You've already forked torvalds-GuitarPedal
mirror of
https://github.com/torvalds/GuitarPedal.git
synced 2026-08-19 05:33:46 +00:00
0c1b9c3db3
'Software' was the directory everything that was not KiCad ended up in, which stopped describing anything a while ago - Validation and the web app are software too. Worse, it put the shared parts inside the firmware, where they read as the firmware's own. They are not. Effects/ has three consumers built from it: the firmware, Validation's bench, and the web app's controls, all generated from the same POT: comments by gen_effects.py. Audio/ has two - the bench compiles the same biquads, the same envelope followers and the same single_sample(), which is the whole reason a measurement on a workstation says anything about the pedal. Neither belongs under Firmware/, so neither is under it any more: Effects/ one file per effect Audio/ the DSP they are built from, and the audio loop Firmware/ the rest of what runs on the pedal, and the submodules WebMIDI/ the web app scripts/ what the build runs Validation/ unchanged Hardware/, Documentation/, Images/ CMakeLists.txt and the wrapper Makefile move to the top with them, because the build now consumes four of those directories and generates into a fifth. board.local and build/ come along; MIDI_CC_MAP.md is generated into Documentation/ rather than into the old Software/ root. scripts/ goes with the build rather than staying under the firmware, because six of the ten had nothing to do with the firmware: gen_effects.py reads Effects/ and writes to three different places, pow2/log2/quarter_sine generate Audio/'s tables, check-readme.py compares Effects/ against the README, and server.py serves the web app. Four of them are invoked from Validation, which was reaching into Firmware/ for tooling - the same burying this commit is undoing. The four that really are about the firmware are ELF checks the top-level build drives anyway, and a second scripts directory would only be a second place to look. C includes say "Audio/foo.h" and the generated map says "Effects/bar.h", with the repository root on the include path for both the firmware and the bench. Spelling the directory out rather than relying on a bare name is what keeps Audio/cycles.h shimmable: a quoted include searches the including file's own directory first. The submodules are renamed as well as moved. git mv updates their paths but leaves the section names, and 'Software/pico-sdk' surviving in .gitmodules would be the word this commit removes, still load-bearing. That meant the nested modules under pico-sdk too - six .git files pointing into .git/modules/Software - which is why 'git submodule update --init --recursive' is worth running once after pulling this. Verified rather than assumed: a clean configure and build, make check (failing only on the missing-eeprom case it already failed on), check-effects, all four analysis pages reproducing every series and drawing every chart, and a flash to the board that still measures a routed reverb where it did before. One latent bug fell out of it. bench/coeff declared only quarter_sine.h of the three generated math tables, and Audio/util.h includes pow2.h and log2.h as well - so building that target with an empty gen/ could never have worked. 'make bench' builds bench/bench first, which generates all three, so it stayed hidden until this rebuilt everything from nothing. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
71 lines
1.8 KiB
C
71 lines
1.8 KiB
C
// NAME: Compressor [COMPRESSOR]
|
|
// PRIORITY: 30
|
|
// POT: "Level" LINEAR(-60.0 -10.0) = -35.0 dB
|
|
// POT: "Attack" LINEAR(2.0 100.0) = 15.0 ms
|
|
// POT: "Release" LINEAR(50.0 500.0) = 150.0 ms
|
|
// POT: "Ratio" EXPONENTIAL(1.0 20.0) = 4.8 x
|
|
// POT: "Boost" LINEAR(0.0 24.0) = 6.0 dB
|
|
//
|
|
// Compressor Effect
|
|
//
|
|
|
|
static struct {
|
|
// Pot values (pre-computed for step calculation convenience)
|
|
float level, ratio, boost;
|
|
|
|
// Envelope follower
|
|
struct envelope envelope;
|
|
|
|
// Compressor state
|
|
float compression;
|
|
} compressor = {
|
|
.level = 1.0,
|
|
.compression = 1.0
|
|
};
|
|
|
|
static inline void compressor_init(unsigned char pot[10])
|
|
{
|
|
float level_db = compressor_level_pot(pot);
|
|
compressor.level = db_to_level(level_db);
|
|
|
|
float attack_ms = compressor_attack_pot(pot);
|
|
float release_ms = compressor_release_pot(pot);
|
|
envelope_init(&compressor.envelope, attack_ms, release_ms);
|
|
|
|
float ratio = compressor_ratio_pot(pot);
|
|
compressor.ratio = 1.0f - (1.0f / ratio);
|
|
|
|
float boost_db = compressor_boost_pot(pot);
|
|
compressor.boost = db_to_level(boost_db);
|
|
}
|
|
|
|
// This may be overkill, but we're doing this by the book
|
|
static inline float mypow(float a, float b)
|
|
{
|
|
return pow2(log2f(a) * b);
|
|
}
|
|
|
|
static inline float compressor_step(float in)
|
|
{
|
|
// Envelope follower
|
|
float env = envelope_step(&compressor.envelope, in);
|
|
|
|
// Compression calculation.
|
|
//
|
|
// When we go over the compression level, we calculate a
|
|
// target compression multiplier:
|
|
//
|
|
// target = (level / env) ^ (1 - 1/ratio)
|
|
//
|
|
float target = 1.0f;
|
|
if (env > compressor.level) {
|
|
target = mypow(compressor.level / env, compressor.ratio);
|
|
compressor_effect.intense = 1;
|
|
}
|
|
|
|
// ... and then we smooth the compression factor to prevent clicks
|
|
compressor.compression = linear(0.01f, compressor.compression, target);
|
|
|
|
return in * compressor.compression * compressor.boost;
|
|
}
|