render: tiled: Add point->tile.

* chickadee/render/tiled.scm (point->tile): New procedure.
* doc/api.texi (Tiled): Document it.
* examples/tiled.scm: Render tile coordinates in bottom-left corner.

1 files changed, 14 insertions, 3 deletions

diff --git a/examples/tiled.scm b/examples/tiled.scm
index 5ff2b7f..e6099df 100644
--- a/examples/tiled.scm
+++ b/examples/tiled.scm
@@ -1,17 +1,23 @@
 (use-modules (chickadee)
              (chickadee math vector)
              (chickadee math rect)
+             (chickadee render font)
              (chickadee render tiled)
-             (ice-9 match))
+             (ice-9 format)
+             (ice-9 match)
+             (srfi srfi-11))
 
 (define map #f)
 (define camera #v(0.0 0.0))
+(define text-position #v(4.0 4.0))
+(define text "0, 0")
 
 (define (load)
   (set! map (load-tile-map "maps/example.tmx")))
 
 (define (draw alpha)
-  (draw-tile-map map #:position camera))
+  (draw-tile-map map #:position camera)
+  (draw-text text text-position))
 
 (define inc 8.0)
 (define (key-press key scancode modifiers repeat?)
@@ -23,9 +29,14 @@
     ('q (abort-game))
     (_ #t)))
 
+(define (mouse-move x y x-rel y-rel buttons)
+  (let-values (((tx ty) (point->tile map x y)))
+    (set! text (format #f "~d, ~d" tx ty))))
+
 (run-game #:window-width 320
           #:window-height 240
           #:window-title "tile map demo"
           #:load load
           #:draw draw
-          #:key-press key-press)
+          #:key-press key-press
+          #:mouse-move mouse-move)