My ground is not lighting up - opengl

Question

Im a bit stuck with my lighting. My light can light up meshes but it does not light up my ground.
Here is some of my code
The light:
glEnable(GL_LIGHT0);
glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, 1.0f);
glEnable(GL_COLOR_MATERIAL);
GLfloat ambient_light0[] = { 0.5f, 0.5f, 0.5f, 1.0f };
GLfloat position_light0[] = { 0.0f, 8.0f, 0.0f, 0.9f };
GLfloat spotDirection_light0[] = {0.0, -1.0, 0.0 };
GLfloat specularLightcolor[] = { 1.0, 1.0, 1.0, 1.0 };
glLightfv( GL_LIGHT0, GL_POSITION, position_light0 );
glLightfv( GL_LIGHT0, GL_SPOT_DIRECTION, spotDirection_light0 );
glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 0.5);
glLightfv( GL_LIGHT0, GL_AMBIENT, ambient_light0 );
glLightfv(GL_LIGHT0, GL_SPECULAR, specularLightcolor);
glLightf( GL_LIGHT0, GL_SPOT_CUTOFF, 60.0f );
glLightf( GL_LIGHT0, GL_SPOT_EXPONENT, 50.0f );
The ground:
void drawGround(int id) {
glEnable(GL_TEXTURE_2D);
glEnable(GL_COLOR_MATERIAL);
getTexture(id);
glBindTexture(GL_TEXTURE_2D, id);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
GLfloat material_diffuse[] = {0.9, 0.9, 0.9, 1.0 };
GLfloat material_specular[] = { 1, 1, 1, 1 };
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, material_diffuse);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, material_specular);
glBegin(GL_QUADS);
for(int i = 0; i<3; i++){
for(int j= 0; j<3; j++){
glNormal3f(0.0f, 1.0f, 0.0f);
glMaterialfv(GL_FRONT, GL_DIFFUSE, material_diffuse);
glMaterialfv(GL_FRONT, GL_SPECULAR, material_specular);
glMaterialf(GL_FRONT, GL_SHININESS, 80.0);
glTexCoord2f(1, 1);
glVertex3f(-floorSize +((j)*(2*floorSize)/3), 0 ,-floorSize +((i)*(2*floorSize)/3));
glTexCoord2f(1, 0);
glVertex3f(-floorSize +((j)*(2*floorSize)/3), 0 ,-floorSize +((i+1)*(2*floorSize)/3));
glTexCoord2f(0,0);
glVertex3f(-floorSize +((j+1)*(2*floorSize)/3), 0 ,-floorSize +((i+1)*(2*floorSize)/3));
glTexCoord2f(0, 1);
glVertex3f(-floorSize +((j+1)*(2*floorSize)/3), 0 ,-floorSize +((i)*(2*floorSize)/3));
}
}
glDepthMask( 1.0 );
glDisable(GL_TEXTURE_2D);
glEnd();
}
Drawing of the ground happens after the light is called.
Has anyone any idea why my ground is not lighting up?
here is a screen shot of my problem --->

Answer 1

The problem is, that default fixed function OpenGL lighting does the illumination at the vertices only, and then just interpolates the resulting color. Since all the 4 vertices of the ground are dimly lit, the whole quad gets dim.
Solutions:
further subdivide your ground, so that there are more light sampling points. So far you've got only 3×3 points, which is not nearly sufficient. Think 100×100 or even more, to get a nice illumination effect.
or
use a fragment shader to implement per pixel lighting.
You're running into a typical OpenGL newbie pitfall there, BTW.
Update:
On a side note: You also did not supply normals for the plane. Therefore lighting will not work at all.