Galaxy-Defender-Game

🎮 Galaxy Defender Game (C++ OpenGL/GLUT)

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🧾 Overview

🚀 This is a 2D space shooting game made in C++ using OpenGL/GLUT. The player controls a rocket, shoots enemies, and survives as long as possible while increasing score.

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⚙️ Game Setup

• 🖥️ A game window is created using GLUT
• 📏 SetCanvasSize() defines screen size
• 🎨 OpenGL handles all drawing (shapes, colors, text)

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🧠 Game Variables

• 🚀 Player position: rx, ry
• 👾 Enemies: ex[], ey[]
• 🔫 Bullets: arrays for position + active state
• ❤️ Lives: lives = 3
• 🧮 Score: score = 0
• 🎮 Game states: start, pause, game over

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🖥️ Display Function (Rendering Engine)

🎯 This function draws everything on screen every frame:

🎬 Start Screen

• Enter player name 🧑
• Press ENTER to start ⌨️

💀 Game Over Screen

• Shows final score 🧮
• Shows player name 🧑
• Stops game

🌌 Gameplay Screen

• 🚀 Draws rocket
• 👾 Draws enemies
• 🔫 Draws bullets
• 🌟 Background stars
• ❤️ Shows lives
• 🧮 Shows score

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⌨️ Controls

🚀 Movement

• ⬅️ Left arrow → move left
• ➡️ Right arrow → move right

🔫 Actions

• SPACE → shoot bullet
• P → pause ⏸️
• R → resume ▶️
• ENTER → start game

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⏱️ Timer Function (Game Engine)

⚡ This is the MOST IMPORTANT part of the game loop.

🔫 Bullet System

• Bullets move upward ⬆️
• Deactivate when out of screen

👾 Enemy System

• Enemies move downward ⬇️
• Reset position when hit or out of screen

💥 Collision Detection

• If bullet touches enemy:

  • 💥 Enemy destroyed
  • 🧮 Score +5
  • 👾 Enemy respawns

❤️ Life System

• If enemy reaches bottom:

  • ❤️ Lives decrease

🚀 Difficulty Increase

• As score increases:

  • 👾 Enemy speed increases

💀 Game Over

• When lives = 0:

  • Game ends
  • Score saved to file 💾 (data.txt)

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💾 File Handling

📁 Stores player results:

• Name 🧑
• Score 🧮

Example:

Name: Saad | Score: 120

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🔁 Game Loop Flow

🚀 The game runs continuously like this:

🖥️ Display → 🎮 Input → ⚡ Timer → 🔁 Repeat

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🧩 Main Function

• Initializes GLUT 🖥️
• Creates window 📦
• Registers functions 🎮
• Starts infinite loop 🔁 (glutMainLoop())

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📌 Summary

🎯 Galaxy Defender is a real-time arcade shooter game where:

• 🚀 Player controls a rocket
• 👾 Enemies fall from top
• 🔫 Player shoots bullets
• 💥 Collision gives score
• ❤️ Lives decrease on miss
• 💀 Game ends at zero lives
• 💾 Score is saved automatically

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