shapefile_basemap.cpp

/******************************************************************************
 *
 * Project:  OpenCPN
 * Purpose:  Shapefile basemap
 *
 ***************************************************************************
 *   Copyright (C) 2012-2023 by David S. Register                          *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,  USA.         *
 ***************************************************************************
 *
 *
 */
 
// Include OCPNPlatform.h before shapefile_basemap.h to prevent obscure syntax
// error when compiling with VS2022
#include "OCPNPlatform.h"
#include "shapefile_basemap.h"
#include "chartbase.h"
#include "glChartCanvas.h"
 
#ifdef ocpnUSE_GL
#include "shaders.h"
#endif
 
#ifdef __WXMSW__
#define __CALL_CONVENTION  //__stdcall
#else
#define __CALL_CONVENTION
#endif
 
extern OCPNPlatform* g_Platform;
extern wxString gWorldShapefileLocation;
 
#ifdef ocpnUSE_GL
 
typedef union {
  GLdouble data[6];
  struct sGLvertex {
    GLdouble x;
    GLdouble y;
    GLdouble z;
    GLdouble r;
    GLdouble g;
    GLdouble b;
  } info;
} GLvertexshp;
#include <list>
 
static std::list<float_2Dpt> g_pvshp;
static std::list<GLvertexshp *> g_vertexesshp;
static int g_typeshp, g_posshp;
static float_2Dpt g_p1shp, g_p2shp;
 
void __CALL_CONVENTION shpscombineCallback(GLdouble coords[3],
                                           GLdouble *vertex_data[4],
                                           GLfloat weight[4],
                                           GLdouble **dataOut) {
  GLvertexshp *vertex;
 
  vertex = new GLvertexshp();
  g_vertexesshp.push_back(vertex);
 
  vertex->info.x = coords[0];
  vertex->info.y = coords[1];
 
  *dataOut = vertex->data;
}
 
void __CALL_CONVENTION shpserrorCallback(GLenum errorCode) {
  const GLubyte *estring;
  estring = gluErrorString(errorCode);
  // wxLogMessage( _T("OpenGL Tessellation Error: %s"), estring );
}
 
void __CALL_CONVENTION shpsbeginCallback(GLenum type) {
  switch (type) {
    case GL_TRIANGLES:
    case GL_TRIANGLE_STRIP:
    case GL_TRIANGLE_FAN:
      g_typeshp = type;
      break;
    default:
      printf("tess unhandled begin type: %d\n", type);
  }
 
  g_posshp = 0;
}
 
void __CALL_CONVENTION shpsendCallback() {}
 
void __CALL_CONVENTION shpsvertexCallback(GLvoid *arg) {
  GLvertexshp *vertex;
  vertex = (GLvertexshp *)arg;
  float_2Dpt p;
  p.y = vertex->info.x;
  p.x = vertex->info.y;
 
  // convert strips and fans into triangles
  if (g_typeshp != GL_TRIANGLES) {
    if (g_posshp > 2) {
      g_pvshp.push_back(g_p1shp);
      g_pvshp.push_back(g_p2shp);
    }
 
    if (g_typeshp == GL_TRIANGLE_STRIP)
      g_p1shp = g_p2shp;
    else if (g_posshp == 0)
      g_p1shp = p;
    g_p2shp = p;
  }
 
  g_pvshp.push_back(p);
  g_posshp++;
}
#endif
 
ShapeBaseChartSet::ShapeBaseChartSet() : _loaded(false) {
}
 
wxPoint2DDouble ShapeBaseChartSet::GetDoublePixFromLL(ViewPort &vp, double lat,
                                                      double lon) {
  wxPoint2DDouble p = vp.GetDoublePixFromLL(lat, lon);
  p.m_x -= vp.rv_rect.x, p.m_y -= vp.rv_rect.y;
  return p;
}
 
ShapeBaseChart &ShapeBaseChartSet::LowestQualityBaseMap() {
  if (_basemap_map.find(Quality::crude) != _basemap_map.end()) {
    return _basemap_map.at(Quality::crude);
  }
  if (_basemap_map.find(Quality::low) != _basemap_map.end()) {
    return _basemap_map.at(Quality::low);
  }
  if (_basemap_map.find(Quality::medium) != _basemap_map.end()) {
    return _basemap_map.at(Quality::medium);
  }
  if (_basemap_map.find(Quality::high) != _basemap_map.end()) {
    return _basemap_map.at(Quality::high);
  }
  return _basemap_map.at(Quality::full);
}
 
