GribOverlayFactory.cpp

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/***************************************************************************
 *   Copyright (C) 2014 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 "wx/wxprec.h"
 
#ifndef WX_PRECOMP
#include "wx/wx.h"
#endif  // precompiled headers
 
#include "pi_gl.h"
 
#include <wx/glcanvas.h>
#include <wx/graphics.h>
#include <wx/progdlg.h>
#include "pi_ocpndc.h"
#include "pi_shaders.h"
 
#ifdef __ANDROID__
#include "qdebug.h"
#endif
 
#include "GribUIDialog.h"
#include "GribOverlayFactory.h"
 
extern int m_Altitude;
extern bool g_bpause;
extern double g_ContentScaleFactor;
float g_piGLMinSymbolLineWidth = 0.9;
 
enum GRIB_OVERLAP { _GIN, _GON, _GOUT };
 
// Calculates if two boxes intersect. If so, the function returns _ON.
// If they do not intersect, two scenario's are possible:
// other is outside this -> return _OUT
// other is inside this -> return _IN
static GRIB_OVERLAP Intersect(PlugIn_ViewPort *vp, double lat_min,
                              double lat_max, double lon_min, double lon_max,
                              double Marge) {
  if (((vp->lon_min - Marge) > (lon_max + Marge)) ||
      ((vp->lon_max + Marge) < (lon_min - Marge)) ||
      ((vp->lat_max + Marge) < (lat_min - Marge)) ||
      ((vp->lat_min - Marge) > (lat_max + Marge)))
    return _GOUT;
 
  // Check if other.bbox is inside this bbox
  if ((vp->lon_min <= lon_min) && (vp->lon_max >= lon_max) &&
      (vp->lat_max >= lat_max) && (vp->lat_min <= lat_min))
    return _GIN;
 
  // Boundingboxes intersect
  return _GON;
}
 
// Is the given point in the vp ??
static bool PointInLLBox(PlugIn_ViewPort *vp, double x, double y) {
  double m_miny = vp->lat_min;
  double m_maxy = vp->lat_max;
  if (y < m_miny || y > m_maxy) return FALSE;
 
  double m_minx = vp->lon_min;
  double m_maxx = vp->lon_max;
 
  if (x < m_maxx - 360.)
    x += 360;
  else if (x > m_minx + 360.)
    x -= 360;
 
  if (x < m_minx || x > m_maxx) return FALSE;
 
  return TRUE;
}
 
#if 0
static wxString MToString( int DataCenterModel )
{
    switch( DataCenterModel ) {
    case NOAA_GFS: return  _T("NOAA_GFS");
    case NOAA_NCEP_WW3: return  _T("NOAA_NCEP_WW3");
    case NOAA_NCEP_SST: return  _T("NOAA_NCEP_SST");
    case NOAA_RTOFS: return  _T("NOAA_RTOFS");
    case FNMOC_WW3_GLB: return  _T("FNMOC_WW3");
    case FNMOC_WW3_MED: return  _T("FNMOC_WW3");
    case NORWAY_METNO: return  _T("NORWAY_METNO");
    default : return  _T("OTHER_DATA_CENTER");
    }
}
#endif
 
#ifdef ocpnUSE_GL
static GLuint texture_format = 0;
#endif
 
#if 0
static GLboolean QueryExtension( const char *extName )
{
    /*
     ** Search for extName in the extensions string. Use of strstr()
     ** is not sufficient because extension names can be prefixes of
     ** other extension names. Could use strtok() but the constant
     ** string returned by glGetString might be in read-only memory.
     */
    char *p;
    char *end;
    int extNameLen;
 
    extNameLen = strlen( extName );
 
    p = (char *) glGetString( GL_EXTENSIONS );
    if( nullptr == p ) {
        return GL_FALSE;
    }
 
    end = p + strlen( p );
 
    while( p < end ) {
        int n = strcspn( p, " " );
        if( ( extNameLen == n ) && ( strncmp( extName, p, n ) == 0 ) ) {
            return GL_TRUE;
        }
        p += ( n + 1 );
    }
    return GL_FALSE;
}
 
#if defined(__WXMSW__)
#define systemGetProcAddress(ADDR) wglGetProcAddress(ADDR)
#elif defined(__WXOSX__)
#include <dlfcn.h>
#define systemGetProcAddress(ADDR) dlsym(RTLD_DEFAULT, ADDR)
#else
#define systemGetProcAddress(ADDR) glXGetProcAddress((const GLubyte *)ADDR)
#endif
 
#endif
 
void LineBuffer::pushLine(float x0, float y0, float x1, float y1) {
  buffer.push_back(x0);
  buffer.push_back(y0);
  buffer.push_back(x1);
  buffer.push_back(y1);
}
 
void LineBuffer::pushPetiteBarbule(int b, int l) {
  int tilt = (l * 100) / 250;
  pushLine(b, 0, b + tilt, -l);
}
 
void LineBuffer::pushGrandeBarbule(int b, int l) {
  int tilt = (l * 100) / 250;
  pushLine(b, 0, b + tilt, -l);
}
 
void LineBuffer::pushTriangle(int b, int l) {
  int dim = (l * 100) / 250;
  pushLine(b, 0, b + dim, -l);
  pushLine(b + (dim * 2), 0, b + dim, -l);
}
 
void LineBuffer::Finalize() {
  count = buffer.size() / 4;
  lines = new float[buffer.size()];
  int i = 0;
  for (std::list<float>::iterator it = buffer.begin(); it != buffer.end(); it++)
    lines[i++] = *it;
};
 
int adjustSpacing(int dialogSetSpacing) {
#ifdef __OCPN__ANDROID__
  // Treat the slider control as a percentage value.
  // Maximum space (100%) is established as one-half of the smaller of screen
  // dismensions x and y.
  wxSize sz = GetOCPNCanvasWindow()->GetClientSize();
  int sizeMin = wxMin(sz.x, sz.y);
  int space = ((double)dialogSetSpacing) * (sizeMin / 2) / 100;
  // qDebug() << "Space: " << dialogSetSpacing << sizeMin << space;
  return space;
 
#else
  return dialogSetSpacing;
#endif
}
 
//----------------------------------------------------------------------------------------------------------
//    Grib Overlay Factory Implementation
//----------------------------------------------------------------------------------------------------------
GRIBOverlayFactory::GRIBOverlayFactory(GRIBUICtrlBar &dlg)
    : m_dlg(dlg), m_Settings(dlg.m_OverlaySettings) {
  if (wxGetDisplaySize().x > 0) {
    // #ifdef __WXGTK__
    //         GdkScreen *screen = gdk_screen_get_default();
    //         m_pixelMM = (double)gdk_screen_get_monitor_width_mm(screen, 0) /
    //         wxGetDisplaySize().x;
    // #else
    m_pixelMM = (double)PlugInGetDisplaySizeMM() /
                wxMax(wxGetDisplaySize().x, wxGetDisplaySize().y);
    // #endif
    m_pixelMM = wxMax(.02, m_pixelMM);  // protect against bad data
  } else
    m_pixelMM = 0.27;  // semi-standard number...
 
  // qDebug() <<  "m_pixelMM: " << m_pixelMM;
 
  m_pGribTimelineRecordSet = nullptr;
  m_last_vp_scale = 0.;
 
  m_oDC = nullptr;
#if wxUSE_GRAPHICS_CONTEXT
  m_gdc = nullptr;
#endif
  m_Font_Message = nullptr;
 
  InitColorsTable();
  for (int i = 0; i < GribOverlaySettings::SETTINGS_COUNT; i++)
    m_pOverlay[i] = nullptr;
 
  m_ParticleMap = nullptr;
  m_tParticleTimer.Connect(
      wxEVT_TIMER, wxTimerEventHandler(GRIBOverlayFactory::OnParticleTimer),
      nullptr, this);
  m_bUpdateParticles = false;
 
  // Generate the wind arrow cache
 
  if (m_pixelMM < 0.2) {
    windArrowSize = 5.0 / m_pixelMM;  // Target scaled arrow size
    windArrowSize = wxMin(
        windArrowSize, wxMax(wxGetDisplaySize().x, wxGetDisplaySize().y) / 20);
  } else
    windArrowSize = 26;  // Standard value for desktop
 
  int r = 5, i = 0;  // wind is very light, draw a circle
  double s = 2 * M_PI / 10.;
  for (double a = 0; a < 2 * M_PI; a += s)
    m_WindArrowCache[0].pushLine(r * sin(a), r * cos(a), r * sin(a + s),
                                 r * cos(a + s));
 
  int dec = -windArrowSize / 2;
  int pointerLength = windArrowSize / 3;
 
  // the barbed arrows
  for (i = 1; i < 14; i++) {
    LineBuffer &arrow = m_WindArrowCache[i];
 
    arrow.pushLine(dec, 0, dec + windArrowSize, 0);                  // hampe
    arrow.pushLine(dec, 0, dec + pointerLength, pointerLength / 2);  // fleche
    arrow.pushLine(dec, 0, dec + pointerLength,
                   -(pointerLength / 2));  // fleche
  }
 
  int featherPosition = windArrowSize / 6;
 
  int b1 =
      dec + windArrowSize - featherPosition;  // position de la 1ere barbule
  int b2 = dec + windArrowSize;  // position de la 1ere barbule si >= 10 noeuds
 
  int lpetite = windArrowSize / 5;
  int lgrande = lpetite * 2;
 
  // 5 ktn
  m_WindArrowCache[1].pushPetiteBarbule(b1, lpetite);
  // 10 ktn
  m_WindArrowCache[2].pushGrandeBarbule(b2, lgrande);
  // 15 ktn
  m_WindArrowCache[3].pushGrandeBarbule(b2, lgrande);
  m_WindArrowCache[3].pushPetiteBarbule(b2 - featherPosition, lpetite);
  // 20 ktn
  m_WindArrowCache[4].pushGrandeBarbule(b2, lgrande);
  m_WindArrowCache[4].pushGrandeBarbule(b2 - featherPosition, lgrande);
  // 25 ktn
  m_WindArrowCache[5].pushGrandeBarbule(b2, lgrande);
  m_WindArrowCache[5].pushGrandeBarbule(b2 - featherPosition, lgrande);
  m_WindArrowCache[5].pushPetiteBarbule(b2 - featherPosition * 2, lpetite);
  // 30 ktn
  m_WindArrowCache[6].pushGrandeBarbule(b2, lgrande);
  m_WindArrowCache[6].pushGrandeBarbule(b2 - featherPosition, lgrande);
  m_WindArrowCache[6].pushGrandeBarbule(b2 - featherPosition * 2, lgrande);
  // 35 ktn
  m_WindArrowCache[7].pushGrandeBarbule(b2, lgrande);
  m_WindArrowCache[7].pushGrandeBarbule(b2 - featherPosition, lgrande);
  m_WindArrowCache[7].pushGrandeBarbule(b2 - featherPosition * 2, lgrande);
  m_WindArrowCache[7].pushPetiteBarbule(b2 - featherPosition * 3, lpetite);
  // 40 ktn
  m_WindArrowCache[8].pushGrandeBarbule(b2, lgrande);
  m_WindArrowCache[8].pushGrandeBarbule(b2 - featherPosition, lgrande);
  m_WindArrowCache[8].pushGrandeBarbule(b2 - featherPosition * 2, lgrande);
  m_WindArrowCache[8].pushGrandeBarbule(b2 - featherPosition * 3, lgrande);
  // 50 ktn
  m_WindArrowCache[9].pushTriangle(b1 - featherPosition, lgrande);
  // 60 ktn
  m_WindArrowCache[10].pushTriangle(b1 - featherPosition, lgrande);
  m_WindArrowCache[10].pushGrandeBarbule(b1 - featherPosition * 2, lgrande);
  // 70 ktn
  m_WindArrowCache[11].pushTriangle(b1 - featherPosition, lgrande);
  m_WindArrowCache[11].pushGrandeBarbule(b1 - featherPosition * 2, lgrande);
  m_WindArrowCache[11].pushGrandeBarbule(b1 - featherPosition * 3, lgrande);
  // 80 ktn
  m_WindArrowCache[12].pushTriangle(b1 - featherPosition, lgrande);
  m_WindArrowCache[12].pushGrandeBarbule(b1 - featherPosition * 2, lgrande);
  m_WindArrowCache[12].pushGrandeBarbule(b1 - featherPosition * 3, lgrande);
  m_WindArrowCache[12].pushGrandeBarbule(b1 - featherPosition * 4, lgrande);
  // > 90 ktn
  m_WindArrowCache[13].pushTriangle(b1 - featherPosition, lgrande);
  m_WindArrowCache[13].pushTriangle(b1 - featherPosition * 3, lgrande);
 
  for (i = 0; i < 14; i++) m_WindArrowCache[i].Finalize();
 
