ernesernesto/hlimgui

Heaps/HashLink native binding for Dear ImGui

Build & Install

First, make sure that HashLink, CMake and a C/C++ compiler are installed on your system. This version of hlimgui uses submodules. Get them prepared like this:

git submodule init
git submodule update

Then the native extension needs to be built with these commands:

cd extension
mkdir build
cd build

cmake ..
cmake --build .

It builds a target hdll file, which you can copy to the root of the project.

Another method is to build it inside Visual Studio Code with CMake Tools extension installed, so you don't have to deal with the command line.

To add this library to your project, you need to include these files:

• The previously compiled hlimgui.hdll file.
• imgui/ImGuiDrawable.hx: this class derives from the standard Heaps Drawable class and contains/displays all ImGui widgets.
• imgui/ImGui.hx: interface to the native extension.
• imgui/ImGuiMacro.hx: Useful helper macros for wrapping hl.Ref.
• imgui/NodeEditor.hx: Wrapper for the imgui-node-editor extension.
• imgui/FieldRef.hx: The macro-helper that emulates missing $fieldref opcode for HL that is required for usage of this library.

See Main.hx to see how to implement this library.

Supported ImGui features

Most of the ImGui functionalities are supported and bound. Look at https://github.com/ocornut/imgui to get documentation on exposed functions AND how ImGui works.

Here is a list of unsupported features and changes:

• ImGui has several functions which take a variable number of parameters in order to format strings. This feature isn't supported in Haxe, so all string formatting must be done in Haxe before passing it to ImGui.

• The function setIniFilename doesn't exist in ImGui, it has been added to modify the filename of the default ini file saved by ImGui (pass null to turn off this feature).

References

Input function often take a Ref<T> / imgui.FieldRef<T> argument. Those are equivalent to hl.Ref however offer an extra feature of referencing an class instance or static field, not only local variables.

However the limitation of Ref is that it does not work properties (get_x / set_y), in which case you will have to manually load said values into local variables or use the wrapper function:

import imgui.ImGuiMacro.*; // Import the `wref` / `wrefv` and `wrefc` macro functions into global scope.
// In order to denote which values should be converted into a reference,
// either use `$(path.to.field)` notation or use `_` and insert the value after the initial call.
// Names are shorthands to:
// wref - With Reference
// wrefv - With Reference (Void call)
// wrefc - With Reference (Conditional assign)

var myString = "Hello!", edited: Boolean;

// Will assign myString regardless of inputText return value.
// `wref` will assign referenced values back regardless of the returned value.
// Wrapper return value is equivalent to wrapped function return value. Incompatible with `:Void` methods.
edited = wref(ImGui.inputText('Text input', $(myString))); // With `$(value)` notation
edited = wref(ImGui.inputText('Text input', _), myString); // With `_` notation

// same as `wref` - `wrefv` will assign value back regardless, but compatible with `:Void` methods.
static var show: Boolean = true;
wrefv(ImGui.showDemoWindow($(edited)));
// Will result in an error! `wrefv` does not return a value.
// edited = wrefv(ImGui.inputText('Text input', $(myString)));

// Compared to `wref` - `wrefc` only assigns back the value if wrapped method returns true.
// Note that it works only with methods that return a boolean.
// Useful when property does some extra logic when it's changes and you don't want it to trigger every frame.
edited = wrefc(ImGui.inputText('Text input', $(myString)));

Heaps integration

This library comes with a built-in Heaps support with the following features:

• imgui.ImGuiApp is a quick-start hxd.App version that overlays ImGui elements as a separate scene.
• imgui.ImGuiDrawable is a primary renderer for ImGui content and can be used to set up your own ImGui integration if ImGuiApp is not viable.
• imgui.ImTextureID is mapped to h3d.mat.Texture.
• A number of methods that take h2d.Tile instead of ImTextureID for easier image rendering.

Bugs

If you find bugs, please report them on the GitHub project page. Most of the bound functions have been tested, but as it's a new library some bugs might remain.

Thanks

• haddock7: I would like to thanks Aidan63 for their Haxe/cpp binding. I have borrowed all the structure declaration code which remains the same between the two bindings.
• This is a fork of haddock7's imgui port for HashLink with advanced usage of HL/Haxe specifics accounted for, thanks to him for initial port of the library.