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diff --git a/src/imgui/docs/EXAMPLES.md b/src/imgui/docs/EXAMPLES.md new file mode 100644 index 0000000..edaddb0 --- /dev/null +++ b/src/imgui/docs/EXAMPLES.md @@ -0,0 +1,245 @@ +_(You may browse this at https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md or view this file with any Markdown viewer)_ + +## Dear ImGui: Examples + +**The [examples/](https://github.com/ocornut/imgui/blob/master/examples) folder example applications (standalone, ready-to-build) for variety of +platforms and graphics APIs.** They all use standard backends from the [backends/](https://github.com/ocornut/imgui/blob/master/backends) folder (see [BACKENDS.md](https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md)). + +The purpose of Examples is to showcase integration with backends, let you try Dear ImGui, and guide you toward +integrating Dear ImGui in your own application/game/engine. +**Once Dear ImGui is setup and running, run and refer to `ImGui::ShowDemoWindow()` in imgui_demo.cpp for usage of the end-user API.** + +You can find Windows binaries for some of those example applications at: + https://www.dearimgui.com/binaries + + +### Getting Started + +Integration in a typical existing application, should take <20 lines when using standard backends. + +```cpp +At initialization: + call ImGui::CreateContext() + call ImGui_ImplXXXX_Init() for each backend. + +At the beginning of your frame: + call ImGui_ImplXXXX_NewFrame() for each backend. + call ImGui::NewFrame() + +At the end of your frame: + call ImGui::Render() + call ImGui_ImplXXXX_RenderDrawData() for your Renderer backend. + +At shutdown: + call ImGui_ImplXXXX_Shutdown() for each backend. + call ImGui::DestroyContext() +``` + +Example (using [backends/imgui_impl_win32.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_win32.cpp) + [backends/imgui_impl_dx11.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_dx11.cpp)): + +```cpp +// Create a Dear ImGui context, setup some options +ImGui::CreateContext(); +ImGuiIO& io = ImGui::GetIO(); +io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable some options + +// Initialize Platform + Renderer backends (here: using imgui_impl_win32.cpp + imgui_impl_dx11.cpp) +ImGui_ImplWin32_Init(my_hwnd); +ImGui_ImplDX11_Init(my_d3d_device, my_d3d_device_context); + +// Application main loop +while (true) +{ + // Beginning of frame: update Renderer + Platform backend, start Dear ImGui frame + ImGui_ImplDX11_NewFrame(); + ImGui_ImplWin32_NewFrame(); + ImGui::NewFrame(); + + // Any application code here + ImGui::Text("Hello, world!"); + + // End of frame: render Dear ImGui + ImGui::Render(); + ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData()); + + // Swap + g_pSwapChain->Present(1, 0); +} + +// Shutdown +ImGui_ImplDX11_Shutdown(); +ImGui_ImplWin32_Shutdown(); +ImGui::DestroyContext(); +``` + +Please read 'PROGRAMMER GUIDE' in imgui.cpp for notes on how to setup Dear ImGui in your codebase. +Please read the comments and instruction at the top of each file. +Please read FAQ at https://www.dearimgui.com/faq + +If you are using any of the backends provided here, you can add the backends/imgui_impl_xxxx(.cpp,.h) +files to your project and use as-in. Each imgui_impl_xxxx.cpp file comes with its own individual +Changelog, so if you want to update them later it will be easier to catch up with what changed. + + +### Examples Applications + +[example_allegro5/](https://github.com/ocornut/imgui/blob/master/examples/example_allegro5/) <BR> +Allegro 5 example. <BR> += main.cpp + imgui_impl_allegro5.cpp + +[example_android_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_android_opengl3/) <BR> +Android + OpenGL3 (ES) example. <BR> += main.cpp + imgui_impl_android.cpp + imgui_impl_opengl3.cpp + +[example_apple_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_metal/) <BR> +OSX & iOS + Metal example. <BR> += main.m + imgui_impl_osx.mm + imgui_impl_metal.mm <BR> +It is based on the "cross-platform" game template provided with Xcode as of Xcode 9. +(NB: imgui_impl_osx.mm is currently not as feature complete as other platforms backends. +You may prefer to use the GLFW Or SDL backends, which will also support Windows and Linux.) + +[example_apple_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_apple_opengl2/) <BR> +OSX + OpenGL2 example. <BR> += main.mm + imgui_impl_osx.mm + imgui_impl_opengl2.cpp <BR> +(NB: imgui_impl_osx.mm is currently not as feature complete as other platforms backends. + You may prefer to use the GLFW Or SDL backends, which will also support Windows and Linux.) + +[example_emscripten_wgpu/](https://github.com/ocornut/imgui/blob/master/examples/example_emscripten_wgpu/) <BR> +Emcripten + GLFW + WebGPU example. <BR> += main.cpp + imgui_impl_glfw.cpp + imgui_impl_wgpu.cpp +Note that the 'example_glfw_opengl3' and 'example_sdl2_opengl3' examples also supports Emscripten! + +[example_glfw_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_metal/) <BR> +GLFW (Mac) + Metal example. <BR> += main.mm + imgui_impl_glfw.cpp + imgui_impl_metal.mm + +[example_glfw_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_opengl2/) <BR> +GLFW + OpenGL2 example (legacy, fixed pipeline). <BR> += main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl2.cpp <BR> +**DO NOT USE THIS IF YOUR CODE/ENGINE IS USING MODERN GL or WEBGL (SHADERS, VBO, VAO, etc.)** <BR> +This code is mostly provided as a reference to learn about Dear ImGui integration, because it is shorter. +If your code is using GL3+ context or any semi modern GL calls, using this renderer is likely to +make things more complicated, will require your code to reset many GL attributes to their initial +state, and might confuse your GPU driver. One star, not recommended. + +[example_glfw_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_opengl3/) <BR> +GLFW (Win32, Mac, Linux) + OpenGL3+/ES2/ES3 example (modern, programmable pipeline). <BR> += main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl3.cpp <BR> +This uses more modern GL calls and custom shaders.<BR> +This support building with Emscripten and targetting WebGL.<BR> +Prefer using that if you are using modern GL or WebGL in your application. + +[example_glfw_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_vulkan/) <BR> +GLFW (Win32, Mac, Linux) + Vulkan example. <BR> += main.cpp + imgui_impl_glfw.cpp + imgui_impl_vulkan.cpp <BR> +This is quite long and tedious, because: Vulkan. +For this example, the main.cpp file exceptionally use helpers function from imgui_impl_vulkan.h/cpp. + +[example_glut_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_glut_opengl2/) <BR> +GLUT (e.g., FreeGLUT on Linux/Windows, GLUT framework on OSX) + OpenGL2 example. <BR> += main.cpp + imgui_impl_glut.cpp + imgui_impl_opengl2.cpp <BR> +Note that GLUT/FreeGLUT is largely obsolete software, prefer using GLFW or SDL. + +[example_null/](https://github.com/ocornut/imgui/blob/master/examples/example_null/) <BR> +Null example, compile and link imgui, create context, run headless with no inputs and no graphics output. <BR> += main.cpp <BR> +This is used to quickly test compilation of core imgui files in as many setups as possible. +Because this application doesn't create a window nor a graphic context, there's no graphics output. + +[example_sdl2_directx11/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_directx11/) <BR> +SDL2 + DirectX11 example, Windows only. <BR> += main.cpp + imgui_impl_sdl2.cpp + imgui_impl_dx11.cpp <BR> +This to demonstrate usage of DirectX with SDL2. + +[example_sdl2_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_metal/) <BR> +SDL2 + Metal example, Mac only. <BR> += main.mm + imgui_impl_sdl2.cpp + imgui_impl_metal.mm + +[example_sdl2_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_opengl2/) <BR> +SDL2 (Win32, Mac, Linux etc.) + OpenGL example (legacy, fixed pipeline). <BR> += main.cpp + imgui_impl_sdl2.cpp + imgui_impl_opengl2.cpp <BR> +**DO NOT USE OPENGL2 CODE IF YOUR CODE/ENGINE IS USING GL OR WEBGL (SHADERS, VBO, VAO, etc.)** <BR> +This code is mostly provided as a reference to learn about Dear ImGui integration, because it is shorter. +If your code is using GL3+ context or any semi modern GL calls, using this renderer is likely to +make things more complicated, will require your code to reset many GL attributes to their initial +state, and might confuse your GPU driver. One star, not recommended. + +[example_sdl2_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_opengl3/) <BR> +SDL2 (Win32, Mac, Linux, etc.) + OpenGL3+/ES2/ES3 example. <BR> += main.cpp + imgui_impl_sdl2.cpp + imgui_impl_opengl3.cpp <BR> +This uses more modern GL calls and custom shaders. <BR> +This support building with Emscripten and targetting WebGL.