {
+        let extension = extension.to_string_lossy();
+        if extension == "tmx" {
+            // Case where source is a nested tileset. Open the .tmx file
+            let file = read_to_string( full_path.clone() )?;
+            let tmx_document = roxmltree::Document::parse( &file )?;
+
+            // Obtain the single (first) <tileset>
+            let tileset = tmx_document.descendants().find( | node | node.tag_name() == "tileset".into() ).ok_or( "invalid file: metatile has no tileset" )?;
+            let tileset_source = tileset.attribute( "source" ).ok_or( "invalid file: metatile tileset has no source" )?.to_string();
+
+            // tileset_source should already point to the _actual_ source we need. Was this tileset source already seen? If so, bail
+            if seen_sources.contains( &tileset_source ) {
+                return Ok( None )
+            } else {
+                seen_sources.insert( tileset_source.clone() );
+            }
+
+            // Load nested tileset into roxmltree document
+            let file = read_to_string( format!( "{}/{}", working_directory, tileset_source ) )?;
+            let nested_tileset = roxmltree::Document::parse( &file )?;
+            let tileset = nested_tileset.descendants().find( | node | node.tag_name() == "tileset".into() ).ok_or( "invalid file: metatile tileset has no tileset" )?;
+
+            // Return nested tileset from tmx file
+            let result = get_tiles( tileset, seen_sources, working_directory )?;
+            if let Some( mut result ) = result {
+                result.source = tileset_source.to_owned();
+                return Ok( Some( result ) )
+            }
+
+            return Ok( result )
+        }
+    }
+
+    // Case where source is an actual image
+    let image = image::open( full_path )?;
 
     // Image must be a multiple of 8 (--system md)
     if image.width() % 8 != 0 { return Err( "invalid file: tileset width not multiple of 8" )? }
@@ -206,7 +256,56 @@ fn get_tiles( tileset: Node, first_gid: usize, working_directory: &str ) -> Resu
         TileOrder::Tile
     };
 
-    Ok( TiledTileset { first_gid, image, palettes, tile_order, sprite_metadata } )
+    Ok( Some( TiledTileset { source: format!( "" ), image, palettes, tile_order, sprite_metadata } ) )
+}
+
+pub fn get_metatile( id: u32, tileset: Node, working_directory: &str ) -> Result<Option<Metatile>, Box<dyn Error>> {
+    // Get the image for the tileset and its source
+    let image = tileset.descendants().find( | node | node.tag_name() == "image".into() ).ok_or( "invalid file: no image object" )?;
+    let source = image.attribute( "source" ).ok_or( "invalid file: no source attribute on image" )?.to_string();
+    let full_path = format!( "{}/{}", working_directory, source );
+    let formatted_path = Path::new( &full_path );
+    if let Some( extension ) = formatted_path.extension() {
+        let extension = extension.to_string_lossy();
+        if extension == "tmx" {
+            // Case where source is a nested tileset. Open the .tmx file
+            let file = read_to_string( full_path.clone() )?;
+            let tmx_document = roxmltree::Document::parse( &file )?;
+
+            // Get width and height from <map> item
+            let map_item = tmx_document.descendants().find( | node | node.tag_name() == "map".into() ).ok_or( "invalid file: no map element in metatile" )?;
+            let width: u16 = map_item.attribute( "width" ).ok_or( "invalid file: map of metatile has no width attribute" )?.parse()?;
+            let height: u16 = map_item.attribute( "height" ).ok_or( "invalid file: map of metatile has no height attribute" )?.parse()?;
+
+            // Obtain the single (first) <tileset>
+            let tileset_count = tmx_document.descendants().filter( | node | node.tag_name() == "tileset".into() ).count();
+            if tileset_count > 1 {
+                return Err( "invalid file: only a single tileset is valid for a metatile file" )?
+            }
+            let tileset = tmx_document.descendants().find( | node | node.tag_name() == "tileset".into() ).ok_or( "invalid file: metatile has no tileset" )?;
+            let source = tileset.attribute( "source" ).ok_or( "invalid file: metatile tileset has no source" )?.to_string();
+
+            // Create metatile object here
+            let data = tmx_document.descendants().find( | node | node.tag_name() == "data".into() ).ok_or( "invalid file: metatile has no data" )?;
+            if data.attribute( "encoding" ) != Some( "csv" ) {
+                return Err( "invalid file: metatile data not in csv format" )?
+            }
+            let data = data.text().ok_or( "invalid file: data node has no text" )?;
+            let values: Vec<&str> = data.split( "," ).collect();
+            // Subtract 1 to each value to account for firstgid. This is a sane assumption because a valid metatile file only contains a single tileset.
+            let tiles: Vec<u32> = values.into_iter().map( | string | {
+                let val = string.trim().parse::<u32>().expect( "fatal: non-u32 value in metatile" );
+                if val == 0 {
+                    val
+                } else {
+                    val - 1
+                }
+            } ).collect();
+            return Ok( Some( Metatile { id, source, width, height, tiles } ) )
+        }
+    }
+
+    Ok( None )
 }
 
