Use logical scaling for proper positioning

The aspect ratio centering correction got a bit gnarly

src/Main.cake

@@ -552,6 +552,9 @@ Rush Hour database from Michael Fogleman.\n\n")
   (var renderer (* SDL_Renderer) null)
   (unless (sdl-intialize-2d-renderer (addr renderer) window) (return 1))
 
+  ;; Scale the render to fit the window
+  (SDL_RenderSetLogicalSize renderer g-window-width g-window-height)
+
   (var background-texture (* SDL_Texture) (sdl-texture-from-bmp (in-data-dir "Board.bmp")
                                                                 renderer))
   (unless background-texture (return 1))
@@ -624,6 +627,48 @@ Rush Hour database from Michael Fogleman.\n\n")
     (var mouse-y int 0)
     (var mouse-button-state Uint32 (SDL_GetMouseState (addr mouse-x) (addr mouse-y)))
     (var mouse-position vec2 (array (type-cast mouse-x float) (type-cast mouse-y float)))
+    (scope ;; Scale mouse position to match logical rendering positions
+     (var window-width int 1)
+     (var window-height int 1)
+     (SDL_GetWindowSize window (addr window-width) (addr window-height))
+     (var logical-width int 1)
+     (var logical-height int 1)
+     (SDL_RenderGetLogicalSize renderer (addr logical-width) (addr logical-height))
+     (when (or (= 0 window-width)
+               (= 0 window-height)
+               (= 0 logical-width)
+               (= 0 logical-height))
+       (set exit-reason "error: window or logical dimension will cause divide by zero")
+       (break))
+     (var to-logical-scale vec2
+          (array
+           (/ (to-float logical-width) window-width)
+           (/ (to-float logical-height) window-height)))
+     ;; (printf "Window scale %f %f\n" (vec-xy to-logical-scale))
+     (var logical-aspect-ratio float (/ logical-width (to-float logical-height)))
+     (var window-aspect-ratio float (/ window-width (to-float window-height)))
+     (if (> window-aspect-ratio logical-aspect-ratio) ;; Remove centering for correct scaling
+         (block
+             (var total-margin float
+                  (- window-width (* window-width (/ logical-aspect-ratio window-aspect-ratio))))
+           (set (vec-x to-logical-scale) (/ logical-width (- window-width total-margin)))
+             (var decentered float
+                  (/ total-margin
+                     2.f))
+           (set (vec-x mouse-position)
+                (- (vec-x mouse-position)
+                   decentered)))
+         (block
+             (var total-margin float
+                  (- window-height (* window-height (/ window-aspect-ratio logical-aspect-ratio))))
+           (set (vec-y to-logical-scale) (/ logical-height (- window-height total-margin)))
+             (var decentered float
+                  (/ total-margin
+                     2.f))
+           (set (vec-y mouse-position)
+                (- (vec-y mouse-position)
+                   decentered))))
+     (set mouse-position (vec2-multiply mouse-position to-logical-scale)))
 
     (if (bit-and mouse-button-state SDL_BUTTON_LMASK)
         (block
@@ -668,6 +713,14 @@ Rush Hour database from Michael Fogleman.\n\n")
       (sdl-print-error)
       (set exit-reason "Render error")))
 
+    ;; Pointer position
+    ;; (scope ;; TODO REMOVE
+    ;;  (var src-rect SDL_Rect (array (vec-xy-to-int piece-primary-origin)
+    ;;                                 166 166))
+    ;;  (var dest-rect SDL_Rect (array (vec-xy-to-int mouse-position)
+    ;;                                166 166))
+    ;;  (SDL_RenderCopy renderer pieces-texture (addr src-rect) (addr dest-rect)))
+
     (scope ;; Draw grid
      (var row int 0)
      (while (< row g-game-board-grid-size)