OpenGL is what?

OpenGL (Open Graphics Library) is a cross-language, cross-platform application programming interface (API) for rendering 2D and 3D vector Graphics. As shown in the

OpenGL ES

OpenGL ES (OpenGL for Embedded Systems) is a subset of OpenGL 3D graphics API, designed for Embedded devices such as mobile phones, PDAs and game consoles.

OpenGL ES is tailored from OpenGL, removing many non-essential or low-performance features.

DirectX

As an important software manufacturer, especially one of the operating system manufacturers, Microsoft has also developed a set of multimedia programming interface applied to Windows system, that is DirectX. Compared with OpenGL/OpenGL ES focus on graphics and image display processing, DirectX covers display, sound, input, network and other functions, is a true multimedia API set.

Metal

Similar to Microsoft, Apple introduced its own graphics technology, Metal, in 2014, which it claims improves 3D rendering performance by a factor of 10.

What does a graphics API do?

The above four graphics apis, the most commonly used graphics processing apis, are mainly responsible for the underlying rendering of graphics, including:

  • Games, commonly seen in the game scene, character rendering, etc
  • Audio and video, commonly seen in video decoded data rendering, etc
  • Map engine, commonly used in map data rendering, etc
  • Animation, commonly seen in animation drawing, etc
  • Video processing, video filter and so on

The essence of a graphics API is that it allows developers to efficiently render graphics using the GPU, and it’s one of the few ways that many developers can get close to the GPU, whereas for iOS developers, the graphics API is the only way to get close to the GPU.