The Matrix digital rain

THE MATRIX DIGITAL RAIN

22 AUGUST 2022

+
+

“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

by W. D. Sadeep Madurange