Interpreter.hh

Go to the documentation of this file.

 
char cmda[] = "ca";
char cmdb[] = { 1,2,3,4,5,0 };
char cmdc[] = { 1,2,3,4,5,0 };
char *cmds[] = { &cmda, &cmdb, &cmdc };
 
class PointCollectionInterpret : public PointCollection2d
{
public:
  PointCollectionInterpret(char** cmds) : cmds(cmds) { current_point.x = 0.0; current_point.y = 0.0; current_vector.dx = 0.0; current_vector.dy = -1.0; }
  int Size() const { return vec.size(); }
  Point2d Index(int i) const
  {
    return vec[i];
  }
 
  void execute(char cmd)
  {
    char *cmdptr = cmds[cmd];
    while(1)
      {
    switch(*cmdptr++)
      {
      case '\0': return;
      case 'c': // funccall: (1, cmdnum)
        {
          char cmdtoexecute = *cmdptr++ - 'a';
          execute(cmdtoexecute);
        }
        break;
      case 'p': // Point
        {
          vec.push_back(current_point);
        }
        break;
      case 'f': // Forward
        {
          current_point += current_vector;
          break;
        }
        break;
      case 'b': // Backward
        {
          current_point += current_vector;
          break;
        }
        break;
      case 'l': // rotate left
        {
          Vector2d v;
          v.dx = current_vector.dx * cos(45.0/2.0*2.0*3.14159/360.0)
        - current_vector.dy * sin(45/2.0*2.0*3.14159/360.0);
          v.dy = current_vector.dx * sin(45.0/2.0*2.0*3.14159/360.0)
        + current_vector.dy * cos(45.0/2.0*2.0*3.14159/360.0);
          current_vector = v;
        }
        break;
      case 'r': // rotate right
        {
          Vector2d v;
          v.dx = current_vector.dx * cos(-45.0/2.0*2.0*3.14159/360.0)
        - current_vector.dy * sin(-45/2.0*2.0*3.14159/360.0);
          v.dy = current_vector.dx * sin(-45.0/2.0*2.0*3.14159/360.0)
        + current_vector.dy * cos(-45.0/2.0*2.0*3.14159/360.0);
          current_vector = v;
        }
        break;
      case 's': // scale down *2
        {
          current_vector /= 2.0;
          break;
        }
      case 'S': // scale up *2
        {
          current_vector *= 2.0;
          break;
        }
      };
      }
  }
private:
  char **cmds;
  std::vector<Point2d> vec;
  Point2d current_point;
  Vector2d current_vector;
};
 
int main()
{
  PointCollectionInterpret d(cmds);
  d.execute(0);
}