UnlitAlphaRotation.shader

Shader "Custom/UnlitAlphaRotation" 
{
    Properties
    {
        _MainTex("Base (RGB) Trans (A)", 2D) = "white" {}
        _RotationY("Rotation over Y-axis", Range(0, 360)) = 45
    }

    SubShader
    {
        Tags 
        {
            "Queue" = "Transparent" 
            "IgnoreProjector" = "True" 
            "RenderType" = "Transparent"
        }

        LOD 100
        ZWrite Off
        Blend SrcAlpha OneMinusSrcAlpha

        Pass 
        {
            CGPROGRAM

            #include "UnityCG.cginc"

            #pragma vertex vert
            #pragma fragment frag
            #pragma target 2.0
            #pragma multi_compile_fog

            sampler2D _MainTex;
            float4 _MainTex_ST;
            float _RotationY;

            struct appdata_t 
            {
                float4 vertex : POSITION;
                float2 texcoord : TEXCOORD0;
                UNITY_VERTEX_INPUT_INSTANCE_ID
            };

            struct v2f 
            {
                float4 vertex : SV_POSITION;
                float2 texcoord : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                UNITY_VERTEX_OUTPUT_STEREO
            };

            float4 RotateAroundYInDegrees(float4 vertex, float degrees)
            {
                float alpha = degrees * UNITY_PI / 180.0;
                float sina, cosa;
                sincos(alpha, sina, cosa);
                float2x2 m = float2x2(cosa, -sina, sina, cosa);
                return float4(mul(m, vertex.xz), vertex.yw).xzyw;
            }

            v2f vert(appdata_t v)
            {
                v2f o;
                UNITY_SETUP_INSTANCE_ID(v);
                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.vertex = RotateAroundYInDegrees(o.vertex, _RotationY);
                o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }

            fixed4 frag(v2f i) : SV_Target
            {
                fixed4 col = tex2D(_MainTex, i.texcoord);
                UNITY_APPLY_FOG(i.fogCoord, col);
                return col;
            }

            ENDCG
        }
    }
}