“All I see is blonde, brunette, red head.” The iconic digital rain from The Matrix in C, with zero dependencies—not even ncurses.

Overview

This is my fork of Domsson’s beautiful Fakesteak. While going through his code, I wondered what it would take to faithfully recreate the original Matrix from the first movie without sacrificing its minimalism.

My implementation supports:

• Unicode characters.
• 24-bit RGB colors (truecolor).
• Glitches in the matrix.
• Ghosting effect of old monochrome CRT displays.
• Closely resembles the Matrix seen in the background during Neo and Cypher’s conversation.

With no dependencies, compilation is trivial:

$ cc -O3 main.c -o matrix
$ ./matrix

How does it work?

The program tracks the state of the terminal, such as code points, background and foreground colors, and cursor position, using multiple internal data buffers. On each frame, it updates these buffers and repaints the screen using ANSI escape codes:

static void term_print(const matrix *mat, size_t row, size_t col)
{
    size_t idx;
    idx = mat_idx(mat, row, col);
    wprintf(L"\x1b[%d;%dH\x1b[38;2;%d;%d;%dm%lc",
        row, col,
        mat->rgb[idx].color[R],
        mat->rgb[idx].color[G],
        mat->rgb[idx].color[B],
        mat->code[idx]);
}

The ghosting effect is achieved by carefully scaling the RGB channels before mixing them:

static void mat_shade(matrix *mat, size_t row, size_t col) 
{
    unsigned char *color;
    color = mat->rgb[mat_idx(mat, row, col)].color;
    color[R] = color[R] - (color[R] - COLOR_BG_RED) / 2;
    color[G] = color[G] - (color[G] - COLOR_BG_GRN) / 2;
    color[B] = color[B] - (color[B] - COLOR_BG_BLU) / 2;
}

The ghosting function emulates the dim after glow by gradually transitioning each raindrop’s color towards the background color. This approach provides two key benefits: straightforward color configuration that integrates naturally with (Unix) ricing and high-fidelity recreation of the Matrix aesthetic.

Customization

While you can alter almost every aspect, including speed, glitch frequency, and rain density, the most common customizations are the color scheme and character set.

There are three color settings: head, tail, and background. You can configure them using COLOR_*_RED, COLOR_*_GRN, and COLOR_*_BLU definitions found in main.c.

The UNICODE_MIN and UNICODE_MAX values control the Unicode block used. For example, setting them to 0x30A1 and 0x30F6 rains Katakana, if a font that supports Katakana is present on the system:

Files: source.tar.gz