L'électron rare
1848368bc2
Context: oscope-sphere is a new openFrameworks app (sibling of
oscope-of) that will render audio analysis on a 3D sphere. This
commit establishes the project tree and reuses the mature capture
and analysis layer from oscope-of.
Approach: Copy four proven source files byte-for-byte from
oscope-of/src/ (no modifications), create the standard oF directory
layout, and add a standalone clang++ test harness that validates two
design assumptions without requiring openFrameworks installed.
Changes:
- Create oscope-sphere/{src,tests,bin/data/shaders} directories
- Copy FFT.h/cpp, AudioAnalyzer.h/cpp, ScopeData.h,
HantekDevice.h/cpp from oscope-of/src (unmodified)
- Add addons.make and .gitignore for oF build system
- Add tests/check.h: lightweight CHECK/REPORT macros
- Add tests/test_analysis.cpp: two tests (FFT peak at bin 64,
per-channel isolation via dual-analyzer trick)
Impact: Test harness compiles with plain clang++ -std=c++17 and
passes 5/5 checks, confirming FFT correctness and AudioAnalyzer
channel isolation before any oF integration work begins.
60 lines
1.7 KiB
C++
60 lines
1.7 KiB
C++
#include "check.h"
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#include "FFT.h"
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#include "AudioAnalyzer.h"
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#include <cmath>
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#include <vector>
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using oscope::AudioAnalyzer;
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using oscope::FFT;
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static int argmax(const std::vector<float>& v) {
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int best = 1;
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float bv = -1.0f;
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for (int i = 1; i < static_cast<int>(v.size()); ++i)
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if (v[i] > bv) { bv = v[i]; best = i; }
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return best;
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}
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static std::vector<float> tone(double freqHz, double srHz, std::size_t n) {
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std::vector<float> s(n);
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for (std::size_t i = 0; i < n; ++i)
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s[i] = static_cast<float>(std::sin(2.0 * M_PI * freqHz * i / srHz));
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return s;
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}
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// FFT of a sine landing exactly on bin 64 must peak at bin 64.
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static void test_fft_peak() {
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const std::size_t N = 2048;
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std::vector<float> in(N);
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for (std::size_t i = 0; i < N; ++i)
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in[i] = static_cast<float>(std::sin(2.0 * M_PI * 64.0 * i / N));
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FFT fft(N);
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std::vector<float> mag;
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fft.magnitude(in, mag);
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CHECK(mag.size() == N / 2);
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int peak = argmax(mag);
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CHECK(peak >= 63 && peak <= 65);
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}
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// Feeding update(chX, chX) must isolate chX — proves the dual-analyzer
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// trick: AudioAnalyzer mixes 0.5*(a+b), so 0.5*(x+x) == x.
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static void test_per_channel_isolation() {
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const double sr = 48000.0; // deci == 1, no decimation
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auto a = tone(1000.0, sr, 2048); // bin width 23.4 Hz -> bin ~43
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auto b = tone(5000.0, sr, 2048); // -> bin ~213
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AudioAnalyzer an1, an2;
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an1.update(a, a, static_cast<float>(sr));
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an2.update(b, b, static_cast<float>(sr));
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int p1 = argmax(an1.magDown());
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int p2 = argmax(an2.magDown());
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CHECK(p1 >= 41 && p1 <= 45);
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CHECK(p2 >= 211 && p2 <= 217);
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CHECK(p1 != p2);
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}
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int main() {
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test_fft_peak();
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test_per_channel_isolation();
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REPORT();
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}
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