UI Gradient.shader

Shader "Custom/UI Gradient" {
    Properties {
        _MainTex ("Texture", 2D) = "white" {}
        _GradientDirection ("Gradient Direction", Range(0, 360)) = 0
        _Color1 ("Color 1", Color) = (1,1,1,1)
        _Color2 ("Color 2", Color) = (0,0,0,1)
    }
 
    SubShader {
        Tags { "Queue"="Transparent" "RenderType"="Transparent" }
        Blend SrcAlpha OneMinusSrcAlpha
 
        Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
 
            struct appdata {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };
 
            struct v2f {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
            };
 
            sampler2D _MainTex;
            float4 _MainTex_ST;
            float _GradientDirection;
            float4 _Color1;
            float4 _Color2;
 
            v2f vert (appdata v) {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }
 
            fixed4 frag (v2f i) : SV_Target {
                float2 uv = i.uv;
                float4 tex = tex2D(_MainTex, uv);
                float angle = (_GradientDirection + 45) / 180 * 3.14159265;
                float2 direction = float2(cos(angle), sin(angle));
                float2 gradientUV = uv - 0.5;
                float gradient = dot(gradientUV, direction) + 0.5;
                fixed4 color = lerp(_Color1, _Color2, gradient);
                return tex * color;
            }
            ENDCG
        }
    }
}