ShapeBaseChart &ShapeBaseChartSet::HighestQualityBaseMap() {
  if (_basemap_map.find(Quality::full) != _basemap_map.end()) {
    return _basemap_map.at(Quality::full);
  }
  if (_basemap_map.find(Quality::high) != _basemap_map.end()) {
    return _basemap_map.at(Quality::high);
  }
  if (_basemap_map.find(Quality::medium) != _basemap_map.end()) {
    return _basemap_map.at(Quality::medium);
  }
  if (_basemap_map.find(Quality::low) != _basemap_map.end()) {
    return _basemap_map.at(Quality::low);
  }
  return _basemap_map.at(Quality::crude);
}
 
ShapeBaseChart &ShapeBaseChartSet::SelectBaseMap(const size_t &scale) {
 
  if (_basemap_map.find(Quality::full) != _basemap_map.end() &&
      _basemap_map.at(Quality::full).IsUsable() &&
      scale <= _basemap_map.at(Quality::full).MinScale()) {
    return _basemap_map.at(Quality::full);
  } else if (_basemap_map.find(Quality::high) != _basemap_map.end() &&
             _basemap_map.at(Quality::high).IsUsable() &&
             scale <= _basemap_map.at(Quality::high).MinScale()) {
    return _basemap_map.at(Quality::high);
  } else if (_basemap_map.find(Quality::medium) != _basemap_map.end() &&
             _basemap_map.at(Quality::medium).IsUsable() &&
             scale <= _basemap_map.at(Quality::medium).MinScale()) {
    return _basemap_map.at(Quality::medium);
  } else if (_basemap_map.find(Quality::low) != _basemap_map.end() &&
             _basemap_map.at(Quality::low).IsUsable() &&
             scale <= _basemap_map.at(Quality::low).MinScale()) {
    return _basemap_map.at(Quality::low);
  }
  return LowestQualityBaseMap();
}
 
void ShapeBaseChartSet::Reset() {
  //      Establish the Shapefile basemap location
  wxString basemap_dir;
  if (gWorldShapefileLocation.empty()) {
    basemap_dir = g_Platform->GetSharedDataDir();
    basemap_dir.Append("basemap_shp");
  } else {
    basemap_dir = gWorldShapefileLocation;
  }
 
  LoadBasemaps(basemap_dir.ToStdString());
}
void ShapeBaseChartSet::LoadBasemaps(const std::string &dir) {
  _loaded = false;
  _basemap_map.clear();
 
  wxColor land_color = wxColor(170, 175, 80);
 
  if (fs::exists(ShapeBaseChart::ConstructPath(dir, "crude_10x10"))) {
    auto c = ShapeBaseChart(ShapeBaseChart::ConstructPath(dir, "crude_10x10"), 300000000,
                            land_color);
    c._dmod= 10;
    _basemap_map.insert(std::make_pair(Quality::crude, c));
  }
 
  if (fs::exists(ShapeBaseChart::ConstructPath(dir, "low"))) {
    _basemap_map.insert(std::make_pair(
        Quality::low, ShapeBaseChart(ShapeBaseChart::ConstructPath(dir, "low"),
                                     15000000, land_color)));
  }
  if (fs::exists(ShapeBaseChart::ConstructPath(dir, "medium"))) {
    _basemap_map.insert(std::make_pair(
        Quality::medium,
        ShapeBaseChart(ShapeBaseChart::ConstructPath(dir, "medium"), 1000000,
                       land_color)));
  }
  if (fs::exists(ShapeBaseChart::ConstructPath(dir, "high"))) {
    _basemap_map.insert(std::make_pair(
        Quality::high,
        ShapeBaseChart(ShapeBaseChart::ConstructPath(dir, "high"), 300000,
                       land_color)));
  }
  if (fs::exists(ShapeBaseChart::ConstructPath(dir, "full"))) {
    _basemap_map.insert(std::make_pair(
        Quality::full,
        ShapeBaseChart(ShapeBaseChart::ConstructPath(dir, "full"), 50000,
                       land_color)));
  }
  _loaded = true;
  //if(_basemap_map.size())
    //LowestQualityBaseMap().LoadSHP();
}
 
