Legacy GM Question About PNG Crush

[RyanC]

Hi All,
After looking in the manual to find out how to compress texture pages I found the gml_pragma("PNGCrush") function.

Couple of questions I could'n't find answers to in the manual:

Does this downgrade the image quality?

Are the images then uncompressed at game start or as they are used?

Will this have a performance impact on the game?

 

[YellowAfterlife]

Does this downgrade the image quality?

No - it tries different ways of compressing the existing data to find the one that produces smallest filesize.

Are the images then uncompressed at game start or as they are used?

PNG is compressed by definition (zlib), so yes.

Will this have a performance impact on the game?

No, as per above.
wiki: https://en.wikipedia.org/wiki/Pngcrush

 

[RyanC]

Finally got around to testing this and I'm wondering if using PNG crush may even boost the game performance, as GMS will be drawing sprites with less file size?

 

[YellowAfterlife]

Finally got around to testing this and I'm wondering if using PNG crush may even boost the game performance, as GMS will be drawing sprites with less file size?

PNG file size is irrelevant because GPU can't decompress PNG images in real-time so any images are uncompressed first.

 

[RyanC]

Oh I see, so it's literally just to save final executable size then.