popo

unity-shader-tutorial-ui

Posted on Edited on

buildin效果图

UI.shader

UI.shader
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
Shader "HHF/Tutorial/UI"
{
    Properties
    {
       [PerRendererData]_MainTex("MainTex",2D) = "white"{}
        _StencilComp ("Stencil Comparison", Float) = 8
        _Stencil ("Stencil ID", Float) = 0
        _StencilOp ("Stencil Operation", Float) = 0
        _StencilWriteMask ("Stencil Write Mask", Float) = 255
        _StencilReadMask ("Stencil Read Mask", Float) = 255

        _ColorMask ("Color Mask", Float) = 15

        [Toggle]_GrayEnabled("Gray Enabled",int) = 0
    }

    SubShader
    {
        Tags{"Queue" = "Transparent"}
        Blend SrcAlpha OneMinusSrcAlpha
        ColorMask [_ColorMask]
        Stencil
        {
            Ref [_Stencil]
            Comp [_StencilComp]
            Pass [_StencilOp]
            ReadMask [_StencilReadMask]
            WriteMask [_StencilWriteMask]
        }

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile _ UNITY_UI_CLIP_RECT
            #pragma multi_compile _ _GRAYENABLED_ON
            #include "UnityCG.cginc"
            #include "UnityUI.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                fixed4 color:COLOR;
            };

            struct v2f
            {
                float4 positionCS : SV_POSITION;
                float2 uv : TEXCOORD0;
                fixed4 color:COLOR;
                float4 positionOS:TEXCOORD1;
            };

            sampler2D _MainTex;
            float4 _ClipRect;

            v2f vert (appdata v)
            {
                v2f o;
                o.positionCS = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                o.color = v.color;
                o.positionOS = v.vertex;

                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 c;
                fixed4 mainTex = tex2D(_MainTex,i.uv);
                c = mainTex;
                c *= i.color;

                #if UNITY_UI_CLIP_RECT
                    // 方法一,利用if来理解原理
                    // if(_ClipRect.x<i.positionOS.x && i.positionOS.x<_ClipRect.z && _ClipRect.y<i.positionOS.y && i.positionOS.y<_ClipRect.w) return 1;
                    // else return 0;

                    // 方法二，利用step优化掉if指令
                    // return step(_ClipRect.x,i.positionOS.x) * step(i.positionOS.x,_ClipRect.z) * step(_ClipRect.y,i.positionOS.y) * step(i.positionOS.y,_ClipRect.w);

                    // 方法三，优化step的数量
                    // fixed2 rect = step(_ClipRect.xy,i.positionOS.xy) * step(i.positionOS.xy,_ClipRect.zw);
                    // c.a *= rect.x * rect.y;

                    // 利用unity自带函数实现
                    c.a *= UnityGet2DClipping(i.positionOS, _ClipRect);
                #endif

                #if _GRAYENABLED_ON
                    // 不精确的单通道去色
                    //c.rgb = c.rrr;
                    //c.rgb = c.b;

                    // 方法二，去色公式dot(rgb,fixed3(0.22,0.707,0.071)).
                    //c.rgb = c.r * 0.22 + c.g * 0.707 + c.b * 0.071;

                    // 方法三，利用内置方法实现
                    c.rgb = Luminance(c.rgb);
                #endif

                return c;
            }
            ENDCG
        }
    }
}