added aseprite script for populating the data texture atlas

MLEM/Textures/DataTextureAtlas.cs

@@ -11,6 +11,8 @@ namespace MLEM.Textures {
     /// <summary>
     /// This class represents an atlas of <see cref="TextureRegion"/> objects which are loaded from a special texture atlas file. 
     /// To load a data texture atlas, you can use <see cref="DataTextureAtlasExtensions.LoadTextureAtlas"/>.
+    /// To see the structure of a Data Texture Atlas, you can check out the sandbox project: <see href="https://github.com/Ellpeck/MLEM/blob/master/Sandbox/Content/Textures/Furniture.atlas"/>.
+    /// Additionally, if you are using Aseprite, there is a script to automatically populate it: <see href="https://github.com/Ellpeck/MLEM/blob/master/Utilities/Populate%20Data%20Texture%20Atlas.lua"/>
     /// </summary>
     public class DataTextureAtlas {
 

Utilities/Populate Data Texture Atlas.lua

@@ -0,0 +1,41 @@
+-- This is a lua script for Aseprite that allows automatically populating a MLEM Data Texture Atlas.
+-- To use this script, you need to select a rectangular area that should be your texture region.
+-- If you want a custom pivot point, you also need to un-select exactly one pixel, the pivot point.
+-- When you then execute the script and input the name of the texture region, it gets appended to the "SpriteName.atlas" file.
+
+-- get the currently selected sprite
+local selection = app.activeSprite.selection
+if selection == nil then return end
+local bounds = selection.bounds
+
+local loc = "loc "..bounds.x.." "..bounds.y.." "..bounds.width.." "..bounds.height.."\n"
+local piv = ""
+
+-- find the pivot point, which should be the only de-selected pixel in the selection
+for x = bounds.x, bounds.x + bounds.width - 1 do
+    for y = bounds.y, bounds.y + bounds.height - 1 do
+        if not selection:contains(x, y) then 
+            piv = "piv "..x.." "..y.."\n"
+            goto foundPivot
+        end
+    end
+end
+::foundPivot:: 
+
+-- open the name dialog
+local dialog = Dialog("Copy Texture Atlas Data")
+    :entry{ id = "name", label = "Region Name", focus = true }
+    :button{ id = "ok", text="&OK" }
+    :button{ text = "&Cancel" }
+dialog:show()
+
+local data = dialog.data
+if not data.ok then return end
+local name = data.name
+
+-- get the atlas file and write the data to it
+local spriteFile = app.activeSprite.filename
+local atlas = spriteFile:match("(.+)%..+")..".atlas"
+local file = io.open(atlas, "a")
+file:write("\n"..name.."\n"..loc..piv)
+file:close()