Viewport Transformation (results in Window Coordinates).Perspective Division (results in Device Coordinates).Outputs: gl_Position (in Clip Coordinates), gl_FrontFacing (auto-generated), gl_PointSize (for Point Sprites), user-defined Varyings (to Fragment Shader).
Inputs: Attributes (vertex position and other per-vertex attributes such as texture positions through Vertex Arrays/Vertex Buffers), Samplers (Textures), Uniforms (Constants).For very detailed explanations, see the OpenGL ES 2.0 specification. We will discuss the individual stages in more detail further below. The following is a rough overview of the OpenGL ES 2.0 pipeline. In some sense, OpenGL ES 2.0 (released 2007) was ahead of its time: for desktop OpenGL, it took until OpenGL 3.1 (released 2009) until legacy functionality was dropped from core functionality. These design decisions result in a much smaller API but also require more in-depth knowledge of the rendering process and more effort (lines of - possibly boilerplate - code) for setting up the rendering pipeline. For example, glFrustum(), glTranslate(), and glRotate() do not exist.
Immediate Mode (glBegin/glEnd) and Display Lists are not supported.Vertex handling only using Vertex Arrays/Vertex Buffers.For standard usage, these shaders are quite simple and mostly copy and paste though. These features must be implemented as custom shaders. This means there is no fixed built-in support for lighting, fog, multitexturing, or vertex transformations (translation/rotation etc.).To those familiar with other OpenGL versions and as a note of warning when browsing the web for OpenGL ES 2.0 information it must be said that the OpenGL ES 2.0 API is quite different from OpenGL <= 3.0 and OpenGL ES 1.x. However, as of 2010 some graphics card manufacturers introduced ES support in their desktop drivers. Desktop graphics card drivers typically do not support the OpenGL ES API directly. Notable platforms supporting OpenGL ES 2.0 include the iPhone 3GS and later, Android 2.2 and later, and WebGL.
It is designed for embedded devices such as mobile phones, PDAs, and video game consoles. OpenGL for Embedded Systems ( OpenGL ES) is a subset of the OpenGL 3D graphics API.
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