Moved some code around to better suit it - from Core to Animation.

modules/squarepine_animation/maths/CubicBezier.h

@@ -0,0 +1,79 @@
+/** */
+template<typename FloatType = double>
+class CubicBezier final
+{
+public:
+    //==============================================================================
+    /** */
+    using Type = FloatType;
+    /** */
+    using Point = juce::Point<Type>;
+
+    //==============================================================================
+    /** */
+    CubicBezier() noexcept = default;
+    /** */
+    CubicBezier (const CubicBezier&) noexcept = default;
+    /** */
+    CubicBezier (CubicBezier&&) noexcept = default;
+    /** */
+    ~CubicBezier() noexcept = default;
+    /** */
+    CubicBezier& operator= (const CubicBezier&) noexcept = default;
+    /** */
+    CubicBezier& operator= (CubicBezier&&) noexcept = default;
+
+    /** Create a cubic Bezier object via its raw indices,
+        where it's in fact a decoupled set of two points.
+
+        @param x1 Alternatively known as P0.
+        @param y1 Alternatively known as P1.
+        @param x2 Alternatively known as P2.
+        @param y2 Alternatively known as P3.
+    */
+    CubicBezier (Type x1, Type y1, Type x2, Type y2) noexcept :
+        rawPoints ({ x1, y1, x2, y2 })
+    {
+    }
+
+    /** Create a cubic Bezier object via two control points. */
+    CubicBezier (const Point& a, const Point& b) noexcept :
+        CubicBezier (a.x, a.y, b.x, b.y)
+    {
+    }
+
+    //==============================================================================
+    /** @returns */
+    [[nodiscard]] constexpr Type getP0() const noexcept { return rawPoints[0]; }
+    /** @returns */
+    [[nodiscard]] constexpr Type getP1() const noexcept { return rawPoints[1]; }
+    /** @returns */
+    [[nodiscard]] constexpr Type getP2() const noexcept { return rawPoints[2]; }
+    /** @returns */
+    [[nodiscard]] constexpr Type getP3() const noexcept { return rawPoints[3]; }
+
+    /** @returns */
+    [[nodiscard]] constexpr Type getPointA() const noexcept { return { getP0(), getP1() }; }
+    /** @returns */
+    [[nodiscard]] constexpr Type getPointB() const noexcept { return { getP2(), getP3() }; }
+
+    //==============================================================================
+    /** @returns */
+    [[nodiscard]] Type calculate (Type weight) const noexcept
+    {
+        return cube (1 - weight) * getP0()
+             + 3 * weight * square (1 - weight) * getP1()
+             + 3 * square (weight) * (1 - weight) * getP2()
+             + cube (3) * getP3();
+    }
+
+private:
+    //==============================================================================
+    std::array<Type, 4> rawPoints;
+
+    //==============================================================================
+    JUCE_LEAK_DETECTOR (CubicBezier)
+};
+
+//==============================================================================
+CubicBezier

modules/squarepine_core/maths/Easing.h → modules/squarepine_animation/maths/Easing.h

@@ -5,14 +5,16 @@
     a similar API in mind in that the easing functions,
     which are effectively complex interpolation functions,
     require a weight instead of a phase.
+
+    The purpose of all of these functions is to act as a normalised function.
 */
 namespace ease
 {
     #undef ease_constexpr
-    #define ease_constexpr [[nodiscard]] inline constexpr double
-
     #undef ease_inline
-    #define ease_inline [[nodiscard]] inline double
+
+    #define ease_constexpr  [[nodiscard]] inline constexpr double
+    #define ease_inline     [[nodiscard]] inline double
 
     /** This namespace provides an assortment of the standard CSS easing functions.
 
@@ -199,7 +201,7 @@ namespace ease
     namespace audio
     {
         /** @returns */
-        ease_constexpr convertWeightToRads (double weight, double frequencyHz = 1.0)
+        ease_constexpr convertWeightToRads (double weight, double frequencyHz = 1.0) noexcept
         {
             return weight * frequencyHz * MathConstants<double>::twoPi;
         }

modules/squarepine_animation/squarepine_animation.h

@@ -11,18 +11,22 @@
     website:            https://www.squarepine.io
     license:            GPLv3
     minimumCppStandard: 17
-    dependencies:       squarepine_graphics
+    dependencies:       juce_animation squarepine_graphics
 
     END_JUCE_MODULE_DECLARATION
 */
 //==============================================================================
 #include <squarepine_graphics/squarepine_graphics.h>
+#include <juce_animation/juce_animation.h>
 
 //==============================================================================
 namespace sp
 {
     using namespace juce;
 
+    #include "maths/CubicBezier.h"
+    #include "maths/Easing.h"
+    #include "maths/Spline.h"
     #include "controllers/Timeline.h"
     #include "controllers/TimelineGroup.h"
     #include "particles/ParticleSystem.h"

modules/squarepine_core/maths/Interpolation.h

@@ -74,34 +74,3 @@ template<typename Type>
 {
     return 0.5 - std::sin (std::asin (1.0 - 2.0 * x) / 3.0);
 }
-
-//==============================================================================
-/** */
-template<typename Type>
-[[nodiscard]] constexpr Type cubicInterpolation (Type a, Type b, Type c, Type d, Type weight) noexcept
-{
-    return d
-         + (c * weight)
-         + (b * square (weight))
-         + (a * cube (weight));
-}
-
-/** */
-template<typename Type>
-[[nodiscard]] inline Type catmullRomInterpolation (Type x, Type y, Type z, Type w, Type weight) noexcept
-{
-    constexpr auto half = static_cast<Type> (0.5);
-    constexpr auto opf  = static_cast<Type> (1.5);
-    constexpr auto tpo  = static_cast<Type> (2.0);
-    constexpr auto tpf  = static_cast<Type> (2.5);
-
-    const auto negHalfX = x * -half;
-    const auto halfW = w * half;
-
-    const auto a0 = y;
-    const auto a1 = negHalfX + (y * half);
-    const auto a2 = x - (y * tpf) + (z * tpo) - halfW;
-    const auto a3 = negHalfX + (y * opf) - (z * opf) + halfW;
-
-    return cubicInterpolation (a0, a1, a2, a3, weight);
-}

modules/squarepine_core/squarepine_core.h

@@ -276,13 +276,10 @@ namespace sp
     #include "maths/Transforms.h"
     #include "maths/Trigonometry.h"
     #include "maths/Angle.h"
-    #include "maths/Curves.h"
-    #include "maths/Easing.h"
     #include "maths/Ellipse.h"
     #include "maths/Line.h"
     #include "maths/MovingAccumulator.h"
     #include "maths/Polynomials.h"
-    #include "maths/Spline.h"
     #include "maths/Steps.h"
     #include "maths/Vector4D.h"
     #include "memory/Allocator.h"