GPUImage shader convert to unity3d shader

hello every !

 I need the distort the texture in unity3d ,

so I convert the GPUImageStretchDistortionFilter glsl to unity3d shader ,it is right disply on pc 。but when I run ios device or andorid device .it is wrong for this .I very Confusion for it.thank you very much.

this is the GPUImage shader

  varying highp vec2 textureCoordinate;
  
  uniform sampler2D inputImageTexture;
  
  uniform highp vec2 center;
  
  void main()
  {
      highp vec2 normCoord = 2.0 * textureCoordinate - 1.0;
      highp vec2 normCenter = 2.0 * center - 1.0;
      
      normCoord -= normCenter;
      mediump vec2 s = sign(normCoord);
      normCoord = abs(normCoord);
      normCoord = 0.5 * normCoord + 0.5 * smoothstep(0.25, 0.5, normCoord) * normCoord;
      normCoord = s * normCoord;
      
      normCoord += normCenter;
         
      mediump vec2 textureCoordinateToUse = normCoord / 2.0 + 0.5;
      
      
      gl_FragColor = texture2D(inputImageTexture, textureCoordinateToUse );
      
  }

this is my unity3d shader

Shader "Custom/Custom-test" { Properties { _MainTex ("Base (RGB)", 2D) = "white" {}

 }
 SubShader {
     Tags { "RenderType"="Opaque" }
     LOD 200
       
     Pass
     {
       
         CGPROGRAM
         #pragma vertex vert
         #pragma fragment frag
         #include "UnityCG.cginc"
           
         sampler2D _MainTex;
           
         float4 _MainTex_ST;
           
         struct v2f
         {
             float4 pos : POSITION;
             float2 uv : TEXCOORD0;
         };
  
         v2f vert(appdata_full v)
         {
               v2f o;
             o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
             o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
             return o;
          
         
         }
           
         float4 frag(v2f i) : COLOR
         {      
             float2 tc = i.uv;
             float2 normCoord = 2.0 * tc -1.0;
             float2 center = float2(0.5,0.5);
             float2 normCenter = 2.0 * center -1.0;
             
             normCoord -= normCenter;
             float2 s = sign(normCoord);
             normCoord = abs( normCoord);
             normCoord = 0.5 * normCoord + 0.5 * smoothstep(0.25,0.5,normCoord) * normCoord;
             normCoord = s * normCoord;
             
             normCoord += normCenter;
             
             float2 newTc = normCoord /2.0f + 0.5;
             
             float3 color = tex2D(_MainTex, newTc).rgb;
             return float4(color, 1.0);
         }
           
         ENDCG
     }
 }
 FallBack "Diffuse"

}

this is the right effect image on pc :