• 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

  1. State changing

  • Transformation functions

  • Attribute functions


  • Graphics Output Primitives
    Line, polygon, sphere, …

  • Attributes
    Color, line width, texture, …

  • Geometric transformations
    Modeling, Viewing

  • Shading and illumination
    Input functions