porting my app to imgui_bundle.imgui

[dcnieho]

This is using pip-installed v0.6.5

I decided to port a project from pyimgui to imgui_bundle as I would like to post it to pypi and I can’t do that with direct dependencies (like pyimgui version 2.0).

So, some observations from porting this program (not yet available online).

First it tried to simple replace
import imgui with from pyimgui to imgui_bundle.imgui. Obviously a bunch of code adjustments are needed, mostly for the different flags (e.g. imgui.TABLE_SCROLL_X -> imgui.ImGuiTableFlags_.scroll_x). These all get a bit long, even if they are very tight to the original imgui header. That said, this naming is not ideal I think and we have some freedom here since in C++ you’d simply directly use ImGuiTableFlags_ScrollX. imgui.TableFlags.scroll_x would be nice, or imgui.table_flags.scroll_x to be more pythonic and have consistent change from camel to snake case. So that’s no double imgui, and no trailing underscore.

Relatedly, autocomplete works very nicely, but is a little confusing as you have each enum twice (e.g. imgui.ImGuiTableFlags and imgui.ImGuiTableFlags_. The former is just an int if I understand correctly. Shall we just have the latter (ideally renamed like above)?
My biggest problem: how do I use imgui by itself? Or is that not the idea? I have no equivalent of from imgui.integrations.glfw import GlfwRenderer in imgui_bundle. Is the idea that you must use the hello_imgui wrapper? That makes it much less of a drop-in replacement. And I think I cannot use that, because I use glfw callbacks for my app, but can’t access those, I think? I have set up:

glfw.set_char_callback(self.window, self.char_callback)
glfw.set_window_focus_callback(self.window, self.focus_callback)
glfw.set_window_pos_callback(self.window, self.pos_callback)
glfw.set_drop_callback(self.window, self.drop_callback)
glfw.swap_interval(globals.settings.vsync_ratio)

And other interaction with glfw (such as window scaling when moving between dpi monitors).
Can I set these up? How?

Does imgui_bundle also expose its opengl binding? Can I port import OpenGL.GL as gl to something in the imgui_bundle, or is that out of scope? I’m asking as my code for instance does:

max_tex_size = gl.glGetIntegerv(gl.GL_MAX_TEXTURE_SIZE)
imgui.io.fonts.texture_desired_width = max_tex_size

Some small observations:

1. The flag imgui_internal.ImGuiSelectableFlagsPrivate_.im_gui_selectable_flags_select_on_click is a bit over the top, some conversion error?
2. FLT_MIN (pyimgui: imgui.FLOAT_MIN) is unavailable. Is ok, can be replaced with np.finfo('single').tiny (untested), but seems a bit heavy to require numpy for just that. That pyimgui provides imgui.FLOAT_MIN is a good solution I think. Users may well get this wrong otherwise, since a python float is a double.
3. This should work, but doesn’t:

   from imgui_bundle import imgui as imgui
   imgui.create_context()
   imgui.get_io().ini_filename = str(utils.get_data_path() / "imgui.ini")
   # raises: AttributeError: can't set attribute
   

4. Are you planning to also bundle your immvision library? I’m not exactly sure on what it does, but the description is interesting!

[dcnieho]

To add, I guess you do not have to add classes like GlfwRenderer in pyimgui, but it would be nice if you could wrap the supported backend, so that you can write code very similar to C++, where i in python could call the equivalent of:

ImGui_ImplOpenGL3_NewFrame();
ImGui_ImplGlfw_NewFrame();
ImGui::NewFrame();

That also raises the question if there should perhaps be a bit more hierarchy in the lib, e.g., should imgui_bundle.imgui_internal be imgui_bundle.imgui.internal? Somehow cleaner to me, to have constituents of imgui as a submodule of imgui. Here it would then be imgui_bundle.imgui.implGlfw (or impl_glfw). Its ok of course to only support a subset of backends, but would be very nice to have. Again, final goal here is to be able to use your imgui without hello_imgui, for those wanting to make a switch and more advanced use cases as i am running into.

