ViewFrustum.cpp

#include "MantidVatesAPI/ViewFrustum.h"
#include "MantidKernel/Matrix.h"
#include <sstream>
#include <cmath>
#include <cfloat>

namespace Mantid {
namespace VATES {
/**
 * Represents a view frustum. It contains the parameters for the six plane
 * equations that define the view frustum. Note that the plane
 * normals point into the box
 * @param leftPlane The left plane.
 * @param rightPlane The right plane.
 * @param topPlane The top plane.
 * @param bottomPlane The bottom plane.
 * @param farPlane The far plane.
 * @param nearPlane The near plane.
 */
ViewFrustum::ViewFrustum(const LeftPlane &leftPlane,
                         const RightPlane &rightPlane,
                         const BottomPlane &bottomPlane,
                         const TopPlane &topPlane, const FarPlane &farPlane,
                         const NearPlane &nearPlane)
    : m_leftPlane(leftPlane), m_rightPlane(rightPlane), m_topPlane(topPlane),
      m_bottomPlane(bottomPlane), m_farPlane(farPlane), m_nearPlane(nearPlane) {
}
/**
 * Copy constructor for the view frustum.
 * @param other The initializing view frustum.
 */
ViewFrustum::ViewFrustum(const ViewFrustum &other)
    : m_leftPlane(other.m_leftPlane), m_rightPlane(other.m_rightPlane),
      m_topPlane(other.m_topPlane), m_bottomPlane(other.m_bottomPlane),
      m_farPlane(other.m_farPlane), m_nearPlane(other.m_nearPlane) {}
/// Destructor
ViewFrustum::~ViewFrustum() {}

/**
 * Assignment operator
 * @param other The assigned view frustum.
 */
ViewFrustum &ViewFrustum::operator=(const ViewFrustum &other) {
  if (&other != this) {
    m_leftPlane = other.m_leftPlane;
    m_rightPlane = other.m_rightPlane;
    m_topPlane = other.m_topPlane;
    m_bottomPlane = other.m_bottomPlane;
    m_farPlane = other.m_farPlane;
    m_nearPlane = other.m_nearPlane;
  }

  return *this;
}

/**
 * Get the extents of the View frustum. We take the minimal rectangular box
 * which in contains the
 * view frustum fully.
 * @returns A vector with the extents
 */
std::vector<std::pair<double, double>> ViewFrustum::toExtents() const {
  // Get the eight corner points of the view frustum
  std::vector<std::vector<double>> frustumPoints;
  frustumPoints.push_back(
      getIntersectionPointThreePlanes<LEFTPLANE, TOPPLANE, FARPLANE, double>(
          m_leftPlane, m_topPlane, m_farPlane));
  frustumPoints.push_back(
      getIntersectionPointThreePlanes<LEFTPLANE, TOPPLANE, NEARPLANE, double>(
          m_leftPlane, m_topPlane, m_nearPlane));

  frustumPoints.push_back(
      getIntersectionPointThreePlanes<LEFTPLANE, BOTTOMPLANE, FARPLANE, double>(
          m_leftPlane, m_bottomPlane, m_farPlane));
  frustumPoints.push_back(
      getIntersectionPointThreePlanes<LEFTPLANE, BOTTOMPLANE, NEARPLANE,
                                      double>(m_leftPlane, m_bottomPlane,
                                              m_nearPlane));

  frustumPoints.push_back(
      getIntersectionPointThreePlanes<RIGHTPLANE, TOPPLANE, FARPLANE, double>(
          m_rightPlane, m_topPlane, m_farPlane));
  frustumPoints.push_back(
      getIntersectionPointThreePlanes<RIGHTPLANE, TOPPLANE, NEARPLANE, double>(
          m_rightPlane, m_topPlane, m_nearPlane));

  frustumPoints.push_back(
      getIntersectionPointThreePlanes<RIGHTPLANE, BOTTOMPLANE, FARPLANE,
                                      double>(m_rightPlane, m_bottomPlane,
                                              m_farPlane));
  frustumPoints.push_back(
      getIntersectionPointThreePlanes<RIGHTPLANE, BOTTOMPLANE, NEARPLANE,
                                      double>(m_rightPlane, m_bottomPlane,
                                              m_nearPlane));

  std::vector<std::pair<double, double>> extents;

  for (int i = 0; i < 3; ++i) {
    std::pair<double, double> minMax(DBL_MAX, -DBL_MAX);
    for (auto &points : frustumPoints) {
      minMax.first = std::min(minMax.first, points[i]);
      minMax.second = std::max(minMax.second, points[i]);
    }
    extents.push_back(minMax);
  }

  return extents;
}

/**
 * Get the extents as a concatenated string.
 * @returns The extens of the view frustum as a concatenated string
 */
std::string ViewFrustum::toExtentsAsString() const {
  std::vector<std::pair<double, double>> extents = toExtents();

  std::stringstream ss;
  for (const auto &extent : extents) {
    ss << extent.first << "," << extent.second << ",";
  }
  auto result = ss.str();

  // remove extra "," at the end of the string.
  result.pop_back();
  return result;
}
}
}