遊戲開發中,角色具備有多種屬性,一般呈現成一個如下圖的多邊形屬性圖。
一、效果圖
二、展示效果
可以調整邊數,調整每個點的數值。
三、實現原理
查看UGUI的代碼可以得知,繪製ui圖的方法其實是繪製mesh,然後對其進行填充。正常一個Image圖片,繪製有四個頂點。
爲了實現多邊形,繼承於MaskableGraphic,重寫OnPopulateMesh,重新繪製頂點。
四、放上代碼
//多邊形繪製
using UnityEngine;
using UnityEngine.UI;
public class MyUIPolygon : MaskableGraphic
{
public bool fill = true;
public float thickness = 5;
[Range(3, 360)]
public int sides = 3;
[Range(0, 360)]
public float rotation = 0;
[Range(0, 1)]
public float[] VerticesDistances = new float[3];
private float size = 0;
public void DrawPolygon(int _sides)
{
sides = _sides;
VerticesDistances = new float[_sides + 1];
for (int i = 0; i < _sides; i++) VerticesDistances[i] = 1; ;
rotation = 0;
}
public void DrawPolygon(int _sides, float[] _VerticesDistances)
{
sides = _sides;
VerticesDistances = _VerticesDistances;
rotation = 0;
}
public void DrawPolygon(int _sides, float[] _VerticesDistances, float _rotation)
{
sides = _sides;
VerticesDistances = _VerticesDistances;
rotation = _rotation;
}
void Update()
{
size = rectTransform.rect.width;
if (rectTransform.rect.width > rectTransform.rect.height)
size = rectTransform.rect.height;
else
size = rectTransform.rect.width;
thickness = (float)Mathf.Clamp(thickness, 0, size / 2);
}
protected override void OnPopulateMesh(VertexHelper vh)
{
vh.Clear();
Vector2 prevX = Vector2.zero;
Vector2 prevY = Vector2.zero;
Vector2 uv0 = new Vector2(0, 0);
Vector2 uv1 = new Vector2(0, 1);
Vector2 uv2 = new Vector2(1, 1);
Vector2 uv3 = new Vector2(1, 0);
Vector2 pos0;
Vector2 pos1;
Vector2 pos2;
Vector2 pos3;
float degrees = 360f / sides;
int vertices = sides + 1;
if (VerticesDistances.Length != vertices)
{
VerticesDistances = new float[vertices];
for (int i = 0; i < vertices - 1; i++) VerticesDistances[i] = 1;
}
// last vertex is also the first!
VerticesDistances[vertices - 1] = VerticesDistances[0];
for (int i = 0; i < vertices; i++)
{
float outer = -rectTransform.pivot.x * size * VerticesDistances[i];
float inner = -rectTransform.pivot.x * size * VerticesDistances[i] + thickness;
float rad = Mathf.Deg2Rad * (i * degrees + rotation);
float c = Mathf.Cos(rad);
float s = Mathf.Sin(rad);
uv0 = new Vector2(0, 1);
uv1 = new Vector2(1, 1);
uv2 = new Vector2(1, 0);
uv3 = new Vector2(0, 0);
pos0 = prevX;
pos1 = new Vector2(outer * c, outer * s);
if (fill)
{
pos2 = Vector2.zero;
pos3 = Vector2.zero;
}
else
{
pos2 = new Vector2(inner * c, inner * s);
pos3 = prevY;
}
prevX = pos1;
prevY = pos2;
SetVbo(new[] { pos0, pos1, pos2, pos3 }, new[] { uv0, uv1, uv2, uv3 });
vh.AddUIVertexQuad(vbo);
}
}
private UIVertex[] vbo = new UIVertex[4];
private void SetVbo(Vector2[] vertices, Vector2[] uvs)
{
for (int i = 0; i < vertices.Length; i++)
{
var vert = UIVertex.simpleVert;
vert.color = color;
vert.position = vertices[i];
vert.uv0 = uvs[i];
vbo[i] = vert;
}
}
}
代碼來自UnityUIExtensions,做了一些修改,不依賴其他擴展基類腳本,裏面還有其他比較實用的UI擴展代碼,以後會逐一介紹。