Editing QuickDraw 3D (section)

==OpenGL in the 1990s==
The canonical 3D API of the 1990s was OpenGL. This had been written by [[Silicon Graphics|SGI]] and initially closely matched the capabilities of their [[workstation]] systems, operating as a hardware abstraction layer. The OpenGL API consisted mostly of state-setting instructions for setting up drawing modes like the paint color or camera position, and system for sending geometry into the system, normally as meshes of triangles. The combination of these instructions was saved into a [[display list]] which was then rendered to produce the output.

OpenGL lacked many features that are needed to produce a complete 3D program. Saving and loading geometry data, collecting that data into groups to produce model objects, and the control of state was all left to the programmer. This was considered to be an advantage in an era when performance was limited and direct control over these sorts of functions was a route to improved performance.

However, this lack of high-level functionality did make it more difficult to quickly write simple programs, as well as leading to a lack of interoperability. A number of efforts started to provide standardized higher level APIs, like OpenGL++ and (later) [[Fahrenheit (graphics API)|Fahrenheit]], which handled many of the more common bookkeeping tasks like loading geometry from files and providing a display. These standardized [[scene graph]] systems meant the programmer only had to provide the GUI for the program.

While OpenGL is mostly low-level, it did include some higher-level concepts that were only really used on SGI systems. This led to another series of APIs that removed these features to make it easier to implement on common hardware. The best known of these is [[MiniGL]], which is not a separate API, but simply a list of those functions in OpenGL that are guaranteed to be supported across all hardware, thus ensuring that a program limiting itself to those calls will run with maximum performance.