Open mouth only when eating.

juanitobebe · May 25, 2020 · 95dfbb3 · 95dfbb3
1 parent 0438295
commit 95dfbb3
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Showing 3 changed files with 32 additions and 35 deletions.
diff --git a/src/main.c b/src/main.c
@@ -81,12 +81,13 @@ void main() {
 
   UINT8 eating = 0;
   UINT8 alive = 1;
+  UBYTE snake_new_direction =
+      0x0;  // Placeholder, snake won't move until joypad press.
   while (alive) {
     AddToTimer();
 
     // Register Input
-    UBYTE snake_previous_direction, snake_new_direction;
-    snake_previous_direction = snake_new_direction = snake_c.direction;
+    UBYTE snake_previous_direction = snake_c.direction;
     switch (joypad()) {
       case J_LEFT:
         snake_new_direction = J_LEFT;
@@ -105,30 +106,31 @@ void main() {
     }
 
     // Move periodically
-    if ((GetTimeFromTimer() & (UBYTE)0x03) == 0) {
+    if ((GetTimeFromTimer() & (UBYTE)0x07) == 0) {
       // Snake collisions
       alive = !SnakeWallCollision(&snake_c, snake_new_direction) &&
-              !SnakeCollision(&snake_c, snake_previous_direction);
-      MoveSnake(&snake_c, snake_new_direction, snake_previous_direction);
-    }
+              !SnakeCollision(&snake_c, snake_new_direction);
 
-    if (alive) {
-      // Prey and Snake collisions
-      eating = EatingPreyCollision(&snake_c, &prey_c);
+      if (alive) {
+        MoveSnake(&snake_c, snake_new_direction, snake_previous_direction);
 
-      // Animation
-      RotateSnakeHead(snake_c.direction);
-      AnimateMouth(snake_c.direction);
+        // Prey and Snake collisions
+        eating = EatingPreyCollision(&snake_c, &prey_c);
 
-      // Prey handling
-      if (eating) {
-        snake_c.size += 1;
-        SpawnPrey(&prey_c, &snake_c);
-      } else if (IsSpecialPrey(&prey_c) && PreyTimeout(&prey_c)) {
-        SpawnPrey(&prey_c, &snake_c);
-      }
+        // Animation
+        RotateSnakeHead(snake_c.direction);
+        AnimateMouth(snake_c.direction, eating);
 
-      Draw(&snake_c, &prey_c);
+        // Prey handling
+        if (eating) {
+          snake_c.size += 1;
+          SpawnPrey(&prey_c, &snake_c);
+        } else if (IsSpecialPrey(&prey_c) && PreyTimeout(&prey_c)) {
+          SpawnPrey(&prey_c, &snake_c);
+        }
+
+        Draw(&snake_c, &prey_c);
+      }
     }
 
     // House keeping

diff --git a/src/snake.c b/src/snake.c
@@ -132,34 +132,31 @@ void RotateSnakeHead(UBYTE direction) {
   }
 }
 
-void AnimateMouth(UBYTE direction) {
+void AnimateMouth(UBYTE direction, UINT8 eating) {
   // Head sprite tiles are:
   //   0: Closed Horizontal
   //   1: Open Horizontal
   //   2: Closed Vertical
   //   3: Open Vertical
-  UINT8 current_tile = get_sprite_tile(0);
-  UBYTE is_mouth_closed = (current_tile == 0 || current_tile == 2) ? 1 : 0;
-
   switch (direction) {
     case J_LEFT:
     case J_RIGHT:
-      set_sprite_tile(0, (is_mouth_closed) ? 1 : 0);
+      set_sprite_tile(0, (eating) ? 1 : 0);
       break;
     case J_UP:
     case J_DOWN:
-      set_sprite_tile(0, (is_mouth_closed) ? 3 : 2);
+      set_sprite_tile(0, (eating) ? 3 : 2);
   }
 }
 
 UINT8
-SnakeCollision(SnakeCharacter* snake_c, UBYTE snake_previous_direction) {
+SnakeCollision(SnakeCharacter* snake_c, UBYTE snake_next_direction) {
   // Collided by going into oposite direction.
   if (snake_c->size > 0 &&
-      ((snake_c->direction == J_LEFT && snake_previous_direction == J_RIGHT) ||
-       (snake_c->direction == J_RIGHT && snake_previous_direction == J_LEFT) ||
-       (snake_c->direction == J_UP && snake_previous_direction == J_DOWN) ||
-       (snake_c->direction == J_DOWN && snake_previous_direction == J_UP))) {
+      ((snake_c->direction == J_LEFT && snake_next_direction == J_RIGHT) ||
+       (snake_c->direction == J_RIGHT && snake_next_direction == J_LEFT) ||
+       (snake_c->direction == J_UP && snake_next_direction == J_DOWN) ||
+       (snake_c->direction == J_DOWN && snake_next_direction == J_UP))) {
     return 1;
   }
 

diff --git a/src/snake.h b/src/snake.h
@@ -27,10 +27,8 @@ void UpdateBody(SnakeCharacter* snake_c, UINT8 snake_prev_x, UINT8 snake_prev_y,
 // I kind of like the way it moves.
 void RotateSnakeHead(UBYTE direction);
 
-// Animates the mouth based on current direction.
-// If the mouth is closed then we open it, if it was open then we close it.
-// TODO(juanitobebe): I liked it more before but I guess I don't really need it.
-void AnimateMouth(UBYTE direction);
+// Animates the mouth to look like eating the prey.
+void AnimateMouth(UBYTE direction, UINT8 eating);
 
 // Returns 1 if there's a collision of the Snake head and body, 0 if not.
 UINT8