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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>
61 lines
1.2 KiB
C
61 lines
1.2 KiB
C
typedef _Complex float complex_t;
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static inline complex_t twiddle_factor(float phase)
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{
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struct sincos sc = fastsincos(phase);
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return __builtin_complex(sc.cos, -sc.sin);
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}
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static inline unsigned reverse_n_bits(unsigned int i, unsigned int bits)
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{
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#ifdef __arm__
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// Newer versions of gcc have this as a builtin
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asm inline("rbit %0,%1":"=r" (i): "r" (i));
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return i >> (32-bits);
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#else
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int res = 0;
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for (int j = 0; j < bits; j++) {
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res <<= 1;
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res |= i & 1;
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i >>= 1;
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}
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return res;
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#endif
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}
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//
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// Cooley-Tukey Radix-2 DIT FFT.
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//
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// Operates in-place on a complex array.
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//
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static inline void fft(complex_t *buf, int bits)
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{
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int n = 1 << bits;
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// Bit-reversal permutation
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for (int i = 0; i < n - 1; i++) {
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int j = reverse_n_bits(i, bits);
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if (i < j) {
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complex_t tmp = buf[i];
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buf[i] = buf[j];
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buf[j] = tmp;
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}
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}
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// Cooley-Tukey butterfly
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for (int shift = 0; shift < bits; shift++) {
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int step = 1 << shift;
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for (int j = 0; j < step; j++) {
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complex_t w = twiddle_factor(u32_to_fraction(j << (31-shift)));
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for (int i = j; i < n; i += step * 2) {
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int match = i + step;
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complex_t tmp = w * buf[match];
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buf[match] =buf[i] - tmp;
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buf[i] += tmp;
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}
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}
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}
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}
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