From e04ce2ab6ca82d0014bec8b217215f35b436ff25 Mon Sep 17 00:00:00 2001 From: Sadeep Madurange Date: Fri, 26 Dec 2025 16:53:45 +0800 Subject: FPM lock journal style. --- _site/log/matrix-digital-rain/index.html | 39 +++++++++++++++++--------------- 1 file changed, 21 insertions(+), 18 deletions(-) (limited to '_site/log/matrix-digital-rain/index.html') diff --git a/_site/log/matrix-digital-rain/index.html b/_site/log/matrix-digital-rain/index.html index f254ed2..8383776 100644 --- a/_site/log/matrix-digital-rain/index.html +++ b/_site/log/matrix-digital-rain/index.html @@ -54,45 +54,48 @@ than it needed to be.

Moved phosphor decay into the 4th byte of the RGB union–should’ve done this -in 2022. What was I thinking.

+in 2022; What was I thinking.

Keeping the RGB union despite portability concerns. All my systems are little-endian and the code is cleaner this way.

Fixed Unicode by introducing a charset array. UNICODE(min, max) packs Unicode -ranges into uint64–low four bytes for start, high four bytes for end. +ranges into uint64: low four bytes for start, high four bytes for end. insert_code() unpacks a random block and picks a character from it:

-
static uint64_t glyphs[] = {
+
#define UNICODE(min, max)  (((uint64_t)max << 32) | min)
+
+static uint64_t glyphs[] = {
     UNICODE(0x0021, 0x007E), /* ASCII */
     UNICODE(0xFF65, 0xFF9F), /* Half-width Katakana */
 };
-

-
-
Full-width Katakana breaks column alignment. Stick to half-width
-(U+FF61-U+FF9F) range. Compile with -DNOKANA to disable Katakana altogether.

 
-
blend() simulates phosphor decay by eroding RGB channels toward
-background color:

-
-
static inline void blend(matrix *mat, size_t row, size_t col)
+static inline void insert_code(matrix *mat,
+    size_t row, size_t col) 
 {
-    unsigned char *color = mat->rgb[index(mat, row, col)].color;
-    color[R] = color[R] - (color[R] - RGB_BG_RED) / DECAY_MPLIER;
-    color[G] = color[G] - (color[G] - RGB_BG_GRN) / DECAY_MPLIER;
-    color[B] = color[B] - (color[B] - RGB_BG_BLU) / DECAY_MPLIER;
+    uint64_t blk;
+    uint32_t min, max;
+
+    blk = glyphs[(rand() % glyphlen)];
+    min = (uint32_t)blk;
+    max = (uint32_t)(blk >> 32);
+    mat->code[index(mat, row, col)] = rand() % (max - min) + min;
 }
 

 
-
That’s still good. Leaving it alone.

+
Full-width Katakana breaks column alignment. Stick to half-width
+(U+FF61-U+FF9F) range. Compile with -DNOKANA to disable Katakana altogether.

+
+
blend() is still good. Leaving it alone.

 
 
Tossed license and automake cruft. Just cc -O3 main.c -o matrix now. Don’t
 need the ceremony.

 
-
Runs at 2-3% CPU on OpenBSD (T490). No regressions. Fans are quiet.

+
Runs at 2-3% CPU on OpenBSD (T490). No cause to measure performance more
+precisely. No regressions. Fans are quiet.

 
 
Commit:
-03f8d87

+69a888a

by W. D. Sadeep Madurange

-- cgit v1.2.3