 pub fn get_objs( node: &Node, object_fields: &Vec<&str> ) -> Result<Vec<Object>, Box<dyn Error>> {
@@ -306,25 +405,34 @@ pub fn get_tiled_tilemap( path: &str, object_fields: &Vec<&str> ) -> Result<Tile
 
         // Build tilesets (current version assumes one tileset per level)
         let mut tilesets: Vec<TiledTileset> = vec![];
-
+        let mut metatiles: Vec<Metatile> = vec![];
+        let mut seen_sources: HashSet<String> = HashSet::new();
         for tileset in map.descendants().filter( | node | node.tag_name() == "tileset".into() ) {
+            let tileset_first_gid = tileset.attribute( "firstgid" ).ok_or( "invalid file: no tileset firstgid" )?;
             let tileset_source_path = tileset.attribute( "source" ).ok_or( "invalid file: no tileset source" )?;
             let tileset_file = read_to_string( format!( "{}/{}", working_directory, tileset_source_path ) )?;
             let tileset_document = roxmltree::Document::parse( &tileset_file )?;
-            let first_gid = tileset.attribute( "firstgid" ).ok_or( "invalid file: no firstgid attribute" )?.parse()?;
             let tileset = tileset_document.descendants().find( | node | node.tag_name() == "tileset".into() ).ok_or( "invalid file: no tileset origin object" )?;
 
-            // Validate referenced tileset dimensions match map dimensions
-            // E.g. if your .tmx specifies 16x16, the acompanying .tsx file should agree
-            let ( tsx_tile_width, tsx_tile_height ): ( usize, usize ) = (
-                tileset.attribute( "tilewidth" ).ok_or( "invalid file: no tilewidth attribute" )?.parse()?,
-                tileset.attribute( "tileheight" ).ok_or( "invalid file: no tileheight attribute" )?.parse()?
-            );
-            if tsx_tile_width != tile_width || tsx_tile_height != tile_height {
-                return Err( "invalid file: referenced tilemap doesn't have same per-tile width and height of parent tilemap" )?
+            // Tilesets may instead contain metatiles
+            // First, load tilesets instead of metatiles
+            // If tileset_source_path was seen, don't proceed
+            if !seen_sources.contains( tileset_source_path ) {
+                seen_sources.insert( tileset_source_path.to_owned() );
+
+                if let Some( mut tiles ) = get_tiles( tileset.clone(), &mut seen_sources, &working_directory )? {
+                    if tiles.source == "" {
+                        tiles.source = tileset_source_path.to_owned();
+                    }
+
+                    tilesets.push( tiles );
+                }
             }
 
-            tilesets.push( get_tiles( tileset, first_gid, &working_directory )? );
+            // Then, check for metatiles
+            if let Some( metatile ) = get_metatile( tileset_first_gid.parse()?, tileset, &working_directory )? {
+                metatiles.push( metatile );
+            }
         }
 
         let tileset = tilesets;
@@ -381,16 +489,7 @@ pub fn get_tiled_tilemap( path: &str, object_fields: &Vec<&str> ) -> Result<Tile
             Vec::new()
         };
 