I can give you access to the now private repo of my program by the way, should you find that helpful.

[pthom]

Thanks for the detailed comments! This is the kind of feedback I appreciate.

For the moment, I am busy solving a weird windows issue (see last comments in #7).

That said, this naming is not ideal I think and we have some freedom here since in C++ you’d simply directly use ImGuiTableFlags_ScrollX. imgui.TableFlags.scroll_x would be nice, or imgui.table_flags.scroll_x to be more pythonic and have consistent change from camel to snake case. So that’s no double imgui, and no trailing underscore.

Hum, I need to ponder whether it is feasible and/or desirable. In the meantime, I added a warning in the readme, that says
Warning : The API might evolve a bit during the month of November 2022. I'll remove this warning once it is more stable.

Relatedly, autocomplete works very nicely

Thanks, that was definitely one of the main goals, as well as to keep the header file documentation intact (can you see it?)

but is a little confusing as you have each enum twice (e.g. imgui.ImGuiTableFlags and imgui.ImGuiTableFlags_. The former is just an int if I understand correctly. Shall we just have the latter (ideally renamed like above)?

Hum, I think not, since users might want to do flags manipulations like:

flags: ImGuiTableFlags = ImGuiTableFlags_.flag_a | ImGuiTableFlags_.flag_b

I have no equivalent of from imgui.integrations.glfw import GlfwRenderer in imgui_bundle. I use glfw callbacks for my app, but can’t access those.

Hum, this one is not easy. For the moment, glfw is statically linked into the library.
However, I am studying a possibility which would be:

1. Link glfw dynamically (see this commit )
2. Use the standard glfw bindings provided by https://github.com/FlorianRhiem/pyGLFW, but somehow force them to use the glfw dynamic library provided by imgui_bundle (this is a tricky point)

Are you planning to also bundle your immvision library? I’m not exactly sure on what it does, but the description is interesting!

Definitely, and I think it will be awesome. I will keep you posted once it is ready.

but it would be nice if you could wrap the supported backend, so that you can write code very similar to C++, where i in python could call the equivalent of ImGui_ImplOpenGL3_NewFrame() and its companions?

Hum, I had not thought of that. Would you be willing to do some tests on this on your side?
For the tests, you can just add the bindings manually into pybind_imgui.cpp at this location:

void py_init_module_imgui_main(py::module& m)
{
// Add your manual bindings there, before the autogenerated code

[pthom]

v0.6.6 is out.
Wheels will be available in a few hours. However you can compile it from source right now (on the "main" branch).

Support for callbacks was added
Immvision was added (although it still requires polishing). It is not enabled by default. To have it, you need to pip install from source, after having installed and configured conan

(see links in release notes)

Please tell me if it works.

Have a nice day!

[dcnieho]

Hi Pascal,

I just looked through the diffs a bit, super cool! I really look forward to trying this out, hopefully still today.

A debate: should imgui_backends be imgui.backends? One the one side its part of dear imgui proper, on the other side its a bit like an addon. I'm voting imgui.backends for that first reason.

Feedback soon!

[dcnieho]

I see the enums still have an ImGui prefix. Did you run into some issue changing that?

edit removed the pip install -v . error, worked fine now...

[dcnieho]

However, both pip install -v . and building the visual studio project generated with CMake fail because SDL cannot be found. Errors like C:\Users\huml-dkn\Desktop\imgui_bundle\external\hello_imgui\src\hello_imgui\..\hello_imgui/hello_imgui.h(70): fatal error C1083: Cannot open include file: 'SDL_main.h': No such file or directory

[pthom]

Did you git submodule update —init?

[dcnieho]

Did it to be sure. It doesn't fix the pip build, still get missing include even though `\imgui_bundle\external` is populated. But i'll wait for the wheel.

