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, we don't need to set the light direction on the GX light, since
the light is positioned far away and that by itself will determine under
which angle our objects will be lit.

f

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 transform 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;
@@ -513,11 +515,6 @@ void glLightfv(GLenum light, GLenum pname, const GLfloat *params)
             glparamstate.lighting.lights[lnum].position[0] = params[0] * 100000;
             glparamstate.lighting.lights[lnum].position[1] = params[1] * 100000;
             glparamstate.lighting.lights[lnum].position[2] = params[2] * 100000;
-
-            float len = 1.0f / sqrtf(params[0] * params[0] + params[1] * params[1] + params[2] * params[2]);
-            glparamstate.lighting.lights[lnum].direction[0] = params[0] * len;
-            glparamstate.lighting.lights[lnum].direction[1] = params[1] * len;
-            glparamstate.lighting.lights[lnum].direction[2] = params[2] * len;
         } else {
             glparamstate.lighting.lights[lnum].position[0] = params[0];
             glparamstate.lighting.lights[lnum].position[1] = params[1];
@@ -532,8 +529,6 @@ void glLightfv(GLenum light, GLenum pname, const GLfloat *params)
                 for (j = 0; j < 4; j++)
                     modv[i][j] = glparamstate.modelview_matrix[j][i];
             guVecMultiply(modv, (guVector *)glparamstate.lighting.lights[lnum].position, (guVector *)glparamstate.lighting.lights[lnum].position);
-            if (params[3] == 0)
-                guVecMultiply(modv, (guVector *)glparamstate.lighting.lights[lnum].direction, (guVector *)glparamstate.lighting.lights[lnum].direction);
         }
         break;
     case GL_DIFFUSE:
@@ -1726,7 +1721,7 @@ 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);
         } else {