# [`globject`][] A [C++11][]/[OpenGL][]>=[1.0][] [object][] library. This library provides a class that is intended to be the base class of several other classes that encapsulate different types of OpenGL objects, making it easy to avoid [common mistakes][]. [`globject`]: https://git.rcrnstn.net/rcrnstn/globject [C++11]: https://en.wikipedia.org/wiki/C++11 [OpenGL]: https://en.wikipedia.org/wiki/OpenGL [1.0]: https://en.wikipedia.org/wiki/OpenGL#Version_history [object]: https://www.khronos.org/opengl/wiki/OpenGL_Object [common mistakes]: https://www.khronos.org/opengl/wiki/Common_Mistakes#The_Object_Oriented_Language_Problem ## Usage ### Template arguments `GLObject` is template specialized the following values. - `GL_TEXTURE` - `GL_BUFFER` - `GL_QUERY` - `GL_PROGRAM` - `GL_SHADER` - `GL_VERTEX_ARRAY` - `GL_FRAMEBUFFER` - `GL_RENDERBUFFER` - `GL_SAMPLER` - `GL_TRANSFORM_FEEDBACK` - `GL_PROGRAM_PIPELINE` The class handles the lifetime of an OpenGL object of the corresponding type. ### Special member functions All [special member functions][] are `protected`. It is impossible to directly instantiate `GLObject`s, or to delete objects through `GLObject` pointers. Instead, use a derived class that encapsulates a specific type of OpenGL object. There are no (non-[`delete`][]d) default constructor, copy constructor, or copy assignment operators. This enforces the invariant that a successfully constructed instance (that has not been moved from) always (is the only instance that) corresponds to a valid OpenGL object. The move constructor/assignment operator's [`noexcept`][] specifiers are only guaranteed to be honored if [`debug()`][] is `0`. The constructor takes as arguments: - `std::string const & label`. Used when printing debug messages, throwing exceptions, and, if OpenGL>=[4.3][] or the [`KHR_debug`][] extension is available, passed to [`glObjectLabel`][]. [special member functions]: https://en.wikipedia.org/wiki/Special_member_functions [`delete`]: https://en.cppreference.com/w/cpp/language/function#Deleted_functions [`noexcept`]: https://en.cppreference.com/w/cpp/language/noexcept_spec [`debug()`]: https://git.rcrnstn.net/rcrnstn/glbase/#debug [4.3]: https://en.wikipedia.org/wiki/OpenGL#Version_history [`KHR_debug`]: https://registry.khronos.org/OpenGL/extensions/KHR/KHR_debug.txt [`glObjectLabel`]: https://registry.khronos.org/OpenGL-Refpages/gl4/html/glObjectLabel.xhtml ### Object `GLuint object() const` returns the underlying OpenGL object. This is guaranteed to be valid, unless the constructor threw an exception or the `GLObject` has been moved from, in which case it is `0`. ### Name `std::string name() const` returns a string representation of the object. ### Debug `void debug_action_(std::string const & action)` calls outputs a debug message containing `action` and `name()`. ### Fail `void fail_action_(std::string const & action) const` throws an exception with a message containing `action` and `name()`. ## Building See [`BUILDING.md`][]. [`BUILDING.md`]: BUILDING.md ## License Licensed under the [ISC License][] unless otherwise noted, see the [`LICENSE`][] file. [ISC License]: https://choosealicense.com/licenses/isc [`LICENSE`]: LICENSE