SineWave: Add quadrature output option

Chowdhury-DSP · Jan 6, 2024 · af87f55 · af87f55
1 parent 67e3f53
commit af87f55
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Showing 2 changed files with 24 additions and 0 deletions.
diff --git a/modules/dsp/chowdsp_sources/Oscillators/chowdsp_SineWave.h b/modules/dsp/chowdsp_sources/Oscillators/chowdsp_SineWave.h
@@ -37,6 +37,12 @@ class SineWave
         return y;
     }
 
+    /** Returns a single-sample sin/cosine pair. */
+    inline auto processSampleQuadrature() noexcept
+    {
+        return std::make_pair (processSample(), -x1);
+    }
+
     /** Processes a block of samples. */
     void processBlock (const BufferView<T>& buffer) noexcept;
 

diff --git a/tests/dsp_tests/chowdsp_sources_test/SineTest.cpp b/tests/dsp_tests/chowdsp_sources_test/SineTest.cpp
@@ -31,6 +31,24 @@ TEST_CASE ("Sine Test", "[dsp][sources]")
         }
     }
 
+    SECTION ("Single-Sample Quadrature Processing Test")
+    {
+        chowdsp::SineWave<double> chowSine;
+        juce::dsp::ProcessSpec spec { fs, 512, 1 };
+        chowSine.prepare (spec);
+        chowSine.setFrequency (freq1);
+
+        // process samples one at a time, and compare to std::sin and std::cos
+        for (int i = 0; i < 2000; i++)
+        {
+            auto [actual_sin, actual_cos] = chowSine.processSampleQuadrature();
+            auto expected_sin = std::sin (juce::MathConstants<double>::twoPi * freq1 * i / fs);
+            auto expected_cos = std::cos (juce::MathConstants<double>::twoPi * freq1 * i / fs);
+            REQUIRE_MESSAGE (actual_sin == Catch::Approx (expected_sin).margin (err), "Sine Wave is inaccurate");
+            REQUIRE_MESSAGE (actual_cos == Catch::Approx (expected_cos).margin (10.0 * err), "Cosine Wave is inaccurate");
+        }
+    }
+
     SECTION ("Buffer Processing Test")
     {
         chowdsp::SineWave<double> chowSine;