2D gold shine/sparkle shader

Hello everyone,
I'm fairly new to hlsl and cg but my first shader turned out pretty good.
Now however, I want to make a shader which imitates a shine or sparkle effect for the reward text the player gets when finishing a level in my game.
I want it to look something like this

Does anyone have an idea how I can do this?

 

After a whole day of messing around, I finally managed to create the shine effect.
If anyone is interested in it, here is the code (it is based on the standard UI shader)

Code (CSharp):

1. Shader "Custom/BlingShader"
2. {
3.     Properties
4.     {
5.         [PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
6.     _Color("Tint", Color) = (1,1,1,1)
7.  
8.         _StencilComp("Stencil Comparison", Float) = 8
9.         _Stencil("Stencil ID", Float) = 0
10.         _StencilOp("Stencil Operation", Float) = 0
11.         _StencilWriteMask("Stencil Write Mask", Float) = 255
12.         _StencilReadMask("Stencil Read Mask", Float) = 255
13.  
14.         _ColorMask("Color Mask", Float) = 15
15.  
16.         [Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip("Use Alpha Clip", Float) = 0
17.  
18.         _Speed("Bling Speed", Float) = 2
19.         _Thickness("Bling Thickness", Range(0, 1)) = 0.8
20.     }
21.  
22.         SubShader
23.     {
24.         Tags
25.     {
26.         "Queue" = "Transparent"
27.         "IgnoreProjector" = "True"
28.         "RenderType" = "Transparent"
29.         "PreviewType" = "Plane"
30.         "CanUseSpriteAtlas" = "True"
31.     }
32.  
33.         Stencil
34.     {
35.         Ref[_Stencil]
36.         Comp[_StencilComp]
37.         Pass[_StencilOp]
38.         ReadMask[_StencilReadMask]
39.         WriteMask[_StencilWriteMask]
40.     }
41.  
42.         Cull Off
43.         Lighting Off
44.         ZWrite Off
45.         ZTest[unity_GUIZTestMode]
46.         Blend SrcAlpha OneMinusSrcAlpha
47.         ColorMask[_ColorMask]
48.  
49.         Pass
50.     {
51.         CGPROGRAM
52. #pragma vertex vert
53. #pragma fragment frag
54.  
55. #include "UnityCG.cginc"
56. #include "UnityUI.cginc"
57.  
58. #pragma multi_compile __ UNITY_UI_ALPHACLIP
59.  
60.     struct appdata_t
61.     {
62.         float4 vertex   : POSITION;
63.         float4 color    : COLOR;
64.         float2 texcoord : TEXCOORD0;
65.     };
66.  
67.     struct v2f
68.     {
69.         float4 vertex   : SV_POSITION;
70.         fixed4 color : COLOR;
71.         half2 texcoord  : TEXCOORD0;
72.         float4 worldPosition : TEXCOORD1;
73.     };
74.  
75.     fixed4 _Color;
76.     fixed4 _TextureSampleAdd;
77.     float4 _ClipRect;
78.  
79.     v2f vert(appdata_t IN)
80.     {
81.         v2f OUT;
82.         OUT.worldPosition = IN.vertex;
83.         OUT.vertex = mul(UNITY_MATRIX_MVP, OUT.worldPosition);
84.  
85.         OUT.texcoord = IN.texcoord;
86.  
87. #ifdef UNITY_HALF_TEXEL_OFFSET
88.         OUT.vertex.xy += (_ScreenParams.zw - 1.0)*float2(-1,1);
89. #endif
90.  
91.         OUT.color = IN.color * _Color;
92.         return OUT;
93.     }
94.  
95.     sampler2D _MainTex;
96.     float _Speed;
97.     float _Thickness;
98.  
99.     fixed4 frag(v2f IN) : SV_Target
100.     {
101.         half4 color = (tex2D(_MainTex, IN.texcoord) + _TextureSampleAdd) * IN.color;
102.  
103.         float x = (IN.worldPosition.x + _ScreenParams[0] / 2) / _ScreenParams[0];
104.         float y = (IN.worldPosition.y + _ScreenParams[1] / 2) / _ScreenParams[1];
105.         float f = 1 + x - (_SinTime[3] * _Speed);
106.         if (_CosTime[3] > 0)
107.         {
108.             if (y >= f && y <= f + _Thickness)
109.                 color /= 1 - (f - y) - _Thickness;
110.             if (y >= f - _Thickness && y <= f)
111.                 color /= 1 + (f - y) - _Thickness;
112.         }
113.         color.a *= UnityGet2DClipping(IN.worldPosition.xy, _ClipRect);
114.  
115. #ifdef UNITY_UI_ALPHACLIP
116.         clip(color.a - 0.001);
117. #endif
118.  
119.         return color;
120.     }
121.         ENDCG
122.     }
123.     }
124. }
125.  

 

Just what I was looking for, thanks for sharing.

I have a question. I recall reading that if's in a shader give a performance hit.
Apparently its ok to use them sometimes and not others (I'm very new to shader coding).
I was wondering if the "if's" in the shader code above are a problem with regards to performance?