Assembly Raycaster

A Wolfenstein 3D–style raycaster engine written in ARM64 assembly, with a minimal C/SDL2 wrapper for cross-platform display.

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Overview

This project implements a classic raycasting engine almost entirely in ARM64 assembly language. It renders a first-person 3D view from an 8×8 tile-based map, focusing on low-level control, determinism, and performance.

Features:

• Real-time raycasting with 64-angle rotation precision
• Distance-based lighting with three brightness zones
• Gradient sky and solid-color floor rendering
• Smooth WASD movement with wall collision detection

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Architecture

main.c          - SDL2 window setup, input handling, render loop
raycaster.asm   - ARM64 assembly raycasting engine

How It Works

1. main.c initializes SDL2, allocates a framebuffer, and polls keyboard input.

2. raycaster.asm is invoked every frame and:

   • Clears the screen (gradient sky + floor)
   • Processes WASD input for movement and rotation
   • Casts 640 rays (one per screen column)
   • Uses precomputed sin/cos lookup tables
   • Computes wall distances and projected heights
   • Applies distance-based lighting and wall colors
   • Writes pixels directly into the framebuffer (ARGB8888)

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Building

Requirements

• macOS on Apple Silicon (ARM64)
• SDL2 (brew install sdl2)
• Xcode Command Line Tools

Compile and Run

# Assemble the raycaster
as -o raycaster.o raycaster.asm

# Compile and link with SDL2
clang -o raycaster main.c raycaster.o \
    -I/opt/homebrew/include \
    -L/opt/homebrew/lib \
    -lSDL2

# Run
./raycaster

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Controls

Key	Action
W	Move forward
S	Move backward
A	Turn left
D	Turn right

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Technical Details

• Resolution: 640×480 @ 60 FPS (capped)
• Map Size: 8×8 tiles (32 pixels per tile)
• Color Format: ARGB8888
• Trig Tables: 64-entry sine and cosine tables (256 fixed-point scale)
• Ray Steps: Up to 64 steps per ray

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