CSE328:Computer Graphics
OpenGL Tutorial
Dongli Zhang
Department of Computer Science, SBU
dozhang@cs.stonybrook.edu
Department of Computer Science, Stony Brook University (SUNYSB)
TA Information
TA Schedule:
• Time: Tuesday: 4:30~6:00pm;
• Location: Computer Science Building, 2110;
• Email: dozhang@cs.stonybrook.edu
Department of Computer Science, Stony Brook University (SUNYSB)
Introduction to OpenGL
What is OpenGL?
• Industrial standard library for doing computer graphics.
• Developed by Silicon Graphics Inc.(SGI) in 1992.
• Latest version: 4.3 (released at Aug 6, 2012).
Features:
• Keep developing. More functions,GLSL,64-bit support.
• OpenGL is a Graphic rendering API (software interface to graphics
hardware)
• consists of lots of commands. for example: GL_BEGIN(GLint TYPE)
• Operating system independent.
References:
• http://en.wikipedia.org/wiki/Opengl
• http://www.opengl.org/
CSE328
Introduction to OpenGL
• If you want to be a Software Engineer in Computer graphics area,
OpenGL is a MUST!
• Giant Companies: NVidia, ATI(AMD),Google, Adobe, Pixar, Blizzard,
Siemens Medical…
CSE328
Introduction to OpenGL
Other 3D Graphics APIs:
• Direct3D --- a competitor to OpenGL.
• Mesa 3D --- an open source implementation of OpenGL.
• Open Inventor --- C++ object oriented 3D graphics API in higher layer
of programming.
• RISpec --- Pixar’s open API for photorealistic off-line rendering.
Other 2D graphics APIs:
• GTK+.
• Java 2D, QT
CSE328
OpenGL programming guide
Things you should know before coding:
1. OpenGL was designed be graphic output-only.
• Provide rendering functions only.
• Core API has no concept of windowing systems, audio, printing to
screening, keyboard/mouse or other input devices.
2. OpenGL need add-on APIs to interact with the host system.
• GLX --- X11
• WGL --- Microsoft Windows
• CGL --- Mac OS X
3. For convenient, people developed libraries to provide
functionality for basic windowing using OpenGL, such as GLUT.
OpenGL need a GUI in window
system.
CSE328
OpenGL programming guide
• Tools for programming:
– C/C++ compiler and debugger: MS, gcc.
– IDE: MS Visual studio, Dev-C++, Eclipse+cdt, Xcode, …
– GUI: GLUT + GLUI, QT, MFC…
• Recommendation:
• VS2010 + GLUT + GLUI(QT)
• Reasons: free, easy for debug.
OpenGL language
• A state machine
1. You put OpenGL into various states that then remain in effect until you change them
2. State is encapsulated in contexts. Each OpenGL window has its own, separate, state.
3. Think of each context as a C/C++ struct with fields for each OpenGL state variable.
• Generally, there are two operations that you do with OpenGL:
1. Draw something
2. Change the state of how OpenGL draws
• OpenGL has two types of things that it can render:
1. Geometric primitives: points, lines and polygons
2. Image Primitives: bitmaps and graphics image
•
Additionally, OpenGL links images and geometric primitives together
using Texture Mapping.
OpenGL language
OpenGL language
OpenGL language
OpenGL language
OpenGL language
OpenGL language
OpenGL geometric primitives
OpenGL geometric primitives
OpenGL geometric primitives
OpenGL geometric primitives
OpenGL geometric primitives
OpenGL geometric primitives
OpenGL geometric primitives
OpenGL geometric primitives
OpenGL geometric primitives
Rendering
Rendering
Controlling current state
GLUT
GLUT
What can GLUT do?
GLUT programming
Initialization
Initialization
Open a window
Open a window
Handle Events
Handle Event
Handle events
GLUT
GLUT
GLUT
GLUT
GLUT
Enter event processing loop
GLUT summary
GLUT Menu
GLUT Menu
Put together
GLUI
GLUI
Examples
Helpful sources