bool ShapeBaseChart::LoadSHP() {
  _reader = new shp::ShapefileReader(_filename);
  auto bounds = _reader->getBounds();
  _is_usable = _reader->getCount() > 1 && bounds.getMaxX() <= 180 &&
               bounds.getMinX() >= -180 && bounds.getMinY() >= -90 &&
               bounds.getMaxY() <=
                   90;  // TODO - Do we care whether the planet is covered?
  _is_usable &= _reader->getGeometryType() == shp::GeometryType::Polygon;
  bool has_x = false;
  bool has_y = false;
  for (auto field : _reader->getFields()) {
    if (field.getName() == "x") {
      has_x = true;
    } else if (field.getName() == "y") {
      has_y = true;
    }
  }
  _is_tiled = (has_x && has_y);
  if (_is_usable && _is_tiled) {
    size_t feat{0};
    for (auto const &feature : *_reader) {
      auto f1 = feature.getAttributes();
      _tiles[LatLonKey(std::any_cast<int>(feature.getAttributes()["y"]),
                       std::any_cast<int>(feature.getAttributes()["x"]))]
          .push_back(feat);
      feat++;
    }
  }
  return _is_usable;
}
 
void ShapeBaseChart::DoDrawPolygonFilled(ocpnDC &pnt, ViewPort &vp,
                                         const shp::Feature &feature) {
  double old_x = -9999999.0, old_y = -9999999.0;
  auto polygon = static_cast<shp::Polygon *>(feature.getGeometry());
  pnt.SetBrush(_color);
  for (auto &ring : polygon->getRings()) {
    wxPoint *poly_pt = new wxPoint[ring.getPoints().size()];
    size_t cnt{0};
    auto bbox = vp.GetBBox();
    for (auto &point : ring.getPoints()) {
      // if (bbox.ContainsMarge(point.getY(), point.getX(), 0.05)) {
      wxPoint2DDouble q =
          ShapeBaseChartSet::GetDoublePixFromLL(vp, point.getY(), point.getX());
      if (round(q.m_x) != round(old_x) || round(q.m_y) != round(old_y)) {
        poly_pt[cnt].x = round(q.m_x);
        poly_pt[cnt].y = round(q.m_y);
        cnt++;
      }
      old_x = q.m_x;
      old_y = q.m_y;
      //}
    }
    if (cnt > 1) {
      pnt.DrawPolygonTessellated(cnt, poly_pt, 0, 0);
    }
    delete[] poly_pt;
  }
}
 
void ShapeBaseChart::AddPointToTessList(shp::Point &point, ViewPort &vp,
                                        GLUtesselator *tobj, bool idl) {
#ifdef ocpnUSE_GL
 
  wxPoint2DDouble q;
  if (glChartCanvas::HasNormalizedViewPort(vp)) {
    q = ShapeBaseChartSet::GetDoublePixFromLL(vp, point.getY(), point.getX());
  } else {  // tesselation directly from lat/lon
    q.m_x = point.getY(), q.m_y = point.getX();
  }
  GLvertexshp *vertex = new GLvertexshp();
  g_vertexesshp.push_back(vertex);
  if (vp.m_projection_type != PROJECTION_POLAR) {
    // need to correctly pick +180 or -180 longitude for projections
    // that have a discontiguous date line
 
    if (idl && (point.getX() == 180)) {
      if (vp.m_projection_type == PROJECTION_MERCATOR ||
          vp.m_projection_type == PROJECTION_EQUIRECTANGULAR) {
        // q.m_x -= 40058986 * 4096.0;  // 360 degrees in normalized
        // viewport
      } else {
        q.m_x -= 360;  // lat/lon coordinates
      }
    }
  }
  vertex->info.x = q.m_x;
  vertex->info.y = q.m_y;
 
  gluTessVertex(tobj, (GLdouble *)vertex, (GLdouble *)vertex);
#endif
}
 
void ShapeBaseChart::DoDrawPolygonFilledGL(ocpnDC &pnt, ViewPort &vp,
                                           const shp::Feature &feature) {
#ifdef ocpnUSE_GL
 
  bool idl =
      vp.GetBBox().GetMinLon() <= -180 || vp.GetBBox().GetMaxLon() >= 180;
  auto polygon = static_cast<shp::Polygon *>(feature.getGeometry());
  for (auto &ring : polygon->getRings()) {
    size_t cnt{0};
    GLUtesselator *tobj = gluNewTess();
 
