# MyEngine

A C++20 game engine project built with CMake and OpenGL.

## Requirements

Ubuntu with the following packages installed:

* CMake >= 3.20
* GCC / G++
* Make or Ninja
* OpenGL development libraries
* GLFW3
* GLM
* spdlog
* fmt

Install the dependencies with:

```bash
sudo apt update

sudo apt install \
    build-essential \
    cmake \
    ninja-build \
    libglfw3-dev \
    libglm-dev \
    libspdlog-dev \
    libfmt-dev \
    libgl1-mesa-dev
```

## Building

Clone the repository and enter the project directory:

```bash
git clone <repository-url>
cd DeerithEngine
```

Create a separate build directory:

```bash
cmake -S . -B build -G Ninja
```

Build the project:

```bash
cmake --build build
```

The project uses C++20.

## Running

After a successful build, run the sandbox application with:

```bash
./build/sandbox/Sandbox
```

If the executable is generated in a different location depending on the CMake configuration, you can find it with:

```bash
find build -type f -executable -name "Sandbox"
```

Then execute the resulting path.

## Project Structure

```text
MyEngine/
├── CMakeLists.txt
│
├── deerith_engine_core/
│   ├── CMakeLists.txt
│   ├── include/
│   │   └── deerith/
│   └── src/
│
├── deerith_engine_client/
│   ├── CMakeLists.txt
│   ├── include/
│   │   └── deerith/
│   ├── src/
│   └── shaders/
│
├── sandbox/
│   ├── CMakeLists.txt
│   └── src/
│       └── main.cpp
│
└── build/
```

The `build/` directory is generated by CMake and should not be committed to Git.

## CMake Targets

### DeerithCore

`DeerithCore` is the engine's core library.

Dependencies:

* `spdlog`
* `fmt`

It exposes its headers through:

```text
deerith_engine_core/include
```

### DeerithClient

`DeerithClient` contains the graphics/client-side engine functionality.

Dependencies:

* `DeerithCore`
* OpenGL
* GLFW
* GLM

It also copies the engine shaders into the build directory automatically.

### Sandbox

`Sandbox` is the executable used to test and develop the engine.

It links against:

```text
DeerithClient
```

## Shader Files

Shaders are located in:

```text
deerith_engine_client/shaders/
```

CMake automatically copies them to the corresponding build directory:

```text
build/deerith_engine_client/shaders/
```

This is done by the `DeerithClientShaders` custom target.

## Clean Build

To completely remove the generated build files:

```bash
rm -rf build
```

Then configure and build again:

```bash
cmake -S . -B build -G Ninja
cmake --build build
```

## Debug Build

For a Debug build:

```bash
cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Debug
cmake --build build
```

Run the application:

```bash
./build/sandbox/Sandbox
```

## Release Build

For a Release build:

```bash
cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build
```

## Development

When adding new `.cpp` files to the engine, CMake automatically detects them through `GLOB_RECURSE` with `CONFIGURE_DEPENDS`.

After adding or removing source files, rebuild normally:

```bash
cmake --build build
```

If CMake does not detect a project configuration change correctly, reconfigure:

```bash
cmake -S . -B build -G Ninja
```