updated readme and fixed folder selection

README.md

@@ -15,6 +15,9 @@ Discord - https://discord.gg/KMDeFebk
 The repo is based entirely on the brilliant framework here:
 https://github.com/floooh/sokol
 
+The sokol api has been built into dll's (this may change in the future) and it is executed in the best (imho) runtime system there is using its amazing ffi module:
+https://luajit.org/
+
 sdf exmample 
 ![alt text](https://github.com/dlannan/sokol-luajit/blob/main/media/2024-10-30_11-48.png "sdf Example")
 

tools/build/rbuilder/ui/panels.lua

@@ -95,8 +95,7 @@ local folder_select = {
             if(bhit) then
                 udata.hit = bhit 
                 if(bhit[2] == "..") then 
-                    udata.folder_path = udata.folder_path:match("(.-)[^\\]-$")
-                    print(udata.folder_path)
+                    udata.folder_path = dirtools.get_folder(udata.folder_path)
                     if(udata.folder_path == nil or udata.folder_path == "") then udata.folder_path = "." end
                 else
                     udata.folder_path = udata.folder_path.."\\"..udata.hit[2]

tools/dirtools.lua

@@ -1,6 +1,9 @@
-local ffi = require("ffi")
+local ffi       = require("ffi")
 
-local dirtools = {}
+local dirtools  = {}
+
+local tinsert   = table.insert
+local tconcat   = table.concat
 
 ---------------------------------------------------------------------------------------
 
@@ -22,6 +25,19 @@ dirtools.add_default_paths = function(path)
     package.path    = package.path..";"..path.."/?.lua"
 end
 
+---------------------------------------------------------------------------------------
+-- Much safer way to build folder than pattern match (very unstable)
+dirtools.get_folder = function(path)
+    local parts = {}
+    local sep = "\\"
+    local patt = "(.-)[\\]"
+    if(ffi.os ~= "Windows") then patt = "(.-)[/]"; sep = "/" end
+    for pseg in string.gmatch(path, patt) do
+        tinsert(parts, pseg)
+    end
+    return tconcat(parts, sep)
+end
+
 ---------------------------------------------------------------------------------------
 
 dirtools.get_app_path = function( expected_root_folder )