2x automatically scaled down?

Audio and Graphics
#1

I am trying to get rid of lower-resolution spritesheets, and only use high-resolution ones. I’m doing it to make my app significantly smaller, since my app has about 70 mb of art. However, I’ve come across a strange problem:

When I use @2x spritesheets with @2x information exported from TexturePacker, all my sprites are displayed at double their original size, instead of automatically being scaled back to look the same as @1x sprites. When I use @2x spritesheets with @1x (no image suffix) information, everything is fine, and the sprite is displayed as normal, but at a higher resolution – this is what I want to see. It seems that Corona automatically scales it down, even though the spritesheet file, buttons.png, has no @2x in it. That is, it’s correctly using the sheet information for a spritesheet where all the dimensions need to be halved. Can anyone tell me:

  1. Why is this working?

  2. Is there a suggested way to transition to using only @2x images without screwing up your ui layout? I have a large code base, but I want to do it the “real” way. Hopefully this doesn’t involve manually editing hundreds of sprite instances. 

I’ve attached a project showing the issue – buttons.lua is @1x, and buttons.png is exported @2x, but it shows just fine.

Help!

#2

You are missing the @2x reference in config.lua

 content = { imageSuffix = { ["@2x"] = 2 } },

Adding @1x images shouldn’t increase your apk size by very much and will stop lower end devices maxing out on texture memory

#3

@adrianM:

  1. I understand I’m missing the @2x reference. That’s what’s confusing me – even without the @2x reference, it’s still loading properly. Why is it working? That’s my question.

  2. I appreciate your concern, but my game doesn’t use so much memory at one time that it matters on slower devices. Having @1x images will will increase my app’s size significantly – by at least 10 or 15 mb. I have a lot of art, and having a larger app just means fewer people will download it. Hence my downsizing.

#4

If you don’t want image scaling then make sure your sprite sheet has the same dimensions as your image sheet.  In your zip - your image sheet is 1024 x 2048 but your sprite sheet is only 512 x 1024.

But your config.lua is set to 320 x 480 so everything will be jumbo-sized without the @2x handling (which maps 4 image pixels to 1 corona pixel).  So you would need to change your config.lua to this

application = { content = { width = 640, height = 960, scale = "letterBox", fps = 30, }, }
#5

You are missing the @2x reference in config.lua

 content = { imageSuffix = { ["@2x"] = 2 } },

Adding @1x images shouldn’t increase your apk size by very much and will stop lower end devices maxing out on texture memory

#6

@adrianM:

  1. I understand I’m missing the @2x reference. That’s what’s confusing me – even without the @2x reference, it’s still loading properly. Why is it working? That’s my question.

  2. I appreciate your concern, but my game doesn’t use so much memory at one time that it matters on slower devices. Having @1x images will will increase my app’s size significantly – by at least 10 or 15 mb. I have a lot of art, and having a larger app just means fewer people will download it. Hence my downsizing.

#7

If you don’t want image scaling then make sure your sprite sheet has the same dimensions as your image sheet.  In your zip - your image sheet is 1024 x 2048 but your sprite sheet is only 512 x 1024.

But your config.lua is set to 320 x 480 so everything will be jumbo-sized without the @2x handling (which maps 4 image pixels to 1 corona pixel).  So you would need to change your config.lua to this

application = { content = { width = 640, height = 960, scale = "letterBox", fps = 30, }, }