// TriMesh.java

public class TriMesh {
   public TriMesh (Vertex av [], int ai [], Color ac [])
   {  lit      = new Color ();
      working  = new Vector ();
      backface = true;
      vertices = av;
      faces    = new TriFace [ai.length / 3];
     int j = 0;
      for (int k = 0; k < faces.length; k++) {
         faces [k] = new TriFace (vertices [ai [j+0]], vertices [ai [j+1]],
                                  vertices [ai [j+2]], ac [k]);
         j += 3;
      }
   }

   public void backface (boolean flag)  {backface = flag;}

   public void draw (Pipeline pipeline, Vector vector)
   {  if (backface) {
         for (int i = 0; i < faces.length; i++) {
            working.load     (faces [i].a.vector);
            working.subtract (vector);
           float f = working.dot (faces [i].normal);
            if (f > 0.0F) {
               pipeline.diffuse  (faces [i].color);
               pipeline.triangle (faces [i].a.vector, faces [i].b.vector,
                                  faces [i].c.vector);
            }
         }
      }
      else {
         for (int j = 0; j < faces.length; j++) {
            pipeline.diffuse  (faces [j].color);
            pipeline.triangle (faces [j].a.vector, faces [j].b.vector,
                               faces [j].c.vector);
         }
      }
   }

   public void draw (Pipeline pipeline, Vector vector, Vector vector1, float f)
   {  if (backface) {
         for (int i = 0; i < faces.length; i++) {
            working.load     (faces [i].a.vector);
            working.subtract (vector);
           float f1 = working.dot (faces [i].normal);
            if (f1 > 0.0F) {
              Color color1 = faces [i].color;
               working.load      (faces [i].a.vector);
               working.subtract  (vector1);
               working.normalize ();
              float f3 = working.dot (faces [i].normal);
               if (f3 < f)  f3 = f;
               lit.r = color1.r * f3;
               lit.g = color1.g * f3;
               lit.b = color1.b * f3;
               lit.clamp ();
               pipeline.diffuse  (lit);
               pipeline.triangle (faces [i].a.vector, faces [i].b.vector,
                                  faces [i].c.vector);
            }
         }
      }
      else {
         for (int j = 0; j < faces.length; j++) {
           Color color =      faces [j].color;
            working.load     (faces [j].a.vector);
            working.subtract (vector1);
            working.normalize ();
           float f2 = working.dot (faces [j].normal);
            if (f2 < f)  f2 = f;
            lit.r = color.r * f2;
            lit.g = color.g * f2;
            lit.b = color.b * f2;
            lit.clamp ();
            pipeline.diffuse  (lit);
            pipeline.triangle (faces [j].a.vector, faces [j].b.vector,
                               faces [j].c.vector);
         }
      }
   }

   public TriMesh subdivide (float f)
   { int i = faces.length;
     Vertex av [] = new Vertex [i * 6];
     int ai [] = new int [i * 4 * 3];
     Color ac [] = new Color [i * 4];
     int j = 0;
     int k = 0;
     int l = 0;
      for (int i1 = 0; i1 < i; i1++) {
         av [j+0] = faces [i1].a;
         av [j+1] = faces [i1].b;
         av [j+2] = faces [i1].c;
         av [j+3] = new Vertex (0.0F, 0.0F, 0.0F);
         av [j+4] = new Vertex (0.0F, 0.0F, 0.0F);
         av [j+5] = new Vertex (0.0F, 0.0F, 0.0F);
         av [j+3].vector.add   (faces [i1].a.vector);
         av [j+3].vector.add   (faces [i1].b.vector);
         av [j+3].vector.scale (0.5F);
         av [j+3].vector.normalize ();
         av [j+3].vector.scale (f);
         av [j+4].vector.add   (faces [i1].b.vector);
         av [j+4].vector.add   (faces [i1].c.vector);
         av [j+4].vector.scale (0.5F);
         av [j+4].vector.normalize ();
         av [j+4].vector.scale (f);
         av [j+5].vector.add   (faces [i1].c.vector);
         av [j+5].vector.add   (faces [i1].a.vector);
         av [j+5].vector.scale (0.5F);
         av [j+5].vector.normalize ();
         av [j+5].vector.scale (f);
         ai [k+0]  = j;
         ai [k+1]  = j + 3;
         ai [k+2]  = j + 5;
         ai [k+3]  = j + 3;
         ai [k+4]  = j + 1;
         ai [k+5]  = j + 4;
         ai [k+6]  = j + 5;
         ai [k+7]  = j + 4;
         ai [k+8]  = j + 2;
         ai [k+9]  = j + 3;
         ai [k+10] = j + 4;
         ai [k+11] = j + 5;
         ac [l+0] = faces [i1].color;
         ac [l+1] = faces [i1].color;
         ac [l+2] = faces [i1].color;
         ac [l+3] = faces [i1].color;
         j += 6;
         k += 12;
         l += 4;
      }
      return new TriMesh (av, ai, ac);
   }

   public Vertex  vertices [];
   public TriFace faces [];
   Color          lit;
   Vector         working;
   boolean        backface;
}