Add main menu

I'm very proud of this drawing :).

src/Main.cake

@@ -727,6 +727,37 @@
 ;; Main
 ;;
 
+;; On return null, play the game, else, exit for returned reason
+(defun-local do-main-menu (renderer (* SDL_Renderer)
+                                    main-menu-texture (* SDL_Texture)
+                                    &return (* (const char)))
+  (var exit-reason (* (const char)) null)
+  (var in-state input-state (array 0))
+  (while (not exit-reason)
+    (var event SDL_Event)
+    (while (SDL_PollEvent (addr event))
+      (when (= (field event type) SDL_QUIT)
+        (set exit-reason "Window event")))
+    (var currentKeyStates (* (const Uint8))  (SDL_GetKeyboardState null))
+    (when (at SDL_SCANCODE_ESCAPE currentKeyStates)
+      (set exit-reason "Escape pressed"))
+
+    (unless (= 0 (SDL_RenderCopy renderer main-menu-texture
+                                 null null))
+      (sdl-print-error)
+      (set exit-reason "Render error"))
+
+    (var mouse-x int 0)
+    (var mouse-y int 0)
+    (var mouse-button-state Uint32 (SDL_GetMouseState (addr mouse-x) (addr mouse-y)))
+    (when (bit-and mouse-button-state SDL_BUTTON_LMASK)
+      ;; Play the game!
+      (return null))
+
+    (SDL_RenderPresent renderer)
+    (SDL_Delay todo-arbitrary-delay-ms))
+  (return exit-reason))
+
 (comptime-cond ('Kitty-Main
 (defun main (num-args int args ([] (* char)) &return int)
   (SDL_Log "Kitty Gridlock\n\n
@@ -798,6 +829,10 @@ Rush Hour database from Michael Fogleman.\n\n")
 
   (read-progression-data)
 
+  (var main-menu-texture (* SDL_Texture)
+       (sdl-texture-from-bmp (in-data-dir "MainMenu.bmp") renderer))
+  (unless main-menu-texture (return 1))
+
   (var background-texture (* SDL_Texture) (sdl-texture-from-bmp (in-data-dir "Board.bmp")
                                                                 renderer))
   (unless background-texture (return 1))
@@ -853,7 +888,8 @@ Rush Hour database from Michael Fogleman.\n\n")
   (unless font-texture (return 1))
 
   (var textures-to-destroy ([] (* SDL_Texture))
-       (array background-texture
+       (array main-menu-texture
+              background-texture
               grid-texture
               pieces-texture
               win-texture
@@ -886,6 +922,9 @@ Rush Hour database from Michael Fogleman.\n\n")
   (sdl-print-time-delta start-load-ticks "Game loop starting")
 
   (var exit-reason (* (const char)) null)
+
+  (set exit-reason (do-main-menu renderer main-menu-texture))
+
   (while (not exit-reason)
     (var event SDL_Event)
     (while (SDL_PollEvent (addr event))
@@ -1110,6 +1149,7 @@ Rush Hour database from Michael Fogleman.\n\n")
     recent-n-perf-counts i
     (var delta-time float (/ (at i recent-n-perf-counts)
                              (type-cast performance-num-ticks-per-second float)))
+    (unless delta-time (continue))
     (SDL_Log "\t%f %fhz\n" delta-time (/ 1.f delta-time))))
 
   ;;