…

On Mon, Nov 21, 2022 at 1:51 PM Pascal Thomet ***@***.***> wrote: Did you git submodule update —init? — Reply to this email directly, view it on GitHub <#14 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AANUOGPM2Q63RH77NGQLQ7TWJNV5NANCNFSM6AAAAAASBDBRUY> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[pthom]

Humm.. Once again, I cannot reproduce the issue here.
It does work on my windows virtual machine with msvc.

I messaged you by phone, tell me if you have a few minutes

[dcnieho]

I don't right now, on the way out. Will try a fresh clone first, to be sure.

…

On Mon, Nov 21, 2022 at 3:58 PM Pascal Thomet ***@***.***> wrote: Humm.. Once again, I cannot reproduce the issue here. It does work on my windows virtual machine with msvc. I messaged you by phone, tell me if you have a few minutes — Reply to this email directly, view it on GitHub <#14 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AANUOGJF7KJVZ2CFAYE3JGLWJOEZFANCNFSM6AAAAAASBDBRUY> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[pthom]

k

[dcnieho]

hmm, with clean clone and new venv it all builds just fine. Maybe some stale cache was left after i pulled the latest version?

[pthom]

There is a folder named _skbuild where some compilation artifacts are stored. May be it was the culprit

[dcnieho]

Should the all in __init__.py be more something like

__all__ = [
"imgui",
"hello_imgui",
"implot",
"imgui_color_text_edit",
"imgui_node_editor",
"imgui_knobs",
"im_file_dialog",
"imspinner",
"imgui_md",
"immvision",
"imgui_backends",
"icons_fontawesome",
"run_anon_block",
"implot_create_global_context",
"ImVec2",
"ImVec4",
"ImColor",
"FLT_MIN",
"FLT_MAX",
"__version__",
]

?
seems a lot is missing. But no idea if that matters.

Further things i ran into (some repeats):

1. The flag imgui_internal.ImGuiSelectableFlagsPrivate_.im_gui_selectable_flags_select_on_click is a bit over the top, some conversion error? More generally, flag naming is still long (imgui.ImGuiTableFlags_.scroll_x -> imgui.table_flags_.scroll_x)
2. This should work, but doesn’t:

   from imgui_bundle import imgui as imgui
   imgui.create_context()
   imgui.get_io().ini_filename = str(utils.get_data_path() / "imgui.ini")
   # raises: AttributeError: can't set attribute
   

3. imgui has a bunch of structs that have explicit or implicit zero argument constructors. Directly wrapping these makes them less convenient to use than is possible in Python (and also c++20 for that matter). E.g. with pyimgui is can do config = imgui.ImFontConfig(merge_mode=True, oversample_h=3, oversample_v=3), whereas now i need to spread this out over four different statements. Would it be possible to wrap these differently (perhaps opt-in), taking advantage of Python's named variable arguments?
4. Some member functions are missing from ImFontAtlas. Specifically, the code i am porting uses GetTexDataAsRGBA32(), but GetTexDataAsAlpha8(), IsBuilt() and SetTexID() are also missing.
5. imgui.ImWchar is missing. It is defined in imgui_bundle\imgui\__init__.pyi, but trying to use it in my code nets me AttributeError: module 'imgui_bundle._imgui_bundle.imgui' has no attribute 'ImWchar'
6. ImFontAtlas.add_font_from_file_ttf() has the wrong signature. The glyph_ranges argument should take a list of ints (ImWchar actually, but see previous item), but only takes a single int. So passing, for instance, [0xf0000, 0xf2000, 0] yields:

   add_font_from_file_ttf(): incompatible function arguments. The following argument types are supported:
      1. (self: imgui_bundle._imgui_bundle.imgui.ImFontAtlas, filename: str, size_pixels: float, font_cfg: imgui_bundle._imgui_bundle.imgui.ImFontConfig = None, glyph_ranges: int = None) -> ImFont
   

6 in particular is a blocking error for me, so i had to stop further porting. I have just committed step 2 (and hey, got a bunch further!) in my private repo that you have access to, so have a look what i did.

