计算机图形学openGL初步.ppt

Programming With OpenGL What is OpenGL? A low-level graphics modeling and rendering library (includes more than 100 functions) State machine A layer of abstraction between graphics hardware and an application program Hardware, Window System and Operating System independent Network Transparent (Client - Server Concept) Where is in the Graphics System Wireframe Models, Viewing, Transformation Antialiasing Flat- And Smooth Shading Shadows Texture Mapping Motion Blur Haze and Fog, Depth -Of -Field Effect Evaluator Function: 1D 2D Bezier Curves, NURBS ... Primitive functions Attribute functions Viewing functions Transformation functions Input functions / control functions OpenGL Library - gl OpenGL Utilities - glu OpenGL Extension to X Windows - glx OpenGL Programming Guide Auxiliary Library - aux Windows Graphics Library - wgl OpenGL Library GL Programming With OpenGL OpenGL Auxiliary Library This is a simple, platform-dependent library Makes programming examples simpler more complete Managing windows Handling input events Drawing classic 3-D objects Managing a background process Running a program Do not use them in a production application WGL Functions This set of functions connects OpenGL to the MS Windows windowing system The functions manage : rendering context display list extension functions font bitmap They are analogous to the GLX extensions that connect OpenGL to the X Windows System The names for these functions have a wgl prefix OpenGL Command Syntax OpenGL commands use : the prefix gl intial captial letters for each word making up the command name OpenGL define constants begin with GL use all capital letters use underscore to separate words OpenGL uses command extensions for clarification whenever the same command exists to use different arguments Examples : glClearColor() GL_COLOR_BUFFER_BIT glColor3fv() OpenGL Command Syntax  glVertex3fv v indicates vector format, if present