Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Raygui – A simple and easy-to-use immediate-mode GUI library

github.com

Post reply on HN
Print view View original

61–70 of 117 posts

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#61

Post by modeless »

AbuAssar wrote: post #53

Does anyone care to explain what immediate mode means?

Immediate mode is a style of API where important state is kept in user code instead of being retained inside the API implementation. For example, an immediate mode GUI checkbox implementation does not store a boolean value determining whether the checkbox is checked. Instead, user code passes that information as a function parameter whenever the UI needs to be drawn. Even the fact that a checkbox exists on screen is not stored in the GUI library. The checkbox is simply drawn when user code requests it each frame.

Couterintuitively this is often less complicated than the traditional "retained mode" style of GUI libraries because there is no duplication of state. That means no setup or teardown of widget object trees, no syncing of state between GUI objects and application code, no hooking up or removing event handlers, no "data binding", etc. The structure and function of your UI is naturally expressed in the code of the functions that draw it, instead of in ephemeral and opaque object trees that only exist in RAM after they're constructed at runtime. You retain control over the event loop and you define the order in which everything happens rather than receiving callbacks in some uncertain order from someone else's event dispatching code.

Crucially, "immediate mode" is a statement about the interface of the library, not the internals. Common objections of the form "immediate mode GUIs can't support X" or "immediate mode GUIs are inefficient because Y" are generally false and based on a misconception that immediate mode GUIs are forbidden from retaining any internal state at all. It is perfectly normal for an immediate mode library to retain various types of internal state for efficiency or other reasons, and this is fine as long as the state stored in user code remains the source of truth. This can even go as far as internally constructing a whole retained widget tree and maintaining it via React-like tree diffing.

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#62

Post by dragonwriter »

999900000999 wrote: post #39
dragonwriter wrote: post #31

Earlier quoted context omitted.

How is: Box( Button( Icon(...) ) ) Weirder than:

Now attach some callbacks. With XML I'm attaching my callbacks via code while defining the UI elsewhere. With pure code, I have to attach the callbacks directly to the object. Theirs a reason you don't just use JavaScript to define React components

> Now attach some callbacks.

Not that any of this is relevant to immediate mode GUI, but the actual attachment of callbacks can be done identically in code no matter how the base UI design is done if you want it separately, but if you do it in code (whether with normal syntax or a funky transform like JSX) you can also have the option of direct attachment.

> With pure code, I have to attach the callbacks directly to the object.

No, you don't, but you can, and as it turns out, that's kind of popular.

> Theirs a reason you don't just use JavaScript to define React components

You can, in fact, but even when you use JSX, there is a reason you don't use actual (HT/X)ML code, but instead a language that compiles to, and let's you freely mix in, JavaScript.

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#63

Post by [deleted] »

flohofwoe wrote: post #60
mortehu wrote: post #58

Earlier quoted context omitted.

It does imply to some degree that the entire geometry of the UI isn't stored in GPU memory. It's possible to store an entire UI, with text and all, in GPU memory and render it with a single call (e.g. glDrawElements).

...and those GPU buffers need to be rebuilt as soon as anything in the UI changes. An immediate mode UI could just as well track state changes and only rebuild GPU buffers if needed. Most just don't this (and instead use dynamic buffers which are updated with new data each frame) because the state diffing would complicate the implementation and is usually "not worth it", but they still implement batching within a sin…

[deleted]

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#64

Post by 999900000999 »

dragonwriter wrote: post #62
999900000999 wrote: post #39

Earlier quoted context omitted.

Now attach some callbacks. With XML I'm attaching my callbacks via code while defining the UI elsewhere. With pure code, I have to attach the callbacks directly to the object. Theirs a reason you don't just use JavaScript to define React components

> Now attach some callbacks. Not that any of this is relevant to immediate mode GUI, but the actual attachment of callbacks can be done identically in code no matter how the base UI design is done if you want it separately, but if you do it in code (whether with normal syntax or a funky transform like JSX) you can also have the option of direct attachment. > With pure code, I have to attach the callbacks directly to…

Let's say you have a really complex UI.

