图像混合模式 正片叠底、滤色、叠加

1 public class OverlayBlendModeTest : MonoBehaviour
2 {
3     // 两张需要混合的图片
4     public Texture2D ima1;
5     public Texture2D ima2;
6
7     public float Opacity = 0.1f;
8
9     private Texture2D tex;
10
11     void Start()
12     {
13          tex = new Texture2D(ima1.width, ima1.height, TextureFormat.ARGB32, false);
14     }
15
16     void Update()
17
18     {   //设置混合度  逐像素读取混合
19         Texture2dHandle.SetOpacity = Opacity;
20         for (int y = 0; y < ima1.height; y++)
21         {
22             for (int x = 0; x < ima1.width; x++)
23             {
24
25                 var dC = ima1.GetPixel(x, y);
26                 var uC = ima2.GetPixel(x, y);
27                 var oC = Texture2dHandle.OverlayBlendMode(uC, dC);
28                 tex.SetPixel(x, y, oC);
29
30             }
31         }
32
33         tex.Apply();
34         gameObject.GetComponent<Renderer>().material.mainTexture = tex;
35     }
36 }

1 public class Texture2dHandle
2 {
3
4  /// <summary>
5     /// 混合度
6     /// </summary>
7     private static float Opacity = 0.3f;
8
9     /// <summary>
10     /// 设置混合度
11     /// </summary>
12     public static float SetOpacity
13     {
14         set
15         {
16             if (value < 0)
17                 value = 0;
18             else if (value > 1)
19                 value = 1;
20
21             Opacity = value;
22         }
23     }
24
25     /// <summary>
26     /// 正片叠底
27     /// </summary>
28     /// <returns></returns>
29     public static Color Multiply(Color b, Color t)
30     {
31         //b.g *= t.g;
32         //b.b *= t.b;
33         //b.r *= t.r;
34         //b.a = 1;
35
36         var c = new Color(b.r * t.r, b.g * t.g, b.b * t.b, 1);
37         return Color.Lerp(b, c, Opacity);
38     }
39
40     /// <summary>
41     /// 滤色
42     /// </summary>
43     /// <param name="b"></param>
44     /// <param name="t"></param>
45     /// <returns></returns>
46     public static Color Screen(Color b, Color t)
47     {
48         b = Minus(b);
49         t = Minus(t);
50
51         var c = Minus(Multiply(Multiply(b, t), 2.0f));
52
53         return Color.Lerp(b, c, Opacity);
54     }
55
56     /// <summary>
57     /// 叠加
58     /// </summary>
59     /// <param name="b"></param>
60     /// <param name="t"></param>
61     /// <returns></returns>
62     public static Color OverlayBlendMode(Color b, Color t)
63     {
64
65         Color c = new Color();
66         c.r = OverlayBlendMode(b.r, t.r);
67         c.g = OverlayBlendMode(b.g, t.g);
68         c.b = OverlayBlendMode(b.b, t.b);
69         c.a = 1;
70
71         return Color.Lerp(b, c, Opacity);
72     }
73
74
75     private static float OverlayBlendMode(float basePixel, float blendPixel)
76     {
77         if (basePixel < 0.5)
78         {
79             return (float)(2.0 * basePixel * blendPixel);
80         }
81
82
83         return (float)(1.0 - 2.0 * (1.0 - basePixel) * (1.0 - blendPixel));
84     }
85
86     /// <summary>
87     /// 倍数
88     /// </summary>
89     /// <param name="c"></param>
90     /// <param name="index"></param>
91     /// <returns></returns>
92     private static Color Multiply(Color c, float index = 1)
93     {
94         c.r *= index;
95         c.g *= index;
96         c.b *= index;
97         return c;
98     }
99
100     private static Color Minus(Color c, int index = 1)
101     {
102         c.r = index - c.r;
103         c.b = index - c.b;
104         c.g = index - c.g;
105         return c;
106     }
107 }