cub3d

This project has been created as part of the 42 curriculum by wlucke, dasal.

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Description

cub3d renders a navigable first-person 3D world from a simple 2D grid map using the DDA (Digital Differential Analysis) raycasting algorithm. Every frame, rays are cast per screen column to determine wall distances and texture offsets — producing a perspective-correct, textured 3D view without any 3D graphics API.

The project is split into two parts: a mandatory raycaster with textured walls and a bonus implementation adding doors, animated sprites, a minimap, and mouse look.

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Features

Mandatory

• DDA raycasting with perspective correction (no fisheye distortion)
• Four directional wall textures (North / South / East / West)
• Configurable floor and ceiling colors (RGB)
• .cub map file parser with full validation (flood-fill enclosed-map check)
• WASD movement + arrow key rotation
• Collision detection

Bonus

• Interactive doors — 11-frame open/close animation, toggleable with Space
• Animated sprites — collectible key with cycling animation frames
• Real-time minimap — 10×10 overhead overlay with player direction indicator
• Mouse look — free-look camera control with configurable sensitivity
• Sprite depth sorting — back-to-front ordering relative to walls

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Controls

Key	Action
W A S D	Move forward / left / backward / right
← →	Rotate camera
Mouse	Free look (horizontal)
Space	Interact with door (requires key)
ESC	Quit

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Map Format

Maps are defined in .cub files:

NO ./textures/walls/brks_b.xpm
SO ./textures/walls/brks_g.xpm
WE ./textures/walls/brks_r.xpm
EA ./textures/walls/brks_y.xpm
C 226,186,255
F 178,255,186

1111111111111111
1E00000D000001
10000000000001
1D00000D000001
10010000001001
11111111111111

Character	Meaning
1	Wall
0	Open floor
D	Door (interactive)
N/S/E/W	Player spawn + initial direction

The parser validates that all walkable areas are fully enclosed by walls using a flood-fill algorithm.

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Build & Run

Requirements: Linux, gcc, X11 dev libraries (libx11-dev, libxext-dev)

# Build
cd cub3d
make

# Run
./cub3d maps/config1.cub

Five example maps are included (config1.cub – config5.cub).

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Technical Details

Constant	Value
Resolution	1920 × 930
Target FPS	59
Texture size	128 × 128 px
FOV	~66°
Move speed	7 units/s
Max sprites	128

Raycasting pipeline (per column, per frame):

1. Compute ray direction from camera plane and player angle
2. Calculate delta distances for DDA grid traversal
3. Step through the grid until a wall is hit
4. Compute perpendicular wall distance (corrects fisheye)
5. Sample the appropriate texture column and rasterize to screen

Sprite rendering: sprites are transformed into camera space, depth-sorted back-to-front, projected onto the screen, and rendered column-by-column — skipping transparent pixels.

Delta time: movement and rotation speeds are frame-rate independent, scaled by elapsed time per frame.

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Project Structure

cub3d/
├── 0_main.c              Entry point, MLX window & event loop
├── 1_init*.c             Initialization, texture loading
├── 2_parsing_*.c         .cub file parsing & map validation
├── 3_render_*.c          Raycasting, walls, doors, sprites, minimap
├── 4_controller_*.c      Keyboard & mouse input, movement
├── 8_errors_0.c          Error handling
├── 9_utils_*.c           Utilities, memory management, timing
├── cub3d.h               Master header (structs, constants, prototypes)
├── maps/                 Example .cub map files
├── textures/             Wall, door, and sprite XPM assets
└── libft/                Custom C standard library (ft_printf, GNL, …)

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Resources

• Lode's Raycasting Tutorial — primary reference for the DDA algorithm
• MinLibX Documentation