    gluTessCallback(tobj, GLU_TESS_VERTEX, (_GLUfuncptr)&shpsvertexCallback);
    gluTessCallback(tobj, GLU_TESS_BEGIN, (_GLUfuncptr)&shpsbeginCallback);
    gluTessCallback(tobj, GLU_TESS_END, (_GLUfuncptr)&shpsendCallback);
    gluTessCallback(tobj, GLU_TESS_COMBINE, (_GLUfuncptr)&shpscombineCallback);
    gluTessCallback(tobj, GLU_TESS_ERROR, (_GLUfuncptr)&shpserrorCallback);
 
    gluTessNormal(tobj, 0, 0, 1);
    gluTessProperty(tobj, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_NONZERO);
 
    gluTessBeginPolygon(tobj, NULL);
    gluTessBeginContour(tobj);
    for (auto &point : ring.getPoints()) {
      AddPointToTessList(point, vp, tobj, idl);
      cnt++;
    }
    gluTessEndContour(tobj);
    gluTessEndPolygon(tobj);
    gluDeleteTess(tobj);
 
    for (auto ver : g_vertexesshp) delete ver;
    g_vertexesshp.clear();
  }
  float_2Dpt *polyv = new float_2Dpt[g_pvshp.size()];
  int cnt = 0;
  for (auto pt : g_pvshp) {
    polyv[cnt++] = pt;
  }
  size_t polycnt = g_pvshp.size();
  g_pvshp.clear();
 
  GLuint vbo = 0;
 
  //  Build the shader viewport transform matrix
  mat4x4 m, mvp;
  mat4x4_identity(m);
  mat4x4_scale_aniso(mvp, m, 2.0 / (float)vp.pix_width,
                     2.0 / (float)vp.pix_height, 1.0);
  mat4x4_translate_in_place(mvp, -vp.pix_width / 2, vp.pix_height / 2, 0);
 
  float *pvt = new float[2 * (polycnt)];
  for (size_t i = 0; i < polycnt; i++) {
    float_2Dpt *pc = polyv + i;
    // wxPoint2DDouble q(pc->y, pc->x);// = vp.GetDoublePixFromLL(pc->y, pc->x);
    wxPoint2DDouble q = vp.GetDoublePixFromLL(pc->y, pc->x);
 
    pvt[i * 2] = q.m_x;
    pvt[(i * 2) + 1] = q.m_y;
  }
 
  GLShaderProgram *shader = pcolor_tri_shader_program[pnt.m_canvasIndex];
  shader->Bind();
 
  float colorv[4];
  colorv[0] = _color.Red() / float(256);
  colorv[1] = _color.Green() / float(256);
  colorv[2] = _color.Blue() / float(256);
  colorv[3] = 1.0;
  shader->SetUniform4fv("color", colorv);
 
  shader->SetAttributePointerf("position", pvt);
 
  glDrawArrays(GL_TRIANGLES, 0, polycnt);
 
  delete[] pvt;
  delete[] polyv;
 
  glDeleteBuffers(1, &vbo);
  shader->UnBind();
#endif
}
 
void ShapeBaseChart::DrawPolygonFilled(ocpnDC &pnt, ViewPort &vp) {
  if (!_is_usable) {
    return;
  }
  if (!_reader) {
    _loading = true;
    _loaded = std::async(std::launch::async, [&]() {
      bool ret = LoadSHP();
      _loading = false;
      return ret;
    });
  }
  if (_loading) {
    if (_loaded.wait_for(std::chrono::milliseconds(0)) ==
        std::future_status::ready) {
      _is_usable = _loaded.get();
    } else {
      return;  // not yet loaded
    }
  }
 
  int pmod = _dmod;
  LLBBox bbox = vp.GetBBox();
 
  int lat_start = floor(bbox.GetMinLat());
  if (lat_start < 0)
    lat_start = lat_start - (pmod + (lat_start % pmod));
  else
    lat_start = lat_start - (lat_start % pmod);
 
  int lon_start = floor(bbox.GetMinLon());
  if (lon_start < 0)
    lon_start = lon_start - (pmod + (lon_start % pmod));
  else
    lon_start = lon_start - (lon_start % pmod);
 
