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• OpenGL is an API (Application Programming Interface) used to render graphics on a computer screen.

Main Features are:

• 3D (and 2D)

• Fast  Hardware

• language, OS, company independent.

• OpenGL architecture review board.

• Broad support

• Low-level (right level!)

• Standard graphics terminology.

OpenGL, GLU and GLUT

• OpenGL: basic functions

• GLU: OpenGL Utility library

• GLUT: OpenGL Utility Toolkit library

• GLU and GLUT: Handy functions for viewing and geometry

OpenGL and Java

• C: glFunction(); gluFunction(); glutFunction();

• Java: JOGL gl.glFunction(); glu.gluFunction(); glut.glutFunction();

• No windowing functions offered by JOGL

OpenGL syntax

• Functions: glFunction: glBegin, glClear, glVertex, …

• Constants: GL_CONSTANT: GL_2D, GL_LINE

• Datatypes: GLtype: GLbyte, GLint, GLfloat

OpenGL State

•   OpenGL is a state machine

•   OpenGL functions are of two types

1. Primitive generating

• Can cause output if primitive is visible.

• How vertices are processed and appearance of primitive are controlled by the state

2. State changing

• Transformation functions

• Attribute functions

Functions

• Graphics Output Primitives
  Line, polygon, sphere, …

• Attributes
  Color, line width, texture, …

• Geometric transformations
  Modeling, Viewing

• Shading and illumination
  Input functions

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