  // Generate Single and Double arrow caches
  for (int i = 0; i < 2; i++) {
    int arrowSize;
    int dec2 = 2;
    int dec1 = 5;
 
    if (i == 0) {
      if (m_pixelMM > 0.2) {
        arrowSize = 5.0 / m_pixelMM;  // Target scaled arrow size
        arrowSize = wxMin(
            arrowSize, wxMax(wxGetDisplaySize().x, wxGetDisplaySize().y) / 20);
        dec1 = arrowSize / 6;  // pointer length
        dec2 = arrowSize / 8;  // space between double lines
      } else
        arrowSize = 26;  // Standard value for desktop
    } else
      arrowSize = 16;
 
    dec = -arrowSize / 2;
 
    m_SingleArrow[i].pushLine(dec, 0, dec + arrowSize, 0);
    m_SingleArrow[i].pushLine(dec - 2, 0, dec + dec1, dec1 + 1);     // fleche
    m_SingleArrow[i].pushLine(dec - 2, 0, dec + dec1, -(dec1 + 1));  // fleche
    m_SingleArrow[i].Finalize();
 
    m_DoubleArrow[i].pushLine(dec, -dec2, dec + arrowSize, -dec2);
    m_DoubleArrow[i].pushLine(dec, dec2, dec + arrowSize, +dec2);
 
    m_DoubleArrow[i].pushLine(dec - 2, 0, dec + dec1, dec1 + 1);     // fleche
    m_DoubleArrow[i].pushLine(dec - 2, 0, dec + dec1, -(dec1 + 1));  // fleche
    m_DoubleArrow[i].Finalize();
  }
}
 
GRIBOverlayFactory::~GRIBOverlayFactory() {
  ClearCachedData();
 
  ClearParticles();
 
  if (m_oDC) delete m_oDC;
  if (m_Font_Message) delete m_Font_Message;
}
 
void GRIBOverlayFactory::Reset() {
  m_pGribTimelineRecordSet = nullptr;
 
  ClearCachedData();
}
 
void GRIBOverlayFactory::SetMessageFont() {
  wxFont fo;
#ifdef __WXQT__
  fo = GetOCPNGUIScaledFont_PlugIn(_("Dialog"));
#else
  fo = *OCPNGetFont(_("Dialog"), 0);
  fo.SetPointSize(
      (fo.GetPointSize() * g_ContentScaleFactor / OCPN_GetWinDIPScaleFactor()));
#endif
  if (m_Font_Message) delete m_Font_Message;
  m_Font_Message = new wxFont(fo);
}
 
void GRIBOverlayFactory::SetGribTimelineRecordSet(
    GribTimelineRecordSet *pGribTimelineRecordSet) {
  Reset();
  m_pGribTimelineRecordSet = pGribTimelineRecordSet;
}
 
void GRIBOverlayFactory::ClearCachedData(void) {
  //    Clear out the cached bitmaps
  for (int i = 0; i < GribOverlaySettings::SETTINGS_COUNT; i++) {
    delete m_pOverlay[i];
    m_pOverlay[i] = nullptr;
  }
}
 
#ifdef __OCPN__ANDROID__
#include "pi_shaders.h"
#endif
 
bool GRIBOverlayFactory::RenderGLGribOverlay(wxGLContext *pcontext,
                                             PlugIn_ViewPort *vp) {
  if (g_bpause) return false;
 
  // qDebug() << "RenderGLGribOverlay" << sw.GetTime();
 
  if (!m_oDC || !m_oDC->UsesGL()) {
    if (m_oDC) {
      delete m_oDC;
    }
#ifdef ocpnUSE_GL
    //  Set the minimum line width
    GLint parms[2];
#ifndef USE_ANDROID_GLES2
    glGetIntegerv(GL_SMOOTH_LINE_WIDTH_RANGE, &parms[0]);
#else
    glGetIntegerv(GL_ALIASED_LINE_WIDTH_RANGE, &parms[0]);
#endif
    g_piGLMinSymbolLineWidth = wxMax(parms[0], 1);
#endif
    m_oDC = new pi_ocpnDC();
  }
 
  m_oDC->SetVP(vp);
  m_oDC->SetDC(nullptr);
 
  m_pdc = nullptr;  // inform lower layers that this is OpenGL render
 
  bool rv = DoRenderGribOverlay(vp);
 
  // qDebug() << "RenderGLGribOverlayDone" << sw.GetTime();
 
  return rv;
}
 
bool GRIBOverlayFactory::RenderGribOverlay(wxDC &dc, PlugIn_ViewPort *vp) {
  if (!m_oDC || m_oDC->UsesGL()) {
    if (m_oDC) {
      delete m_oDC;
    }
    m_oDC = new pi_ocpnDC(dc);
  }
 
  m_oDC->SetVP(vp);
  m_oDC->SetDC(&dc);
 
  m_pdc = &dc;
#if 0
#if wxUSE_GRAPHICS_CONTEXT
    wxMemoryDC *pmdc;
    pmdc = dynamic_cast<wxMemoryDC*>(&dc);
    wxGraphicsContext *pgc = wxGraphicsContext::Create( *pmdc );
    m_gdc = pgc;
#endif
    m_pdc = &dc;
#endif
  bool rv = DoRenderGribOverlay(vp);
 
  return rv;
}
 
void GRIBOverlayFactory::SettingsIdToGribId(int i, int &idx, int &idy,
                                            bool &polar) {
  idx = idy = -1;
  polar = false;
  switch (i) {
    case GribOverlaySettings::WIND:
      idx = Idx_WIND_VX + m_Altitude, idy = Idx_WIND_VY + m_Altitude;
      break;
    case GribOverlaySettings::WIND_GUST:
      if (!m_Altitude) {
        idx = Idx_WIND_GUST;
      }
      break;
    case GribOverlaySettings::PRESSURE:
      if (!m_Altitude) {
        idx = Idx_PRESSURE;
      }
      break;
    case GribOverlaySettings::WAVE:
      if (!m_Altitude) {
        idx = Idx_HTSIGW, idy = Idx_WVDIR, polar = true;
      }
      break;
    case GribOverlaySettings::CURRENT:
      if (!m_Altitude) {
        idx = Idx_SEACURRENT_VX, idy = Idx_SEACURRENT_VY;
      }
      break;
    case GribOverlaySettings::PRECIPITATION:
      if (!m_Altitude) {
        idx = Idx_PRECIP_TOT;
      }
      break;
    case GribOverlaySettings::CLOUD:
      if (!m_Altitude) {
        idx = Idx_CLOUD_TOT;
      }
      break;
    case GribOverlaySettings::AIR_TEMPERATURE:
      if (!m_Altitude) {
        idx = Idx_AIR_TEMP;
      }
      break;
    case GribOverlaySettings::SEA_TEMPERATURE:
      if (!m_Altitude) {
        idx = Idx_SEA_TEMP;
      }
      break;
    case GribOverlaySettings::CAPE:
      if (!m_Altitude) {
        idx = Idx_CAPE;
      }
      break;
    case GribOverlaySettings::COMP_REFL:
      if (!m_Altitude) {
        idx = Idx_COMP_REFL;
      }
      break;
  }
}
 
bool GRIBOverlayFactory::DoRenderGribOverlay(PlugIn_ViewPort *vp) {
  if (!m_pGribTimelineRecordSet) {
    DrawMessageWindow((m_Message), vp->pix_width, vp->pix_height,
                      m_Font_Message);
    return false;
  }
 
  // setup numbers texture if needed
  if (!m_pdc) {
    m_TexFontNumbers.Build(*m_Font_Message);
 
    if (m_oDC) m_oDC->SetFont(*m_Font_Message);
  }
 
  m_Message_Hiden.Empty();
 
  //    If the scale has changed, clear out the cached bitmaps in DC mode
  if (m_pdc && vp->view_scale_ppm != m_last_vp_scale) ClearCachedData();
 
  m_last_vp_scale = vp->view_scale_ppm;
 
  //     render each type of record
  GribRecord **pGR = m_pGribTimelineRecordSet->m_GribRecordPtrArray;
  wxArrayPtrVoid **pIA = m_pGribTimelineRecordSet->m_IsobarArray;
 
  for (int overlay = 1; overlay >= 0; overlay--) {
    for (int i = 0; i < GribOverlaySettings::SETTINGS_COUNT; i++) {
      if (i == GribOverlaySettings::WIND) {
        if (overlay) { /* render overlays first */
          if (m_dlg.m_bDataPlot[i]) RenderGribOverlayMap(i, pGR, vp);
        } else {
          if (m_dlg.m_bDataPlot[i]) {
            RenderGribBarbedArrows(i, pGR, vp);
            RenderGribIsobar(i, pGR, pIA, vp);
            RenderGribNumbers(i, pGR, vp);
            RenderGribParticles(i, pGR, vp);
          } else {
            if (m_Settings.Settings[i].m_iBarbedVisibility)
              RenderGribBarbedArrows(i, pGR, vp);
          }
        }
        continue;
      }
      if (i == GribOverlaySettings::PRESSURE) {
        if (!overlay) { /*no overalay for pressure*/
          if (m_dlg.m_bDataPlot[i]) {
            RenderGribIsobar(i, pGR, pIA, vp);
            RenderGribNumbers(i, pGR, vp);
          } else {
            if (m_Settings.Settings[i].m_iIsoBarVisibility)
              RenderGribIsobar(i, pGR, pIA, vp);
          }
        }
        continue;
      }
      if (m_dlg.InDataPlot(i) && !m_dlg.m_bDataPlot[i]) continue;
 
      if (overlay) /* render overlays first */
        RenderGribOverlayMap(i, pGR, vp);
      else {
        RenderGribBarbedArrows(i, pGR, vp);
        RenderGribIsobar(i, pGR, pIA, vp);
        RenderGribDirectionArrows(i, pGR, vp);
        RenderGribNumbers(i, pGR, vp);
        RenderGribParticles(i, pGR, vp);
      }
    }
  }
  if (m_Altitude) {
    if (!m_Message_Hiden.IsEmpty()) m_Message_Hiden.Append(_T("\n"));
    m_Message_Hiden.Append(_("Warning : Data at Geopotential Height"))
        .Append(_T(" "))
        .Append(m_Settings.GetAltitudeFromIndex(
            m_Altitude,
            m_Settings.Settings[GribOverlaySettings::PRESSURE].m_Units))
        .Append(_T(" "))
        .Append(m_Settings.GetUnitSymbol(GribOverlaySettings::PRESSURE))
        .Append(_T(" ! "));
  }
  if (m_dlg.ProjectionEnabled()) {
    int x, y;
    m_dlg.GetProjectedLatLon(x, y);
    DrawProjectedPosition(x, y);
  }
  if (!m_Message_Hiden.IsEmpty()) m_Message_Hiden.Append(_T("\n"));
  m_Message_Hiden.Append(m_Message);
  DrawMessageWindow(m_Message_Hiden, vp->pix_width, vp->pix_height,
                    m_Font_Message);
 
  if (m_dlg.m_highlight_latmax - m_dlg.m_highlight_latmin > 0.01 &&
      m_dlg.m_highlight_lonmax - m_dlg.m_highlight_lonmin > 0.01) {
    wxPoint p1, p2;
    GetCanvasPixLL(vp, &p1, m_dlg.m_highlight_latmin, m_dlg.m_highlight_lonmin);
    GetCanvasPixLL(vp, &p2, m_dlg.m_highlight_latmax, m_dlg.m_highlight_lonmax);
    if (m_pdc) {
      m_pdc->SetPen(wxPen(wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHT)));
      m_pdc->SetBrush(
          wxBrush(wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHT),
                  wxBRUSHSTYLE_CROSSDIAG_HATCH));
      m_pdc->DrawRectangle(p1.x, p1.y, p2.x - p1.x, p2.y - p1.y);
    } else {
#ifdef ocpnUSE_GL
      // GL
      m_oDC->SetPen(wxPen(wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHT)));
      m_oDC->SetBrush(
          wxBrush(wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHT),
                  wxBRUSHSTYLE_CROSSDIAG_HATCH));
      m_oDC->DrawRectangle(p1.x, p1.y, p2.x - p1.x, p2.y - p1.y);
#endif
    }
  }
  return true;
}
 
// isClearSky checks that there is no rain or clouds at all.
static inline bool isClearSky(int settings, double v) {
  return ((settings == GribOverlaySettings::PRECIPITATION) ||
          (settings == GribOverlaySettings::CLOUD)) &&
         v < 0.01;
}
 
