shader计算图像翻转
fixed4 frag (v2f i) : SV_Target
{
//旋转180
//i.uv = mul(i.uv, float2x2(-1, 0, 0, -1)) +float2(1, 1);
//x,y翻转
i.uv.xy = float2(i.uv.x, 1-i.uv.y);
fixed4 col = tex2D(_MainTex, i.uv);
// apply fog
//UNITY_APPLY_FOG(i.fogCoord, col);
return col;
}