Game Development Fundamentals: Pygame, Unity, and Graphics

Posted on Mar 30, 2026 in Computers

1. Basic Pygame Functions

Pygame is a Python library used to create games.

Common Functions

  • pygame.init(): Initializes all Pygame modules
  • pygame.display.set_mode((width, height)): Creates the game window
  • pygame.display.set_caption(“Title”): Sets window title
  • screen.fill(color): Fills screen with a color
  • pygame.display.update(): Updates the screen
  • pygame.time.Clock(): Controls game speed (FPS)

2. Events (Keyboard & Mouse)

Pygame detects user actions using an event loop.

Key Concepts Summary

  • Game Loop: Runs continuously
  • Events: Handle input (keyboard/mouse)
  • Coordinates: Control object position
  • Frame Rate (FPS): Smooth movement

Mouse Events

  • pygame.MOUSEBUTTONDOWN: Mouse click
  • pygame.MOUSEBUTTONUP: Mouse release
  • pygame.MOUSEMOTION: Mouse movement

3. DirectX Fundamentals

DirectX is a collection of APIs by Microsoft used for handling graphics, sound, and input in games. Direct3D is the main part used for 3D graphics rendering.

Device & Context

  • Device: Represents the GPU (graphics hardware). Used to create resources like buffers, textures, and shaders. Think: Device = Resource creator.
  • Device Context: Used to control rendering operations. Sends commands to GPU (draw calls, set shaders, bind resources). Think: Context = Command executor.

Swap Chain & Page Flipping

A swap chain manages multiple buffers used for displaying images.

  • Front Buffer: Currently displayed
  • Back Buffer: Where rendering happens

Page Flipping Process

  1. Render scene to back buffer
  2. Call Present()
  3. Back buffer becomes front buffer
  4. Old front buffer becomes back buffer

This avoids flickering and provides smooth animation.

4. Unity Game Engine

Unity is a popular game engine used to develop 2D, 3D, AR, and VR games.

GameObjects & Components

  • GameObject: The basic object in Unity (e.g., Player, Camera, Light). It does nothing by itself.
  • Components: Add functionality to GameObjects.

Common Components

  • Transform: Position, rotation, scale
  • Renderer: Shows object
  • Collider: Detects collision
  • Rigidbody: Physics

GameObject = container, Components = behavior.

Collision Events

Collision events occur when two objects with colliders interact:

  • OnCollisionEnter(): When collision starts
  • OnCollisionStay(): While colliding
  • OnCollisionExit(): When collision ends

5. Game Engine Overview

A game engine is a software framework used to design and develop video games, providing tools to build games without creating everything from scratch.

Key Functions

  • Graphics Rendering: Displays 2D/3D visuals
  • Physics Engine: Handles motion, gravity, collisions
  • Input Handling: Keyboard, mouse, controller support
  • Sound System: Music and sound effects
  • Scripting: Controls game logic and behavior

Examples

  • Unity: Popular for 2D/3D games
  • Unreal Engine: High-quality graphics
  • Godot: Free and open-source

6. Homogeneous Coordinate System

A mathematical representation used in computer graphics to handle transformations like translation, rotation, and scaling easily.

Basic Idea

  • 2D: (x, y) becomes (x, y, w)
  • 3D: (x, y, z) becomes (x, y, z, w)

Conversion to Normal Coordinates

  • x = X / w
  • y = Y / w
  • z = Z / w

7. Types of Vectors

A vector is a quantity that has both magnitude (size) and direction.

  • Zero Vector: Zero magnitude, undefined direction.
  • Unit Vector: Magnitude 1, represents direction only.
  • Position Vector: Position of a point from origin.
  • Equal Vectors: Same magnitude and direction.
  • Negative Vector: Same magnitude, opposite direction.
  • Parallel Vectors: Same or opposite direction.
  • Collinear Vectors: Lying on the same line.
  • Co-initial Vectors: Same starting point.

8. Game Logic

Game logic refers to the set of rules and instructions that control how a game works and behaves.

Key Elements

  • Rules: Win/lose conditions
  • Player Actions: Movement, jumping, shooting
  • Game State: Score, level, health
  • AI Behavior: Controls NPCs
  • Collision Handling: Object interaction