add tile atlas to mapfile

1 files changed, 31 insertions, 5 deletions

diff --git a/tools/createmap.py b/tools/createmap.py
index 59fb315..36f6ca9 100755
--- a/tools/createmap.py
+++ b/tools/createmap.py
@@ -1,12 +1,33 @@
 #!/usr/bin/env python
 import sys
+from math import ceil, log
+from PIL import Image
 
 outfile = "map.tiles"
 
-WIDTH = 500
-HEIGHT = 100
+ATLASFILE = "atlas.png"
+
+TILESIZE = 16
+WIDTH = 1024
+HEIGHT = 1024
+
+# create atlas bytes
+image = Image.open(ATLASFILE).convert("RGBA")
+
+
+# check if atlas is suitable
+if image.width % TILESIZE != 0 or image.height % TILESIZE != 0:
+    print(f"Atlas image must be divisible by {TILESIZE}", file=sys.err)
+    sys.exit(1)
+
+# calculate number of possible tiles (adding 1 for the empty tile)
+tilecount = (image.width * image.height) / (TILESIZE**2) + 1
+
+atlas_width = image.width // TILESIZE
+atlas_height = image.width // TILESIZE
+
 # number of bytes each tile needs to represent
-TILEBYTES = 25
+tilebytes = ceil(log(tilecount, 256))
 
 HEADER = "TILEFILEv1"
 
@@ -14,10 +35,15 @@ with open(outfile, "wb") as file:
     file.write(bytes(HEADER, "ascii"))
     file.write(WIDTH.to_bytes(4, 'big'));
     file.write(HEIGHT.to_bytes(4, 'big'));
-    file.write(TILEBYTES.to_bytes(4, 'big'));
+    file.write(tilebytes.to_bytes(4, 'big'));
+
 
     for y in range(HEIGHT):
         for x in range(WIDTH):
             index = (x + y) % 5
-            file.write(index.to_bytes(TILEBYTES, 'big'));
+            file.write(index.to_bytes(tilebytes, 'big'));
 
+    file.write(TILESIZE.to_bytes(4, 'big'));
+    file.write(atlas_width.to_bytes(4, 'big'));
+    file.write(atlas_height.to_bytes(4, 'big'));
+    file.write(image.tobytes())