CSE328:Fundamentals of Computer Graphics. OpenGL tutorial. Shuchu Han (Jerome) Department of Computer Science, SBU

Transcription

1 CSE328:Fundamentals of Computer Graphics OpenGL tutorial Shuchu Han (Jerome) Department of Computer Science, SBU Department of Computer Science, Stony Brook University (SUNYSB)

2 Outline Outline: 1.TA & Homework information 2.Introduction to OpenGL 3.OpenGL programming guide 4.OpenGL language syntax 5.GLUT+GLUI 6.Examples 7.Helpful Sources 8.Summary CSE328

3 TA Information TA Schedule: Time: Tuesday, Friday: 2:15~3:45pm; Location: Computer Science Building, C2110; Other Issues: your questions to me, I will reply to you asap. Please place a CSE328 tag in the title. Tutorial slides will be put to my department homepage. (under construction ) Department of Computer Science, Stony Brook University (SUNYSB)

4 Homework Info Homework Info: Submit them to my box; Name your file, and Zip: (for example) HW_1_ShuchuHan_107******.rar Write a README file with your programs. Please include all important information related to the codes and.exe, for example: Folder structure, Compiler info, 3th-party lib. Mac and Linux users please compile a MS Windows.EXE for me. Thanks. C/C++ codes only. CSE328

5 Introduction to OpenGL What is OpenGL? Industrial standard library for doing computer graphics. Developed by Silicon Graphics Inc.(SGI) in Managed by the non-profit technology consortium Khronos Group. Latest version: 4.1 (released at July 26, 2010). 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: CSE328

6 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

7 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, wxwidgets ( use OpenGL as backend). CSE328

8 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, SDL and GLFW. OpenGL need a GUI in window system. CSE328

9 Programming overview: OpenGL programming guide

10 OpenGL programming guide Tools for programming: C/C++ compiler and debugger: MS, gcc, intel. IDE: MS Visual studio, Dev-C++, Eclipse+cdt, Xcode, GUI: GLUT + GLUI, QT, MFC Usually, OpenGL libs are integrated with compiler toolkit together. Recommendation: VS GLUT + GLUI Reasons: free, easy for debug. Download links:

11 OpenGL programming guide 1. Download VS2008+GLUT+GLUI. 2. Location of GL/gl.h : 3. GLUT libs looks like:

12 OpenGL programming guide 4. Compile GLUI. including glut.h, linking glut32.lib. Error while compile GLUI: error C2381: 'exit' : redefinition; declspec(noreturn) differs To solve this, make the following changes to glut.h around line 145. #if defined(_win32) # ifndef GLUT_BUILDING_LIB /*extern _CRTIMP void cdecl exit(int);*/ _CRTIMP declspec(noreturn) void cdecl exit(int); # endif

13 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.

14 OpenGL language

15 OpenGL language

16 OpenGL language

17 OpenGL language

18 OpenGL language

19 OpenGL language

20 OpenGL geometric primitives

21 OpenGL geometric primitives

22 OpenGL geometric primitives

23 OpenGL geometric primitives

24 OpenGL geometric primitives

25 OpenGL geometric primitives

26 OpenGL geometric primitives

27 OpenGL geometric primitives

28 OpenGL geometric primitives

29 Rendering

30 Rendering

31 Controlling current state

32 GLUT

33 What can GLUT do? GLUT

34 GLUT programming

35 Initialization

36 Initialization

37 Open a window

38 Open a window

39 Handle Events

40 Handle Event

41 Handle events

42 GLUT

43 GLUT

44 GLUT

45 GLUT

46 GLUT

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48 Enter event processing loop

49 GLUT summary

50 GLUT Menu

51 GLUT Menu

52 Put together

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55 GLUI

56 GLUI

57 Examples

58 Helpful sources Links: GLUT tutorial: GLUI manual:..\glui-2.35\src\doc\glui_manual.pdf GLUI examples:..\glui-2.35\src\example\example*.cpp Nehe(for game develop): Books: Red Book:

59 Summary Introduced OpenGL language Programming toolset Examples Homework One tips

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