[dcnieho]

In imgui_example_glfw_opengl3.py, should imgui.render_platform_windows_default(glfw.make_context_current(backup_current_context)) be

imgui.render_platform_windows_default()
glfw.make_context_current(backup_current_context)

?

thats what imgui example code does

[dcnieho]

I ran into the next problem when porting my app. I manually modify the default style by modifying the values in the ImGuiStyle::Colors (imgui.get_style().colors in pyimgui). This doesn't seem to exist in your port. How do i set specific colors/modify my current style?

Same for KeysDown (should be imgui.get_io().keys_down) and a bunch of other arrays in the ImGuiIO struct. As these have known size, i guess there is a bigger chance they may be wrappable?

[dcnieho]

Another thing i ran into, might be user error. I have an image i want to draw. It is uploaded through OpenGL and i have a texture id. I then call draw_list.add_image_rounded(texture_id, pos, pos2, *args, flags=flags, **kwargs) and get the following error

TypeError: add_image_rounded(): incompatible function arguments. The following argument types are supported:
    1. (self: imgui_bundle._imgui_bundle.imgui.ImDrawList, user_texture_id: capsule, p_min: imgui_bundle._imgui_bundle.imgui.ImVec2, p_max: imgui_bundle._imgui_bundle.imgui.ImVec2, uv_min: imgui_bundle._imgui_bundle.imgui.ImVec2, uv_max: imgui_bundle._imgui_bundle.imgui.ImVec2, col: int, rounding: float, flags: int = 0) -> None

Invoked with: <imgui_bundle._imgui_bundle.imgui.ImDrawList object at 0x000001973685C630>, 2, <imgui_bundle._imgui_bundle.imgui.ImVec2 object at 0x000001973685C0F0>, <imgui_bundle._imgui_bundle.imgui.ImVec2 object at 0x000001973685C1B0>; kwargs: flags=<ImDrawFlags_.round_corners_all: 240>, rounding=6.0

Removing *args from the call (its an empty tuple) and explicitly naming the other two arguments as p_min and p_max doesn't change this, same incompatible arguments error.

type(self.texture_id) returns <class 'numpy.uintc'>, as is (apparently) returned by gl.glGenTextures(1) (import OpenGL.GL as gl)

[dcnieho]

I think ImGuiTableSortSpecs isn't wrapped correctly. specs should be a list of TableColumnSortSpecs, not a single one. My pyimgui code has for sort_spec in sort_specs_in.specs, where sort_specs_in is a ImGuiTableSortSpecs gotten from imgui.table_get_sort_specs().

[dcnieho]

Ok, last comment for now. Nice work man on the wrapper, i got my first windows to show even though not everything works yet. Anyway, what i run in now is that there are two versions of ´imgui.selectable´ (and i guess there are more like this one) where one takes a bool and returns a bool, and the other takes a pointer to bool and returns a tuple of two bools. Here i made it error so you can see the signatures:

TypeError: selectable(): incompatible function arguments. The following argument types are supported:
    1. (label: str, selected: bool = False, flags: int = 0, size: imgui_bundle._imgui_bundle.imgui.ImVec2 = <imgui_bundle._imgui_bundle.imgui.ImVec2 object at 0x00000285EAB525F0>) -> bool
    2. (label: str, p_selected: bool, flags: int = 0, size: imgui_bundle._imgui_bundle.imgui.ImVec2 = <imgui_bundle._imgui_bundle.imgui.ImVec2 object at 0x00000285EA6D2770>) -> Tuple[bool, bool]

I want to use the latter, but get the former. Even though both are defined in the generated pybind code. I guess that is because their python function syntax is identical? Both just take a bool. Perhaps this is user error. How do i call the latter one with signature returning -> Tuple[bool, bool]?

By the way, it would be nice to provide __str__() for imgui.ImVec2 and co, would make the above output much nicer. And given how much ImVec2 is used and returned throughout the code, much more legible and usable.

