feat: update layers Z-offset so the upper layer will be at offset 0 a…

…nd layers behind will have negative offset values

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Add the possibility for the user to use a custom physics backend and add an associated example (#30)
 - Add a note about isometric (staggered) maps which are not supported and add a dedicated example
 - Add a bit of documentation
+- Update layers Z-offset so the upper layer will be at offset 0 and layers behind will have negative offset values
 
 ### Bugfixes
 

src/loader.rs

@@ -396,7 +396,8 @@ fn load_map(
 
     // Order of the differents layers in the .TMX file is important:
     // a layer appearing last in the .TMX should appear "on top" of previous layers
-    let mut offset_z = 0.;
+    // Start with a negative offset so the upper layer will be at Z-offset = 0
+    let mut offset_z = tiled_map.map.layers().len() as f32 * (-100.0);
 
     // Once materials have been created/added we need to then create the layers.
     for (layer_index, layer) in tiled_map.map.layers().enumerate() {