Isometric tileset changes for 3d vision (#2036)

* unassign t_open_air

* tr_ledge use empty

* add zlevel_height

* fix empty png

old png causes compiling to fail

* fix value

* fix other value

* lint json

* Revert "fix empty png"

This reverts commit 9b9c535.

* Revert "unassign t_open_air"

This reverts commit 40ff3e2.

* Update 687_t_open_air_0.png

gfx/HitButton_iso/pngs_full_iso_16x20/trap/lighting_hidden_t_hole_tr_ledge_0.json

@@ -1 +1 @@
-{"id": ["lighting_hidden", "t_hole", "tr_ledge"], "bg": ["2_lighting_hidden_0"], "fg": []}
+{"id": ["lighting_hidden", "t_hole", "tr_ledge"], "bg": ["empty_16x20"], "fg": []}

gfx/HitButton_iso/tile_info.json

@@ -3,6 +3,7 @@
     "height": 20,
     "iso": true,
     "width": 16,
+    "zlevel_height": 10,
     "pixelscale": 2
   },
   {

gfx/Ultica_iso/pngs_normal_32x32/tr_ledge.json

@@ -0,0 +1,4 @@
+{
+    "id": "tr_ledge",
+    "fg": "empty_32x32"
+}

gfx/Ultica_iso/tile_info.json

@@ -4,6 +4,7 @@
     "pixelscale": 1,
     "width": 48,
     "height": 24,
+    "zlevel_height": 96,
     "retract_dist_min": 2.5,
     "retract_dist_max": 6.0,
     "//": "We assume a base area of 90cm x 90cm."

tools/compose.py

@@ -259,6 +259,7 @@ def __init__(
         info_path = self.source_dir.joinpath('tile_info.json')
         self.sprite_width = 16
         self.sprite_height = 16
+        self.zlevel_height = 0
         self.pixelscale = 1
         self.iso = False
         self.retract_dist_min = -1.0
@@ -272,6 +273,8 @@ def __init__(
             self.info = json.load(file)
             self.sprite_width = self.info[0].get('width', self.sprite_width)
             self.sprite_height = self.info[0].get('height', self.sprite_height)
+            self.zlevel_height = self.info[0].get('zlevel_height',
+                                                  self.zlevel_height)
             self.pixelscale = self.info[0].get('pixelscale', self.pixelscale)
             self.retract_dist_min = self.info[0].get('retract_dist_min',
                                                      self.retract_dist_min)
@@ -471,6 +474,7 @@ def create_tile_entries_for_unused(
                 'pixelscale': self.pixelscale,
                 'width': self.sprite_width,
                 'height': self.sprite_height,
+                'zlevel_height': self.zlevel_height,
                 'iso': self.iso,
                 'retract_dist_min': self.retract_dist_min,
                 'retract_dist_max': self.retract_dist_max