 
  if (_is_tiled) {
    for (int i = lat_start; i < ceil(bbox.GetMaxLat()) + pmod; i+=pmod) {
      for (int j = lon_start; j < ceil(bbox.GetMaxLon()) + pmod; j+=pmod) {
        int lon{j};
        if (j < -180) {
          lon = j + 360;
        } else if (j >= 180) {
          lon = j - 360;
        }
        for (auto fid : _tiles[LatLonKey(i, lon)]) {
          auto const &feature = _reader->getFeature(fid);
          if (pnt.GetDC()) {
            DoDrawPolygonFilled(pnt, vp,
                                feature);  // Parallelize using std::async?
          } else {
            DoDrawPolygonFilledGL(pnt, vp,
                                  feature);  // Parallelize using std::async?
          }
        }
      }
    }
  } else {
    for (auto const &feature : *_reader) {
      if (pnt.GetDC()) {
        DoDrawPolygonFilled(pnt, vp,
                            feature);  // Parallelize using std::async?
      } else {
        DoDrawPolygonFilledGL(pnt, vp,
                              feature);  // Parallelize using std::async?
      }
    }
  }
}
 
bool ShapeBaseChart::CrossesLand(double &lat1, double &lon1, double &lat2,
                                 double &lon2) {
  double latmin = std::min(lat1, lat2);
  double lonmin = std::min(lon1, lon2);
  double latmax = std::min(lat1, lat2);
  double lonmax = std::min(lon1, lon2);
 
  auto A = std::make_pair(lat1, lon1);
  auto B = std::make_pair(lat2, lon2);
 
  if (_is_tiled) {
    for (int i = floor(latmin); i < ceil(latmax); i++) {
      for (int j = floor(lonmin); j < ceil(lonmax); j++) {
        int lon{j};
        if (j < -180) {
          lon = j + 360;
        } else if (j >= 180) {
          lon = j - 360;
        }
        for (auto fid : _tiles[LatLonKey(i, lon)]) {
          auto const &feature = _reader->getFeature(fid);
          if (PolygonLineIntersect(feature, A, B)) {
            return true;
          }
        }
      }
    }
  } else {
    for (auto const &feature : *_reader) {
      if (PolygonLineIntersect(feature, A, B)) {
        return true;
      }
    }
  }
 
  return false;
}
 
bool ShapeBaseChart::LineLineIntersect(const std::pair<double, double> &A,
                                       const std::pair<double, double> &B,
                                       const std::pair<double, double> &C,
                                       const std::pair<double, double> &D) {
  // Line AB represented as a1x + b1y = c1
  double a1 = B.second - A.second;
  double b1 = A.first - B.first;
  double c1 = a1 * (A.first) + b1 * (A.second);
 
  // Line CD represented as a2x + b2y = c2
  double a2 = D.second - C.second;
  double b2 = C.first - D.first;
  double c2 = a2 * (C.first) + b2 * (C.second);
 
  double determinant = a1 * b2 - a2 * b1;
 
  if (determinant == 0) {
    // The lines are parallel
    return false;
  } else {
    // The lines intersect at x,y
    double x = (b2 * c1 - b1 * c2) / determinant;
    double y = (a1 * c2 - a2 * c1) / determinant;
    // x,y must be on both the segments we are checking
    if (std::min(A.first, B.first) <= x && x <= std::max(A.first, B.first) &&
        std::min(A.second, B.second) <= y &&
        y <= std::max(A.second, B.second) && std::min(C.first, D.first) <= x &&
        x <= std::max(C.first, D.first) && std::min(C.second, D.second) <= y &&
        y <= std::max(C.second, D.second)) {
      return true;
    }
  }
  return false;
}
 
bool ShapeBaseChart::PolygonLineIntersect(const shp::Feature &feature,
                                          const std::pair<double, double> &A,
                                          const std::pair<double, double> &B) {
  auto polygon = static_cast<shp::Polygon *>(feature.getGeometry());
  std::pair<double, double> previous_point;
  for (auto &ring : polygon->getRings()) {
    size_t cnt{0};
    for (auto &point : ring.getPoints()) {
      auto pnt = std::make_pair(point.getY(), point.getX());
      if (cnt > 0) {
        // TODO: Is it faster to first check if we are in the boundong box of
        // the line?
        if (LineLineIntersect(A, B, previous_point, pnt)) {
          return true;
        }
      }
      previous_point = pnt;
      cnt++;
    }
  }
  return false;
}
 
void ShapeBaseChartSet::RenderViewOnDC(ocpnDC &dc, ViewPort &vp) {
  if (IsUsable()) {
    SelectBaseMap(vp.chart_scale).RenderViewOnDC(dc, vp);
  }
}