Omlete 🍳

This is a highly opinionated CMake template using contemporary C++ to wrap "modern" OpenGL, SDL3, Dear ImGui, glbindings, and GLM.

Template or Library?

Consider this repository as a template that helps you creating a canonical Hello World in the context of OpenGL programming: a colorful rotating triangle!

In contrast to a library or a full-fledged game engine, this template does note even try to hide OpenGL details from you but instead provides you with a good (this is the part that is highly opinionated) starting point with convenient helper functions that wraps, for instance, the annoying VAO/VBO fiddling. However, none of the files under omlete/ should be considered out of bounds: Open them, read them, change them! (Maybe except for omelet/source/glsl_program.cpp; here be dragons🐉)

How to use it?

Checkout the repository including its various submodules and build it with CMake. A layman approach (on Linux🐧) is to type:

bash git clone --recurse-submodules https://github.com/avitase/omelet mkdir -p omelet/build && cd omelet/build/ cmake .. && make -j

If you have installed OpenGL on your system, this will build SDL3, Dear ImGui, glbindings, and GLM and finally compile the template in omelet/. (If not, it will fail spectacularly💥)

Compiling the dependencies does take some time but will eventually create an executable under build/install/bin. Run it, it's safe!✋

./install/bin/omelete

You should see a spinning triangle and a Dear ImGui window with the position of your cursor and an FPS counter.

How to use it properly?

This template will give you a CMake Superbuild that builds SDL3, Dear ImGui, glbindings, and GLM as dependencies and the actual SDL3/OpenGL template. Typically, building the Superbuild only has to be done once, you can then navigate to omelete/ (the subdirectory) and start fouling around here.

The subproject omelet/ expects to find its dependencies under build/install. This happens automatically if you use our CMakeUserPresets.json.EXAMPLE (click on the link to learn more about what this is), e.g., by copying it:

```bash

project root (not omelet/omelet!)

cp CMakeUserPresets.json.EXAMPLE CMakeUserPresets.json ```

This will make a new preset release available that you can use to build the Superbuild:

bash cmake --preset=release cmake --build --preset=release

Similar to before, this should install everything under build/install and you can now navigate to the subproject omelet/. Here, you'll find again a CMakeUserPresets.json.EXAMPLE that sets CMAKE_PREFIX_PATH for you and exposes two presets dev and dev-clang-tidy. Feel free to change these presets to your own needs and then run, e.g.,

```bash

run this in omelet/omelet

cmake --preset=dev cmake --build --preset=dev ```

Next steps

Everything you find under omelet/ is nothing but a template, and you might have to change all files eventually. However, consider starting your journey in omelet/source/triangle.cpp and omelet/source/world.cpp, and then gradually work yourself through the includes, when needed.

When you feel lost, have a look into omelet/source/main.cpp where we define int main(int, char**) and start the life of the window.

Seeing link-time errors?

The super build script is not bullet-proof and assumes that all your dependencies that are build during the process are linked statically. If this is not possible, one has to adopt the rpath, e.g., by adding the following the build recipe:

ExternalProject_Add( omelet [...] CMAKE_ARGS [...] -DCMAKE_INSTALL_RPATH:STRING=<INSTALL_DIR>/lib;<INSTALL_DIR>/lib64 -DCMAKE_BUILD_WITH_INSTALL_RPATH=ON