Request: Examples that blit

[phrohdoh]

[tac-tics]

Is there any update on this? I just started playing with sdl2, but I can't seem to figure out how to blit. (Although I learned SDL nearly a decade ago, and maybe the terminology changed. Is this what Canvas.copy does?).

[Cobrand]

@tac-tics This may help you:

Canvas represents a "Renderer" under the SDL terms, meaning generally a generic interface for OpenGL, DirectX, OpenGLES, ... (usually your graphic card). A Canvas can hold "Texture"s. Textures are representations of the backend (OpenGL, DirectX)'s textures: we cannot manipulate it directly without calling functions of Canvas.

A Surface is simply a buffer of width * height * 4 bytes stored in RAM. Quick manipulations are much faster since you do not need to call the graphic driver every time you want to do something, but rendering on screen is slower (since you need to "send" the buffer to the graphic card every time).

If you want to manipulate a Surface using another Surface directly: https://docs.rs/sdl2/0.31.0/sdl2/surface/struct.Surface.html#method.blit will help you.
Otherwise, if you want to change your "screen" (or Canvas) using a Texture, use Canvas.copy. You can convert Surface into Textures with https://docs.rs/sdl2/0.31.0/sdl2/render/struct.TextureCreator.html#method.create_texture_from_surface.

I strongly recommend you look a tutorial on SDL2 to understand how it works exactly -- while I'm trying my best to explain the basics, I still think having a good understanding of the C library is the most efficient way to learn how the rust bindings work.

Hope that helps!

[tac-tics]

Thanks a bunch! I'll take a look. It seems like the fundamental C concepts have changed quite a bit since SDL1, so I'll have to catch up a bit.