-        Ok(
-            TiledTilemap {
-                tileset,
-                layers,
-                objects,
-                collision,
-                width,
-                height
-            }
-        )
+        Ok( TiledTilemap { tileset, metatiles, layers, objects, collision, width, height } )
     } else {
         Err( "invalid file: this does not appear to be valid Tiled .tmx file" )?
     }
diff --git a/src/reskit/level/system.rs b/src/reskit/level/system.rs
index c9afecc..195357e 100644
--- a/src/reskit/level/system.rs
+++ b/src/reskit/level/system.rs
@@ -1,4 +1,4 @@
-use std::{error::Error, convert::TryInto, collections::HashMap};
+use std::{error::Error, collections::HashMap};
 use image::GenericImageView;
 use crate::reskit::{tileset::image_to_tiles, utility::symbol_to_pascal, cli::settings::TileOrder};
 use super::converter::{TiledTilemap, Layer, SystemPlane, TiledTileset};
@@ -109,90 +109,147 @@ pub fn get_tiles( tilemap: &TiledTilemap ) -> Result<(Vec<u8>, Vec<u8>), Box<dyn
 }
 
 /**
- * Output the .map file defining the hardware tilemap for the given Tiled Tilemap.
- * In `--system md`, this outputs tilemap B and then tilemap A
+ * Get the .map file containing metatile definitions, as well as B and A metatile-based maps.
+ *
+ * Format:
+ * <<< HEADER >>>
+ * 2 bytes: The offset to the instances table
+ * (n) 2 byte offsets: For the number of defined metatiles, 16-bit offsets into the file
+ * pointing to the metatile definition. Index into this table = the metatile ID.
+ *
+ * <<< DEFINITIONS >>>
+ * For each metatile definition:
+ * 2 bytes: Width of the metatile, in 16-bit words.
+ * 2 bytes: Height of the metatile, in 16-bit words.
+ * (n) bytes: The nametable definition for the metatile. Stamp this into vram on each layer.
+ *
+ * <<< INSTANCES >>>
+ * For B, then A layers:
+ * 2 bytes: Number of metatile instances in this layer.
+ * For each metatile instance:
+ * 2 bytes: Metatile ID.
+ * 2 bytes: X coordinate (world, divide by 8 to get tile coordinate).
+ * 2 bytes: Y coordinate (world, divide by 8 to get tile coordinate).
  */
-pub fn get_tilemap( tilemap: &TiledTilemap ) -> Result<Vec<u8>, Box<dyn Error>> {
-    let mut all_palettes: Vec<Option<u8>> = vec![];
-    for tileset in &tilemap.tileset {
-        all_palettes.extend( tileset.palettes.iter() );
+pub fn get_metatile_maps( tilemap: &TiledTilemap ) -> Result<Vec<u8>, Box<dyn Error>> {
+    // Assemble header of offsets (as we go)
+    let header_offset = ( tilemap.metatiles.len() * 2 ) + 2;
+    let mut header: Vec<u8> = vec![];
+
+    // Assemble definitions
+    let mut definitions: Vec<u8> = vec![];
+    for metatile in &tilemap.metatiles {
+        let mut subdefinitions: Vec<u8> = vec![];
+        subdefinitions.extend( metatile.width.to_be_bytes() );
+        subdefinitions.extend( metatile.height.to_be_bytes() );
+
+        let ( tilemap_index, palettes ) = metatile_tilemap_index( &metatile.source, &tilemap.tileset )?;
+        for tile in &metatile.tiles {
+            let palette = {
+                if *tile == 0 {
+                    0
+                } else {
+                    let palette = palettes.get( *tile as usize ).ok_or( "internal error: no correlation between tile index and palette index" )?;
+                    if let Ok( palette ) = palette.ok_or( "" ) {
+                        palette
+                    } else {
+                        println!( "{:?}", palettes );
+                        return Err( format!( "invalid file: tile \"{}\" in metatile tilemap does not name reskit-palette attribute", tile ) )?;
+                    }
+                }
+            };
+
+            let nametable_entry: u16 = ( ( palette as u16 ) << 13 ) | ( ( tile + tilemap_index as u32 ) as u16 );
+            subdefinitions.extend( nametable_entry.to_be_bytes() );
+        }
+
+        let this_offset = header_offset + definitions.len();
+        header.extend( ( this_offset as u16 ).to_be_bytes() );
+
+        definitions.extend( subdefinitions );
     }
 
