feat: Add rabbit element with jumping and movement behaviors

This commit introduces a new rabbit element with the following features:
- Jumping mechanics with variable height
- Random direction changes
- Falling and basic ground interaction
- Color variations
- Avoidance of water

The changes include:
- Added RABBIT constant to element types
- Created rabbit.js with updateRabbit function
- Added RABBIT_COLORS to constants
- Implemented basic rabbit movement and behavior logic

js/constants.js

@@ -17,6 +17,7 @@ const FLOWER_COLORS = ['#FF0000', '#FFFF00', '#FF00FF', '#FFA500', '#FFFFFF', '#
 const LEAF_COLOR = '#228B22';
 const FIRE_COLORS = ['#FF0000', '#FF3300', '#FF6600', '#FF9900', '#FFCC00', '#FFFF00'];
 const LAVA_COLORS = ['#FF0000', '#FF3300', '#FF4500', '#FF6600', '#FF8C00'];
+const RABBIT_COLORS = ['#FFFFFF', '#E0E0E0', '#D3C8B4']; // White, Light Gray, Light Brown
 
 // Color variation functions
 function getRandomColorVariation(baseColor, range) {
@@ -58,6 +59,7 @@ const TREE_SEED = 11;
 const LEAF = 12;
 const FIRE = 13;
 const LAVA = 14;
+const RABBIT = 15;
 
 // Flammable materials
 const FLAMMABLE_MATERIALS = [GRASS, WOOD, SEED, GRASS_BLADE, FLOWER, TREE_SEED, LEAF];

js/elements/rabbit.js

@@ -0,0 +1,110 @@
+// Rabbit element behaviors
+function updateRabbit(x, y) {
+    const metadata = getMetadata(x, y) || {};
+    
+    // Initialize rabbit metadata if it doesn't exist
+    if (!metadata.initialized) {
+        metadata.initialized = true;
+        metadata.jumpCooldown = 0;
+        metadata.direction = Math.random() > 0.5 ? 1 : -1; // 1 for right, -1 for left
+        metadata.jumpHeight = 0;
+        metadata.colorIndex = Math.floor(Math.random() * RABBIT_COLORS.length);
+        setMetadata(x, y, metadata);
+        return true;
+    }
+    
+    // Update metadata
+    metadata.jumpCooldown = Math.max(0, metadata.jumpCooldown - 1);
+    
+    // Check if rabbit is on solid ground
+    const onGround = getPixel(x, y + 1) !== EMPTY && getPixel(x, y + 1) !== WATER;
+    
+    // Rabbit falls if there's nothing below
+    if (!onGround && metadata.jumpHeight <= 0) {
+        if (getPixel(x, y + 1) === EMPTY) {
+            setPixel(x, y, EMPTY);
+            setPixel(x, y + 1, RABBIT);
+            moveMetadata(x, y, x, y + 1);
+            return true;
+        }
+        // Rabbit can swim but prefers not to
+        else if (getPixel(x, y + 1) === WATER) {
+            // 50% chance to swim down or stay in place
+            if (Math.random() < 0.5) {
+                setPixel(x, y, EMPTY);
+                setPixel(x, y + 1, RABBIT);
+                moveMetadata(x, y, x, y + 1);
+                return true;
+            }
+            // When in water, try to jump out
+            metadata.jumpCooldown = 0;
+        }
+    }
+    
+    // Rabbit jumps occasionally when on ground
+    if (onGround && metadata.jumpCooldown === 0) {
+        // Start a jump
+        metadata.jumpHeight = 3 + Math.floor(Math.random() * 2); // Jump 3-4 blocks high
+        metadata.jumpCooldown = 30 + Math.floor(Math.random() * 50); // Wait 30-80 frames before next jump
+        
+        // Randomly change direction sometimes
+        if (Math.random() < 0.3) {
+            metadata.direction = -metadata.direction;
+        }
+        
+        setMetadata(x, y, metadata);
+    }
+    
+    // Execute jump if jump height is positive
+    if (metadata.jumpHeight > 0) {
+        // Move up
+        if (getPixel(x, y - 1) === EMPTY) {
+            setPixel(x, y, EMPTY);
+            setPixel(x, y - 1, RABBIT);
+            moveMetadata(x, y, x, y - 1);
+            metadata.jumpHeight--;
+            setMetadata(x, y - 1, metadata);
+            return true;
+        }
+        // If can't move up, try moving diagonally up in current direction
+        else if (getPixel(x + metadata.direction, y - 1) === EMPTY) {
+            setPixel(x, y, EMPTY);
+            setPixel(x + metadata.direction, y - 1, RABBIT);
+            moveMetadata(x, y, x + metadata.direction, y - 1);
+            metadata.jumpHeight--;
+            setMetadata(x + metadata.direction, y - 1, metadata);
+            return true;
+        }
+        // If can't move diagonally up, try moving horizontally
+        else if (getPixel(x + metadata.direction, y) === EMPTY) {
+            setPixel(x, y, EMPTY);
+            setPixel(x + metadata.direction, y, RABBIT);
+            moveMetadata(x, y, x + metadata.direction, y);
+            metadata.jumpHeight = 0; // End jump if blocked
+            setMetadata(x + metadata.direction, y, metadata);
+            return true;
+        }
+        // If completely blocked, end jump
+        else {
+            metadata.jumpHeight = 0;
+            setMetadata(x, y, metadata);
+        }
+    }
+    // Move horizontally when not jumping
+    else if (metadata.jumpCooldown > 0 && metadata.jumpCooldown < 15 && onGround) {
+        // Hop horizontally between jumps
+        if (getPixel(x + metadata.direction, y) === EMPTY) {
+            setPixel(x, y, EMPTY);
+            setPixel(x + metadata.direction, y, RABBIT);
+            moveMetadata(x, y, x + metadata.direction, y);
+            return true;
+        }
+        // If blocked, try to change direction
+        else {
+            metadata.direction = -metadata.direction;
+            setMetadata(x, y, metadata);
+        }
+    }
+    
+    return false;
+}