[dcnieho]

Well, some more:
ini = imgui.save_ini_settings_to_memory() fails even though the one input argument is optional:

TypeError: save_ini_settings_to_memory(): incompatible function arguments. The following argument types are supported:
    1. (out_ini_size: int = None) -> str

Invoked with:

calling it with e.g. 1000 as argument works fine.

And in my port i don't get font loading to work. That is, my icons show up as question marks. I have tried adding

imgui_backends.opengl3_destroy_fonts_texture()
imgui_backends.opengl3_create_fonts_texture()

after the calls to imgui.font_atlas_add_font_from_file_ttf which i think should be needed because else the new font texture doesn't get built (not needed in your demo though, as you call these before the very first frame is rendered, and fonts are set up in ImGui_ImplOpenGL3_CreateDeviceObjects() which is called the first frame). So adding those calls didn't help. Guess i am doing something wrong as your demo does work. But what i have now worked with pyimgui, so i am wondering what the difference/my oversight is...

[dcnieho]

Ok, last comment for now. Nice work man on the wrapper, i got my first windows to show even though not everything works yet. Anyway, what i run in now is that there are two versions of ´imgui.selectable´ (and i guess there are more like this one) where one takes a bool and returns a bool, and the other takes a pointer to bool and returns a tuple of two bools. Here i made it error so you can see the signatures:

TypeError: selectable(): incompatible function arguments. The following argument types are supported:
    1. (label: str, selected: bool = False, flags: int = 0, size: imgui_bundle._imgui_bundle.imgui.ImVec2 = <imgui_bundle._imgui_bundle.imgui.ImVec2 object at 0x00000285EAB525F0>) -> bool
    2. (label: str, p_selected: bool, flags: int = 0, size: imgui_bundle._imgui_bundle.imgui.ImVec2 = <imgui_bundle._imgui_bundle.imgui.ImVec2 object at 0x00000285EA6D2770>) -> Tuple[bool, bool]

I want to use the latter, but get the former. Even though both are defined in the generated pybind code. I guess that is because their python function syntax is identical? Both just take a bool. Perhaps this is user error. How do i call the latter one with signature returning -> Tuple[bool, bool]?

We had a closely related discussion about this before, IIRC. The two functions are redundant for the python binding, so we have to choose one style. for pyimgui compatibility (and because i know of no other good reason) and additional flexibility (this form is more informative) i vote to only expose version 2. I'm not sure if this case can be automatically detected (that two different c++ function lead to a python function with the same arguments) and the choice automated.

By the way, I'll go through all this and make separate issues of each thing, so its possible to track them. Right now its become a mess thanks to me.

[dcnieho]

I think i have now poored all this into separate issues. Hope i didn't miss anything. Thanks again for the hard work, i'm excited where this is heading!

[pthom]

Thanks for taking the time to separate this into issues, this is helpful!

I will answer in those

[dcnieho]

Thanks for looking at all the requests and your offers of help. I hope to look at them later today! Else probably friday or latest the weekend.

…

Message ID: ***@***.***>

[dcnieho]

