示例#1
0
bool rasterpolys(const vector<Poly> &polys,
		 const Vector2d &min, const Vector2d &max, double resolution,
		 Cairo::RefPtr<Cairo::ImageSurface> &surface,
		 Cairo::RefPtr<Cairo::Context> &context)
{
  Vector2d diag = max - min;
  int width  = (int)ceil(diag.x()/resolution);
  int height = (int)ceil(diag.y()/resolution);
  if (height <= 0 || width <= 0)
    return false;
  surface = Cairo::ImageSurface::create(Cairo::FORMAT_A8, width, height);
  //surface->set_device_offset(-min.x()/resolution, -min.y()/resolution);
  context = Cairo::Context::create (surface);
  context->set_fill_rule(Cairo::FILL_RULE_WINDING);
  context->set_antialias(Cairo::ANTIALIAS_DEFAULT);
  context->scale(1/resolution, 1/resolution);
  context->translate(-min.x(), -min.y());
  context->set_source_rgb (0,0,0);
  //cerr << min << endl <<getMatrix(context) << endl;

  // draw boundary
  // context->begin_new_path();
  // context->set_line_width(0.5);
  // context->move_to(min.x(),min.y());
  // context->line_to(max.x(),min.y());
  // context->line_to(max.x(),max.y());
  // context->line_to(min.x(),max.y());
  // // context->move_to(0,0);
  // // context->line_to(diag.x(),0);
  // // context->line_to(diag.x(),diag.y());
  // // context->line_to(0,diag.y());
  // context->close_path();
  // context->stroke();

  context->begin_new_path();
  context->set_line_width(0);
  for (uint i=0; i<polys.size(); i++) {
    Vector2d v = polys[i][0];
    context->move_to(v.x(),v.y());
    for (uint j=0; j<polys[i].size(); j++) {
      Vector2d v = polys[i][j];
      context->line_to(v.x(),v.y());
    }
  }
  context->fill();
  return true;
}