render: tiled: Add support for external tilesets.

* chickadee/render/tiled.scm (load-tile-map): Handle both internal and
external tilesets.

1 files changed, 13 insertions, 3 deletions

diff --git a/chickadee/render/tiled.scm b/chickadee/render/tiled.scm
index cce0683..42b6793 100644
--- a/chickadee/render/tiled.scm
+++ b/chickadee/render/tiled.scm
@@ -259,9 +259,10 @@
             (vector-set! tiles i tile))
           (loop (+ i 1))))
       tiles))
-  (define (parse-tileset node)
-    (let* ((first-gid (attr node 'firstgid string->number))
-           (name (attr node 'name))
+  (define (first-gid node)
+    (attr node 'firstgid string->number))
+  (define (parse-internal-tileset node first-gid)
+    (let* ((name (attr node 'name))
            (tile-width (attr node 'tilewidth string->number))
            (tile-height (attr node 'tileheight string->number))
            (margin (or (attr node 'margin string->number) 0))
@@ -276,6 +277,15 @@
                             ((sxpath '(properties property)) node))))
       (%make-tileset name first-gid size tile-width tile-height
                      atlas tiles  properties)))
+  (define (parse-external-tileset node)
+    (let* ((first-gid (attr node 'firstgid string->number))
+           (source (scope (attr node 'source)))
+           (tree (call-with-input-file source xml->sxml)))
+      (parse-internal-tileset (car ((sxpath '(tileset)) tree)) first-gid)))
+  (define (parse-tileset node)
+    (if (attr node 'source)
+        (parse-external-tileset node)
+        (parse-internal-tileset node (first-gid node))))
   (define (tile-gid->map-tile gid tilesets x y tile-width tile-height)
     (let* ((tileset (find (lambda (t)
                             (and (>= gid (tileset-first-gid t))