Would you really define your UI in code over XML or HTML

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#66

Post by lolinder »

modeless wrote: post #61
AbuAssar wrote: post #53

Does anyone care to explain what immediate mode means?

Immediate mode is a style of API where important state is kept in user code instead of being retained inside the API implementation. For example, an immediate mode GUI checkbox implementation does not store a boolean value determining whether the checkbox is checked. Instead, user code passes that information as a function parameter whenever the UI needs to be drawn. Even the fact that a checkbox exists on screen is…

Jetpack Compose on Android has an API exactly like you describe, but I've never heard it described as an immediate-mode GUI. Is it one, or is there something else that makes a GUI toolkit immediate-mode?

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#67

Post by theonething »

modeless wrote: post #61
AbuAssar wrote: post #53

Does anyone care to explain what immediate mode means?

Immediate mode is a style of API where important state is kept in user code instead of being retained inside the API implementation. For example, an immediate mode GUI checkbox implementation does not store a boolean value determining whether the checkbox is checked. Instead, user code passes that information as a function parameter whenever the UI needs to be drawn. Even the fact that a checkbox exists on screen is…

sounds like html over the wire in the web world. State only resides on the backend. I think it's a good direction.

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#68

Post by throwaway684936 »

synergy20 wrote: post #19

I have seen quite often 'immediate mode gui' on HN and elsewhere these days,I rarely do GUI myself, where are these im-gui's use cases? gaming only? or some embedded boards with limited resources can benefit to draw some pixels on a small LCD for a simple GUI(even that people are more likely use some light-weight x11 like libraries instead of im-gui library)? Other than game-development why is im-gui better than thos…

Immediate mode GUIs can be used for almost anything that retained mode GUI toolkits (GTK, Qt) can be used for. It removes a lot of the overhead and boilerplate to speed up development.

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#69

Post by Adverblessly »

synergy20 wrote: post #19

I have seen quite often 'immediate mode gui' on HN and elsewhere these days,I rarely do GUI myself, where are these im-gui's use cases? gaming only? or some embedded boards with limited resources can benefit to draw some pixels on a small LCD for a simple GUI(even that people are more likely use some light-weight x11 like libraries instead of im-gui library)? Other than game-development why is im-gui better than thos…

IMO The main benefit of immediate mode GUI is that (unlike "normal widget kits"), the data required to "drive" the widgets is not actually owned by the widgets themselves, making widgets controlled directly by the "program's" data. You make some sort of change to the program's data and it is immediately reflected on the screen. This is as opposed to the "normal widget kits" where you need some "glue" to reflect those changes for example maybe you need to let the widget know its contents were updated and it needs to redraw or redo its layout.

This makes it easier to create certain types of UIs where the main interaction is to modify some data structure directly, which is how many simple tools behave.

Re: Raygui – A simple and easy-to-use immediate-mode GUI library

#70

Post by throwaway684936 »

quotemstr wrote: post #30
synergy20 wrote: post #19

I have seen quite often 'immediate mode gui' on HN and elsewhere these days,I rarely do GUI myself, where are these im-gui's use cases? gaming only? or some embedded boards with limited resources can benefit to draw some pixels on a small LCD for a simple GUI(even that people are more likely use some light-weight x11 like libraries instead of im-gui library)? Other than game-development why is im-gui better than thos…

Many people at a certain point in their careers become infatuated with the idea of making a "small", "simple", and "opinionated" component free from legacy "BS". They have the skill to implement the core of that component but lack the wisdom and humility to understand that the "BS" complexity exists for good reasons, that their "small" component is subject to those reasons, and that they haven't actually found a fund…

Immediate mode is generally used for quick and dirty developer tools. It's rarely used for user-facing UI. You're free to waste your time carefully architecting an MVC application any time you want a few text boxes and sliders to fiddle with something. Microsoft, Google, Nvidia, Valve, Id, Blizzard, Ubisoft will continue to use immediate mode where they deem it useful, in spite of your advice.
Post reply on HN