OpenGL Multiple Lights - opengl

Question

I'm attempting to add a second light to my scene. I was under the impression that all I needed to do, was enable another light (LIGHT1 in this case), and set it's parameters in order for it to work alongside the existing light. With this in mind, this is my lighting initialization:
void ThemePark::lightInit(GLfloat sun_position[], GLfloat light1_position[])
{
// Enable Lighting
glEnable(GL_LIGHTING);
glLightModelf(GL_LIGHT_MODEL_LOCAL_VIEWER, 0);
glLightfv(GL_LIGHT0, GL_POSITION, sun_position); // Position the lights
glLightfv(GL_LIGHT1, GL_POSITION, light1_position);
// Set light intensity and color for each component
glLightf(GL_LIGHT0, GL_DIFFUSE, (0.5,0.5,0.5,1));
glLightf(GL_LIGHT0, GL_AMBIENT, (0.5,0.5,0.5,1));
glLightf(GL_LIGHT0, GL_SPECULAR, (1,1,1,1));
glLightf(GL_LIGHT1, GL_DIFFUSE, (0.7,0.7,0.7,1));
glLightf(GL_LIGHT1, GL_AMBIENT, (0.3,0.3,0.3,1));
glLightf(GL_LIGHT1, GL_SPECULAR, (1,1,1,1));
// Set attenuation
glLightf(GL_LIGHT0, GL_CONSTANT_ATTENUATION, 0.5);
glLightf(GL_LIGHT0, GL_LINEAR_ATTENUATION, -1.0);
glLightf(GL_LIGHT1, GL_CONSTANT_ATTENUATION, 0.2);
// Enable Lights
glEnable(GL_LIGHT0);
glEnable(GL_LIGHT1);
}
I am also positioning my lights again in my display function as follows:
if(lighting)
{
glLightfv(GL_LIGHT0, GL_POSITION, sun_position);
glLightfv(GL_LIGHT1, GL_POSITION, light1_position);
}
Their positions are:
GLfloat sun_position[] = {10, 10, -2, 1};
GLfloat light1_position[] = {1, 1, 1, 1};
However, when doing this I still only have a single active light, LIGHT0. Taking out the enable statement for LIGHT0 gives me a scene with no lights. As a test, I modified the lighting initialization function to the following, which essentially makes LIGHT1 the same as LIGHT0, but never enables or initializes LIGHT0.
void ThemePark::lightInit(GLfloat sun_position[], GLfloat light1_position[])
{
// Enable Lighting
glEnable(GL_LIGHTING);
glLightModelf(GL_LIGHT_MODEL_LOCAL_VIEWER, 0);
glLightfv(GL_LIGHT1, GL_POSITION, sun_position);
// Set light intensity and color for each component
glLightf(GL_LIGHT1, GL_DIFFUSE, (0.5,0.5,0.5,1));
glLightf(GL_LIGHT1, GL_AMBIENT, (0.5,0.5,0.5,1));
glLightf(GL_LIGHT1, GL_SPECULAR, (1,1,1,1));
// Set attenuation
glLightf(GL_LIGHT1, GL_CONSTANT_ATTENUATION, 0.5);
glLightf(GL_LIGHT1, GL_LINEAR_ATTENUATION, -1.0);
// Enable Lights
glEnable(GL_LIGHT1);
}
I also modified my display function accordingly. However, I still see no lighting in my scene. Is there something I'm missing here?

Answer 1

GL_LIGHT1-7 actually have different defaults than GL_LIGHT0 ... so you will have to find the ones you forgot to set. Perhaps GL_QUADRATIC_ATTENUATION? If not try setting all the params in the spec Many of them default to zero/off states for GL_LIGHT1-7.