w
argstoglViewportareleftbottomwidthheight
glViewport00500500
NBdefaultviewporthassamecoordsasi
myi
it
fsothiscouldbeomitted
drawcircle250250100
a
dflushthatbuffertothescree
glFlush
voiddisplay3画圆
glClearGL_COLOR_BUFFER_BITclearthewi
dow

viewportstuff


setupaviewporti
thescree
wi
dow
argstoglViewportareleftbottomwidthheight
glViewport00500500
NBdefaultviewporthassamecoordsasi
myi
it
sothiscouldbeomitted
drawEllipse2502506040
a
dflushthatbuffertothescree
glFlush
i
tmai
i
targccharargv
Sta
dardGLUTi
itializatio

glutI
itargcargv
glutI
itDisplayModeGLUT_SINGLEGLUT_RGBdefault
ot
eeded
glutI
itWi
dowSize500500500x500pixelwi
dow
glutI
itWi
dowPositio
00placewi
dowtoplefto
display
cout