#ifdef ocpnUSE_GL
void GRIBOverlayFactory::GetCalibratedGraphicColor(int settings, double val_in,
                                                   unsigned char *data) {
  unsigned char r, g, b, a;
  a = m_Settings.m_iOverlayTransparency;
 
  if (val_in != GRIB_NOTDEF) {
    val_in = m_Settings.CalibrateValue(settings, val_in);
    // set full transparency if no rain or no clouds at all
    // TODO: make map support this
    if ((settings == GribOverlaySettings::PRECIPITATION ||
         settings == GribOverlaySettings::CLOUD) &&
        val_in < 0.01)
      a = 0;
    if ((settings == GribOverlaySettings::COMP_REFL) && val_in < 5) a = 0;
 
    GetGraphicColor(settings, val_in, r, g, b);
  } else
    r = 255, g = 255, b = 255, a = 0;
 
  data[0] = r;
  data[1] = g;
  data[2] = b;
  data[3] = a;
}
 
bool GRIBOverlayFactory::CreateGribGLTexture(GribOverlay *pGO, int settings,
                                             GribRecord *pGR) {
  bool repeat =
      pGR->getLonMin() == 0 && pGR->getLonMax() + pGR->getDi() >= 360.;
 
  // create the texture to the size of the grib data plus a transparent border
  int tw, th, samples = 1;
  double delta = 0;
  ;
  if (pGR->getNi() > 1024 || pGR->getNj() > 1024) {
    // downsample
    samples = 0;
    tw = pGR->getNi();
    th = pGR->getNj();
    double dw, dh;
    dw = (tw > 1022) ? 1022. / tw : 1.;
    dh = (th > 1022) ? 1022. / th : 1.;
    delta = wxMin(dw, dh);
    th *= delta;
    tw *= delta;
    tw += 2 * !repeat;
    th += 2;
  } else
    for (;;) {
      // oversample up to 16x
      tw = samples * (pGR->getNi() - 1) + 1 + 2 * !repeat;
      th = samples * (pGR->getNj() - 1) + 1 + 2;
      if (tw >= 512 || th >= 512 || samples == 16) break;
      samples *= 2;
    }
 
  //    Dont try to create enormous GRIB textures
  if (tw > 1024 || th > 1024) return false;
 
  pGO->m_iTexDataDim[0] = tw;
  pGO->m_iTexDataDim[1] = th;
 
#ifdef USE_ANDROID_GLES2
  int width_pot = tw;
  int height_pot = th;
 
  // If required by platform, grow the texture to next larger NPOT size.
  //  Retain actual data size in class storage, for later render scaling
  // if( b_pot )
  {
    int xp = tw;
    if (((xp != 0) && !(xp & (xp - 1))))  // detect already exact POT
      width_pot = xp;
    else {
      int a = 0;
      while (xp) {
        xp = xp >> 1;
        a++;
      }
      width_pot = 1 << a;
    }
 
    xp = th;
    if (((xp != 0) && !(xp & (xp - 1))))
      height_pot = xp;
    else {
      int a = 0;
      while (xp) {
        xp = xp >> 1;
        a++;
      }
      height_pot = 1 << a;
    }
  }
 
  tw = width_pot;
  th = height_pot;
#endif
 
  unsigned char *data = new unsigned char[tw * th * 4];
  if (samples == 0) {
    for (int j = 0; j < pGR->getNj(); j++) {
      for (int i = 0; i < pGR->getNi(); i++) {
        double v = pGR->getValue(i, j);
        int y = (j + 1) * delta;
        int x = (i + !repeat) * delta;
        int doff = 4 * (y * tw + x);
        GetCalibratedGraphicColor(settings, v, data + doff);
      }
    }
  } else if (samples == 1) {  // optimized case when there is only 1 sample
    for (int j = 0; j < pGR->getNj(); j++) {
      for (int i = 0; i < pGR->getNi(); i++) {
        double v = pGR->getValue(i, j);
        int y = j + 1;
        int x = i + !repeat;
        int doff = 4 * (y * tw + x);
        GetCalibratedGraphicColor(settings, v, data + doff);
      }
    }
  } else {
    for (int j = 0; j < pGR->getNj(); j++) {
      for (int i = 0; i < pGR->getNi(); i++) {
        double v00 = pGR->getValue(i, j), v01 = GRIB_NOTDEF;
        double v10 = GRIB_NOTDEF, v11 = GRIB_NOTDEF;
        if (i < pGR->getNi() - 1) {
          v01 = pGR->getValue(i + 1, j);
          if (j < pGR->getNj() - 1) v11 = pGR->getValue(i + 1, j + 1);
        }
        if (j < pGR->getNj() - 1) v10 = pGR->getValue(i, j + 1);
 
        for (int ys = 0; ys < samples; ys++) {
          int y = j * samples + ys + 1;
          double yd = (double)ys / samples;
          double v0, v1;
          double a0 = 1, a1 = 1;
          if (v10 == GRIB_NOTDEF) {
            v0 = v00;
            if (v00 == GRIB_NOTDEF)
              a0 = 0;
            else
              a0 = 1 - yd;
          } else if (v00 == GRIB_NOTDEF)
            v0 = v10, a0 = yd;
          else
            v0 = (1 - yd) * v00 + yd * v10;
          if (v11 == GRIB_NOTDEF) {
            v1 = v01;
            if (v01 == GRIB_NOTDEF)
              a1 = 0;
            else
              a1 = 1 - yd;
          } else if (v01 == GRIB_NOTDEF)
            v1 = v11, a1 = yd;
          else
            v1 = (1 - yd) * v01 + yd * v11;
 
          for (int xs = 0; xs < samples; xs++) {
            int x = i * samples + xs + !repeat;
            double xd = (double)xs / samples;
            double v, a;
            if (v1 == GRIB_NOTDEF)
              v = v0, a = (1 - xd) * a0;
            else if (v0 == GRIB_NOTDEF)
              v = v1, a = xd * a1;
            else {
              v = (1 - xd) * v0 + xd * v1;
              a = (1 - xd) * a0 + xd * a1;
            }
 
            int doff = 4 * (y * tw + x);
            GetCalibratedGraphicColor(settings, v, data + doff);
            data[doff + 3] *= a;
 
            if (i == pGR->getNi() - 1) break;
          }
          if (j == pGR->getNj() - 1) break;
        }
      }
    }
  }
 
  /* complete borders */
  memcpy(data, data + 4 * tw * 1, 4 * tw);
  memcpy(data + 4 * tw * (th - 1), data + 4 * tw * (th - 2), 4 * tw);
  for (int x = 0; x < tw; x++) {
    int doff = 4 * x;
    data[doff + 3] = 0;
    doff = 4 * ((th - 1) * tw + x);
    data[doff + 3] = 0;
  }
 
  if (!repeat)
    for (int y = 0; y < th; y++) {
      int doff = 4 * y * tw, soff = doff + 4;
      memcpy(data + doff, data + soff, 4);
      data[doff + 3] = 0;
      doff = 4 * (y * tw + tw - 1), soff = doff - 4;
      memcpy(data + doff, data + soff, 4);
      data[doff + 3] = 0;
    }
 
  GLuint texture;
  glGenTextures(1, &texture);
  glBindTexture(texture_format, texture);
 
  glTexParameteri(texture_format, GL_TEXTURE_WRAP_S,
                  repeat ? GL_REPEAT : GL_CLAMP_TO_EDGE);
  glTexParameteri(texture_format, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
  glTexParameteri(texture_format, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  glTexParameteri(texture_format, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 
#if 0  // ndef USE_ANDROID_GLES2
  glPushClientAttrib(GL_CLIENT_PIXEL_STORE_BIT);
 
  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
  glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
  glPixelStorei(GL_UNPACK_ROW_LENGTH, tw);
 
  glTexImage2D(texture_format, 0, GL_RGBA, tw, th, 0, GL_RGBA, GL_UNSIGNED_BYTE,
               data);
 
  glPopClientAttrib();
#else
  glTexImage2D(texture_format, 0, GL_RGBA, tw, th, 0, GL_RGBA, GL_UNSIGNED_BYTE,
               data);
#endif
 
  delete[] data;
 
  pGO->m_iTexture = texture;
  pGO->m_iTextureDim[0] = tw;
  pGO->m_iTextureDim[1] = th;
 
  return true;
}
#endif
 
wxImage GRIBOverlayFactory::CreateGribImage(int settings, GribRecord *pGR,
                                            PlugIn_ViewPort *vp,
                                            int grib_pixel_size,
                                            const wxPoint &porg) {
  wxPoint pmin;
  GetCanvasPixLL(vp, &pmin, pGR->getLatMin(), pGR->getLonMin());
  wxPoint pmax;
  GetCanvasPixLL(vp, &pmax, pGR->getLatMax(), pGR->getLonMax());
 
  int width = abs(pmax.x - pmin.x);
  int height = abs(pmax.y - pmin.y);
 
  //    Dont try to create enormous GRIB bitmaps ( no more than the screen size
  //    )
  if (width > m_ParentSize.GetWidth() || height > m_ParentSize.GetHeight())
    return wxNullImage;
 
  //    This could take a while....
  wxImage gr_image(width, height);
  gr_image.InitAlpha();
 
  wxPoint p;
  for (int ipix = 0; ipix < (width - grib_pixel_size + 1);
       ipix += grib_pixel_size) {
    for (int jpix = 0; jpix < (height - grib_pixel_size + 1);
         jpix += grib_pixel_size) {
      double lat, lon;
      p.x = ipix + porg.x;
      p.y = jpix + porg.y;
      GetCanvasLLPix(vp, p, &lat, &lon);
 
      double v = pGR->getInterpolatedValue(lon, lat);
      if (v != GRIB_NOTDEF) {
        v = m_Settings.CalibrateValue(settings, v);
        wxColour c = GetGraphicColor(settings, v);
 
        // set full transparency if no rain or no clouds at all
        unsigned char a =
            isClearSky(settings, v) ? 0 : m_Settings.m_iOverlayTransparency;
 
        unsigned char r = c.Red();
        unsigned char g = c.Green();
        unsigned char b = c.Blue();
 
        for (int xp = 0; xp < grib_pixel_size; xp++)
          for (int yp = 0; yp < grib_pixel_size; yp++) {
            gr_image.SetRGB(ipix + xp, jpix + yp, r, g, b);
            gr_image.SetAlpha(ipix + xp, jpix + yp, a);
          }
      } else {
        for (int xp = 0; xp < grib_pixel_size; xp++)
          for (int yp = 0; yp < grib_pixel_size; yp++)
            gr_image.SetAlpha(ipix + xp, jpix + yp, 0);
      }
    }
  }
 
  return gr_image.Blur(4);
}
 
struct ColorMap {
  double val;
  wxString text;
  unsigned char r;
  unsigned char g;
  unsigned char b;
};
 
static ColorMap CurrentMap[] = {
    {0, _T("#d90000")},  {1, _T("#d92a00")},  {2, _T("#d96e00")},
    {3, _T("#d9b200")},  {4, _T("#d4d404")},  {5, _T("#a6d906")},
    {7, _T("#06d9a0")},  {9, _T("#00d9b0")},  {12, _T("#00d9c0")},
    {15, _T("#00aed0")}, {18, _T("#0083e0")}, {21, _T("#0057e0")},
    {24, _T("#0000f0")}, {27, _T("#0400f0")}, {30, _T("#1c00f0")},
    {36, _T("#4800f0")}, {42, _T("#6900f0")}, {48, _T("#a000f0")},
    {56, _T("#f000f0")}};
 
static ColorMap GenericMap[] = {
    {0, _T("#00d900")},  {1, _T("#2ad900")},  {2, _T("#6ed900")},
    {3, _T("#b2d900")},  {4, _T("#d4d400")},  {5, _T("#d9a600")},
    {7, _T("#d90000")},  {9, _T("#d90040")},  {12, _T("#d90060")},
    {15, _T("#ae0080")}, {18, _T("#8300a0")}, {21, _T("#5700c0")},
    {24, _T("#0000d0")}, {27, _T("#0400e0")}, {30, _T("#0800e0")},
    {36, _T("#a000e0")}, {42, _T("#c004c0")}, {48, _T("#c008a0")},
    {56, _T("#c0a008")}};
 
//    HTML colors taken from zygrib representation
static ColorMap WindMap[] = {
    {0, _T("#288CFF")},  {3, _T("#00AFFF")},  {6, _T("#00DCE1")},
    {9, _T("#00F7B0")},  {12, _T("#00EA9C")}, {15, _T("#82F059")},
    {18, _T("#F0F503")}, {21, _T("#FFED00")}, {24, _T("#FFDB00")},
    {27, _T("#FFC700")}, {30, _T("#FFB400")}, {33, _T("#FF9800")},
    {36, _T("#FF7E00")}, {39, _T("#F77800")}, {42, _T("#EC7814")},
    {45, _T("#E4711E")}, {48, _T("#E06128")}, {51, _T("#DC5132")},
    {54, _T("#D5453C")}, {57, _T("#CD3A46")}, {60, _T("#BE2C50")},
    {63, _T("#B41A5A")}, {66, _T("#AA1464")}, {70, _T("#962878")},
    {75, _T("#8C328C")}};
 
