Tower Defense Frontend Code Overview

1. HTML Structure

  • Help Section: Explains gameplay, tower placement, upgrades, coins, and tips.
  • Points Display: Shows player points (top left).
  • Coin Display: Shows player coins (top right).
  • Health Bar: Shows player health (centered above the game area).
  • Game Container: Main area where the game is rendered.
  • Tower Menu: Appears below the map for dragging towers onto the field.

2. Styling (CSS)

  • Dark Theme: Black background, white borders, and colored highlights.
  • Game Area: Fixed size, background image, and border.
  • Towers/Enemies: Absolutely positioned, with z-index layering.
  • Health Bar: Gradient color changes based on health.
  • Points/Coins: Styled for visibility and contrast.
  • Tower Radius: Dashed circles show tower attack range.

3. JavaScript Functionality

Constants & Utilities

  • Tower and Enemy Data: Arrays define tower types, images, costs, and radii.
  • Path Points: Array of coordinates for enemy movement.
  • Utility Functions: lerp (linear interpolation), dist (distance calculation).

Points API Integration

  • Class Points: Handles fetching, updating, and displaying player points from a backend API. Points auto-increment every 20 seconds.

Game Classes

  • Enemy: Handles enemy movement along the path, health, death, and DOM updates.
  • Tower: Represents a placed tower, stores its type, position, and state.
  • Projectile: Animates projectiles from towers to enemies, applies damage on hit.
  • Game: Main controller for game state, UI, enemy spawning, tower placement, upgrades, and attack logic.
  • Upgrades: Handles tower upgrades, applying new abilities and stats per level.

Gameplay Logic

  • Enemy Spawning: Multiple enemy types spawn at intervals, with increasing difficulty.
  • Tower Placement: Drag-and-drop from the menu, with checks to prevent invalid placement (e.g., on the path or overlapping).
  • Tower Attacks: Each tower type has unique attack logic (e.g., lasers, projectiles, AoE, support buffs).
  • Upgrades: Towers can be upgraded up to level 5, unlocking new abilities and increasing stats.
  • Health & Game Over: Player loses health when enemies reach the end. Game over popup appears when health is zero, with a restart option.

UI Interactions

  • Tower Menu: Drag towers onto the map.
  • Upgrade Button: Click a tower to upgrade if enough coins.
  • Dynamic UI: All elements update in real-time (coins, health, points, tower visuals).

Event Handling

  • Drag-and-Drop: For tower placement.
  • Click Events: For upgrades and restarting after game over.
  • Responsive Positioning: Coin and points displays reposition on window resize.

4. External Assets

  • Images: Towers, enemies, projectiles, and background are loaded from external URLs.

Summary:
The code implements a feature-rich, interactive Tower Defense game in the browser using vanilla JavaScript, HTML, and CSS. It supports OOP design, real-time DOM manipulation, drag-and-drop UI, API integration for points, and a robust upgrade system for towers.

5. Technical Illustrations

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