I get a whole bunch of compile errors right now, despite a completely clean check out of dev. some excerpts of what `pip install .` gives me (rather baffling): ``` FAILED: CMakeFiles/imgui_color_text_edit.dir/external/ImGuiColorTextEdit/TextEditor.cpp.obj C:\PROGRA~1\MIB055~1\2022\COMMUN~1\VC\Tools\MSVC\1434~1.319\bin\Hostx86\x64\cl.exe /nologo /TP -DIMGUI_BUNDLE_BUILD_PYTHON -DIMGUI_BUNDLE_PYTHON_API -DIMGUI_USER_CONFIG=\"C:/Users/huml-dkn/Desktop/imgui_bundle/cmake/imgui_bundle_config.h\" -DImTextureID=int -IC:\Users\huml-dkn\Desktop\imgui_bundle\external\ImGuiColorTextEdit\.. -IC:\Users\huml-dkn\Desktop\imgui_bundle\cmake\..\external -IC:\Users\huml-dkn\Desktop\imgui_bundle\external\imgui /DWIN32 /D_WINDOWS /GR /EHsc /O2 /Ob2 /DNDEBUG -MD -std:c++17 /showIncludes /FoCMakeFiles\imgui_color_text_edit.dir\external\ImGuiColorTextEdit\TextEditor.cpp.obj /FdCMakeFiles\imgui_color_text_edit.dir\imgui_color_text_edit.pdb /FS -c C:\Users\huml-dkn\Desktop\imgui_bundle\external\ImGuiColorTextEdit\TextEditor.cpp C:\Users\huml-dkn\Desktop\imgui_bundle\external\ImGuiColorTextEdit\TextEditor.h(75): error C3861: 'assert': identifier not found C:\Users\huml-dkn\Desktop\imgui_bundle\external\ImGuiColorTextEdit\TextEditor.cpp(228): error C3861: 'assert': identifier not found ``` ``` FAILED: CMakeFiles/imgui_bundle.dir/src/imgui_bundle/imgui_bundle.cpp.obj [...] C:\Users\huml-dkn\Desktop\imgui_bundle\external\imgui\imgui.h(3067): warning C4297: 'ImGuiViewport::~ImGuiViewport': function assumed not to throw an exception but does C:\Users\huml-dkn\Desktop\imgui_bundle\external\imgui\imgui.h(3067): note: destructor or deallocator has a (possibly implicit) non-throwing exception specification C:\Users\huml-dkn\Desktop\imgui_bundle\src\imgui_bundle\imgui_bundle.cpp(28): error C2440: '=': cannot convert from 'int' to 'void *' C:\Users\huml-dkn\Desktop\imgui_bundle\src\imgui_bundle\imgui_bundle.cpp(28): note: Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or parenthesized function-style cast ``` ``` FAILED: CMakeFiles/imgui_md.dir/external/imgui_md/imgui_md/imgui_md.cpp.obj C:\Users\huml-dkn\Desktop\imgui_bundle\external\imgui_md\imgui_md\imgui_md.cpp(699): error C3861: 'assert': identifier not found ``` Will try again later.

…

On Wed, Dec 7, 2022 at 9:01 AM Diederick C. Niehorster ***@***.***> wrote: Thanks for looking at all the requests and your offers of help. I hope to look at them later today! Else probably friday or latest the weekend. > Message ID: ***@***.***> >

[pthom]

It should be solved now. I don't know why suddenly this include became necessary, but it is cleaner with it.

[dcnieho]

Thanks, installed fine now :)

…

Message ID: ***@***.***>

[pthom]

If you want to test immvision, install like this:

# - when building wheels for windows, the env variable
#   IMGUIBUNDLE_OPENCV_WIN_USE_OFFICIAL_PREBUILT_460 is set before running pip.
#   This way, an official release from OpenCV 4.6.0 for windows will be downloaded.
#   It includes an "opencv_world.dll" (a dll that groups all the code for all OpenCV modules).
#   This dll is deployed into imgui_bundle package (under windows)
#   "Funny" note on how to set this env var under windows: choose your poison
#     * with PowerShell
#	      Set-Item -Path 'Env:IMGUIBUNDLE_OPENCV_WIN_USE_OFFICIAL_PREBUILT_460' -Value 'ON'
#     * With bash:
#	      export IMGUIBUNDLE_OPENCV_WIN_USE_OFFICIAL_PREBUILT_460=ON
#      * With dos:
#         set IMGUIBUNDLE_OPENCV_WIN_USE_OFFICIAL_PREBUILT_460=ON

[dcnieho]

I will do so later, don't need it for glassesValidator but for another (C++) project. That one will be more involved to port to hello_imgui with all bells and whistles, but also very worth it! Man, I am tantalizingly close now to making it all work! Mostly fixing small things now where pyimgui deviated from the imgui api, and i have to now change names of arguments or so. Those are great kinds of problems to have :)

…

Message ID: ***@***.***>

[pthom]

I will transfer this issue to discussions. This will be a good way for us to exchange on the subject.