introduction to opengl keng shih-ling 2003 spring
TRANSCRIPT
ExampleOpenGL example
OpenGL is a Graphics API
A software interface for graphics hardware.Provide the low-level functions to access graphics hardware directly.OpenGL / Direct3DOpenGL functions use the prefix gl.
OpenGL is a Graphics API
Application
GDI
Display Device
OpenGL
Hardware Driver
…
OpenGL library
Microsoft’s implementation– From Win95 OSR2, Microsoft Windows
ship with OpenGL32.DLL.– For old Win95 users, you still can
download OPENGL95.EXE via Microsoft website.
– Header files and import library files are already included in Win32 Platform SDK.
OpenGL library
Microsoft’s OpenGL32.DLL applies a hardware accelerated driver registered in Registry.
– HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\OpenGLDrivers
– You can search it by using REGEDIT.EXE
API Hierarchy
OpenGL Utility Library
The OpenGL Utility Library(GLU) provides many of the modeling features, such as quadric surfaces and NURBS curves and surfaces. GLU is a standard part of every OpenGL implementationGLU routines use the prefix glu.– gluLookAt( … );– …
Windows system related helper library
For every window system, there is a library that extends the functionality of that window system to support OpenGL rendering. – X Window System -> GLX – Microsoft Windows -> WGL– IBM OS/2 -> PGL
OpenGL Utility Toolkit
The OpenGL Utility Toolkit (GLUT) is a window system-independent toolkit, written by Mark Kilgard, to hide the complexities of differing window system APIs. GLUT routines use the prefix glut.– glutPostRedisplay();– …
OpenGL Utility Toolkit
You can download this toolkit in the following website– Win32
• http://www.xmission.com/~nate/glut.html
– Linux• http://www.mesa3d.org
We focus on this toolkit
Basic Setup (GLUT)
On Microsoft Visual C++ 6:– Put glut.h into <MSVC>/include/GL/– Put glut.lib into <MSVC>/lib/– Put glut32.dll into <window>/System32/
On Microsoft Visual C++ .NET:– Put glut.h into
<MSVC>/platformSDK/include/GL/– Put glut.lib into <MSVC>/platformSDK/lib/– Put glut32.dll into <window>/System32
How to Compile (VC6.0)
On Microsoft Visual C++ 6:– Create a new Project with Win32
Console Application– Open Project Settings dialog and add
opengl32.lib glu32.lib glut32.lib into Link/Objects/library modules.
– Writing your OpenGL code.– Compile it.
How to Compile (.NET)
On Microsoft Visual C++ .NET:– 建立Win32專案– 在應用程式設定，選擇主控台應用程式– 開啟專案屬性，在連結器 /輸入 /其他相依性中輸入 opengl32.lib glu32.lib glut32.lib 。
– Writing your OpenGL code.– Compile it.
How to Compile (.NET)
The Simplest Program#include <GL/glut.h>void GL_display(){
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);glClear(GL_COLOR_BUFFER_BIT);glColor3f(1.0f, 1.0f, 1.0f);glutSolidCube(1.0);glFlush();
}void GL_reshape(GLsizei w, GLsizei h){
glViewport(0, 0, w, h);glMatrixMode(GL_PROJECTION);glLoadIdentity();glOrtho(-2.0f, 2.0f, -2.0f, 2.0f, -2.0f, 2.0f);glMatrixMode(GL_MODELVIEW);glLoadIdentity();
}
The Simplest Program
void main(void){
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);glutCreateWindow("Sample");glutDisplayFunc(GL_display);glutReshapeFunc(GL_reshape);glutMainLoop();
}
The Simplest Program
Reference
Official site of OpenGL– http://www.opengl.org
Useful Sites– NeHe’s OpenGL Tutorials– The Developer’s Gallery
Reference
Further Reading– OpenGL Programming Guide (Red
Book)– OpenGL Reference Manual (Blue
Book)– OpenGL Super Bible (中文版 )
Any Question?
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