Fix support for directional lights

The default light is a directional one, so we must initialize its
position (which, according to the standard, is (0, 0, 1)) following the
same algorithm we apply when glLightfv() is called for directional
lights: we multiply its position by 100000. The reason why we do this is
that GX does not support ideal directional lights, so we simulate them
by placing the light very far away and disabling the distance
attenuation.

Also, the light direction parameter was not set on the GX light, so we
fix that too.

src/gc_gl.c

@@ -324,9 +324,11 @@ void ogx_initialize()
         glparamstate.lighting.lights[i].atten[1] = 0;
         glparamstate.lighting.lights[i].atten[2] = 0;
 
+        /* The default value for light position is (0, 0, 1), but since it's a
+         * directional light we need to transorm it to 100000. */
         glparamstate.lighting.lights[i].position[0] = 0;
         glparamstate.lighting.lights[i].position[1] = 0;
-        glparamstate.lighting.lights[i].position[2] = 1;
+        glparamstate.lighting.lights[i].position[2] = 100000;
         glparamstate.lighting.lights[i].position[3] = 0;
 
         glparamstate.lighting.lights[i].direction[0] = 0;
@@ -1726,9 +1728,12 @@ int __prepare_lighting()
 
         // FIXME: Need to consider spotlights
         if (glparamstate.lighting.lights[i].position[3] == 0) {
-            // Directional light, it's a point light very far without atenuation
+            // Directional light, it's a point light very far without attenuation
             GX_InitLightAttn(&glparamstate.lighting.lightobj[i], 1, 0, 0, 1, 0, 0);
             GX_InitLightAttn(&glparamstate.lighting.lightobj[i + 4], 1, 0, 0, 1, 0, 0);
+            float *dir = glparamstate.lighting.lights[i].direction;
+            GX_InitLightDir(&glparamstate.lighting.lightobj[i], dir[0], dir[1], dir[2]);
+            GX_InitLightDir(&glparamstate.lighting.lightobj[i + 4], dir[0], dir[1], dir[2]);
         } else {
             // Point light
             GX_InitLightAttn(&glparamstate.lighting.lightobj[i], 1, 0, 0,