GL: Graphic Library
    Visual Studio设置openGL:https://content.byui.edu/file/2315e65e-a34a-48d3-814d-4175a2b74ed5/1/intro/165-opengl-visualStudio2017.html#:~:text=Configure%20Visual%20Studio%20for%20OpenGL&text=With%20your%20project%20open%20in,type%3A%20Install%2DPackage%20nupengl.
    **
    Properties for Open GL:

    • OpenGL is independent of windows system
    • OpenGL does not work by itself
    • GULT(OpenGL Utility Toolkit) -provides basic functions to operate windows
    • image.png
    • header file: #include

    image.pngimage.png
    glColor4f： 4->(r,g,b,alpha); f->float note: -> glVertex2fv(a) a stands for an array
    g]lBegin -> set to be polygon w->waitng
    glBertex2f -> set vertexs
    note: RGB (0,0,0)=black
    image.png
    (link in lecture notes)

    example:
    image.png

    image.png
    DOUBLE->buffering
    glutInit(&argc,argv) ->pass commend line options
    glutInitWindowSize -> set window size
    glutCreateWindow -> cause the window to appear, (“”) -> title for the window
    init() -> function defined by coder
    glutMainLoop -> blocking until the window is closed

    image.png
    keep going thru the evensts, whenever a event is present, corresponding call back function will activate

    CallBackFunctions:
    image.png
    Inbuild functions?
    image.png eg. sphere: image.pngimage.png
    apply: image.png
    Glint slice: larger number as smoother sphere (longitudinal lines)
    Glint stacks: horizontal lines
    image.png

    Viewing
    Default Camera Location:
    image.png
    gluLookAt:
    image.png

    order of translating and rotating is important

    glLoadMatrix(), glMultMatrix()
    image.png
    glLoadMatrix - replaces current matrix with the one whose elements are specified by m.
    glMultMatrix - multiplies the current matrix with the one specified using m, and replaces the current matrix with the product

    note: current matirx is the projection matrix, modelview matrix, or texture matrix depending on the current matrix mode
    image.png

    Translate:
    image.png
    eg.image.png
    Rotate:
    image.png
    eg.image.png
    Scale
    image.png
    eg.image.pngimage.png