refactor: optimize snake sprite rendering using preloaded directional assets and implement HUD caching

include/game_render.h

@@ -5,22 +5,38 @@
 
 #include "game_state.h"
 
+struct HudCache {
+    int score = -1;
+    bool cursed = false;
+    bool paused = false;
+    bool gameOver = false;
+    bool musicEnabled = false;
+    bool hardMode = false;
+    bool dirty = true;
+};
+
 struct RenderAssets {
     PrintConsole *topScreen = nullptr;
     PrintConsole *bottomScreen = nullptr;
 
     u16 *gfx_segment = nullptr;
     u16 *gfx_segment_small = nullptr;
-    u16 *gfx_head = nullptr;
+    u16 *gfx_head_h = nullptr;
+    u16 *gfx_head_v = nullptr;
     u16 *gfx_apple = nullptr;
-    u16 *gfx_tail = nullptr;
+    u16 *gfx_apple_blink = nullptr;
+    u16 *gfx_tail_h[2] = {nullptr, nullptr};
+    u16 *gfx_tail_v[2] = {nullptr, nullptr};
     u16 *gfx_apple_rotten = nullptr;
     u16 *gfx_apple_cursed = nullptr;
+
+    HudCache hudCache;
 };
 
+void invalidate_hud(RenderAssets &assets);
 void draw_game(const GameState &state, const RenderAssets &assets);
-void draw_stats(const GameState &state, bool internals, bool musicEnabled, uint8_t frame);
-void draw_menu(const GameState &state, const RenderAssets &assets, bool musicEnabled);
+void draw_stats(const GameState &state, RenderAssets &assets, bool internals, bool musicEnabled, uint8_t frame);
+void draw_menu(const GameState &state, RenderAssets &assets, bool musicEnabled);
 void blink_apples(const GameState &state, u16 *gfx_apple);
 
 #endif