Stamper Tutorial

Introduction

The purpose of this tutorial is to provide explanation on how to use the classes defined in this library to perform feature stamping. The examples provided in this tutorial refer to test cases that are in the /tutorial/TutStamping.cpp source file.

The library contains classes for performing feature stamping. The basic idea is to associate cross sections with a center line to produce a new feature (a "fill" embankment, a "cut" channel). The output from the feature stamp is a TIN and a set of break lines defining distinct characteristics of the new feature, such as the center line, shoulder, toe, and end cap.

The xms::StStamperIo class is used to set up the inputs to the stamp operation and it also contains the outputs of the operation in the member variables m_outTin and m_outBreakLines;

Example - Fill Embankment Feature Stamp

The following example shows how to use the stamper to make a simple fill embankment. The testing code for this example is TutStampingTests::test_StampFillEmbankment.

//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
void TutStampingUnitTests::test_StampFillEmbankment()
{
  // declare a XmStamperIo class to create the inputs
  xms::XmStamperIo io;
  // set as a "fill" stamp
  io.m_stampingType = 1;
  // define the center line
  io.m_centerLine = {{0, 0, 15}, {0, 10, 15}};
  // define a cross section at each point on the center line. This will
  // be a symmetric cross section. The top width will be 10 and the side
  // slope will be 1. The cross section will have a total width of 40.
  xms::XmStampCrossSection cs;
  cs.m_left = {{0, 15}, {5, 15}, {6, 14}};
  cs.m_leftMax = 20;
  cs.m_idxLeftShoulder = 1;
  cs.m_right = cs.m_left;
  cs.m_rightMax = cs.m_leftMax;
  cs.m_idxRightShoulder = cs.m_idxLeftShoulder;
  io.m_cs.push_back(cs);
  io.m_cs.push_back(cs);
  // create a Raster to stamp to
  const int numPixelsX = 41, numPixelsY = 11;
  const double pixelSize = 1.0;
  const xms::Pt3d minPt(-20.0, 0.0);
  const std::vector<double> rasterVals(numPixelsX * numPixelsY, 5);
  xms::XmStampRaster raster(numPixelsX, numPixelsY, pixelSize, pixelSize, minPt, rasterVals, XM_NODATA);
  // set the raster member of the raster class.  The values are interpolated from io.m_outTin in
  // the XmStamper::DoStamp function.
  io.m_raster = raster;
  // create a XmStamper class. This class performs the stamp operation.
  BSHP<xms::XmStamper> st = xms::XmStamper::New();
  st->DoStamp(io);
  std::string rasterFileName(XMS_TEST_PATH + std::string("stamping/rasterTestFiles/testFillEmbankment_out.asc"));
  std::string baseFile(XMS_TEST_PATH + std::string("stamping/rasterTestFiles/testFillEmbankment_base.asc"));
  io.m_raster.WriteGridFile(rasterFileName, xms::XmStampRaster::XmRasterFormatEnum::RS_ARCINFO_ASCII);
  TS_ASSERT_TXT_FILES_EQUAL(baseFile, rasterFileName);
  // verify the outputs
  TS_ASSERT(io.m_outTin); // the output TIN should exist
  xms::VecPt3d basePts = {{0, 0, 15},   {0, 10, 15}, {-5, 0, 15}, {-20, 0, 0}, {-5, 10, 15},
                          {-20, 10, 0}, {5, 0, 15},  {20, 0, 0},  {5, 10, 15}, {20, 10, 0}};
  TS_ASSERT_DELTA_VECPT3D(basePts, io.m_outTin->Points(), 1e-9);
  TS_ASSERT_EQUALS(7, io.m_outBreakLines.size());
  xms::VecInt baseLines = {0, 1}; // centerline
  TS_ASSERT_EQUALS_VEC(baseLines, io.m_outBreakLines[0]);
  baseLines = {3, 2, 0, 6, 7}; // first cross section
  TS_ASSERT_EQUALS_VEC(baseLines, io.m_outBreakLines[1]);
  baseLines = {5, 4, 1, 8, 9}; // second cross section
  TS_ASSERT_EQUALS_VEC(baseLines, io.m_outBreakLines[2]);
  baseLines = {3, 5}; // left toe
  TS_ASSERT_EQUALS_VEC(baseLines, io.m_outBreakLines[3]);
  baseLines = {7, 9}; // right toe
  TS_ASSERT_EQUALS_VEC(baseLines, io.m_outBreakLines[4]);
  baseLines = {2, 4}; // left shoulder
  TS_ASSERT_EQUALS_VEC(baseLines, io.m_outBreakLines[5]);
  baseLines = {6, 8}; // right shoulder
  TS_ASSERT_EQUALS_VEC(baseLines, io.m_outBreakLines[6]);
  // Write output TIN for viewing in XMS
  std::string tinFileName(XMS_TEST_PATH + std::string("stamping/rasterTestFiles/testFillEmbankmentTin_out.tin"));
  std::ofstream ofs(tinFileName, std::ofstream::trunc);
  io.m_outTin->ExportTinFile(ofs);
} // TutStampingUnitTests::test_StampFillEmbankment