Initial commit.

1 files changed, 107 insertions, 0 deletions

diff --git a/src/main/java/com/anthonyhilyard/iceberg/util/Easing.java b/src/main/java/com/anthonyhilyard/iceberg/util/Easing.java
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index 0000000..da41927
--- /dev/null
+++ b/src/main/java/com/anthonyhilyard/iceberg/util/Easing.java
@@ -0,0 +1,107 @@
+package com.anthonyhilyard.iceberg.util;
+
+/**
+ * Helper functions for smooth easing/interpolation.  If you need linear, use net.minecraft.util.math.MathHelper.lerp instead.
+ */
+public final class Easing
+{
+	public static enum EasingType
+	{
+		None, // Produces step-wise interpolation.
+		Quad,
+		Cubic
+	}
+
+	public static enum EasingDirection
+	{
+		In,
+		Out,
+		InOut
+	}
+
+	public static float Ease(float a, float b, float t)
+	{
+		return Ease(a, b, t, EasingType.Quad);
+	}
+
+	public static float Ease(float a, float b, float t, EasingType type)
+	{
+		return Ease(a, b, t, type, EasingDirection.InOut);
+	}
+
+	public static float Ease(float a, float b, float t, EasingType type, EasingDirection direction)
+	{
+		switch (type)
+		{
+			case None:
+			default:
+				return None(a, b, t);
+			case Quad:
+				return Quad(a, b, t, direction);
+			case Cubic:
+				return Cubic(a, b, t, direction);
+		}
+	}
+
+	private static float None(float a, float b, float t)
+	{
+		if (t < 0.5f)
+		{
+			return a;
+		}
+		else
+		{
+			return b;
+		}
+	}
+
+	private static float Quad(float a, float b, float t, EasingDirection direction)
+	{
+		switch (direction)
+		{
+			case In:
+				return a + (b - a) * t * t;
+			case Out:
+				return a + (b - a) * (1.0f - (1.0f - t) * (1.0f - t));
+			case InOut:
+			default:
+			{
+				t *= 2.0f;
+				if (t < 1.0f)
+				{
+					return a + (b - a) * 0.5f * t * t;
+				}
+				else
+				{
+					t -= 2.0f;
+					return a + (a - b) * 0.5f * (t * t - 2.0f);
+				}
+			}
+		}
+	}
+
+	private static float Cubic(float a, float b, float t, EasingDirection direction)
+	{
+		switch (direction)
+		{
+			case In:
+				return a + (b - a) * t * t * t;
+			case Out:
+				return a + (b - a) * (1.0f - (1.0f - t) * (1.0f - t) * (1.0f - t));
+			case InOut:
+			default:
+			{
+				t *= 2.0f;
+				if (t < 1.0f)
+				{
+					return a + (b - a) * 0.5f * t * t * t;
+				}
+				else
+				{
+					t -= 2.0f;
+					return a + (b - a) * 0.5f * (t * t * t + 2.0f);
+				}
+			}
+		}
+	}
+}
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