From 542bd28a283fe0c9886c16fd5c00b7cf63ccc2f6 Mon Sep 17 00:00:00 2001
From: Paul Fd <paul@ferrand.cc>
Date: Tue, 10 Mar 2020 14:12:46 +0100
Subject: [PATCH] Use @falktx's way for the math constants

---
 src/sfizz/MathHelpers.h | 29 +++++++++++++----------------
 src/sfizz/SIMDHelpers.h |  2 +-
 src/sfizz/Voice.cpp     |  6 +++---
 3 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/src/sfizz/MathHelpers.h b/src/sfizz/MathHelpers.h
index a8c97be6..ac755a11 100644
--- a/src/sfizz/MathHelpers.h
+++ b/src/sfizz/MathHelpers.h
@@ -124,9 +124,7 @@ inline float midiNoteFrequency(const int noteNumber)
 template<class T>
 constexpr T clamp( T v, T lo, T hi )
 {
-    v = min(v, hi);
-    v = max(v, lo);
-    return v;
+    return max(min(v, hi), lo);
 }
 
 template<int Increment = 1, class T>
@@ -148,19 +146,18 @@ constexpr ValueType linearInterpolation(ValueType left, ValueType right, ValueTy
     return left * leftCoeff + right * rightCoeff;
 }
 
-constexpr double dPi { 3.141592653589793238462643383279502884};
-constexpr double dTwoPi { dPi * 2 };
-constexpr double dPiTwo { dPi / 2 };
-constexpr double dPiFour { dPi / 4 };
-constexpr double dSqrtTwo { 1.414213562373095048801688724209698078569671875376948073176 };
-constexpr double dSqrtTwoInv { 0.707106781186547524400844362104849039284835937688474036588 };
-
-constexpr float fPi { 3.141592653589793238462643383279502884};
-constexpr float fTwoPi { fPi * 2 };
-constexpr float fPiTwo { fPi / 2 };
-constexpr float fPiFour { fPi / 4 };
-constexpr float fSqrtTwo { 1.414213562373095048801688724209698078569671875376948073176 };
-constexpr float fSqrtTwoInv { 0.707106781186547524400844362104849039284835937688474036588 };
+template<class Type>
+constexpr Type pi() { return static_cast<Type>(3.141592653589793238462643383279502884); };
+template<class Type>
+constexpr Type twoPi() { return pi<Type>() * 2; };
+template<class Type>
+constexpr Type piTwo() { return pi<Type>() / 2; };
+template<class Type>
+constexpr Type piFour() { return pi<Type>() / 4; };
+template<class Type>
+constexpr Type sqrtTwo() { return static_cast<Type>(1.414213562373095048801688724209698078569671875376948073176); };
+template<class Type>
+constexpr Type sqrtTwoInv() { return static_cast<Type>(0.707106781186547524400844362104849039284835937688474036588); };
 
 /**
    @brief A fraction which is parameterized by integer type
diff --git a/src/sfizz/SIMDHelpers.h b/src/sfizz/SIMDHelpers.h
index 253c125a..00761dae 100644
--- a/src/sfizz/SIMDHelpers.h
+++ b/src/sfizz/SIMDHelpers.h
@@ -748,7 +748,7 @@ namespace _internals {
         int i = 0;
 
         for (; i < panSize; ++i)
-            pan[i] = std::cos(i * (dPiTwo / (panSize - 1)));
+            pan[i] = std::cos(i * (twoPi<double>() / (panSize - 1)));
 
         for (; i < static_cast<int>(pan.size()); ++i)
             pan[i] = pan[panSize - 1];
diff --git a/src/sfizz/Voice.cpp b/src/sfizz/Voice.cpp
index d74c8964..f92ec40b 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -479,7 +479,7 @@ void sfz::Voice::fillWithGenerator(AudioSpan<float> buffer) noexcept
         auto bends = tempSpan2.first(buffer.getNumFrames());
         auto phases = tempSpan2.first(buffer.getNumFrames());
 
-        const float step = baseFrequency * fTwoPi / sampleRate;
+        const float step = baseFrequency * twoPi<float>() / sampleRate;
         fill<float>(jumps, step);
 
         if (region->bendStep > 1)
@@ -496,8 +496,8 @@ void sfz::Voice::fillWithGenerator(AudioSpan<float> buffer) noexcept
         copy<float>(leftSpan, rightSpan);
 
         // Wrap the phase so we don't loose too much precision on longer notes
-        const auto numTwoPiWraps = static_cast<int>(phase / fTwoPi);
-        phase -= fTwoPi * static_cast<float>(numTwoPiWraps);
+        const auto numTwoPiWraps = static_cast<int>(phase / twoPi<float>());
+        phase -= twoPi<float>() * static_cast<float>(numTwoPiWraps);
     }
 }