//    HTML colors taken from zygrib representation
static ColorMap AirTempMap[] = {
    {0, _T("#283282")},  {5, _T("#273c8c")},  {10, _T("#264696")},
    {14, _T("#2350a0")}, {18, _T("#1f5aaa")}, {22, _T("#1a64b4")},
    {26, _T("#136ec8")}, {29, _T("#0c78e1")}, {32, _T("#0382e6")},
    {35, _T("#0091e6")}, {38, _T("#009ee1")}, {41, _T("#00a6dc")},
    {44, _T("#00b2d7")}, {47, _T("#00bed2")}, {50, _T("#28c8c8")},
    {53, _T("#78d2aa")}, {56, _T("#8cdc78")}, {59, _T("#a0eb5f")},
    {62, _T("#c8f550")}, {65, _T("#f3fb02")}, {68, _T("#ffed00")},
    {71, _T("#ffdd00")}, {74, _T("#ffc900")}, {78, _T("#ffab00")},
    {82, _T("#ff8100")}, {86, _T("#f1780c")}, {90, _T("#e26a23")},
    {95, _T("#d5453c")}, {100, _T("#b53c59")}};
 
//  Color map similar to:
//  https://www.ospo.noaa.gov/data/sst/contour/global.cf.gif
static ColorMap SeaTempMap[] = {
    {-2, _T("#cc04ae")}, {2, _T("#8f06e4")},  {6, _T("#486afa")},
    {10, _T("#00ffff")}, {15, _T("#00d54b")}, {19, _T("#59d800")},
    {23, _T("#f2fc00")}, {27, _T("#ff1500")}, {32, _T("#ff0000")},
    {36, _T("#d80000")}, {40, _T("#a90000")}, {44, _T("#870000")},
    {48, _T("#690000")}, {52, _T("#550000")}, {56, _T("#330000")}};
 
//    HTML colors taken from ZyGrib representation
static ColorMap PrecipitationMap[] = {
    {0, _T("#ffffff")},   {.01, _T("#c8f0ff")}, {.02, _T("#b4e6ff")},
    {.05, _T("#8cd3ff")}, {.07, _T("#78caff")}, {.1, _T("#6ec1ff")},
    {.2, _T("#64b8ff")},  {.5, _T("#50a6ff")},  {.7, _T("#469eff")},
    {1.0, _T("#3c96ff")}, {2.0, _T("#328eff")}, {5.0, _T("#1e7eff")},
    {7.0, _T("#1476f0")}, {10, _T("#0a6edc")},  {20, _T("#0064c8")},
    {50, _T("#0052aa")}};
 
//    HTML colors taken from ZyGrib representation
static ColorMap CloudMap[] = {
    {0, _T("#ffffff")},  {1, _T("#f0f0e6")},  {10, _T("#e6e6dc")},
    {20, _T("#dcdcd2")}, {30, _T("#c8c8b4")}, {40, _T("#aaaa8c")},
    {50, _T("#969678")}, {60, _T("#787864")}, {70, _T("#646450")},
    {80, _T("#5a5a46")}, {90, _T("#505036")}};
 
static ColorMap REFCMap[] = {
    {0, _T("#ffffff")},  {5, _T("#06E8E4")},  {10, _T("#009BE9")},
    {15, _T("#0400F3")}, {20, _T("#00F924")}, {25, _T("#06C200")},
    {30, _T("#009100")}, {35, _T("#FAFB00")}, {40, _T("#EBB608")},
    {45, _T("#FF9400")}, {50, _T("#FD0002")}, {55, _T("#D70000")},
    {60, _T("#C20300")}, {65, _T("#F900FE")}, {70, _T("#945AC8")}};
 
static ColorMap CAPEMap[] = {
    {0, _T("#0046c8")},    {5, _T("#0050f0")},    {10, _T("#005aff")},
    {15, _T("#0069ff")},   {20, _T("#0078ff")},   {30, _T("#000cff")},
    {45, _T("#00a1ff")},   {60, _T("#00b6fa")},   {100, _T("#00c9ee")},
    {150, _T("#00e0da")},  {200, _T("#00e6b4")},  {300, _T("#82e678")},
    {500, _T("#9bff3b")},  {700, _T("#ffdc00")},  {1000, _T("#ffb700")},
    {1500, _T("#f37800")}, {2000, _T("#d4440c")}, {2500, _T("#c8201c")},
    {3000, _T("#ad0430")},
};
 
static ColorMap WindyMap[] = {
    {0, _T("#6271B7")},  {3, _T("#3961A9")},  {6, _T("#4A94A9")},
    {9, _T("#4D8D7B")},  {12, _T("#53A553")}, {15, _T("#53A553")},
    {18, _T("#359F35")}, {21, _T("#A79D51")}, {24, _T("#9F7F3A")},
    {27, _T("#A16C5C")}, {30, _T("#A16C5C")}, {33, _T("#813A4E")},
    {36, _T("#AF5088")}, {39, _T("#AF5088")}, {42, _T("#754A93")},
    {45, _T("#754A93")}, {48, _T("#6D61A3")}, {51, _T("#44698D")},
    {54, _T("#44698D")}, {57, _T("#5C9098")}, {60, _T("#7D44A5")},
    {63, _T("#7D44A5")}, {66, _T("#7D44A5")}, {69, _T("#E7D7D7")},
    {72, _T("#E7D7D7")}, {75, _T("#E7D7D7")}, {78, _T("#DBD483")},
    {81, _T("#DBD483")}, {84, _T("#DBD483")}, {87, _T("#CDC470")},
    {90, _T("#CDC470")}, {93, _T("#CDC470")}, {96, _T("#CDC470")},
    {99, _T("#808080")}};
 
#if 0
static ColorMap *ColorMaps[] = {CurrentMap, GenericMap, WindMap, AirTempMap, SeaTempMap, PrecipitationMap, CloudMap};
#endif
 
enum {
  GENERIC_GRAPHIC_INDEX,
  WIND_GRAPHIC_INDEX,
  AIRTEMP__GRAPHIC_INDEX,
  SEATEMP_GRAPHIC_INDEX,
  PRECIPITATION_GRAPHIC_INDEX,
  CLOUD_GRAPHIC_INDEX,
  CURRENT_GRAPHIC_INDEX,
  CAPE_GRAPHIC_INDEX,
  REFC_GRAPHIC_INDEX,
  WINDY_GRAPHIC_INDEX
};
 
static void InitColor(ColorMap *map, size_t maplen) {
  wxColour c;
  for (size_t i = 0; i < maplen; i++) {
    c.Set(map[i].text);
    map[i].r = c.Red();
    map[i].g = c.Green();
    map[i].b = c.Blue();
  }
}
 
void GRIBOverlayFactory::InitColorsTable() {
  InitColor(CurrentMap, (sizeof CurrentMap) / (sizeof *CurrentMap));
  InitColor(GenericMap, (sizeof GenericMap) / (sizeof *GenericMap));
  InitColor(WindMap, (sizeof WindMap) / (sizeof *WindMap));
  InitColor(AirTempMap, (sizeof AirTempMap) / (sizeof *AirTempMap));
  InitColor(SeaTempMap, (sizeof SeaTempMap) / (sizeof *SeaTempMap));
  InitColor(PrecipitationMap,
            (sizeof PrecipitationMap) / (sizeof *PrecipitationMap));
  InitColor(CloudMap, (sizeof CloudMap) / (sizeof *CloudMap));
  InitColor(CAPEMap, (sizeof CAPEMap) / (sizeof *CAPEMap));
  InitColor(REFCMap, (sizeof REFCMap) / (sizeof *REFCMap));
  InitColor(WindyMap, (sizeof WindyMap) / (sizeof *WindyMap));
}
 
void GRIBOverlayFactory::GetGraphicColor(int settings, double val_in,
                                         unsigned char &r, unsigned char &g,
                                         unsigned char &b) {
  int colormap_index = m_Settings.Settings[settings].m_iOverlayMapColors;
  ColorMap *map;
  int maplen;
 
  /* normalize input value */
  double min = m_Settings.GetMin(settings), max = m_Settings.GetMax(settings);
 
  val_in -= min;
  val_in /= max - min;
 
  switch (colormap_index) {
    case CURRENT_GRAPHIC_INDEX:
      map = CurrentMap;
      maplen = (sizeof CurrentMap) / (sizeof *CurrentMap);
      break;
    case GENERIC_GRAPHIC_INDEX:
      map = GenericMap;
      maplen = (sizeof GenericMap) / (sizeof *GenericMap);
      break;
    case WIND_GRAPHIC_INDEX:
      map = WindMap;
      maplen = (sizeof WindMap) / (sizeof *WindMap);
      break;
    case AIRTEMP__GRAPHIC_INDEX:
      map = AirTempMap;
      maplen = (sizeof AirTempMap) / (sizeof *AirTempMap);
      break;
    case SEATEMP_GRAPHIC_INDEX:
      map = SeaTempMap;
      maplen = (sizeof SeaTempMap) / (sizeof *SeaTempMap);
      break;
    case PRECIPITATION_GRAPHIC_INDEX:
      map = PrecipitationMap;
      maplen = (sizeof PrecipitationMap) / (sizeof *PrecipitationMap);
      break;
    case CLOUD_GRAPHIC_INDEX:
      map = CloudMap;
      maplen = (sizeof CloudMap) / (sizeof *CloudMap);
      break;
    case CAPE_GRAPHIC_INDEX:
      map = CAPEMap;
      maplen = (sizeof CAPEMap) / (sizeof *CAPEMap);
      break;
    case REFC_GRAPHIC_INDEX:
      map = REFCMap;
      maplen = (sizeof REFCMap) / (sizeof *REFCMap);
      break;
    case WINDY_GRAPHIC_INDEX:
      map = WindyMap;
      maplen = (sizeof WindyMap) / (sizeof *WindyMap);
      break;
    default:
      return;
  }
 
  /* normalize map from 0 to 1 */
  double cmax = map[maplen - 1].val;
 
  for (int i = 1; i < maplen; i++) {
    double nmapvala = map[i - 1].val / cmax;
    double nmapvalb = map[i].val / cmax;
    if (nmapvalb > val_in || i == maplen - 1) {
      if (m_bGradualColors) {
        double d = (val_in - nmapvala) / (nmapvalb - nmapvala);
        r = (1 - d) * map[i - 1].r + d * map[i].r;
        g = (1 - d) * map[i - 1].g + d * map[i].g;
        b = (1 - d) * map[i - 1].b + d * map[i].b;
      } else {
        r = map[i].r;
        g = map[i].g;
        b = map[i].b;
      }
      return;
    }
  }
  /* unreachable */
}
 
wxColour GRIBOverlayFactory::GetGraphicColor(int settings, double val_in) {
  unsigned char r, g, b;
  GetGraphicColor(settings, val_in, r, g, b);
  return wxColour(r, g, b);
}
 
wxString GRIBOverlayFactory::getLabelString(double value, int settings) {
  int p;
  wxString f = _T("%.*f");
 
  switch (settings) {
    case GribOverlaySettings::PRESSURE: /* 2 */
      p = 0;
      if (m_Settings.Settings[settings].m_Units == 2)
        p = 2;
      else if (m_Settings.Settings[settings].m_Units == 0 &&
               m_Settings.Settings[settings].m_bAbbrIsoBarsNumbers) {
        value -= floor(value / 100.) * 100.;
        f = _T("%02.*f");
      }
      break;
    case GribOverlaySettings::WAVE:            /* 3 */
    case GribOverlaySettings::CURRENT:         /* 4 */
    case GribOverlaySettings::AIR_TEMPERATURE: /* 7 */
    case GribOverlaySettings::SEA_TEMPERATURE: /* 8 */
      p = 1;
      break;
    case GribOverlaySettings::PRECIPITATION: /* 5 */
      p = value < 100. ? 2 : value < 10. ? 1 : 0;
      p += m_Settings.Settings[settings].m_Units == 1 ? 1 : 0;
      break;
    default:
      p = 0;
  }
  return wxString::Format(f, p, value);
}
 
