Experimental game engine.

Note: The commands that follow assume you are working in Cygwin.

Visual Studio solution:

cmake -S. -B./build -G"Visual Studio 16 2019"

The solution is present in the build folder.

To make a compilation database (compile_commands.json) for external tools:

cmake -S. -B./build -G"NMake Makefiles" -DCMAKE_EXPORT_COMPILE_COMMANDS=ON

Only the configure step is required to make the compilation database. For ease of integration, make a symlink to it in the root of the project:

ln -s ./build/compile_commands.json compile_commands.json

Note: Dependency installation is not necessary. However, it will result in dependencies being downloaded each time the build directory is blown away.

Warning: Changes to dependency configurations will require a deletion of the installed dependency and a rebuild.

To avoid having dependencies re-downloaded when the build directory is deleted, dependencies can be installed through cmake.

# Configure cmake with generator of choice, for example:
cmake -S. -B./build -G"Visual Studio 16 2019"

# Build
cmake --build build

# Install dependencies
cmake --install build

By default this installs them to a _deps in the root of the repository.

Next time cmake configuration is done, the packages will be picked up from the _deps location. Very helpful if you need to blow away build or when a file is added/removed from the project.

To develop one or more of the dependencies while working on RTek, point FetchContent to the local repo by overriding the cmake cache value.

For example, to develop sdslib:

cmake -S. -B./build -G"Visual Studio 16 2019" -DFETCHCONTENT_SOURCE_DIR_SDSLIB=<PATH_TO_REPO_ROOT>

These are done through preprocessor defines and/or cmake options.

See CMakeLists.txt options for the available feature toggles.

General:

• RK_ASSERTIONS_ENABLED: If present, enable assertions. Otherwise they are compiled out. Note, critical assertions are always enabled.

Logging:

• RK_LOG_LEVEL: Log level compiled into the application. One of RK_LOG_LEVEL_{OFF, TRACE, DEBUG, INFO, WARN, ERROR, CRITICAL}. Levels listed in order of least to most precendence. Levels of equals or less precedence are removed.
• RK_LOGGING_OFF: Remove all logging. Takes precedence over RK_LOG_LEVEL.
• RK_LOGGING_PERF: Compile in minimal logging (for performance). Takes precedence over RK_LOG_LEVEL.

Graphics:

• RK_OGL_DEBUG: Display debug messages from OpenGL, including errors.
• RK_SHADER_BASE_DIR: Directory containing all the shaders. Prepended to the path of the shader being opened.
• RK_REQUEST_HIGH_PERF_RENDERER: Ask for a high performance renderer. For systems with an iGPU and dGPU, this typically means the dGPU.

Engine macros are prefixed with RK_. Engine internal macros that should not be used are prefixed with RK_I_.

All internal representation of strings and text output are UTF-8. The engine is unicode only and does not support ANSI strings. It follows the principles of UTF-8 everywhere.

NOTE: UTF-8 is backwards compatible with ASCII¹. Therefore searching for ASCII characters/strings in UTF-8 strings is a valid.

Programming guidelines:

• std::string and char* variables are considered UTF-8, anywhere in the program.
• Use what's available in platform/stdlib/* over those in the standard library. These functions take UTF-8 strings.²
• Do not use wchar_t or std::wstring in any place other than adjacent point to APIs accepting UTF-16.
• Do not use L"" literals in any place other than parameters to APIs accepting UTF-16.
• Windows:
  • Do not use types, functions, or their derivatives that are sensitive to the UNICODE constant, such as LPTSTR, CreateWindow() or the _T() macro. Instead, use LPWSTR, CreateWindowW(), and explicit L"" literals.
  • UNICODE and _UNICODE are always defined to avoid passing narrow UTF-8 strings to ANSI WinAPI getting silently compiled.
  • Only use Win32 functions that accept widechars (LPWSTR), never those which accept LPTSTR or LPSTR. Pass parameters this way:

    std::array<wchar_t, MAX_PATH> wpath;
    if (!unicode::widen(wpath.data(), wpath.size(), some_string)) {
        return Status::unicode_error;
    }
    SetWindowTestW(wpath.data());

    • Output from windows API functions require unicode::narrow to re-encode to UTF-8 for use internally.

Working with files, filenames, and fstreams:

• Always produce text output files in UTF-8.
• Use what's available in platform/stdlib/* over those in the standard library. These functions take UTF-8 strings.²