cpp_raytracer
Building a ray tracer using modern C++
Getting Started
This repo is space to practise and hone my C++, tooling and graphics knowledge by working through tutorials and making something.
If you spot bugs or suggestions for improving the codebase feel free to open an issue!
Resources
I am loosely working through Peter Shirley's Ray Tracer in One Weekend Trilogy and setup the project with Jason Turner's cpp_starter_project.
I am using nothings/stb for image writing to both jpg / png.
Dependencies
Necessary Dependencies
- A C++ compiler that supports C++17. See cppreference.com to see which features are supported by each compiler. The following compilers should work:
- gcc 7+
- clang 6+
- Visual Studio 2017 or higher. The minimum compiler version is 19.15; this version ships with version 15.8 of the IDE.
- Conan - it's recommended that you install using pip
- CMake 3.15+
Build Instructions
Make a build directory
$ mkdir build && cd build
Configure your build
To configure the project and write makefiles, you could use cmake with a
bunch of command line options. The easier option is to run cmake interactively,
with the Cmake Curses Dialog Command Line tool:
$ ccmake ..
Once ccmake has finished setting up, press 'c' to configure the project,
press 'g' to generate, and 'q' to quit.
Build
Once you have selected all the options you would like to use, you can build the project:
$ cmake --build . # build all targets
Build using an alternate compiler
Conan and CMake use the environment variables CC and CXX to decide which compiler to use. If you don't set these variables yourself, the system default compiler will be used.
Be aware that CMake will detect which compiler was used to build each of the Conan targets. If you build all of your Conan targets with one compiler, and then build your CMake targets with a different compiler, the project may fail to build.
To build using clang, you can use these commands:
$ CC=clang CXX=clang++ ccmake ..
$ CC=clang CXX=clang++ cmake --build .
Troubleshooting
Update Conan
Many problems that users have can be resolved by updating Conan, so if you are having any trouble with this project, you should start by doing that.
To update conan:
$ pip install --user --upgrade conan
You may need to use pip3 instead of pip in this command, depending on your
platform.
Clear Conan cache
If you continue to have trouble with your Conan dependencies, you can try clearing your Conan cache:
$ conan remove -f '*'
The next time you run cmake or cmake --build, your Conan dependencies will
be rebuilt. If you aren't using your system's default compiler, don't forget to
set the CC, CXX, CMAKE_C_COMPILER, and CMAKE_CXX_COMPILER variables, as
described in the 'Build using an alternate compiler' section above.
Identifying misconfiguration of Conan dependencies
If you have a dependency 'A' that requires a specific version of another dependency 'B', and your project is trying to use the wrong version of dependency 'B', Conan will produce warnings about this configuration error when you run CMake. These warnings can easily get lost between a couple hundred or thousand lines of output, depending on the size of your project.
If your project has a Conan configuration error, you can use conan info to
find it. conan info displays information about the dependency graph of your
project, with colorized output in some terminals.
$ cd build
$ conan info .
In my terminal, the first couple lines of conan info's output show all of the
project's configuration warnings in a bright yellow font.
For example, the package spdlog/1.5.0 depends on the package fmt/6.1.2.
If you were to modify the file cmake/Conan.cmake so that it requires an
earlier version of fmt, such as fmt/6.0.0, and then run:
$ conan remove -f '*' # clear Conan cache
$ rm -rf build # clear previous CMake build
$ mkdir build && cd build
$ cmake .. # rebuild Conan dependencies
$ conan info .
...the first line of output would be a warning that spdlog needs a more recent
version of fmt.