The idea behind this repo is for it to be used as a minimal starting point for development of a game, demo or experiment.

It utilizes SDL2 for the windowing system, bgfx (by @bkaradzic) for the graphics library and Dear ImGui (by @ocornut) for the user interface.

The code in main.cpp is derived from two excellent bgfx tutorials (hello-bgfx by Phil Peron and bgfx-ubuntu) by Sandeep Nambiar. I highly recommend checking them out!

This repo does not directly include any of these libraries but contains instructions on how to download and install them so this project can use them.

Warning: There is a little bit of setup required (please see the prerequisites below) but once you're setup you should be good to go.

In future batch/shell scripts will likely be provided to automate the initial bootstrap.

Before doing anything else create a directory to hold the repo

mkdir sdl-bgfx-imgui-starter && cd sdl-bgfx-imgui-starter

Then clone the repo

git clone https://github.com/pr0g/sdl-bgfx-imgui-starter.git .

Before attempting to build this project all third party dependencies (SDL, bgfx and imgui) must be downloaded and installed. These will be self contained in the repo and are not installed to the system.

To achieve this CMake must be installed on your system (repo tested with 3.15).

Please see the third-party README for full instructions on how to do this.

Note: third-party/libs is added to the .gitignore file to ensure the dependencies aren't added to the project.

Once all third party libraries have been downloaded and installed, follow these build instructions to compile the repo (linking to the previously built dependencies).

Shaders for bgfx also must be compiled to be loaded by the application. The starter has an incredibly simple shader supporting vertex colours.

Info: Ninja was chosen as the generator for CMake as it's consistent across both macOS and Windows (the Visual Studio/MSVC generator supports multiple configurations which is cool but just makes things more complicated when dealing with cross platform commands).

The added benefit of Ninja is it also supports creating a compile_commands.json file (by providing -DCMAKE_EXPORT_COMPILE_COMMANDS=ON to the CMake configure command). This is useful for many different reasons, one of the highlights being offering perfect intellisense for VSCode 😁.

Finally all listed CMake configure commands specify -DCMAKE_BUILD_TYPE=Debug but when building the dependencies you can also use Release or RelWithDebInfo to get an optimized build. All dependencies make use of CMAKE_DEBUG_POSTFIX which means all built libraries get a 'd' suffix (the convention) appended, so you can build and install both Debug and Release libraries to the same location.

Attn: If you build the dependencies in Debug and then try and build the starter project in Release (or vice versa) you're likely to get link errors.

Note: configure.bat located in the root provides the first line below

cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Debug -DCMAKE_PREFIX_PATH=%cd%/third-party/libs/SDL2-2.0.12/install;%cd%/third-party/libs/bgfx/install;%cd%/third-party/libs/imgui/install -DCMAKE_EXPORT_COMPILE_COMMANDS=ON

cmake --build build

third-party\libs\bgfx\install\bin\shaderc.exe -f shader\v_simple.sc -o shader\v_simple.bin --platform windows --type vertex --verbose -i ./ -p vs_5_0

third-party\libs\bgfx\install\bin\shaderc.exe -f shader\f_simple.sc -o shader\f_simple.bin --platform windows --type fragment --verbose -i ./ -p ps_5_0

Note: configure.sh located in the root provides the first line below

cmake -S . -B build -DCMAKE_CXX_COMPILER=/usr/bin/clang++ -DCMAKE_PREFIX_PATH="$(pwd)/third-party/libs/SDL2-2.0.12/install;$(pwd)/third-party/libs/imgui/install;$(pwd)/third-party/libs/bgfx/install" -DCMAKE_EXPORT_COMPILE_COMMANDS=ON

cmake --build build

./third-party/libs/bgfx/install/bin/shaderc -f shader/v_simple.sc -o shader/v_simple.bin --platform osx --type vertex --verbose -i ./ -p metal

./third-party/libs/bgfx/install/bin/shaderc -f shader/f_simple.sc -o shader/f_simple.bin --platform osx --type fragment --verbose -i ./ -p metal

While getting this project setup I discovered a number of excellent resources I'd highly recommend checking them out to learn more about bgfx and Dear ImGui.

• bgfx - bgfx main repo
• bgfx-docs - extensive docs covering much of bgfx's API
• bgfx-cmake - a complimentary repo to add CMake support to bgfx (used by this repo)
• hello-bgfx (tutorial) - a great intro to bgfx and covers most of the code in the main.cpp of this repo
• bgfx-ubuntu(tutorial) - another great tutorial on bgfx (showing how to get setup on ubuntu)
• minimal-bgfx - a similar repo to this one only using premake and git submodules instead of CMake and with no imgui.
• dear-imgui - Dear ImGui main repo - lots of documentation and examples are available there
• cmakefied - a complimentary repo to add CMake support to imgui (used by this repo)

• Бранимир Караџић (@bkaradzic) for the excellent bgfx
• Omar Cornut (@ocornut) for the brilliant Dear Imgui
• Widberg/MissingBitStudios for the bgfx CMake support
• Tamas Kenez for the Dear Imgui CMake support
• Richard Gale (@richardg4) for the bgfx implementation for Dear ImGui
• Phil Peron (@pperon) and Sandeep Nambiar (@_sandeepnambiar) for the great bgfx setup tutorials.