2x2x2 Rubik's Cube bitboard generator, for edges. By @protolambda

main.dart

/*
 * Quick but powerful Rubik's cube bitboard generator. For 2x2x2 cubes, could be extended for 3x3x3.
 * Made by @protolambda
 * 
 * The bitboards are used for rotating the edges of a face clockwise or counter-clockwise.
 * 
 */

void main() {
  
  
List<Face> fa = [];
  
  for(int i = 0; i < 3; i++){
    for(int j = 0; j < 2; j++){
    	fa.add(new Face(i, j));
    }
  }
  
  fa.forEach((Face f){
    fa.where((a)=>a.dim != f.dim).forEach((a){
      f.edges.add(new Edge(f, a));
    });
  });
  
  print("edges done");
  
  fa.forEach((Face a){
    fa.forEach((Face b){
    	Edge x = a.edges.firstWhere((e)=>e.edging == b, orElse: ()=> null);
      Edge y = b.edges.firstWhere((e)=>e.edging == a, orElse: ()=> null);
      if(x == null || y == null) return;
      x.mirror = y;
      y.mirror = x;
    });
  });
  
  print("mirrors done");
  
  Face white = fa.first;
  Face blue = white.edges.first.edging;
  Face green = white.edges.firstWhere((e)=> e.edging != blue && !e.edging.edges.any((a)=>a == blue)).edging;
  Face red = white.edges.firstWhere((e)=> e.edging != blue && e.edging != green).edging;
  Face orange = white.edges.firstWhere((e)=> e.edging != blue && e.edging != green && e.edging != red).edging;
  Face yellow = orange.edges.firstWhere((e)=> e.edging != white && e.edging != green && e.edging != blue).edging;
  
  white.name = "white";
  blue.name = "blue";
  green.name = "green";
  red.name = "red";
  orange.name = "orange";
  yellow.name = "yellow";
  
  print("$white, $blue, $green, $red, $orange, $yellow");
  
  //top
  white.getEdge(blue).clockwise = white.getEdge(red);
  white.getEdge(red).clockwise = white.getEdge(green);
  white.getEdge(green).clockwise = white.getEdge(orange);
  white.getEdge(orange).clockwise = white.getEdge(blue);
  
  print("top done");
  
  //sides top
  white.edges.forEach((e){
    Face top = e.edging;
    Face cw = e.clockwise.edging, ccw = e.counterClockwise.edging;
    top.getEdge(cw).clockwise = e.mirror;
    top.getEdge(ccw).counterClockwise = e.mirror;
  });
  
  print("sides top done");
  
  //bottom
  yellow.getEdge(blue).clockwise = yellow.getEdge(orange);
  yellow.getEdge(orange).clockwise = yellow.getEdge(green);
  yellow.getEdge(green).clockwise = yellow.getEdge(red);
  yellow.getEdge(red).clockwise = yellow.getEdge(blue);
  
  print("bottom done");
  
  //sides bottom
  yellow.edges.forEach((e){
    Face top = e.edging;
    Face cw = e.clockwise.edging, ccw = e.counterClockwise.edging;
    top.getEdge(cw).clockwise = e.mirror;
    top.getEdge(ccw).counterClockwise = e.mirror;
  });
  
  print("sides bottom done");
  
  //connect sides with bottom
  fa.forEach((f)=>f.edges.forEach((e){
    if(e != null && e.counterClockwise != null && e.clockwise != null && e.clockwise.clockwise == null){
      e.clockwise.clockwise = f.edges.firstWhere((a) => a != e && a != e.clockwise && a != e.counterClockwise);
      e.clockwise.clockwise.clockwise = e.counterClockwise;
    }
  }));
  
  print("connect done");
  
  fa.forEach((f){
    
    Edge a = f.edges.first, b = f.edges.first.clockwise, c = f.edges.first.clockwise.clockwise, d = f.edges.first.counterClockwise;
    
    //sort edges
    f.edges = [a, b, c, d];
  });
  
  print("clockwise sort done");
  
  
  fa = [white, blue, red, green, orange, yellow];
  
  print("face sort done");
  print("outputting bitboards...\n\n");
  
  
  fa.forEach((Face face){
    Edge e;
    //this, clockwise, counterclockwise, clockwise board-index, counterclockwise board-index
    int w, cw, ccw, cw_i, ccw_i;
    String line = "\tedge${face.name.substring(0, 1).toUpperCase()+face.name.substring(1)}:\t.long ";
    List<String> entries = [];
    for(Face f in fa){
      e = face.edges.firstWhere((e)=>e.edging == f, orElse: ()=> null);
      if(e == null){
        entries.add("0x00000000");
        continue;
      }
      w = e.mirror.onto.edges.indexOf(e.mirror);
      cw = e.clockwise.mirror.onto.edges.indexOf(e.clockwise.mirror);
      ccw = e.counterClockwise.mirror.onto.edges.indexOf(e.counterClockwise.mirror);
      int
        cw_i = fa.indexOf(e.clockwise.edging),
      	ccw_i = fa.indexOf(e.counterClockwise.edging),
        aW = 1 << w,
        bW = 1 << ((w + 1) % 4),
        aCW = 1 << cw,
        bCW = 1 << ((cw + 1) % 4),
        aCCW = 1 << ccw,
        bCCW = 1 << ((ccw + 1) % 4);

      entries.add("0x"+hex(cw_i)+hex(ccw_i)+hex(aW)+hex(bW)+hex(aCW)+hex(bCW)+hex(aCCW)+hex(bCCW));

    }
    print(line + entries.join(", "));
  });
}

String hex(int i) => i.toRadixString(16);


class Face {
  final int dim, side;
  int get face => dim * 3 + side;
  List<Edge> edges = [];
  Face(this.dim, this.side);
  
  String name;
 
  Edge getEdge(Face a){
    return edges.firstWhere((e)=>e.edging == a);
  }
}

class Edge {
  
  final Face onto, edging;
  
  
  Edge mirror, _clockwise, _counterClockwise;
  
  Edge get clockwise => _clockwise;
  Edge get counterClockwise => _counterClockwise;
  
  set clockwise(Edge e){
    _clockwise = e;
    e._counterClockwise = this;
  }
  
  set counterClockwise(Edge e){
    _counterClockwise = e;
    e._clockwise = this;
  }


  
  Edge(this.onto, this.edging);
  
  
}