hypno-tunnel

A little excercise for myself creating yet another demoscene'ish program, showing off classic Amiga demoscene-like graphics, On Linux.

Made with C using SDL2 that implements a perspective checkered spinning tunnel, Bresenham's Line Algortihm moving starfield and a isometric polygon cube moving floor. Now with a soundbyte bgm loop!

Should work on any Linux distribution that has SDL2 + SDL2_mixer.

Demo the demo:

https://www.youtube.com/watch?v=lOe61e6V5B4

https://www.youtube.com/watch?v=LgyQCojUx4M - Hi-Res version

Required:

sudo apt-get install build-essential libsdl2-dev libsdl2-mixer-dev

Usage:

$ hypno-tunnel -f / --fullscreen /  -w 1280 -h 720 / --width 1280 --height 720

What:

• -O3 optimized demoscene binary (20KB).
• 40KB soundbyte loop (courtesy of k!M), making the total size 60KB!

How:

• Perspective Tunneling: Rings scale with non-linear power distribution ($r^{2.2}$) to give a 3D depth-vanishing effect toward the horizon vanishing point.
• Animated Luminance: A sine-driven travelling wave calculates greyscale intensity ($lum \in [10, 250]$) across the concentric rings along with subtle axial rotation ($t \times 0.2$).
• Back-to-Front Compositing: The tunnel renders first directly onto the backbuffer, allowing the isometric floor cubes to cleanly occlude the bottom portion of the tunnel.
• It uses Bresenham's Line Algorithm for parrallax star trails.
• Isometric cube floor: We replace ASCII characters with filled polygonal quads, dramatically increasing the visual quality while keeping the same 2:1 isometric projection math and back-to-front rendering order.