テキストをアーチ状に曲げる(動画あり・GUI/TextMeshPro)【Unity】

using UnityEngine;
using TMPro;
using System.Collections;
#if UNITY_EDITOR
using UnityEditor;
#endif
[ExecuteInEditMode]
public class ArchedText : MonoBehaviour 
{
	public enum TextVAlignment
	{
		Base,
		Top,
		Bottom,
	}
	[SerializeField]
	private TextVAlignment vAlignment;
	[SerializeField]
	private TextAlignment hAlignment;
	[SerializeField]
	private AnimationCurve vertexCurve = new AnimationCurve (new Keyframe (0, 0), new Keyframe (0.5f, 0.25f), new Keyframe (1, 0f));
	private TMP_Text textComponent;
	void Awake ()
	{
		textComponent = gameObject.GetComponent<TMP_Text> ();
	}
	void Update ()
	{
		if (!textComponent.havePropertiesChanged) 
		{
			return;
		}
		UpdateCurveMesh ();
	}
	void UpdateCurveMesh ()
	{
		textComponent.ForceMeshUpdate();
		TMP_TextInfo textInfo = textComponent.textInfo;
		int characterCount = textInfo.characterCount;
		if (characterCount == 0)
			return;
		Vector3 baseline = new Vector3();
		Vector3 prevAngleDirection = new Vector3();
		Vector3 prevOffsetToMidBaseline = new Vector3();
		Vector3[] vertices;
		Matrix4x4 matrix;
		float defaultBaseLine = 0;
		float maxBaseLine = float.MinValue;
		float minBaseLine = float.MaxValue;
		bool isFirst = true;
		for (int i = 0; i < characterCount; i++) 
		{
			if (!textInfo.characterInfo [i].isVisible)
				continue;
			int vertexIndex = textInfo.characterInfo [i].vertexIndex;
			int materialIndex = textInfo.characterInfo [i].materialReferenceIndex;
			vertices = textInfo.meshInfo [materialIndex].vertices;
			//文字の真ん中の点と文字の基準となるベースラインの高さを取得
			Vector3 offsetToMidBaseline = new Vector2 ((vertices [vertexIndex + 0].x + vertices [vertexIndex + 2].x) / 2, textInfo.characterInfo [i].baseLine);
			//文字の中央の下が原点となるように頂点を移動（これから回転と移動をさせるため）
			vertices [vertexIndex + 0] += -offsetToMidBaseline;
			vertices [vertexIndex + 1] += -offsetToMidBaseline;
			vertices [vertexIndex + 2] += -offsetToMidBaseline;
			vertices [vertexIndex + 3] += -offsetToMidBaseline;
			//曲線の傾き(agnle)の計算
			float x0 = (float)(i + 1) / (characterCount + 1);
			float x1 = x0 + 0.0001f;
			float y0 = vertexCurve.Evaluate (x0);
			float y1 = vertexCurve.Evaluate (x1);
			Vector3 horizontal = new Vector3 (1, 0, 0);
			Vector3 tangent = new Vector3 (0.0001f, (y1 - y0));
			Vector3 angleDirection = tangent.normalized;
			float angle = Mathf.Acos (Vector3.Dot (horizontal, angleDirection)) * Mathf.Rad2Deg;
			Vector3 cross = Vector3.Cross (horizontal, tangent);
			angle = cross.z > 0 ? angle : 360 - angle;
			//angle回転させた頂点位置の計算
			matrix = Matrix4x4.Rotate (Quaternion.Euler (0, 0, angle));
			vertices [vertexIndex + 0] = matrix.MultiplyPoint3x4 (vertices [vertexIndex + 0]);
			vertices [vertexIndex + 1] = matrix.MultiplyPoint3x4 (vertices [vertexIndex + 1]);
			vertices [vertexIndex + 2] = matrix.MultiplyPoint3x4 (vertices [vertexIndex + 2]);
			vertices [vertexIndex + 3] = matrix.MultiplyPoint3x4 (vertices [vertexIndex + 3]);
			//文字間の計算
			float characterSpace;
			if (isFirst) 
			{
				baseline = offsetToMidBaseline;
				defaultBaseLine = baseline.y;
				characterSpace = 0;
				isFirst = false;
			} 
			else 
			{
				characterSpace = (offsetToMidBaseline - prevOffsetToMidBaseline).magnitude;
			}
			prevOffsetToMidBaseline = offsetToMidBaseline;
			//文字位置を計算して移動
			baseline = baseline + (angleDirection + prevAngleDirection).normalized * characterSpace;
			vertices [vertexIndex + 0] += baseline;
			vertices [vertexIndex + 1] += baseline;
			vertices [vertexIndex + 2] += baseline;
			vertices [vertexIndex + 3] += baseline;
			prevAngleDirection = angleDirection;
			minBaseLine = Mathf.Min (minBaseLine, baseline.y);
			maxBaseLine = Mathf.Max (maxBaseLine, baseline.y);
		}
		//揃えの計算
		if (hAlignment != TextAlignment.Left || vAlignment != TextVAlignment.Base) 
		{
			float hOffset = 0;
			if (hAlignment == TextAlignment.Center)
				hOffset = (prevOffsetToMidBaseline.x - baseline.x) * 0.5f;
			else if (hAlignment == TextAlignment.Right)
				hOffset = (prevOffsetToMidBaseline.x - baseline.x);
			float vOffset = 0;
			if (vAlignment == TextVAlignment.Bottom)
				vOffset = defaultBaseLine - minBaseLine;
			else if (vAlignment == TextVAlignment.Top)
				vOffset = defaultBaseLine - maxBaseLine;
			
			Vector3 alignOffset = new Vector3 (hOffset, vOffset, 0);
			for (int i = 0; i < characterCount; i++) 
			{
				if (!textInfo.characterInfo [i].isVisible)
					continue;
				int vertexIndex = textInfo.characterInfo [i].vertexIndex;
				int materialIndex = textInfo.characterInfo [i].materialReferenceIndex;
				vertices = textInfo.meshInfo [materialIndex].vertices;
				vertices [vertexIndex + 0] += alignOffset;
				vertices [vertexIndex + 1] += alignOffset;
				vertices [vertexIndex + 2] += alignOffset;
				vertices [vertexIndex + 3] += alignOffset;
			}
		}
		textComponent.UpdateVertexData ();
	}
		
#if UNITY_EDITOR
	protected virtual void OnValidate()
	{
		UpdateCurveMesh ();
	}
	void OnEnable()
	{
		UpdateCurveMesh ();
	}
	void OnDisable()
	{
		textComponent.ForceMeshUpdate();
	}
#endif
}