#include #include #include #include #define pi 3.14159265358979323846264338327950288 // pi
lresult callback wndproc(hwnd,uint,wparam,lparam);
int winapi winmain(hinstance hinstance,hinstance hprevinstance,pstr szcmdline,int icmdshow)
text("the opengl program"), // window caption
cw_usedefault, // initial x position
cw_usedefault, // initial y position
400, // initial x size
400, // initial y size
null, // parent window handle
null, // window menu handle
hinstance, // program instance handle
null); // creation parameters
showwindow(hwnd,icmdshow);
updatewindow(hwnd);
while(getmessage(&msg,null,0,0))
return msg.wparam;
}lresult callback wndproc(hwnd hwnd,uint message,wparam wparam,lparam lparam)
glviewport(0,0,rc.right,rc.bottom);
glmatrixmode(gl_projection);
glloadidentity();
x2y=(glfloat)rc.right/(glfloat)rc.bottom;
// 設定視口的大小
gluperspective(90.0,x2y,1.0,10.0);
glmatrixmode(gl_modelview);
glloadidentity();
return 0;
case wm_timer:
glclear(gl_color_buffer_bit | gl_depth_buffer_bit);
//glloadidentity();
//gltranslatef(0.0,0.0,-1.0);
glbegin(gl_points);
//近平面，注意近平面不能完全與near相等，要加個小量?
glcolor3f(0.0f,0.0f,1.0f); //藍色
glvertex3f( 0.0, 0.0, -1.0000001); //螢幕正中心
glvertex3f( 0.0, tan(pi*90.0/360.0), -1.0000001); //螢幕正中上方
glvertex3f( 0.0, -tan(pi*90.0/360.0), -1.0000001); //螢幕正中下方
glvertex3f( -x2y*tan(pi*90.0/360.0), 0.0, -1.0000001); //螢幕正中左方
glvertex3f( x2y*tan(pi*90.0/360.0), 0.0, -1.0000001); //螢幕正中右方
glvertex3f( 0.0, 0.5*tan(pi*90.0/360.0), -1.0000001); //螢幕正中上方1/2
glvertex3f( 0.0, -0.5*tan(pi*90.0/360.0), -1.0000001); //螢幕正中下方1/2
glvertex3f( -0.5*x2y*tan(pi*90.0/360.0), 0.0, -1.0000001); //螢幕正中左方1/2
glvertex3f( 0.5*x2y*tan(pi*90.0/360.0), 0.0, -1.0000001); //螢幕正中右方1/2
//遠平面
glcolor3f(1.0f,0.0f,0.0f); //紅色
glvertex3f(-x2y*10.0*tan(pi*90.0/360.0), 10.0*tan(pi*90.0/360.0), -10.0); //螢幕左上角
glvertex3f( x2y*10.0*tan(pi*90.0/360.0), 10.0*tan(pi*90.0/360.0), -10.0); //螢幕右上角
glvertex3f(-x2y*10.0*tan(pi*90.0/360.0), -10.0*tan(pi*90.0/360.0), -10.0); //螢幕左下角
glvertex3f( x2y*10.0*tan(pi*90.0/360.0), -10.0*tan(pi*90.0/360.0), -10.0); //螢幕右下角
//在遠近平面中心的一點投射在近平面上
glcolor3f(0.0f,1.0f,0.0f); //綠色
glvertex3f( 0.0, 0.0, -1.0000001); //螢幕正中心
glend();
swapbuffers(hdc);
return 0;
case wm_destroy:
killtimer(hwnd, 1);
// make the rendering context not current
wglmakecurrent(null,null) ;
// delete the rendering context
wgldeletecontext(hrc);
postquitmessage(0);
return 0;
}return defwindowproc(hwnd,message,wparam,lparam);
}
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