better image handling

ReadMe.md

@@ -30,6 +30,8 @@ Use transparency. 25% works well.
   width/height
   - (path relative to the JSON file? or relative to the executable?)
 
+Images are only loaded if they will be displayed.
+
 ## Example JSON
 
 ```json

map.json

@@ -82,7 +82,7 @@
     "Farm Region": [-235, 80, -100, true, {"radius": 230, "color": [0, 0.5, 0, 0.15], "offset": [-54, 0]}],
     "Mount Sharpe": [735, 110, 685, "mountainous region", {"radius": 165, "color": [1, 1, 1, 0.1], "offset": [-54, 4]}],
     "approximate area of extreme mountains": [-50, 100, 750, true, {"radius": [570, 525], "color": [1, 1, 1, 0.15]}],
-    "map_3": [448, 64, 448, false, {"image": "map_3.png", "size": [1024, 1024], "color": [1, 1, 1, 0.5]}],
+    "map_3": [448, 64, 448, false, {"image": "images/map_3.png", "size": [1024, 1024], "color": [1, 1, 1, 0.5]}],
     "unnamed hill": [400, 100, 235, true, {"radius": [110, 100], "offset": [-40, 0]}],
     "unnamed plains": [40, 100, 140, true, {"radius": [115, 85], "offset": [-50, 0]}],
     "original worldborder": [0, 87, 0, false, {"box": [1000, 1000], "mode": "line"}]

src/main.lua

@@ -39,7 +39,7 @@ local function load_map(map_file_name)
   edges = map.edges or {}
   areas = map.areas or {}
   for _, area in pairs(map.areas) do
-    local image_file_name = area[5] and area[5].image
+    local image_file_name = (area[4] or area[4] == nil) and area[5] and area[5].image
     if image_file_name then
       local file = io.open(image_file_name, "rb")
       local data = file:read("*all")

test map.json

@@ -5,5 +5,8 @@
     "BottomLeft": [0, 0, 900, true],
     "BottomRight": [1600, 0, 900, true]
   },
-  "edges": []
+  "edges": [],
+  "areas": {
+    "test image": [100, 0, 100, true, {"image": "test image.png", "size": [200, 200], "color": [1, 1, 1, 1]}]
+  }
 }