[Mesa3d-users] Help: glLight*

[Zhongli X. <zho...@gm...>]

Hi, all,

I'm confused by lights in OpenGL.
In OpenGL Programming Guide or 'The Red Book', it says

"when glLight*() is called to specify the position or the direction of a
light source, the position or direction is transformed by the current
modelview matrix and stored in eye coordinates."

And this my codes:
//I specified the parameters of the light before rendering objects.
float lightPosConst[4]=3D{0.0,0.0,1.0,1.0};
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
glLightfv(lightNum,GL_POSITION,lightPosConst);
glLightfv(lightNum,GL_AMBIENT,constColor);
glLightfv(lightNum,GL_DIFFUSE,lightColorv);
glLightfv(lightNum,GL_SPECULAR,lightColorv);
glPopMatrix();

The light should be stationary, but when I rotated my objects and the light
rotated in the reverse direction. Any suggestion is welcomed!
Thank you!

ps: the opengl lib I use is Mesa 6.4