Just because you're attempting to re-make a game in C++/SFML from a game engine doesn't guarentee improved performance. A lot of these popular engines have invested a lot of resources (time, money etc..) into development and I'd imagine in a lot of cases out perform a lot of home-brew engines.
Anther thing to note, Game Maker does convert the "textures" into texture pages which can reduce the impact the texture sizes loaded in memory.
Probably my fault, i assumed true the "game maker has bad performance" statement you can see everywhere around, maybe it's just not that true after all.
Isn't a texture page just a bigger texture with more textures in it opposed to having multiple smaller textures?
I think you should really look further into why Game Maker has "bad performance" and where. I'm not saying it isn't true; but my point being, a company who has a huge amount of resources going into this engine versus a hobby programmer new to C++. Not to say it's impossible, but you should really get a better understanding of:
- Where GM lacks performance and why.
- What you actually want to achieve.
- C++ and SFML (if this is the right library for your task).
- Profiling.
Also, regarding the texture pages; they remove a lot of "empty space" and compact the textures, pretty much a texture atlas. The point of the texture page is indeed to have 1 texture instead of many - for sprite batching.