-    let layer_b: Option<&Layer> = tilemap.layers.iter().find( | layer | matches!( layer, Layer::Tile { system_plane: SystemPlane::MdPlaneB, tiles: _ } ) );
-    let layer_a: Option<&Layer> = tilemap.layers.iter().find( | layer | matches!( layer, Layer::Tile { system_plane: SystemPlane::MdPlaneA, tiles: _ } ) );
+    // Assemble instances
+    let mut instances: Vec<u8> = vec![];
 
-    // Each entry in a `--system md` tilemap is 16 bits
-    let mut total_nametable: Vec<u16> = Vec::new();
-
-    let mut nametable: Vec<u16> = vec![ 0; tilemap.width * tilemap.height ];
+    let layer_b: Option<&Layer> = tilemap.layers.iter().find( | layer | matches!( layer, Layer::Metatile { system_plane: SystemPlane::MdPlaneB, tiles: _ } ) );
     if let Some( layer_b ) = layer_b {
-        let layer_b = match layer_b {
-            Layer::Tile { system_plane: _, tiles } => tiles,
-            _ => return Err( "internal error: invalid object type" )?
-        };
+        let tiles = match layer_b { Layer::Metatile { system_plane: _, tiles } => tiles };
+        let mut subdefinitions: Vec<u8> = vec![];
 
-        for y in 0..tilemap.height {
-            for x in 0..tilemap.width {
-                let target_tile: u32 = *layer_b.get( ( y * tilemap.width ) + x ).ok_or( "internal error: invalid data in tilemap" )?;
-                let target_tile: u16 = target_tile.try_into()?;
-                if target_tile > 0 {
-                    let source_tile = target_tile - 1;
+        for tile_y in 0..tilemap.height {
+            for tile_x in 0..tilemap.width {
+                let item_at = tiles.get( ( tile_y * tilemap.width ) + tile_x ).ok_or( "internal error: tilemap does not correlate to width/height" )?;
+                if *item_at != 0 {
+                    // What index-ID was that?
+                    let index_id = tilemap.metatiles.iter().position( | metatile | metatile.id == *item_at ).ok_or( "invalid file: metatile id not found" )?;
 
-                    // From the starting point of x, y "stamp" the target tile's indices
-                    let nametable_entry = target_tile;
-                    let selected_pal = all_palettes[ source_tile as usize ];
-                    if let Some( selected_pal ) = selected_pal {
-                        nametable[ ( y * tilemap.width ) + x ] = ( ( selected_pal as u16 ) << 13 ) | nametable_entry;
-                    } else {
-                        return Err( format!( "invalid setting: tile {} in tileset has no defined palette", source_tile ) )?
-                    }
+                    // Write the data to subdefinitions
+                    subdefinitions.extend( ( index_id as u16 ).to_be_bytes() );
+                    subdefinitions.extend( ( ( tile_x * 8 ) as u16 ).to_be_bytes() );
+                    subdefinitions.extend( ( ( tile_y * 8 ) as u16 ).to_be_bytes() );
                 }
             }
         }
-    }
-    total_nametable.extend( nametable.iter() );
 
