Simple DirectMedia Layer 2 (SDL2) isn't a GUI library itself; it’s a low-level "chassis" designed to manage windows, hardware, and input. When you talk about an "SDL2 GUI," you’re essentially choosing between or plugging in a third-party toolkit . The DIY Experience: "Pixel-Perfect Masochism"
Since SDL2 provides the window, these libraries provide the buttons: Is SDL2 suitable for GUI development? : r/C_Programming sdl2 gui
You have to manually handle every "boring" interaction, like click detection, text wrapping, and focus management. Popular Add-on Toolkits Simple DirectMedia Layer 2 (SDL2) isn't a GUI