/* return cached wxImage for a given number, or create it if not in the cache */
wxImage &GRIBOverlayFactory::getLabel(double value, int settings,
                                      wxColour back_color) {
  std::map<double, wxImage>::iterator it;
  it = m_labelCache.find(value);
  if (it != m_labelCache.end()) return m_labelCache[value];
 
  wxString labels = getLabelString(value, settings);
 
  wxColour text_color;
  GetGlobalColor(_T ( "UBLCK" ), &text_color);
  wxPen penText(text_color);
 
  wxBrush backBrush(back_color);
 
  wxFont mfont(9, wxFONTFAMILY_DEFAULT, wxFONTSTYLE_NORMAL,
               wxFONTWEIGHT_NORMAL);
 
  wxScreenDC sdc;
  int w, h;
  sdc.GetTextExtent(labels, &w, &h, nullptr, nullptr, &mfont);
 
  int label_offset = 5;
 
  wxBitmap bm(w + label_offset * 2, h + 2);
  wxMemoryDC mdc(bm);
  mdc.Clear();
 
  mdc.SetFont(mfont);
  mdc.SetPen(penText);
  mdc.SetBrush(backBrush);
  mdc.SetTextForeground(text_color);
  mdc.SetTextBackground(back_color);
 
  int xd = 0;
  int yd = 0;
  //    mdc.DrawRoundedRectangle(xd, yd, w+(label_offset * 2), h+2, -.25);
  mdc.DrawRectangle(xd, yd, w + (label_offset * 2), h + 2);
  mdc.DrawText(labels, label_offset + xd, yd + 1);
 
  mdc.SelectObject(wxNullBitmap);
 
  m_labelCache[value] = bm.ConvertToImage();
 
  m_labelCache[value].InitAlpha();
 
  return m_labelCache[value];
}
 
double square(double x) { return x * x; }
 
void GRIBOverlayFactory::RenderGribBarbedArrows(int settings, GribRecord **pGR,
                                                PlugIn_ViewPort *vp) {
  if (!m_Settings.Settings[settings].m_bBarbedArrows) return;
 
  //  Need two records to draw the barbed arrows
  GribRecord *pGRX, *pGRY;
  int idx, idy;
  bool polar;
  SettingsIdToGribId(settings, idx, idy, polar);
  if (idx < 0 || idy < 0) return;
 
  pGRX = pGR[idx];
  pGRY = pGR[idy];
 
  if (!pGRX || !pGRY) return;
 
  wxColour colour;
  GetGlobalColor(_T ( "YELO2" ), &colour);
 
#ifdef ocpnUSE_GL
  if (!m_pdc) {
#ifndef __OCPN__ANDROID__
    //      Enable anti-aliased lines, at best quality
    glEnable(GL_LINE_SMOOTH);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
    glLineWidth(2);
#else
    glLineWidth(5);  // 5 pixels for dense displays
#endif
 
    glEnableClientState(GL_VERTEX_ARRAY);
  }
#endif
 
  if (m_Settings.Settings[settings].m_bBarbArrFixSpac) {
    // set spacing between arrows
    int space = adjustSpacing(m_Settings.Settings[settings].m_iBarbArrSpacing);
 
    PlugIn_ViewPort uvp = *vp;
    uvp.rotation = uvp.skew = 0;
 
    int arrowSize = 16;
 
    for (int i = 0; i < m_ParentSize.GetWidth(); i += (space + arrowSize)) {
      for (int j = 0; j < m_ParentSize.GetHeight(); j += (space + arrowSize)) {
        double lat, lon;
        GetCanvasLLPix(vp, wxPoint(i, j), &lat, &lon);
 
        double vkn, ang;
        if (GribRecord::getInterpolatedValues(vkn, ang, pGRX, pGRY, lon, lat))
          drawWindArrowWithBarbs(settings, i, j, vkn * 3.6 / 1.852,
                                 (ang - 90) * M_PI / 180, (lat < 0.), colour,
                                 vp->rotation);
      }
    }
  } else {
    // set minimum spacing between arrows
    double minspace = wxMax(m_Settings.Settings[settings].m_iBarbArrSpacing,
                            windArrowSize * 1.2);
    double minspace2 = square(minspace);
 
    //    Get the the grid
    int imax = pGRX->getNi();  // Longitude
    int jmax = pGRX->getNj();  // Latitude
 
    wxPoint firstpx(-1000, -1000);
    wxPoint oldpx(-1000, -1000);
    wxPoint oldpy(-1000, -1000);
 
    for (int i = 0; i < imax; i++) {
      double lonl, latl;
 
      /* at midpoint of grib so as to avoid problems in projection on
         gribs that go all the way to the north or south pole */
      pGRX->getXY(i, pGRX->getNj() / 2, &lonl, &latl);
      wxPoint pl;
      GetCanvasPixLL(vp, &pl, latl, lonl);
 
      if (pl.x <= firstpx.x &&
          square(pl.x - firstpx.x) + square(pl.y - firstpx.y) <
              minspace2 / 1.44)
        continue;
 
      if (square(pl.x - oldpx.x) + square(pl.y - oldpx.y) < minspace2) continue;
 
      oldpx = pl;
      if (i == 0) firstpx = pl;
 
      double lon = lonl;
      for (int j = 0; j < jmax; j++) {
        double lat = pGRX->getY(j);
 
        if (!PointInLLBox(vp, lon, lat)) continue;
 
        wxPoint p;
        GetCanvasPixLL(vp, &p, lat, lon);
 
        if (square(p.x - oldpy.x) + square(p.y - oldpy.y) < minspace2) continue;
 
        oldpy = p;
 
        if (lon > 180) lon -= 360;
 
        double vx = pGRX->getValue(i, j);
        double vy = pGRY->getValue(i, j);
 
        if (vx != GRIB_NOTDEF && vy != GRIB_NOTDEF) {
          double vkn, ang;
          vkn = sqrt(vx * vx + vy * vy);
          ang = atan2(vy, -vx);
          drawWindArrowWithBarbs(settings, p.x, p.y, vkn * 3.6 / 1.852, ang,
                                 (lat < 0.), colour, vp->rotation);
        }
      }
    }
  }
 
#ifdef ocpnUSE_GL
  if (!m_pdc) glDisableClientState(GL_VERTEX_ARRAY);
#endif
}
 
void GRIBOverlayFactory::RenderGribIsobar(int settings, GribRecord **pGR,
                                          wxArrayPtrVoid **pIsobarArray,
                                          PlugIn_ViewPort *vp) {
  if (!m_Settings.Settings[settings].m_bIsoBars) return;
 
  //  Need magnitude to draw isobars
  int idx, idy;
  bool polar;
  SettingsIdToGribId(settings, idx, idy, polar);
  if (idx < 0) return;
 
  GribRecord *pGRA = pGR[idx], *pGRM = nullptr;
 
  if (!pGRA) return;
 
  wxColour back_color;
  GetGlobalColor(_T ( "DILG1" ), &back_color);
 
  //    Initialize the array of Isobars if necessary
  if (!pIsobarArray[idx]) {
    // build magnitude from multiple record types like wind and current
    if (idy >= 0 && !polar && pGR[idy]) {
      pGRM = GribRecord::MagnitudeRecord(*pGR[idx], *pGR[idy]);
      if (!pGRM->isOk()) {
        m_Message_Hiden.Append(_("IsoBar Unable to compute record magnitude"));
        delete pGRM;
        return;
      }
      pGRA = pGRM;
    }
 
    pIsobarArray[idx] = new wxArrayPtrVoid;
    IsoLine *piso;
 
    wxGenericProgressDialog *progressdialog = nullptr;
    wxDateTime start = wxDateTime::Now();
 
    double min = m_Settings.GetMin(settings);
    double max = m_Settings.GetMax(settings);
 
    /* convert min and max to units being used */
    double factor = (settings == GribOverlaySettings::PRESSURE &&
                     m_Settings.Settings[settings].m_Units == 2)
                        ? 0.03
                        : 1.;  // divide spacing by 1/33 for PRESURRE & inHG
 
    for (double press = min; press <= max;
         press += (m_Settings.Settings[settings].m_iIsoBarSpacing * factor)) {
      if (progressdialog)
        progressdialog->Update(press - min);
      else {
        wxDateTime now = wxDateTime::Now();
        if ((now - start).GetSeconds() > 3 && press - min < (max - min) / 2) {
          progressdialog = new wxGenericProgressDialog(
              _("Building Isobar map"), _("Wind"), max - min + 1, nullptr,
              wxPD_SMOOTH | wxPD_ELAPSED_TIME | wxPD_REMAINING_TIME);
        }
      }
 
      piso = new IsoLine(press,
                         m_Settings.CalibrationFactor(settings, press, true),
                         m_Settings.CalibrationOffset(settings), pGRA);
 
      pIsobarArray[idx]->Add(piso);
    }
    delete progressdialog;
 
    delete pGRM;
  }
 
  //    Draw the Isobars
  for (unsigned int i = 0; i < pIsobarArray[idx]->GetCount(); i++) {
    IsoLine *piso = (IsoLine *)pIsobarArray[idx]->Item(i);
    piso->drawIsoLine(this, m_pdc, vp, true);  // g_bGRIBUseHiDef
 
    // Draw Isobar labels
 
    int density = 40;
    int first = 0;
    if (m_pdc)
      piso->drawIsoLineLabels(this, m_pdc, vp, density, first,
                              getLabel(piso->getValue(), settings, back_color));
    else
      piso->drawIsoLineLabelsGL(this, vp, density, first,
                                getLabelString(piso->getValue(), settings),
                                back_color, m_TexFontNumbers);
  }
}
 
void GRIBOverlayFactory::FillGrid(GribRecord *pGR) {
  //    Get the the grid
  int imax = pGR->getNi();  // Longitude
  int jmax = pGR->getNj();  // Latitude
 
  for (int i = 0; i < imax; i++) {
    for (int j = 1; j < jmax - 1; j++) {
      if (pGR->getValue(i, j) == GRIB_NOTDEF) {
        double acc = 0;
        double div = 0;
        if (pGR->getValue(i, j - 1) != GRIB_NOTDEF) {
          acc += pGR->getValue(i, j - 1);
          div += 1;
        }
        if (pGR->getValue(i, j + 1) != GRIB_NOTDEF) {
          acc += pGR->getValue(i, j + 1);
          div += 1;
        }
        if (div > 1) pGR->setValue(i, j, acc / div);
      }
    }
  }
 
  for (int j = 0; j < jmax; j++) {
    for (int i = 1; i < imax - 1; i++) {
      if (pGR->getValue(i, j) == GRIB_NOTDEF) {
        double acc = 0;
        double div = 0;
        if (pGR->getValue(i - 1, j) != GRIB_NOTDEF) {
          acc += pGR->getValue(i - 1, j);
          div += 1;
        }
        if (pGR->getValue(i + 1, j) != GRIB_NOTDEF) {
          acc += pGR->getValue(i + 1, j);
          div += 1;
        }
        if (div > 1) pGR->setValue(i, j, acc / div);
      }
    }
  }
 
  pGR->setFilled(true);
}
 
void GRIBOverlayFactory::RenderGribDirectionArrows(int settings,
                                                   GribRecord **pGR,
                                                   PlugIn_ViewPort *vp) {
  if (!m_Settings.Settings[settings].m_bDirectionArrows) return;
  //   need two records or a polar record to draw arrows
  GribRecord *pGRX, *pGRY;
  int idx, idy;
  bool polar;
  SettingsIdToGribId(settings, idx, idy, polar);
  if (idx < 0 || idy < 0) return;
 
  pGRX = pGR[idx];
  pGRY = pGR[idy];
  if (!pGRX || !pGRY) return;
  if (!pGRX->isFilled()) FillGrid(pGRX);
  if (!pGRY->isFilled()) FillGrid(pGRY);
 
  // Set arrows Size
  int arrowWidth = 2;
  int arrowSize,
      arrowSizeIdx = m_Settings.Settings[settings].m_iDirectionArrowSize;
  if (arrowSizeIdx == 0) {
    if (m_pixelMM > 0.2)
      arrowSize = 26;
    else
      arrowSize = 5. / m_pixelMM;
  } else
    arrowSize = 16;
 
  // set default colour
  wxColour colour;
  GetGlobalColor(_T ( "DILG3" ), &colour);
 
#ifdef ocpnUSE_GL
  if (!m_pdc) {
    if (m_pixelMM > 0.2) {
      //      Enable anti-aliased lines, at best quality
      glEnable(GL_LINE_SMOOTH);
      glEnable(GL_BLEND);
      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
      glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
    } else {
      if (m_Settings.Settings[settings].m_iDirectionArrowForm == 0)  // Single?
        arrowWidth = 4;
      else
        arrowWidth = 3;
    }
 
    glEnableClientState(GL_VERTEX_ARRAY);
  }
#endif
 
  if (m_Settings.Settings[settings].m_bDirArrFixSpac) {  // fixed spacing
 
    // Set spacing between arrows
    int space = adjustSpacing(m_Settings.Settings[settings].m_iDirArrSpacing);
 
    for (int i = 0; i < m_ParentSize.GetWidth(); i += (space + arrowSize)) {
      for (int j = 0; j < m_ParentSize.GetHeight(); j += (space + arrowSize)) {
        double lat, lon, sh, dir;
        double scale = 1.0;
        GetCanvasLLPix(vp, wxPoint(i, j), &lat, &lon);
 
        if (polar) {  // wave arrows
          sh = pGRX->getInterpolatedValue(lon, lat, true);
          dir = pGRY->getInterpolatedValue(lon, lat, true, true);
 
          if (dir == GRIB_NOTDEF || sh == GRIB_NOTDEF) continue;
 
