1 files changed, 59 insertions, 0 deletions
diff --git a/core/cubic_tables.cpp b/core/cubic_tables.cpp
new file mode 100644
index 00000000..73ec6b3f
--- /dev/null
+++ b/core/cubic_tables.cpp
@@ -0,0 +1,59 @@
+
+#include "cubic_tables.h"
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <cmath>
+#include <limits>
+#include <memory>
+#include <stdexcept>
+
+#include "alnumbers.h"
+#include "core/mixer/defs.h"
+
+
+namespace {
+
+using uint = unsigned int;
+
+struct SplineFilterArray {
+    alignas(16) CubicCoefficients mTable[CubicPhaseCount]{};
+
+    constexpr SplineFilterArray()
+    {
+        /* Fill in the main coefficients. */
+        for(size_t pi{0};pi < CubicPhaseCount;++pi)
+        {
+            const double mu{static_cast<double>(pi) / CubicPhaseCount};
+            const double mu2{mu*mu}, mu3{mu2*mu};
+            mTable[pi].mCoeffs[0] = static_cast<float>(-0.5*mu3 +      mu2 + -0.5*mu);
+            mTable[pi].mCoeffs[1] = static_cast<float>( 1.5*mu3 + -2.5*mu2           + 1.0);
+            mTable[pi].mCoeffs[2] = static_cast<float>(-1.5*mu3 +  2.0*mu2 +  0.5*mu);
+            mTable[pi].mCoeffs[3] = static_cast<float>( 0.5*mu3 + -0.5*mu2);
+        }
+
+        /* Fill in the coefficient deltas. */
+        for(size_t pi{0};pi < CubicPhaseCount-1;++pi)
+        {
+            mTable[pi].mDeltas[0] = mTable[pi+1].mCoeffs[0] - mTable[pi].mCoeffs[0];
+            mTable[pi].mDeltas[1] = mTable[pi+1].mCoeffs[1] - mTable[pi].mCoeffs[1];
+            mTable[pi].mDeltas[2] = mTable[pi+1].mCoeffs[2] - mTable[pi].mCoeffs[2];
+            mTable[pi].mDeltas[3] = mTable[pi+1].mCoeffs[3] - mTable[pi].mCoeffs[3];
+        }
+
+        const size_t pi{CubicPhaseCount - 1};
+        mTable[pi].mDeltas[0] = -mTable[pi].mCoeffs[0];
+        mTable[pi].mDeltas[1] = -mTable[pi].mCoeffs[1];
+        mTable[pi].mDeltas[2] = 1.0f - mTable[pi].mCoeffs[2];
+        mTable[pi].mDeltas[3] = -mTable[pi].mCoeffs[3];
+    }
+
+    constexpr auto getTable() const noexcept { return al::as_span(mTable); }
+};
+
+constexpr SplineFilterArray SplineFilter{};
+
+} // namespace
+
+const CubicTable gCubicSpline{SplineFilter.getTable()};