Gradient Shader in Unity

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/gradient" {
Properties
{
_TopColor("Top Color", Color) = (1, 1, 1, 1)
_BottomColor("Bottom Color", Color) = (1, 1, 1, 1)
_RampTex("Ramp Texture", 2D) = "white" {}
}
SubShader
{
Pass
{
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
struct vertexIn {
float4 pos : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
v2f vert(vertexIn input)
{
v2f output;
output.pos = UnityObjectToClipPos(input.pos);
output.uv = input.uv;
return output;
}
fixed4 _TopColor, _BottomColor;
sampler2D _RampTex;
fixed4 frag(v2f input) : COLOR
{
return lerp(_BottomColor, _TopColor, input.uv.x);
}
ENDCG
}
}
}