        } else {  // current arrows
          if (!GribRecord::getInterpolatedValues(sh, dir, pGRX, pGRY, lon, lat))
            continue;
          scale = wxMax(1.0, sh);  // Size depends on magnitude.
        }
 
        dir = (dir - 90) * M_PI / 180.;
 
        // draw arrows
        if (m_Settings.Settings[settings].m_iDirectionArrowForm == 0)
          drawSingleArrow(i, j, dir + vp->rotation, colour, arrowWidth,
                          arrowSizeIdx, scale);
        else if (m_Settings.Settings[settings].m_iDirectionArrowForm == 1)
          drawDoubleArrow(i, j, dir + vp->rotation, colour, arrowWidth,
                          arrowSizeIdx, scale);
        else
          drawSingleArrow(i, j, dir + vp->rotation, colour,
                          wxMax(1, wxMin(8, (int)(sh + 0.5))), arrowSizeIdx,
                          scale);
      }
    }
 
  } else {  // end fixed spacing -> minimum spacing
 
    // set minimum spacing between arrows
    double minspace =
        wxMax(m_Settings.Settings[settings].m_iDirArrSpacing,
              m_Settings.Settings[settings].m_iDirectionArrowSize * 1.2);
    double minspace2 = square(minspace);
 
    //    Get the the grid
    int imax = pGRX->getNi();  // Longitude
    int jmax = pGRX->getNj();  // Latitude
 
    wxPoint firstpx(-1000, -1000);
    wxPoint oldpx(-1000, -1000);
    wxPoint oldpy(-1000, -1000);
 
    for (int i = 0; i < imax; i++) {
      double lonl, latl;
      pGRX->getXY(i, pGRX->getNj() / 2, &lonl, &latl);
 
      wxPoint pl;
      GetCanvasPixLL(vp, &pl, latl, lonl);
 
      if (pl.x <= firstpx.x &&
          square(pl.x - firstpx.x) + square(pl.y - firstpx.y) <
              minspace2 / 1.44)
        continue;
 
      if (square(pl.x - oldpx.x) + square(pl.y - oldpx.y) < minspace2) continue;
 
      oldpx = pl;
      if (i == 0) firstpx = pl;
 
      for (int j = 0; j < jmax; j++) {
        double lon, lat;
        pGRX->getXY(i, j, &lon, &lat);
 
        wxPoint p;
        GetCanvasPixLL(vp, &p, lat, lon);
 
        if (square(p.x - oldpy.x) + square(p.y - oldpy.y) >= minspace2) {
          oldpy = p;
 
          if (lon > 180) lon -= 360;
 
          if (PointInLLBox(vp, lon, lat)) {
            double sh, dir, wdh;
            double scale = 1.0;
            if (polar) {  // wave arrows
              dir = pGRY->getValue(i, j);
              sh = pGRX->getValue(i, j);
 
              if (dir == GRIB_NOTDEF || sh == GRIB_NOTDEF) continue;
 
              wdh = sh + 0.5;
            } else {
              if (!GribRecord::getInterpolatedValues(sh, dir, pGRX, pGRY, lon,
                                                     lat, false))
                continue;
 
              wdh = (8 / 2.5 * sh) + 0.5;
              scale = wxMax(1.0, sh);  // Size depends on magnitude.
            }
 
            dir = (dir - 90) * M_PI / 180.;
 
            // draw arrows
            if (m_Settings.Settings[settings].m_iDirectionArrowForm == 0)
              drawSingleArrow(p.x, p.y, dir + vp->rotation, colour, arrowWidth,
                              arrowSizeIdx, scale);
            else if (m_Settings.Settings[settings].m_iDirectionArrowForm == 1)
              drawDoubleArrow(p.x, p.y, dir + vp->rotation, colour, arrowWidth,
                              arrowSizeIdx, scale);
            else
              drawSingleArrow(p.x, p.y, dir + vp->rotation, colour,
                              wxMax(1, wxMin(8, (int)wdh)), arrowSizeIdx,
                              scale);
          }
        }
      }
    }
  }
 
#ifdef ocpnUSE_GL
  if (!m_pdc) glDisableClientState(GL_VERTEX_ARRAY);
#endif
}
 
void GRIBOverlayFactory::RenderGribOverlayMap(int settings, GribRecord **pGR,
                                              PlugIn_ViewPort *vp) {
  if (!m_Settings.Settings[settings].m_bOverlayMap) return;
 
  const int grib_pixel_size = 4;
  bool polar;
  int idx, idy;
  SettingsIdToGribId(settings, idx, idy, polar);
  if (idx < 0 || !pGR[idx]) return;
 
  GribRecord *pGRA = pGR[idx], *pGRM = nullptr;
  if (!pGRA) return;
 
  if (idy >= 0 && !polar && pGR[idy]) {
    pGRM = GribRecord::MagnitudeRecord(*pGR[idx], *pGR[idy]);
    if (!pGRM->isOk()) {
      m_Message_Hiden.Append(
          _("OverlayMap Unable to compute record magnitude"));
      delete pGRM;
      return;
    }
    pGRA = pGRM;
  }
 
  if (!pGRA->isFilled()) FillGrid(pGRA);
 
  wxPoint porg;
  GetCanvasPixLL(vp, &porg, pGRA->getLatMax(), pGRA->getLonMin());
 
  //    Check two BBoxes....
  //    TODO Make a better Intersect method
  bool bdraw = false;
  if (Intersect(vp, pGRA->getLatMin(), pGRA->getLatMax(), pGRA->getLonMin(),
                pGRA->getLonMax(), 0.) != _GOUT)
    bdraw = true;
  if (Intersect(vp, pGRA->getLatMin(), pGRA->getLatMax(),
                pGRA->getLonMin() - 360., pGRA->getLonMax() - 360.,
                0.) != _GOUT)
    bdraw = true;
 
  if (bdraw) {
    // If needed, create the overlay
    if (!m_pOverlay[settings]) m_pOverlay[settings] = new GribOverlay;
 
    GribOverlay *pGO = m_pOverlay[settings];
 
    if (!m_pdc)  // OpenGL mode
    {
#ifdef ocpnUSE_GL
 
      texture_format = GL_TEXTURE_2D;
 
      if (!texture_format)  // it's very unlikely to not have any of the above
                            // extensions
        m_Message_Hiden.Append(
            _("Overlays not supported by this graphics hardware (Disable "
              "OpenGL)"));
      else {
        if (!pGO->m_iTexture) CreateGribGLTexture(pGO, settings, pGRA);
 
        if (pGO->m_iTexture)
          DrawGLTexture(pGO, pGRA, vp);
        else
          m_Message_Hiden.IsEmpty()
              ? m_Message_Hiden
                    .Append(_("Overlays too wide and can't be displayed:"))
                    .Append(_T(" "))
                    .Append(GribOverlaySettings::NameFromIndex(settings))
              : m_Message_Hiden.Append(_T(",")).Append(
                    GribOverlaySettings::NameFromIndex(settings));
      }
#endif
    } else  // DC mode
    {
      if (fabs(vp->rotation) > 0.1) {
        m_Message_Hiden.Append(_(
            "overlays suppressed if not north-up in DC mode (enable OpenGL)"));
      } else {
        if (!pGO->m_pDCBitmap) {
          wxImage bl_image =
              CreateGribImage(settings, pGRA, vp, grib_pixel_size, porg);
          if (bl_image.IsOk()) {
            //    Create a Bitmap
            pGO->m_pDCBitmap = new wxBitmap(bl_image);
            wxMask *gr_mask =
                new wxMask(*(pGO->m_pDCBitmap), wxColour(0, 0, 0));
            pGO->m_pDCBitmap->SetMask(gr_mask);
          }
        }
 
        if (pGO->m_pDCBitmap)
          m_pdc->DrawBitmap(*(pGO->m_pDCBitmap), porg.x, porg.y, true);
        else
          m_Message_Hiden.IsEmpty()
              ? m_Message_Hiden
                    .Append(_(
                        "Please Zoom or Scale Out to view invisible overlays:"))
                    .Append(_T(" "))
                    .Append(GribOverlaySettings::NameFromIndex(settings))
              : m_Message_Hiden.Append(_T(",")).Append(
                    GribOverlaySettings::NameFromIndex(settings));
      }
    }
  }
 
  delete pGRM;
}
 
void GRIBOverlayFactory::RenderGribNumbers(int settings, GribRecord **pGR,
                                           PlugIn_ViewPort *vp) {
  if (!m_Settings.Settings[settings].m_bNumbers) return;
 
  //  Need magnitude to draw numbers
  int idx, idy;
  bool polar;
  SettingsIdToGribId(settings, idx, idy, polar);
  if (idx < 0) return;
 
  GribRecord *pGRA = pGR[idx], *pGRM = nullptr;
 
  if (!pGRA) return;
 
  /* build magnitude from multiple record types like wind and current */
  if (idy >= 0 && !polar && pGR[idy]) {
    pGRM = GribRecord::MagnitudeRecord(*pGR[idx], *pGR[idy]);
    if (!pGRM->isOk()) {
      m_Message_Hiden.Append(
          _("GribNumbers Unable to compute record magnitude"));
      delete pGRM;
      return;
    }
    pGRA = pGRM;
  }
 
  // set an arbitrary width for numbers
  int wstring;
  m_TexFontNumbers.GetTextExtent(_T("1234"), &wstring, nullptr);
 
  if (m_Settings.Settings[settings].m_bNumFixSpac) {  // fixed spacing
 
    // Set spacing between numbers
    int space = adjustSpacing(m_Settings.Settings[settings].m_iNumbersSpacing);
 
    PlugIn_ViewPort uvp = *vp;
    uvp.rotation = uvp.skew = 0;
 
    wxPoint ptl, pbr;
    GetCanvasPixLL(&uvp, &ptl, wxMin(pGRA->getLatMax(), 89.0),
                   pGRA->getLonMin());  // top left corner position
    GetCanvasPixLL(&uvp, &pbr, wxMax(pGRA->getLatMin(), -89.0),
                   pGRA->getLonMax());  // bottom right corner position
    if (ptl.x >= pbr.x) {
      // 360
      ptl.x = 0;
      pbr.x = m_ParentSize.GetWidth();
    }
 
    for (int i = wxMax(ptl.x, 0); i < wxMin(pbr.x, m_ParentSize.GetWidth());
         i += (space + wstring)) {
      for (int j = wxMax(ptl.y, 0); j < wxMin(pbr.y, m_ParentSize.GetHeight());
           j += (space + wstring)) {
        double lat, lon, val;
        GetCanvasLLPix(vp, wxPoint(i, j), &lat, &lon);
        val = pGRA->getInterpolatedValue(lon, lat, true);
        if (val != GRIB_NOTDEF) {
          double value = m_Settings.CalibrateValue(settings, val);
          wxColour back_color = GetGraphicColor(settings, value);
 
          DrawNumbers(wxPoint(i, j), value, settings, back_color);
        }
      }
    }
  } else {
    // set minimum spacing between arrows
    double minspace =
        wxMax(m_Settings.Settings[settings].m_iNumbersSpacing, wstring * 1.2);
    double minspace2 = square(minspace);
 
    //    Get the the grid
    int imax = pGRA->getNi();  // Longitude
    int jmax = pGRA->getNj();  // Latitude
 
    wxPoint firstpx(-1000, -1000);
    wxPoint oldpx(-1000, -1000);
    wxPoint oldpy(-1000, -1000);
 
    for (int i = 0; i < imax; i++) {
      double lonl, latl;
      pGRA->getXY(i, pGRA->getNj() / 2, &lonl, &latl);
 
      wxPoint pl;
      GetCanvasPixLL(vp, &pl, latl, lonl);
 
      if (pl.x <= firstpx.x &&
          square(pl.x - firstpx.x) + square(pl.y - firstpx.y) <
              minspace2 / 1.44)
        continue;
 
      if (square(pl.x - oldpx.x) + square(pl.y - oldpx.y) >= minspace2) {
        oldpx = pl;
        if (i == 0) firstpx = pl;
 
        for (int j = 0; j < jmax; j++) {
          double lon, lat;
          pGRA->getXY(i, j, &lon, &lat);
 
          wxPoint p;
          GetCanvasPixLL(vp, &p, lat, lon);
 
          if (square(p.x - oldpy.x) + square(p.y - oldpy.y) >= minspace2) {
            oldpy = p;
 
            if (lon > 180) lon -= 360;
 
            if (PointInLLBox(vp, lon, lat)) {
              double mag = pGRA->getValue(i, j);
 
              if (mag != GRIB_NOTDEF) {
                double value = m_Settings.CalibrateValue(settings, mag);
                wxColour back_color = GetGraphicColor(settings, value);
 
