ARBcreatecontext

ARBcreatecontext is a function introduced to the OpenGL specification in version 3.2 that allows applications to request the creation of a new OpenGL context with specific attributes. The function was added to provide developers with finer control over the features and capabilities of rendering contexts, such as version number, debug flags, and robustness options, which were not available through the operating system's native context‑creation APIs in earlier versions.

The API signature is defined as follows:

void ARBcreatecontext(ARB_context *ctx, int *attribList)

The first argument is a pointer to a context object that will be initialized by the function. The second argument is a NULL‑terminated array of attribute/value pairs that specify the desired properties of the new context. Common attributes include GL_CONTEXT_MAJOR_VERSION, GL_CONTEXT_MINOR_VERSION, GL_CONTEXT_FLAGS, GL_CONTEXT_PROFILE_MASK, and GL_CONTEXT_RESET_NOTIFICATION, among others.

Internal behavior of ARBcreatecontext is implemented by the driver layer. When invoked, the function queries the driver's supported context profiles, matches the requested attributes against the maximum supported values, and creates a new context object that can subsequently be made current or used for off‑screen rendering. If the requested features are not supported, the function fails and returns an error code.

ARBcreatecontext became officially part of the core OpenGL specification with the release of OpenGL 3.2, after initially appearing as an ARB (Architecture Review Board) extension. It has since been superseded by newer context‑creation mechanisms provided by platform–specific windowing libraries such as GLX, WGL, EGL, and the modern OpenGL EGLStream APIs. Nevertheless, ARBcreatecontext remains a useful reference for legacy systems and for developers working in environments where the newer APIs are unavailable.

In summary, ARBcreatecontext provides a standardized, extension‑free mechanism for requesting an OpenGL context with precise attributes, facilitating portability and consistency across different hardware and driver implementations.