unity3d：文字渐变色

灰太狼 2022-12-17 08:55 236阅读 0赞

using UnityEngine;
    using System.Collections.Generic;
    using UnityEngine.UI;
    
    namespace Effects
    { 
    
        [AddComponentMenu("UI/Effects/Gradient")]
        public class Gradient : BaseMeshEffect
        { 
            public enum Type
            { 
                Vertical,
                Horizontal
            }
            [SerializeField]
            public Type GradientType = Type.Vertical;
    
            [SerializeField]
            [Range(-1.5f, 1.5f)]
            public float Offset = 0f;
    
            [SerializeField]
            public Color32 StartColor = Color.white;
            [SerializeField]
            public Color32 EndColor = Color.black;
    
            public override void ModifyMesh(VertexHelper helper)
            { 
                if (!IsActive() || helper.currentVertCount == 0)
                    return;
    
                List<UIVertex> _vertexList = new List<UIVertex>();
                helper.GetUIVertexStream(_vertexList);
    
                int nCount = _vertexList.Count;
                switch (GradientType)
                { 
                    case Type.Vertical:
                        { 
                            float fBottomY = _vertexList[0].position.y;
                            float fTopY = _vertexList[0].position.y;
                            float fYPos = 0f;
    
                            for (int i = nCount - 1; i >= 1; --i)
                            { 
                                fYPos = _vertexList[i].position.y;
                                if (fYPos > fTopY)
                                    fTopY = fYPos;
                                else if (fYPos < fBottomY)
                                    fBottomY = fYPos;
                            }
    
                            float fUIElementHeight = 1f / (fTopY - fBottomY);
                            UIVertex v = new UIVertex();
    
                            for (int i = 0; i < helper.currentVertCount; i++)
                            { 
                                helper.PopulateUIVertex(ref v, i);
                                v.color = Color32.Lerp(EndColor, StartColor, (v.position.y - fBottomY) * fUIElementHeight - Offset);
                                helper.SetUIVertex(v, i);
                            }
                        }
                        break;
                    case Type.Horizontal:
                        { 
                            float fLeftX = _vertexList[0].position.x;
                            float fRightX = _vertexList[0].position.x;
                            float fXPos = 0f;
    
                            for (int i = nCount - 1; i >= 1; --i)
                            { 
                                fXPos = _vertexList[i].position.x;
                                if (fXPos > fRightX)
                                    fRightX = fXPos;
                                else if (fXPos < fLeftX)
                                    fLeftX = fXPos;
                            }
    
                            float fUIElementWidth = 1f / (fRightX - fLeftX);
                            UIVertex v = new UIVertex();
    
                            for (int i = 0; i < helper.currentVertCount; i++)
                            { 
                                helper.PopulateUIVertex(ref v, i);
                                v.color = Color32.Lerp(EndColor, StartColor, (v.position.x - fLeftX) * fUIElementWidth - Offset);
                                helper.SetUIVertex(v, i);
                            }
    
                        }
                        break;
                    default:
                        break;
                }
            }
        }
    }