OpenGL Graphics API

OpenGL (Open Graphics Library) is a cross-language, cross-platform application programming interface (API) for rendering 2D and 3D vector graphics, maintained by the Khronos Group. Originally developed by Silicon Graphics Inc. (SGI) in 1992 as an open alternative to their proprietary IRIS GL, OpenGL has become the most widely adopted 2D and 3D graphics API in the industry, used in CAD, virtual reality, scientific visualization, information visualization, flight simulation, and video games. Although largely superseded by Vulkan for new high-performance applications, OpenGL remains widely used and supported on virtually all platforms. Key features include: cross-platform (running on Windows, macOS, Linux, iOS via OpenGL ES, Android, and WebGL in browsers), immediate mode and retained mode (supporting both fixed-function pipeline for legacy applications and programmable pipeline with shaders for modern rendering), vertex and fragment shaders (GLSL - OpenGL Shading Language for GPU programming, with geometry, tessellation, and compute shaders added in later versions), state machine architecture (managing rendering state through a global state machine with configurable settings for lighting, blending, depth testing, textures, and framebuffers), VBO and VAO (Vertex Buffer Objects and Vertex Array Objects for efficiently uploading and managing vertex data on the GPU), framebuffer objects (render-to-texture capabilities for post-processing, shadow mapping, and deferred rendering), texture mapping (supporting 1D, 2D, 3D, cube map, and array textures with mipmapping and anisotropic filtering), GLSL compute shaders (general-purpose GPU computing for physics simulation, image processing, and parallel algorithms), and backward compatibility (maintaining compatibility with earlier versions through the compatibility profile, ensuring legacy applications continue to work).