-    // Just do the same for layer a
-    // Copy pasted because i'm lazy and tired
-    let mut nametable: Vec<u16> = vec![ 0; tilemap.width * tilemap.height ];
+        instances.extend( ( ( subdefinitions.len() / 6 ) as u16 ).to_be_bytes() );
+        instances.extend( subdefinitions );
+    } else {
+        instances.extend( ( 0 as u16 ).to_be_bytes() );
+    }
+
+    let layer_a: Option<&Layer> = tilemap.layers.iter().find( | layer | matches!( layer, Layer::Metatile { system_plane: SystemPlane::MdPlaneA, tiles: _ } ) );
     if let Some( layer_a ) = layer_a {
-        let layer_a = match layer_a {
-            Layer::Tile { system_plane: _, tiles } => tiles,
-            _ => return Err( "internal error: invalid object type" )?
-        };
+        let tiles = match layer_a { Layer::Metatile { system_plane: _, tiles } => tiles };
+        let mut subdefinitions: Vec<u8> = vec![];
 
-        for y in 0..tilemap.height {
-            for x in 0..tilemap.width {
-                let target_tile: u32 = *layer_a.get( ( y * tilemap.width ) + x ).ok_or( "internal error: invalid data in tilemap" )?;
-                let target_tile: u16 = target_tile.try_into()?;
-                if target_tile > 0 {
-                    let source_tile = target_tile - 1;
+        for tile_y in 0..tilemap.height {
+            for tile_x in 0..tilemap.width {
+                let item_at = tiles.get( ( tile_y * tilemap.width ) + tile_x ).ok_or( "internal error: tilemap does not correlate to width/height" )?;
+                if *item_at != 0 {
+                    // What index-ID was that?
+                    let index_id = tilemap.metatiles.iter().position( | metatile | metatile.id == *item_at ).ok_or( "invalid file: metatile id not found" )?;
 
-                    // From the starting point of x, y "stamp" the target tile's indices
-                    let nametable_entry = target_tile;
-                    let selected_pal = all_palettes[ source_tile as usize ];
-                    if let Some( selected_pal ) = selected_pal {
-                        nametable[ ( y * tilemap.width ) + x ] = ( ( selected_pal as u16 ) << 13 ) | nametable_entry;
-                    } else {
-                        return Err( format!( "invalid setting: tile {} in tileset has no defined palette", source_tile ) )?
-                    }
+                    // Write the data to subdefinitions
+                    subdefinitions.extend( ( index_id as u16 ).to_be_bytes() );
+                    subdefinitions.extend( ( ( tile_x * 8 ) as u16 ).to_be_bytes() );
+                    subdefinitions.extend( ( ( tile_y * 8 ) as u16 ).to_be_bytes() );
                 }
             }
         }
-    }
-    total_nametable.extend( nametable.iter() );
 
-    // Convert the u16's to a series of u8 data
-    let mut result: Vec<u8> = Vec::new();
-    for i in 0..total_nametable.len() {
-		let bytes = total_nametable[ i ].to_be_bytes();
-		for i in 0..2 {
-			result.push( bytes[ i ] );
-		}
+        instances.extend( ( ( subdefinitions.len() / 6 ) as u16 ).to_be_bytes() );
+        instances.extend( subdefinitions );
+    } else {
+        instances.extend( ( 0 as u16 ).to_be_bytes() );
     }
+
+    // Write the final result
+    let mut result: Vec<u8> = vec![];
+    let offset_to_instances = header_offset + definitions.len();
+    result.extend( ( offset_to_instances as u16 ).to_be_bytes() );
+    result.extend( header );
+    result.extend( definitions );
+    result.extend( instances );
+
     Ok( result )
 }
 
+fn metatile_tilemap_index( target_source: &str, tilesets: &Vec<TiledTileset> ) -> Result<(usize, Vec<Option<u8>>), Box<dyn Error>> {
+    // Everything starts at 1 for the blank buffer tile
+    let mut index: usize = 1;
+
+    for tileset in tilesets {
+        if tileset.source == target_source {
+            return Ok( ( index, tileset.palettes.clone() ) )
+        } else {
+            index += ( ( tileset.image.width() / 8 ) * ( tileset.image.height() / 8 ) ) as usize;
+        }
+    }
+
+    Err( format!( "internal error: could not find metatile with target source \"{}\"", target_source ) )?
+}
+
 /**
  * Get the .lvc collision map (u8 sized for the map dimensions, collision areas are either 0 or 1)
  */