using TMPro;
using UnityEngine;
[RequireComponent(typeof(TMP_Text))]
public class TMP_Text_Curved : MonoBehaviour
{
    public TMP_Text m_TextComponent;
    public float height = 1;
    public float allWidth = 800;
    public float radian_angle = 30f;
    private void OnValidate()
    {
        if (m_TextComponent == null)
        {
            m_TextComponent = GetComponent<TMP_Text>();
        }
        SetTextCurved();
    }
    private void Awake()
    {
        if (m_TextComponent == null)
        {
            m_TextComponent = GetComponent<TMP_Text>();
        }
    }
    private void LateUpdate()
    {
        SetTextCurved();
    }
    void SetTextCurved()
    {
        m_TextComponent.ForceMeshUpdate();
        TMP_TextInfo textInfo = m_TextComponent.textInfo;
        if (textInfo == null) return;
        int characterCount = textInfo.characterCount;
        if (characterCount == 0) return;
        Quaternion rotation;
        Vector3 center;
        var charInfo = textInfo.characterInfo[characterCount - 1];
        Vector3[] vertices;
        int vertexIndex;
        for (int i = 0; i < characterCount; i++)
        {
            charInfo = textInfo.characterInfo[i];
            if (!charInfo.isVisible) continue;
            vertices = textInfo.meshInfo[charInfo.materialReferenceIndex].vertices;
            vertexIndex = charInfo.vertexIndex;
            center = (vertices[vertexIndex + 0] + vertices[vertexIndex + 1] + vertices[vertexIndex + 2] + vertices[vertexIndex + 3]) / 4;

            float angle = center.x < 0 ? vertices[vertexIndex + 0].x / allWidth : vertices[vertexIndex + 3].x / allWidth;
            rotation = Quaternion.Euler(0, 0, -angle * radian_angle);
            vertices[vertexIndex + 0] = rotation * (vertices[vertexIndex + 0] - center) + center;
            vertices[vertexIndex + 1] = rotation * (vertices[vertexIndex + 1] - center) + center;
            vertices[vertexIndex + 2] = rotation * (vertices[vertexIndex + 2] - center) + center;
            vertices[vertexIndex + 3] = rotation * (vertices[vertexIndex + 3] - center) + center;
            Vector3 offset = Vector3.up * (Mathf.Cos(angle * Mathf.PI) - 1f) * height;
            vertices[vertexIndex + 0] += offset;
            vertices[vertexIndex + 1] += offset;
            vertices[vertexIndex + 2] += offset;
            vertices[vertexIndex + 3] += offset;
        }
        for (int i = 0; i < textInfo.meshInfo.Length; i++)
        {
            var meshInfo = textInfo.meshInfo[i];
            meshInfo.mesh.vertices = meshInfo.vertices;
            m_TextComponent.UpdateGeometry(meshInfo.mesh, i);
        }
    }
}