Cmpe 466 computer graphics. Computer graphics software. (Chapter 3) презентация

CMPE 466 COMPUTER GRAPHICS Chapter 3 Computer Graphics Software Instructor: D. Arifler

Coordinate representations

Graphics functions Output primitives: plot character strings, points, straight lines, curved lines, polygons, etc. Attributes: set properties of output primitives such as color specifications, line styles, fill patterns, etc. Geometric transformations: change size, position, orientation of an object Viewing transformations: select a view of the scene, type of projection to be used, location on video monitor where the view is to be displayed Input functions: control and process the data flow from interactive devices Control operations: house-keeping tasks such as clearing a screen display area

Software standards Primary goal: Portability Graphical Kernel System (GKS) Programmer’s Hierarchical Interactive Graphics System (PHIGS) and PHIGS+ Graphics Library (GL) OpenGL (hardware-independent version of GL)

Language binding A language binding is defined for a particular high-level programming language This binding gives the syntax for accessing various graphics functions OpenGL bindings for C and C++ are the same OpenGL bindings are also available for Java and Python

Other graphics packages Open Inventor Virtual Reality Modeling Language (VRML) Java 2D Java 3D RenderMan Interface Libraries for Mathematica, MATLAB, and Maple

OpenGL OpenGL basic (core) library Function names start with “gl” OpenGL Utility (GLU) library Constants and data type names begin with “GL” Function names start with “glu” Window management operations are device-dependent OpenGL extensions to the X Windows System (GLX) Apple GL (AGL) Windows GL (WGL) OpenGL Utility Toolkit (GLUT) library Library of functions for interacting with any windowing system Functions are prefixed with “glut”

OpenGL header files Windows #include <windows.h> #include <GL/gl.h> #include <GL/glu.h> or simply #include <GL/glut.h> GLUT ensures that gl.h and glu.h are included Apple OS X #include <GLUT/glut.h>

An example program

An example program

An example program