So, this is better explain with screenshots so here is the app without a config.lua:
And here it is with the recommended configuration here https://coronalabs.com/blog/2013/09/10/modernizing-the-config-lua/
Here’s the code in config.lua:
--calculate the aspect ratio of the device local aspectRatio = display.pixelHeight / display.pixelWidth application = { content = { width = aspectRatio \> 1.5 and 800 or math.ceil( 1200 / aspectRatio ), height = aspectRatio \< 1.5 and 1200 or math.ceil( 800 \* aspectRatio ), scale = "letterBox", fps = 30, imageSuffix = { ["@2x"] = 1.3, }, }, }
What am I doing wrong? The background image is 640x1136px.