                DrawNumbers(p, value, settings, back_color);
              }
            }
          }
        }
      }
    }
  }
 
  delete pGRM;
}
 
void GRIBOverlayFactory::DrawNumbers(wxPoint p, double value, int settings,
                                     wxColour back_color) {
  if (m_pdc) {
    wxImage &label = getLabel(value, settings, back_color);
    // set alpha chanel
    int w = label.GetWidth(), h = label.GetHeight();
    for (int y = 0; y < h; y++)
      for (int x = 0; x < w; x++)
        label.SetAlpha(x, y, m_Settings.m_iOverlayTransparency);
 
    m_pdc->DrawBitmap(label, p.x, p.y, true);
  } else {
#ifdef ocpnUSE_GL
#if 0  // ndef USE_ANDROID_GLES2
 
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glColor4ub(back_color.Red(), back_color.Green(), back_color.Blue(),
               m_Settings.m_iOverlayTransparency);
 
    glLineWidth(1);
 
    wxString label = getLabelString(value, settings);
    int w, h;
    m_TexFontNumbers.GetTextExtent(label, &w, &h);
 
    int label_offsetx = 5, label_offsety = 1;
    int x = p.x - label_offsetx, y = p.y - label_offsety;
    w += 2 * label_offsetx, h += 2 * label_offsety;
 
    /* draw bounding rectangle */
    glBegin(GL_QUADS);
    glVertex2i(x, y);
    glVertex2i(x + w, y);
    glVertex2i(x + w, y + h);
    glVertex2i(x, y + h);
    glEnd();
 
    glColor4ub(0, 0, 0, m_Settings.m_iOverlayTransparency);
 
    glBegin(GL_LINE_LOOP);
    glVertex2i(x, y);
    glVertex2i(x + w, y);
    glVertex2i(x + w, y + h);
    glVertex2i(x, y + h);
    glEnd();
 
    glEnable(GL_TEXTURE_2D);
    m_TexFontNumbers.RenderString(label, p.x, p.y);
    glDisable(GL_TEXTURE_2D);
#else
 
#ifdef __WXQT__
    wxFont font = GetOCPNGUIScaledFont_PlugIn(_("Dialog"));
#else
    wxFont font(9, wxFONTFAMILY_DEFAULT, wxFONTSTYLE_NORMAL,
                wxFONTWEIGHT_NORMAL);
#endif
 
    wxString label = getLabelString(value, settings);
 
    m_oDC->SetFont(font);
    int w, h;
    m_oDC->GetTextExtent(label, &w, &h);
 
    int label_offsetx = 5, label_offsety = 1;
    int x = p.x - label_offsetx, y = p.y - label_offsety;
    w += 2 * label_offsetx, h += 2 * label_offsety;
 
    m_oDC->SetBrush(wxBrush(back_color));
    m_oDC->DrawRoundedRectangle(x, y, w, h, 0);
 
    /* draw bounding rectangle */
    m_oDC->SetPen(wxPen(wxColour(0, 0, 0), 1));
    m_oDC->DrawLine(x, y, x + w, y);
    m_oDC->DrawLine(x + w, y, x + w, y + h);
    m_oDC->DrawLine(x + w, y + h, x, y + h);
    m_oDC->DrawLine(x, y + h, x, y);
 
    m_oDC->DrawText(label, p.x, p.y);
 
#endif
#endif
  }
}
 
void GRIBOverlayFactory::RenderGribParticles(int settings, GribRecord **pGR,
                                             PlugIn_ViewPort *vp) {
  if (!m_Settings.Settings[settings].m_bParticles) return;
 
  //   need two records or a polar record to draw arrows
  GribRecord *pGRX, *pGRY;
  int idx, idy;
  bool polar;
  SettingsIdToGribId(settings, idx, idy, polar);
  if (idx < 0 || idy < 0) return;
 
  pGRX = pGR[idx];
  pGRY = pGR[idy];
 
  if (!pGRX || !pGRY) return;
 
  wxStopWatch sw;
  sw.Start();
 
  if (m_ParticleMap && m_ParticleMap->m_Setting != settings) ClearParticles();
 
  if (!m_ParticleMap) m_ParticleMap = new ParticleMap(settings);
 
  std::vector<Particle> &particles = m_ParticleMap->m_Particles;
 
  const int max_duration = 50;
  const int run_count = 6;
 
  double density = m_Settings.Settings[settings].m_dParticleDensity;
  //    density = density * sqrt(vp.view_scale_ppm);
 
  int history_size = 27 / sqrt(density);
  history_size = wxMin(history_size, MAX_PARTICLE_HISTORY);
 
  std::vector<Particle>::iterator it;
  // if the history size changed
  if (m_ParticleMap->history_size != history_size) {
    for (unsigned int i = 0; i < particles.size(); i++) {
      Particle &it = particles[i];
      if (m_ParticleMap->history_size > history_size &&
          it.m_HistoryPos >= history_size) {
        it = particles[particles.size() - 1];
        particles.pop_back();
        i--;
        continue;
      }
 
      it.m_HistorySize = it.m_HistoryPos + 1;
    }
    m_ParticleMap->history_size = history_size;
  }
 
  // Did the viewport change?  update cached screen coordinates
  // we could use normalized coordinates in opengl and avoid this
  PlugIn_ViewPort &lvp = m_ParticleMap->last_viewport;
  if (lvp.bValid == false || vp->view_scale_ppm != lvp.view_scale_ppm ||
      vp->skew != lvp.skew || vp->rotation != lvp.rotation) {
    for (it = particles.begin(); it != particles.end(); it++)
      for (int i = 0; i < it->m_HistorySize; i++) {
        Particle::ParticleNode &n = it->m_History[i];
        float(&p)[2] = n.m_Pos;
        if (p[0] == -10000) continue;
 
        wxPoint ps;
        GetCanvasPixLL(vp, &ps, p[1], p[0]);
        n.m_Screen[0] = ps.x;
        n.m_Screen[1] = ps.y;
      }
 
    lvp = *vp;
  } else  // just panning, do quicker update
    if (vp->clat != lvp.clat || vp->clon != lvp.clon) {
      wxPoint p1, p2;
      GetCanvasPixLL(vp, &p1, 0, 0);
      GetCanvasPixLL(&lvp, &p2, 0, 0);
 
      p1 -= p2;
 
      for (it = particles.begin(); it != particles.end(); it++)
        for (int i = 0; i < it->m_HistorySize; i++) {
          Particle::ParticleNode &n = it->m_History[i];
          float(&p)[2] = n.m_Pos;
          if (p[0] == -10000) continue;
 
          n.m_Screen[0] += p1.x;
          n.m_Screen[1] += p1.y;
        }
      lvp = *vp;
    }
 
  double ptime = 0;
 
  // update particle map
  if (m_bUpdateParticles) {
    for (unsigned int i = 0; i < particles.size(); i++) {
      Particle &it = particles[i];
 
      // Update the interpolation factor
      if (++it.m_Run < run_count) continue;
      it.m_Run = 0;
 
      // don't allow particle to live too long
      if (it.m_Duration > max_duration) {
        it = particles[particles.size() - 1];
        particles.pop_back();
        i--;
        continue;
      }
 
      it.m_Duration++;
 
      float(&pp)[2] = it.m_History[it.m_HistoryPos].m_Pos;
 
      // maximum history size
      if (++it.m_HistorySize > history_size) it.m_HistorySize = history_size;
 
      if (++it.m_HistoryPos >= history_size) it.m_HistoryPos = 0;
 
      Particle::ParticleNode &n = it.m_History[it.m_HistoryPos];
      float(&p)[2] = n.m_Pos;
      double vkn = 0, ang;
 
      if (it.m_Duration < max_duration - history_size &&
          GribRecord::getInterpolatedValues(vkn, ang, pGRX, pGRY, pp[0],
                                            pp[1]) &&
          vkn > 0 && vkn < 100) {
        vkn = m_Settings.CalibrateValue(settings, vkn);
        double d;
        if (settings == GribOverlaySettings::CURRENT)
          d = vkn * run_count;
        else
          d = vkn * run_count / 4;
 
        ang += 180;
 
#if 0    // elliptical very accurate but incredibly slow
                double dp[2];
                PositionBearingDistanceMercator_Plugin(pp[1], pp[0], ang,
                                                       d, &dp[1], &dp[0]);
                p[0] = dp[0];
                p[1] = dp[1];
#elif 0  // really fast rectangular.. not really good at high latitudes
 
        float angr = ang / 180 * M_PI;
        p[0] = pp[0] + sinf(angr) * d / 60;
        p[1] = pp[1] + cosf(angr) * d / 60;
#else  // spherical (close enough)
        float angr = ang / 180 * M_PI;
        float latr = pp[1] * M_PI / 180;
        float D = d / 3443;  // earth radius in nm
        float sD = sinf(D), cD = cosf(D);
        float sy = sinf(latr), cy = cosf(latr);
        float sa = sinf(angr), ca = cosf(angr);
 
        p[0] = pp[0] + asinf(sa * sD / cy) * 180 / M_PI;
        p[1] = asinf(sy * cD + cy * sD * ca) * 180 / M_PI;
#endif
        wxPoint ps;
        GetCanvasPixLL(vp, &ps, p[1], p[0]);
 
        n.m_Screen[0] = ps.x;
        n.m_Screen[1] = ps.y;
 
        wxColor c = GetGraphicColor(settings, vkn);
 
        n.m_Color[0] = c.Red();
        n.m_Color[1] = c.Green();
        n.m_Color[2] = c.Blue();
      } else
        p[0] = -10000;
      ptime += sw.Time();
    }
  }
  m_bUpdateParticles = false;
 
  int total_particles = density * pGRX->getNi() * pGRX->getNj();
 
  // set max cap to avoid locking the program up
  if (total_particles > 60000) total_particles = 60000;
 
  // remove particles if needed;
  int remove_particles = ((int)particles.size() - total_particles) / 16;
  for (int i = 0; i < remove_particles; i++) particles.pop_back();
 
  // add new particles as needed
  int run = 0;
  int new_particles = (total_particles - (int)particles.size()) / 64;
 
  for (int npi = 0; npi < new_particles; npi++) {
    float p[2];
    double vkn, ang;
    for (int i = 0; i < 20; i++) {
      // random position in the grib area
      p[0] =
          (float)rand() / RAND_MAX * (pGRX->getLonMax() - pGRX->getLonMin()) +
          pGRX->getLonMin();
      p[1] =
          (float)rand() / RAND_MAX * (pGRX->getLatMax() - pGRX->getLatMin()) +
          pGRX->getLatMin();
 
      if (GribRecord::getInterpolatedValues(vkn, ang, pGRX, pGRY, p[0], p[1]) &&
          vkn > 0 && vkn < 100)
        vkn = m_Settings.CalibrateValue(settings, vkn);
      else
        continue;  // try again
 
      /* try hard to find a random position where current is faster than 1 knot
       */
      if (settings != GribOverlaySettings::CURRENT || vkn > 1 - (double)i / 20)
        break;
    }
 
    Particle np;
    np.m_Duration = rand() % (max_duration / 2);
    np.m_HistoryPos = 0;
    np.m_HistorySize = 1;
    np.m_Run = run++;
    if (run == run_count) run = 0;
 
    memcpy(np.m_History[np.m_HistoryPos].m_Pos, p, sizeof p);
 
    wxPoint ps;
    GetCanvasPixLL(vp, &ps, p[1], p[0]);
    np.m_History[np.m_HistoryPos].m_Screen[0] = ps.x;
    np.m_History[np.m_HistoryPos].m_Screen[1] = ps.y;
 
    wxColour c = GetGraphicColor(settings, vkn);
    np.m_History[np.m_HistoryPos].m_Color[0] = c.Red();
    np.m_History[np.m_HistoryPos].m_Color[1] = c.Green();
    np.m_History[np.m_HistoryPos].m_Color[2] = c.Blue();
 
    particles.push_back(np);
  }
 
  // settings for opengl lines
  if (!m_pdc) {
    //      Enable anti-aliased lines, at best quality
    glEnable(GL_LINE_SMOOTH);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
    glLineWidth(2.3f);
  }
 
  int cnt = 0;
  unsigned char *&ca = m_ParticleMap->color_array;
  float *&va = m_ParticleMap->vertex_array;
  float *&caf = m_ParticleMap->color_float_array;
 
  if (m_ParticleMap->array_size < particles.size() && !m_pdc) {
    m_ParticleMap->array_size = 2 * particles.size();
    delete[] ca;
    delete[] va;
    delete[] caf;
 
    ca =
        new unsigned char[m_ParticleMap->array_size * MAX_PARTICLE_HISTORY * 8];
    caf = new float[m_ParticleMap->array_size * MAX_PARTICLE_HISTORY * 8];
    va = new float[m_ParticleMap->array_size * MAX_PARTICLE_HISTORY * 4];
  }
 
