Add cubic bezier functions.

Assets/Cryville/Common/Math/CubicBezier.cs

@@ -0,0 +1,44 @@
+using SMath = System.Math;
+
+namespace Cryville.Common.Math {
+	// Ported from https://github.com/arian/cubic-bezier/blob/master/index.js
+	public static class CubicBezier {
+		public static float Evaluate(float t, float x1, float y1, float x2, float y2, float epsilon) {
+			float x = t, t0, t1, t2, tx, d2, i;
+			for (t2 = x, i = 0; i < 8; i++) {
+				tx = CurveX(t2, x1, x2) - x;
+				if (SMath.Abs(tx) < epsilon) return CurveY(t2, y1, y2);
+				d2 = DerivativeCurveX(t2, x1, x2);
+				if (SMath.Abs(d2) < 1e-6) break;
+				t2 -= tx / d2;
+			}
+
+			t0 = 0; t1 = 1; t2 = x;
+
+			if (t2 < t0) return CurveY(t0, y1, y2);
+			if (t2 > t1) return CurveY(t1, y1, y2);
+
+			while (t0 < t1) {
+				tx = CurveX(t2, x1, x2);
+				if (SMath.Abs(tx - x) < epsilon) return CurveY(t2, y1, y2);
+				if (x > tx) t0 = t2;
+				else t1 = t2;
+				t2 = (t1 - t0) * .5f + t0;
+			}
+
+			return CurveY(t2, y1, y2);
+		}
+		static float CurveX(float t, float x1, float x2) {
+			float v = 1 - t;
+			return 3 * v * v * t * x1 + 3 * v * t * t * x2 + t * t * t;
+		}
+		static float CurveY(float t, float y1, float y2) {
+			float v = 1 - t;
+			return 3 * v * v * t * y1 + 3 * v * t * t * y2 + t * t * t;
+		}
+		static float DerivativeCurveX(float t, float x1, float x2) {
+			float v = 1 - t;
+			return 3 * (2 * (t - 1) * t + v * v) * x1 + 3 * (-t * t * t + 2 * v * t) * x2;
+		}
+	}
+}

Assets/Cryville/Common/Math/CubicBezier.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 17dd6f775fc965f43960da7166b55b87
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Cryville/Crtr/PdtEvaluator.cs

@@ -1,4 +1,5 @@
 using Cryville.Common;
+using Cryville.Common.Math;
 using Cryville.Common.Pdt;
 using Cryville.Crtr.Event;
 using System;
@@ -152,6 +153,11 @@ namespace Cryville.Crtr {
 			_ctxops.Add(IdentifierManager.SharedInstance.Request("max"), new func_max(() => ContextSelfValue));
 			_ctxops.Add(IdentifierManager.SharedInstance.Request("abs"), new func_abs(() => ContextSelfValue));
 			_ctxops.Add(IdentifierManager.SharedInstance.Request("anim"), new func_anim(() => ContextSelfValue));
+			_ctxops.Add(IdentifierManager.SharedInstance.Request("cubic_bezier"), new func_cubic_bezier(() => ContextSelfValue));
+			_ctxops.Add(IdentifierManager.SharedInstance.Request("ease"), new func_cubic_bezier_fixed(0.25f, 0.1f, 0.25f, 1f, () => ContextSelfValue));
+			_ctxops.Add(IdentifierManager.SharedInstance.Request("ease_in"), new func_cubic_bezier_fixed(0.42f, 0f, 1f, 1f, () => ContextSelfValue));
+			_ctxops.Add(IdentifierManager.SharedInstance.Request("ease_out"), new func_cubic_bezier_fixed(0f, 0f, 0.58f, 1f, () => ContextSelfValue));
+			_ctxops.Add(IdentifierManager.SharedInstance.Request("ease_in_out"), new func_cubic_bezier_fixed(0.42f, 0f, 0.58f, 1f, () => ContextSelfValue));
 
 			Func<int, PropSrc> cccb = k => ContextCascadeLookup(k);
 			_ctxops.Add(IdentifierManager.SharedInstance.Request("attack_timing"), new func_attack_timing(cccb));
@@ -533,6 +539,43 @@ namespace Cryville.Crtr {
 				}
 			}
 		}
+		class func_cubic_bezier : PdtOperator {
+			readonly Func<PropSrc> _ctxcb;
+			public func_cubic_bezier(Func<PropSrc> ctxcb) : base(5) {
+				_ctxcb = ctxcb;
+			}
+			protected override unsafe void Execute() {
+				float x1 = GetOperand(0).AsNumber(), y1 = GetOperand(1).AsNumber();
+				float x2 = GetOperand(2).AsNumber(), y2 = GetOperand(3).AsNumber();
+				float time;
+				switch (LoadedOperandCount) {
+					case 4: time = oputil.AsNumber(_ctxcb()); break;
+					case 5: time = GetOperand(4).AsNumber(); break;
+					default: throw new ArgumentException("Argument count not 4 or 5");
+				}
+				GetReturnFrame(PdtInternalType.Number, sizeof(float))
+					.SetNumber(CubicBezier.Evaluate(time, x1, y1, x2, y2, 1e-5f));
+			}
+		}
+		class func_cubic_bezier_fixed : PdtOperator {
+			readonly float x1, y1, x2, y2;
+			readonly Func<PropSrc> _ctxcb;
+			public func_cubic_bezier_fixed(float x1, float y1, float x2, float y2, Func<PropSrc> ctxcb) : base(1) {
+				this.x1 = x1; this.y1 = y1;
+				this.x2 = x2; this.y2 = y2;
+				_ctxcb = ctxcb;
+			}
+			protected override void Execute() {
+				float time;
+				switch (LoadedOperandCount) {
+					case 0: time = oputil.AsNumber(_ctxcb()); break;
+					case 1: time = GetOperand(0).AsNumber(); break;
+					default: throw new ArgumentException("Argument count not 0 or 1");
+				}
+				GetReturnFrame(PdtInternalType.Number, sizeof(float))
+					.SetNumber(CubicBezier.Evaluate(time, x1, y1, x2, y2, 1e-5f));
+			}
+		}
 		#endregion
 		#region Judge Functions
 		static readonly int _var_fn = IdentifierManager.SharedInstance.Request("fn");