<BR> +Prefer using that if you are using modern GL or WebGL in your application. + +[example_sdl2_sdlrenderer2/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_sdlrenderer2/) <BR> +SDL2 (Win32, Mac, Linux, etc.) + SDL_Renderer for SDL2 (most graphics backends are supported underneath) <BR> += main.cpp + imgui_impl_sdl2.cpp + imgui_impl_sdlrenderer.cpp <BR> +This requires SDL 2.0.18+ (released November 2021) <BR> + +[example_sdl2_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_vulkan/) <BR> +SDL2 (Win32, Mac, Linux, etc.) + Vulkan example. <BR> += main.cpp + imgui_impl_sdl2.cpp + imgui_impl_vulkan.cpp <BR> +This is quite long and tedious, because: Vulkan. <BR> +For this example, the main.cpp file exceptionally use helpers function from imgui_impl_vulkan.h/cpp. + +[example_win32_directx9/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx9/) <BR> +DirectX9 example, Windows only. <BR> += main.cpp + imgui_impl_win32.cpp + imgui_impl_dx9.cpp + +[example_win32_directx10/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx10/) <BR> +DirectX10 example, Windows only. <BR> += main.cpp + imgui_impl_win32.cpp + imgui_impl_dx10.cpp + +[example_win32_directx11/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx11/) <BR> +DirectX11 example, Windows only. <BR> += main.cpp + imgui_impl_win32.cpp + imgui_impl_dx11.cpp + +[example_win32_directx12/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx12/) <BR> +DirectX12 example, Windows only. <BR> += main.cpp + imgui_impl_win32.cpp + imgui_impl_dx12.cpp <BR> +This is quite long and tedious, because: DirectX12. + +[example_win32_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_opengl3/) <BR> +Raw Windows + OpenGL3 + example (modern, programmable pipeline) <BR> += main.cpp + imgui_impl_win32.cpp + imgui_impl_opengl3.cpp <BR> + + +### Miscellaneous + +**Building** + +Unfortunately nowadays it is still tedious to create and maintain portable build files using external +libraries (the kind we're using here to create a window and render 3D triangles) without relying on +third party software and build systems. For most examples here we choose to provide: + - Makefiles for Linux/OSX + - Batch files for Visual Studio 2008+ + - A .sln project file for Visual Studio 2012+ + - Xcode project files for the Apple examples +Please let us know if they don't work with your setup! +You can probably just import the imgui_impl_xxx.cpp/.h files into your own codebase or compile those +directly with a command-line compiler. + +If you are interested in using Cmake to build and links examples, see: + https://github.com/ocornut/imgui/pull/1713 and https://github.com/ocornut/imgui/pull/3027 + +**About mouse cursor latency** + +Dear ImGui has no particular extra lag for most behaviors, +e.g. the last value passed to 'io.AddMousePosEvent()' before NewFrame() will result in windows being moved +to the right spot at the time of EndFrame()/Render(). At 60 FPS your experience should be pleasant. + +However, consider that OS mouse cursors are typically drawn through a very specific hardware accelerated +path and will feel smoother than the majority of contents rendered via regular graphics API (including, +but not limited to Dear ImGui windows). Because UI rendering and interaction happens on the same plane +as the mouse, that disconnect may be jarring to particularly sensitive users. +You may experiment with enabling the io.MouseDrawCursor flag to request Dear ImGui to draw a mouse cursor +using the regular graphics API, to help you visualize the difference between a "hardware" cursor and a +regularly rendered software cursor. +However, rendering a mouse cursor at 60 FPS will feel sluggish so you likely won't want to enable that at +all times. It might be beneficial for the user experience to switch to a software rendered cursor _only_ +when an interactive drag is in progress. + +Note that some setup or GPU drivers are likely to be causing extra display lag depending on their settings. +If you feel that dragging windows feels laggy and you are not sure what the cause is: try to build a simple +drawing a flat 2D shape directly under the mouse cursor! + |