render the tileset

1 files changed, 34 insertions, 12 deletions

diff --git a/src/tilemap.scm b/src/tilemap.scm
index e80978e..d789422 100644
--- a/src/tilemap.scm
+++ b/src/tilemap.scm
@@ -1,5 +1,5 @@
 (module tilemap
-(load-tilemap)
+*
 (import scheme
 	(chicken io)
 	(chicken base)
@@ -11,7 +11,8 @@
 	(srfi 1)
 	expat
 	defstruct
-	(prefix sdl2-image "img:"))
+	(prefix sdl2-image "img:")
+	(prefix sdl2 "sdl2:"))
 
 (defstruct tileset
   tilewidth
@@ -47,6 +48,10 @@
   layers
   objects)
 
+(defstruct tile
+  id
+  rect)
+
 (define (maybe-do action)
   (lambda (value)
     (if (eq? value #f)
@@ -61,7 +66,7 @@
 
 (define (string-alist->alist string-alist)
   (map (lambda (pair) (cons (string->symbol (car pair))
-		       (maybe-string->number (cdr pair))))
+			    (maybe-string->number (cdr pair))))
        string-alist))
 
 (define (parse-tileset string-tileset)
@@ -86,15 +91,15 @@
   (call-with-input-file file-name
     (lambda (port)
       (let* ((tileset (parse-tileset (read-string #f port)))
-	    (image-source (tileset-image-source tileset))
-	    (base-path (pathname-directory file-name))
-	    (img-to-load (if (absolute-pathname? image-source)
-					 image-source
-					 (pathname-replace-directory
-					  image-source
-					  (if (pathname-directory image-source)
-					      (format "~a/~a" base-path (pathname-directory image-source))
-					      base-path)))))
+	     (image-source (tileset-image-source tileset))
+	     (base-path (pathname-directory file-name))
+	     (img-to-load (if (absolute-pathname? image-source)
+			      image-source
+			      (pathname-replace-directory
+			       image-source
+			       (if (pathname-directory image-source)
+				   (format "~a/~a" base-path (pathname-directory image-source))
+				   base-path)))))
 	(tileset-image-set! tileset (img:load img-to-load))
 	tileset))))
 
@@ -136,6 +141,23 @@
     (expat:parse parser string-tilemap)
     tilemap))
 
+(define (tileset-rows tileset)
+  "Return the number of rows in the tileset"
+  (inexact->exact (ceiling (/ (tileset-tilecount tileset) (tileset-columns tileset)))))
+
+(define (tileset-tile tileset tile-id)
+  ;; Use the tileset's columns setting and the tileheight/tilewidth to
+  ;; find the tile's x,y location and create a rect
+  (let* ((tile-width (tileset-tilewidth tileset))
+	 (tile-height (tileset-tileheight tileset))
+	 (tile-x (modulo tile-id (tileset-columns tileset)))
+	 (tile-y (inexact->exact (floor (/ tile-id (tileset-columns tileset)))))
+	 (x (* tile-x tile-width))
+	 (y (* tile-y tile-height)))
+    (make-tile
+     tile-id
+     (sdl2:make-rect x y tile-width tile-height))))
+
 (define (load-tilemap file-name)
   (call-with-input-file file-name
     (lambda (port)