Return zeros in empty query result

I have this query:

SELECT 
    --DGC.Name
    [GameChannel], 
    SUM([AdjustedGames] ) *100. / SUM(SUM([AdjustedGames])) OVER()  [Percentage]
FROM #GameChannelResults1 GC
--LEFT OUTER JOIN [WarehouseMgmt].[DimGameChannel] DGC ON DGC.Name = GC.[GameChannel]
GROUP BY [GameChannel]--DGC.Name

But when there is no match it returns empty result(nothing).I want to put somehow all values from [WarehouseMgmt].[DimGameChannel].Name as GameChannel and 0 for percentage if there is no match or result is empty. How i can do that?