C++ Matrix::setConstant方法代码示例

// Create a texture that hides the integer translation in the parametrization
void line_texture(Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic> &texture_R,
                  Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic> &texture_G,
                  Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic> &texture_B)
{
  unsigned size = 128;
  unsigned size2 = size/2;
  unsigned lineWidth = 3;
  texture_R.setConstant(size, size, 255);
  for (unsigned i=0; i<size; ++i)
    for (unsigned j=size2-lineWidth; j<=size2+lineWidth; ++j)
      texture_R(i,j) = 0;
  for (unsigned i=size2-lineWidth; i<=size2+lineWidth; ++i)
    for (unsigned j=0; j<size; ++j)
      texture_R(i,j) = 0;

  texture_G = texture_R;
  texture_B = texture_R;
}

Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor> Interpolation::generate_DEM(PointCloudElement* pElement, float post_spacing) 
{
	   StepResource pStep("Generating DEM", "app", "ffe16048-1e58-11e4-b4be-b2227cce2b54");
	   
	   ProgressResource pResource("ProgressBar");
	   Progress *pProgress = pResource.get(); 
	   pProgress-> setSettingAutoClose(true);

	   Eigen::Matrix<float, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor> demRM;// dem stored in a Row major eigen matrix

	   /* Main processing loop */
	   FactoryResource<PointCloudDataRequest> req;
	   req->setWritable(true);
	   PointCloudAccessor acc(pElement->getPointCloudAccessor(req.release()));
	   if (!acc.isValid())
	   {
		   interpolation_msg += "Unable to write to point cloud for generating DEM.\n";
		   pProgress->updateProgress("Unable to write to point cloud for generating DEM.", 0, ERRORS);
		   pStep->finalize(Message::Abort, interpolation_msg);
		   return demRM.matrix(); // in this way it should return NULL matrix, see http://eigen.tuxfamily.org/dox/classEigen_1_1Matrix.html: Matrix(): For dynamic-size matrices, creates an empty matrix of size 0. Does not allocate any array. Such a matrix is called a null matrix. This constructor is the unique way to create null matrices: resizing a matrix to 0 is not supported.
	   }
	   const PointCloudDataDescriptor* pDesc = static_cast<const PointCloudDataDescriptor*>(pElement->getDataDescriptor());
	   double xMin = pDesc->getXMin() * pDesc->getXScale() + pDesc->getXOffset();
	   double xMax = pDesc->getXMax() * pDesc->getXScale() + pDesc->getXOffset();
	   double yMin = pDesc->getYMin() * pDesc->getYScale() + pDesc->getYOffset();
	   double yMax = pDesc->getYMax() * pDesc->getYScale() + pDesc->getYOffset();

	   int mDim = static_cast<int>(std::ceil((xMax - xMin) / post_spacing));  //columns
	   int nDim = static_cast<int>(std::ceil((yMax - yMin) / post_spacing)); //rows
	   xMax = xMin + mDim * post_spacing;
	   yMin = yMax - nDim * post_spacing;

	   const float badVal = -9999.f;
	   demRM.setConstant(nDim, mDim, badVal);

	   int prog = 0;
	   uint32_t adv = pDesc->getPointCount() / 100;
	   for (size_t idx = 0; idx < pDesc->getPointCount(); ++idx)
	   {
		  if (!acc.isValid())
		  {
			  interpolation_msg += "Unable to access data for generating DEM.\n";
			  pProgress->updateProgress("Unable to access data for generating DEM.", 0, ERRORS);
			  pStep->finalize(Message::Abort, interpolation_msg);
			  return demRM.matrix();// in this way it should return NULL matrix, see http://eigen.tuxfamily.org/dox/classEigen_1_1Matrix.html: Matrix(): For dynamic-size matrices, creates an empty matrix of size 0. Does not allocate any array. Such a matrix is called a null matrix. This constructor is the unique way to create null matrices: resizing a matrix to 0 is not supported.
		  }
		  if (idx % adv == 0)
		  {
			  pProgress->updateProgress("Generating DEM", ++prog, NORMAL);
		  }
		  if (!acc->isPointValid())
		  {
			 acc->nextValidPoint();
			 continue;
		  }
		  double x = acc->getXAsDouble(true);
		  double y = acc->getYAsDouble(true);
		  float z = static_cast<float>(acc->getZAsDouble(true));
		  
		  // calculate nearest DEM point
		  int xIndex = std::max(0, static_cast<int>(std::floor((x - xMin) / post_spacing)));
		  int yIndex = std::max(0, static_cast<int>(std::floor((yMax - y) / post_spacing)));
		  
		  float demVal = demRM(yIndex, xIndex);
		  if (demVal == badVal || demVal < z)
		  {
			 demRM(yIndex, xIndex) = z; 
		  }

		  acc->nextValidPoint();
	   }
	   pProgress->updateProgress("DEM generation is complete.", 100, NORMAL);
	   pStep->finalize();
	   return demRM;
}