Allow specifying a UI scale factor

Currently this is quite blurry, and the pick hospital screen is broken.
CorsixTH · TheCycoONE · Dec 3, 2025 · Dec 3, 2025 · Dec 3, 2025 · Dec 3, 2025
commit a4ba86aeef7729775f1bfec697fef69139f1af10
diff --git a/CorsixTH/Lua/config_finder.lua b/CorsixTH/Lua/config_finder.lua
@@ -96,6 +96,7 @@ local config_defaults = {
   fullscreen = false,
   width = 800,
   height = 600,
+  ui_scale = 1,
   language = [[English]],
   audio = true,
   free_build_mode = false,
@@ -206,11 +207,15 @@ local string_01 = [=[
 -- Screen size. Must be at least 640x480. Larger sizes will require better
 -- hardware in order to maintain a playable framerate. The fullscreen setting
 -- can be true or false, and the game will run windowed if not fullscreen.
+-- ui_scale can be set to 1, 2, or 3 to scale the user interface for higher
+-- resolution displays. For example, at 1920x1080 resolution, setting ui_scale
+-- to 2 will make the interface elements twice as large.
 --]=] .. '\n' ..
 'fullscreen = ' .. tostring(config_values.fullscreen) .. '\n' ..
 '\n' ..
 'width = ' .. tostring(config_values.width) .. '\n' ..
-'height = ' .. tostring(config_values.height) .. '\n' .. [=[
+'height = ' .. tostring(config_values.height) .. '\n' ..
+'ui_scale = ' .. tostring(config_values.ui_scale) .. '\n' .. [=[
 
 -------------------------------------------------------------------------------
 -- Language to use for ingame text. Between the square braces should be one of:

diff --git a/CorsixTH/Lua/game_ui.lua b/CorsixTH/Lua/game_ui.lua
@@ -257,11 +257,13 @@ function GameUI:draw(canvas)
     self:setZoom(1)
     app.map:draw(canvas, dx, dy, config.width, config.height, 0, 0)
   end
+  canvas:scale(TheApp.config.ui_scale)
   Window.draw(self, canvas, 0, 0) -- NB: not calling UI.draw on purpose
   self:drawTooltip(canvas)
   if self.simulated_cursor then
     self.simulated_cursor.draw(canvas, self.cursor_x, self.cursor_y)
   end
+  canvas:scale(1)
 end
 
 function GameUI:onChangeResolution()

diff --git a/CorsixTH/Lua/ui.lua b/CorsixTH/Lua/ui.lua
@@ -314,11 +314,13 @@ function UI:draw(canvas)
       self.background:draw(canvas, math.floor((screen_w - bg_w) / 2), math.floor((screen_h - bg_h) / 2))
     end
   end
+  canvas:scale(TheApp.config.ui_scale)
   Window.draw(self, canvas, 0, 0)
   self:drawTooltip(canvas)
   if self.simulated_cursor then
     self.simulated_cursor.draw(canvas, self.cursor_x, self.cursor_y)
   end
+  canvas:scale(1)
 end
 
 --! Register a key handler / hotkey for a window.

diff --git a/CorsixTH/Lua/window.lua b/CorsixTH/Lua/window.lua
@@ -76,6 +76,9 @@ function Window:setPosition(x, y)
   self.y_original = y
   -- Convert x and y to absolute pixel positions with regard to top/left
   local w, h = TheApp.config.width, TheApp.config.height
+  local scale = TheApp.config.ui_scale
+  w = w / scale
+  h = h / scale
   if x < 0 then
     x = math.ceil(w - self.width + x)
   elseif x < 1 then