how to clamp only one axis of a texture?

1. looking for my problem on the forum i got that you can edit the sampler
2. but unfortunely i can't get it working i am doing something wrong?
3. 
   
4. Code (CSharp):

   1. texture _MainTex;
   2. Shader "Unlit/LinearGradient"
   3. {
   4.     Properties{
   5.         _TopColor("Color1", Color) = (1,1,1,1)
   6.         _BottomColor("Color2", Color) = (1,1,1,1)
   7.         _MainTex("Main Texture", 2D) = "white" {}
   8.     }
   9.         SubShader
   10.     {
   11.         Tags{ "RenderType" = "Transparent" "Queue" = "Transparent" }
   12.         Pass
   13.     {
   14.         ZWrite Off
   15.         Blend SrcAlpha OneMinusSrcAlpha
   16.  
   17.         CGPROGRAM
   18. #pragma vertex vert
   19. #pragma fragment frag
   20.  
   21. #include "UnityCG.cginc"
   22.  
   23.     //sampler2D _MainTex;
   24.     float4 _MainTexSampler_ST;
   25.  
   26.  
   27. texture _MainTex;
   28. sampler2D _MainTexSampler = sampler_state
   29. {
   30.     Texture = <_MainTex>;
   31.     AddressU = REPEAT;
   32.     AddressV = WRAP;
   33.     MinFilter = LINEAR;
   34.     MagFilter = LINEAR;
   35.     MipFilter = LINEAR;
   36. };
   37.     fixed4 _TopColor;
   38.     fixed4 _BottomColor;
   39.     half _Value;
   40.  
   41.     struct v2f {
   42.         float4 position : SV_POSITION;
   43.         fixed4 color : COLOR;
   44.         float2 uv : TEXCOORD0;
   45.     };
   46.  
   47.     v2f vert(appdata_full v)
   48.     {
   49.         v2f o;
   50.         o.position = mul(UNITY_MATRIX_MVP, v.vertex);
   51.         o.uv = TRANSFORM_TEX(v.texcoord, _MainTexSampler);
   52.         o.color = lerp(_TopColor,_BottomColor, v.texcoord.y);
   53.         return o;
   54.     }
   55.  
   56.     fixed4 frag(v2f i) : SV_Target
   57.     {
   58.         float4 color;
   59.     color.rgb = i.color.rgb;
   60.     color.a = tex2D(_MainTexSampler, i.uv).a + i.color.rgb;
   61.     return color;
   62.     }
   63.         ENDCG
   64.     }
   65.     }
   66. }
   67.  
   68.  
   69. };

note that the image i select on the inspector is not a white square is a cloud, that i need to clamp in just horizontal.

if someone can point me in some direction i will apreciate it much... sorry by my english btw..
thanks in advance.

 

Just saturate the X component of your UV's.

 

thanks a lot man!, i'm pretty new on shaders, i woulded take ages to figurate it by myself. thanks again!