Added unit tests

ui.c

@@ -30,6 +30,16 @@ static bool is_animating;
 static Vector2 new_tile = {-1, 1};
 static float new_tile_animation_progress;
 
+typedef struct {
+  Vector2 from;
+  Vector2 to;
+  // We need to store this to know when to (show the) merge, if merging
+  Vector2 position;
+  int value;
+} animated_tile_t;
+
+static animated_tile_t animated_tiles[BOARD_WIDTH * BOARD_HEIGHT];
+
 // Common logic shared between both input handlers
 static void after_input(GameState_t *game_state) {
   spawn_tile(game_state, &new_tile);
@@ -132,21 +142,20 @@ void handle_keyboard_input(GameState_t *game_state) {
   }
 }
 
-void animate_new_tile() {
+static void animate_new_tile() {
   if (new_tile.x == -1 && new_tile.y == -1)
     return;
 
-  // Simple pop-in animation that scales the tile from 0 to full size
-  new_tile_animation_progress += GetFrameTime() * 5; // Adjust speed as needed
+  new_tile_animation_progress += GetFrameTime() * 5;
   if (new_tile_animation_progress >= 1.0f) {
-    new_tile_animation_progress = 0.3f;
+    new_tile_animation_progress = 0.0f;
     new_tile = (Vector2){-1, -1}; // Reset after animation completes
     is_animating = false;
   }
 }
 
 // Main render loop, responsible ONLY for redering
-void render(GameState_t *game_state) {
+bool render(GameState_t *game_state) {
   if (is_animating) {
     animate_new_tile();
   }
@@ -163,7 +172,7 @@ void render(GameState_t *game_state) {
       }
 
       if (is_animating && new_tile.x == x && new_tile.y == y) {
-        float scale = new_tile_animation_progress; // Scale from 0 to 1
+        float scale = 1.0 - 0.2 * sin(new_tile_animation_progress * PI);
         int scaled_size = (int)(TILE_SIZE * scale);
         int offset = (TILE_SIZE - scaled_size) / 2;
         DrawRectangle(pos_x + offset, pos_y + offset, scaled_size, scaled_size, tile_colors[color_index]);
@@ -207,4 +216,5 @@ void render(GameState_t *game_state) {
     DrawRectangle(400 - 100, 450, 200, 40, RED);
     DrawText("Try again", 400 - MeasureText("Try again", 20) / 2, 455 + 4, 20, WHITE);
   }
+  return is_animating;
 }