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Diffstat (limited to '_log/matrix-digital-rain.md')
| -rw-r--r-- | _log/matrix-digital-rain.md | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/_log/matrix-digital-rain.md b/_log/matrix-digital-rain.md index 8512208..f1553e1 100644 --- a/_log/matrix-digital-rain.md +++ b/_log/matrix-digital-rain.md @@ -16,44 +16,46 @@ than it needed to be. </video> 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: ``` +#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](https://git.asciimx.com/matrix-digital-rain/commit/?id=03f8d87ba7c2e46bd3f3cc4c772fb3a2ac740c92) +[69a888a](https://git.asciimx.com/matrix-digital-rain/commit/main.c?id=69a888a5b0bc4ef4bce4f86c1556a06f0f131fda) |