Allow user-specified component ids in ECS

src/reskit/level/converter.rs

@@ -1,5 +1,6 @@
-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::HashMap};
 use image::{DynamicImage, GenericImageView};
+use regex::Regex;
 use roxmltree::Node;
 use crate::reskit::{utility::print_warning, cli::settings::TileOrder};
 use super::ecs;
@@ -9,6 +10,7 @@ pub struct TiledTilemap {
     pub tileset: Vec<TiledTileset>,
     pub layers: Vec<Layer>,
     pub ecs: Vec<ecs::Entity>,
+    pub ecs_component_ids: HashMap<String, u8>,
     pub width: usize,
     pub height: usize
 }
@@ -252,8 +254,28 @@ pub fn get_tiled_tilemap( path: &str ) -> Result<TiledTilemap, Box<dyn Error>> {
         }
 
         // Get the entity-component system
+        let mut ecs_component_ids = HashMap::new();
         let object_group = map.descendants().find( | node | node.tag_name() == "objectgroup".into() );
         let ecs = if let Some( object_group ) = object_group {
+            let object_group_properties = object_group.descendants().find( | node | node.tag_name() == "properties".into() );
+            if let Some( object_group_properties ) = object_group_properties {
+                let component_id_properties = object_group_properties.descendants()
+                                                                     .filter( | node | node.attribute( "name" ).unwrap_or( "" ).starts_with( "reskit-component-id" ) );
+                for property in component_id_properties {
+                    let name_attribute = property.attribute( "name" ).ok_or( "internal error: no name attribute" )?;
+                    let id: u8 = property.attribute( "value" ).ok_or( "internal error: no property value in object layer" )?.parse()?;
+
+                    // Set up regex to remove individual parts
+                    let regex = Regex::new( r#"reskit-component-id\[([a-z0-9_]+)\]"# )?;
+                    let captures = regex.captures( name_attribute ).ok_or( "invalid file: invalid reskit-component-id key in object layer" )?;
+                    let component_name = captures.get( 1 ).ok_or( "internal error: regex did not match properly" )?.as_str();
+                    ecs_component_ids.insert( component_name.to_owned(), id );
+                }
+            }
+
+            // Add the "position" component by default
+            ecs_component_ids.insert( "position".to_owned(), ecs_component_ids.len() as u8 );
+
             ecs::get_ecs( object_group )?
         } else {
             Vec::new()
@@ -264,6 +286,7 @@ pub fn get_tiled_tilemap( path: &str ) -> Result<TiledTilemap, Box<dyn Error>> {
                 tileset,
                 layers,
                 ecs,
+                ecs_component_ids,
                 width,
                 height
             }

src/reskit/level/system.rs

@@ -226,8 +226,7 @@ pub fn get_ecs( tilemap: &TiledTilemap ) -> Result<Vec<u8>, Box<dyn Error>> {
 
     let mut result: Vec<u8> = Vec::new();
 
-    // Build a complete set of component IDs and types
+    // Build a complete set of types
-    let mut component_ids: LinkedHashSet<String> = LinkedHashSet::new();
     let mut types: LinkedHashSet<LinkedHashSet<String>> = LinkedHashSet::new();
     for entity in &tilemap.ecs {
         // Get the list of components attached to this entity
@@ -236,9 +235,6 @@ pub fn get_ecs( tilemap: &TiledTilemap ) -> Result<Vec<u8>, Box<dyn Error>> {
         components.sort();
         let components: LinkedHashSet<String> = components.into_iter().collect();
 
-        // Assign an index to each unique component id by inserting it into `component_ids`
-        component_ids.extend( components.clone() );
-
         // Assign this unique combination of components a type id
         // by inserting it into `types`
         types.insert_if_absent( components );
@@ -263,7 +259,7 @@ pub fn get_ecs( tilemap: &TiledTilemap ) -> Result<Vec<u8>, Box<dyn Error>> {
 
         for component in ecs_type {
             type_component_ids.push(
-                component_ids.iter().position( | value | component == value ).ok_or( "internal error: no component" )? as u8
+                *tilemap.ecs_component_ids.get( component ).ok_or( format!( "invalid file: undefined component symbol \"{}\"", component ) )?
             );
         }
 
@@ -387,12 +383,6 @@ pub fn get_ecs( tilemap: &TiledTilemap ) -> Result<Vec<u8>, Box<dyn Error>> {
         }
     }
 
-    // Output IDs to terminal
-    let component_ids: Vec<String> = component_ids.into_iter().collect();
-    for i in 0..component_ids.len() {
-        print_info( &format!( "Component ID {}: {}", i, component_ids[ i ] ) );
-    }
-
     // Output type structures to terminal
     let mut visited_types: LinkedHashSet<LinkedHashSet<String>> = LinkedHashSet::new();
     for entity in &tilemap.ecs {