Sorry if this comment sounds a lot like "why don't you just"-ing, I'm just trying to understand what I'm missing and I don't expect to be right. But is renderi

Sorry if this comment sounds a lot like "why don't you just"-ing, I'm just trying to understand what I'm missing and I don't expect to be right. But is rendering twice really that much of a problem if you only have to do it on a state-changing event (even if that includes things like hover events or live data)? Even games that run with 30-60 FPS aren't really a problem anymore on weak hardware so why would a GUI that updates "once in a blue moon" (relatively speaking) be? Apart from that, I don't know how Dear ImGui or other immediate mode GUI frameworks do it but if a framework handles page tearing with double rendering it could skip the actual paint (i.e. pixel drawing) in the first render. In case the user wants to avoid some needless work (like rendering labels or graphs that never affect state) in the first render the framework could also pass the calling context (update or paint) to the render function.