  // draw particles
  for (std::vector<Particle>::iterator it = particles.begin();
       it != particles.end(); it++) {
    wxUint8 alpha = 250;
 
    int i = it->m_HistoryPos;
 
    bool lip_valid = false;
    float *lp = nullptr, lip[2];
    wxUint8 lc[4];
    float lcf[4];
 
    for (;;) {
      float(&dp)[2] = it->m_History[i].m_Pos;
      if (dp[0] != -10000) {
        float(&sp)[2] = it->m_History[i].m_Screen;
        wxUint8(&ci)[3] = it->m_History[i].m_Color;
 
        wxUint8 c[4] = {ci[0], ci[1], (unsigned char)(ci[2] + 240 - alpha / 2),
                        alpha};
        float cf[4];
        cf[0] = ci[0] / 256.;
        cf[1] = ci[1] / 256.;
        cf[2] = ((unsigned char)(ci[2] + 240 - alpha / 2)) / 256.;
        cf[3] = alpha / 256.;
 
        if (lp && fabsf(lp[0] - sp[0]) < vp->pix_width) {
          float sip[2];
 
          // interpolate between points..  a cubic interpolation
          // might allow a much higher run_count
          float d = (float)it->m_Run / run_count;
          for (int j = 0; j < 2; j++) sip[j] = d * lp[j] + (1 - d) * sp[j];
 
          if (lip_valid && fabsf(lip[0] - sip[0]) < vp->pix_width) {
            if (m_pdc) {
              m_pdc->SetPen(wxPen(wxColour(c[0], c[1], c[2]), 2));
              m_pdc->DrawLine(sip[0], sip[1], lip[0], lip[1]);
            } else {
              memcpy(ca + 4 * cnt, c, sizeof lc);
              memcpy(caf + 4 * cnt, cf, sizeof lcf);
              memcpy(va + 2 * cnt, lip, sizeof sp);
              cnt++;
              memcpy(ca + 4 * cnt, lc, sizeof c);
              memcpy(caf + 4 * cnt, lcf, sizeof cf);
              memcpy(va + 2 * cnt, sip, sizeof sp);
              cnt++;
            }
          }
 
          memcpy(lip, sip, sizeof lip);
          lip_valid = true;
        }
 
        memcpy(lc, c, sizeof lc);
        memcpy(lcf, cf, sizeof lcf);
 
        lp = sp;
      }
 
      if (--i < 0) {
        i = history_size - 1;
        if (i >= it->m_HistorySize) break;
      }
 
      if (i == it->m_HistoryPos) break;
 
      alpha -= 240 / history_size;
    }
  }
 
  if (!m_pdc) {
    if (m_oDC) {
      m_oDC->DrawGLLineArray(cnt, va, caf, ca, false);
    }
  }
 
  //  On some platforms, especially slow ones, the GPU will lag behind the CPU.
  //  This affects the UI in strange ways.
  //  So, force the GPU to flush all of its outstanding commands on the outer
  //  loop This will have no real affect on most machines.
#ifdef __WXMSW__
  if (!m_pdc) glFlush();
#endif
 
  int time = sw.Time();
 
  //  Try to run at 20 fps,
  //  But also arrange not to consume more than 33% CPU(core) duty cycle
  m_tParticleTimer.Start(wxMax(50 - time, 2 * time), wxTIMER_ONE_SHOT);
 
#if 0
    static int total_time;
    total_time += time;
    static int total_count;
    if(++total_count == 100) {
        printf("time: %.2f\n", (double)total_time / total_count);
        total_time = total_count = 0;
    }
#endif
}
 
void GRIBOverlayFactory::OnParticleTimer(wxTimerEvent &event) {
  m_bUpdateParticles = true;
 
  // If multicanvas are active, render the overlay on the right canvas only
  if (GetCanvasCount() > 1)               // multi?
    GetCanvasByIndex(1)->Refresh(false);  // update the last rendered canvas
  else
    GetOCPNCanvasWindow()->Refresh(false);
}
 
void GRIBOverlayFactory::DrawProjectedPosition(int x, int y) {
  if (m_pdc) {
    wxDC &dc = *m_pdc;
    dc.SetPen(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
    dc.SetBrush(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOW));
    dc.DrawRectangle(x, y, 20, 20);
    dc.DrawLine(x, y, x + 20, y + 20);
    dc.DrawLine(x, y + 20, x + 20, y);
  } else {
    if (m_oDC) {
      m_oDC->SetPen(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
      m_oDC->SetBrush(wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOW));
      m_oDC->DrawRectangle(x - 10, y - 10, 20, 20);
      m_oDC->StrokeLine(x - 10, y - 10, x + 10, y + 10);
      m_oDC->StrokeLine(x - 10, y + 10, x + 10, y - 10);
    }
  }
}
 
void GRIBOverlayFactory::DrawMessageWindow(wxString msg, int x, int y,
                                           wxFont *mfont) {
  if (msg.empty()) return;
 
  int ScaleBare_H = 30;  // futur : get the position/size from API?
 
  if (m_pdc) {
    wxDC &dc = *m_pdc;
    dc.SetFont(*mfont);
    dc.SetPen(*wxTRANSPARENT_PEN);
 
    dc.SetBrush(wxColour(243, 229, 47));
    int w, h;
    dc.GetMultiLineTextExtent(msg, &w, &h);
    h += 2;
    int yp = y - (ScaleBare_H + GetChartbarHeight() + h);
 
    int label_offset = 10;
    int wdraw = w + (label_offset * 2);
    dc.DrawRectangle(0, yp, wdraw, h);
    dc.DrawLabel(msg, wxRect(label_offset, yp, wdraw, h),
                 wxALIGN_LEFT | wxALIGN_CENTRE_VERTICAL);
  } else {
    if (m_oDC) {
      m_oDC->SetFont(*mfont);
      m_oDC->SetPen(*wxTRANSPARENT_PEN);
 
      m_oDC->SetBrush(wxColour(243, 229, 47));
      int w, h;
      m_oDC->GetTextExtent(msg, &w, &h);
      h += 2;
 
      int label_offset = 10;
      int wdraw = w + (label_offset * 2);
      wdraw *= g_ContentScaleFactor;
      h *= g_ContentScaleFactor;
      int yp = y - (ScaleBare_H + GetChartbarHeight() + h);
 
      m_oDC->DrawRectangle(0, yp, wdraw, h);
      m_oDC->DrawText(msg, label_offset, yp);
    }
    /*
            m_TexFontMessage.Build(*mfont);
            int w, h;
            m_TexFontMessage.GetTextExtent( msg, &w, &h);
            h += 2;
            int yp = y - ( 2 * GetChartbarHeight() + h );
 
            glColor3ub( 243, 229, 47 );
 
            glBegin(GL_QUADS);
            glVertex2i(0, yp);
            glVertex2i(w, yp);
            glVertex2i(w, yp+h);
            glVertex2i(0, yp+h);
            glEnd();
 
            glEnable(GL_BLEND);
            glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 
            glColor3ub( 0, 0, 0 );
            glEnable(GL_TEXTURE_2D);
            m_TexFontMessage.RenderString( msg, 0, yp);
            glDisable(GL_TEXTURE_2D);
    */
  }
}
 
void GRIBOverlayFactory::drawDoubleArrow(int x, int y, double ang,
                                         wxColour arrowColor, int arrowWidth,
                                         int arrowSizeIdx, double scale) {
  if (m_pdc) {
    wxPen pen(arrowColor, 2);
    m_pdc->SetPen(pen);
    m_pdc->SetBrush(*wxTRANSPARENT_BRUSH);
#if wxUSE_GRAPHICS_CONTEXT
    if (m_hiDefGraphics && m_gdc) m_gdc->SetPen(pen);
#endif
  } else {
    if (m_oDC) {
      wxPen pen(arrowColor, arrowWidth);
      m_oDC->SetPen(pen);
    }
  }
 
  drawLineBuffer(m_DoubleArrow[arrowSizeIdx], x, y, ang, scale);
}
 
void GRIBOverlayFactory::drawSingleArrow(int x, int y, double ang,
                                         wxColour arrowColor, int arrowWidth,
                                         int arrowSizeIdx, double scale) {
  if (m_pdc) {
    wxPen pen(arrowColor, arrowWidth);
    m_pdc->SetPen(pen);
    m_pdc->SetBrush(*wxTRANSPARENT_BRUSH);
#if wxUSE_GRAPHICS_CONTEXT
    if (m_hiDefGraphics && m_gdc) m_gdc->SetPen(pen);
#endif
  } else {
    if (m_oDC) {
      wxPen pen(arrowColor, arrowWidth);
      m_oDC->SetPen(pen);
    }
  }
 
  drawLineBuffer(m_SingleArrow[arrowSizeIdx], x, y, ang, scale);
}
 
void GRIBOverlayFactory::drawWindArrowWithBarbs(int settings, int x, int y,
                                                double vkn, double ang,
                                                bool south, wxColour arrowColor,
                                                double rotate_angle) {
  if (m_Settings.Settings[settings].m_iBarbedColour == 1)
    arrowColor = GetGraphicColor(settings, vkn);
 
// TODO
//   Needs investigation
//   This conditional should not really be necessary, but is safe.
#ifndef __MSVC__
  float penWidth = .6 / m_pixelMM;
#else
  float penWidth = .4 / m_pixelMM;
#endif
  penWidth = wxMin(penWidth, 3.0);
 
  if (m_pdc) {
    wxPen pen(arrowColor, 2);
    m_pdc->SetPen(pen);
    m_pdc->SetBrush(*wxTRANSPARENT_BRUSH);
 
#if wxUSE_GRAPHICS_CONTEXT
    if (m_hiDefGraphics && m_gdc) m_gdc->SetPen(pen);
#endif
  }
#ifdef ocpnUSE_GL
  else {
    if (m_oDC) {
      wxPen pen(arrowColor, penWidth);
      m_oDC->SetPen(pen);
    }
    //         else
    //             glColor3ub(arrowColor.Red(), arrowColor.Green(),
    //             arrowColor.Blue());
  }
#endif
 
  int cacheidx;
 
  if (vkn < 1)
    cacheidx = 0;
  else if (vkn < 2.5)
    cacheidx = 1;
  else if (vkn < 40)
    cacheidx = (int)(vkn + 2.5) / 5;
  else if (vkn < 90)
    cacheidx = (int)(vkn + 5) / 10 + 4;
  else
    cacheidx = 13;
 
  ang += rotate_angle;
 
  drawLineBuffer(m_WindArrowCache[cacheidx], x, y, ang, 1.0, south,
                 m_bDrawBarbedArrowHead);
}
 
void GRIBOverlayFactory::drawLineBuffer(LineBuffer &buffer, int x, int y,
                                        double ang, double scale, bool south,
                                        bool head) {
  // transform vertexes by angle
  float six = sinf(ang), cox = cosf(ang), siy, coy;
  if (south)
    siy = -six, coy = -cox;
  else
    siy = six, coy = cox;
 
  float vertexes[40];
  int count = buffer.count;
 
  if (!head) {
    count -= 2;
  }
  wxASSERT(sizeof vertexes / sizeof *vertexes >= (unsigned)count * 4);
  for (int i = 0; i < 2 * count; i++) {
    int j = i;
    if (!head && i > 1) j += 4;
    float *k = buffer.lines + 2 * j;
    vertexes[2 * i + 0] = k[0] * cox * scale + k[1] * siy * scale + x;
    vertexes[2 * i + 1] = k[0] * six * scale - k[1] * coy * scale + y;
  }
 
  if (m_pdc) {
    for (int i = 0; i < count; i++) {
      float *l = vertexes + 4 * i;
#if wxUSE_GRAPHICS_CONTEXT
      if (m_hiDefGraphics && m_gdc)
        m_gdc->StrokeLine(l[0], l[1], l[2], l[3]);
      else
#endif
        m_pdc->DrawLine(l[0], l[1], l[2], l[3]);
    }
  } else {  // OpenGL mode
#ifdef ocpnUSE_GL
    if (m_oDC) {
      for (int i = 0; i < count; i++) {
        float *l = vertexes + 4 * i;
        if (m_hiDefGraphics)
          m_oDC->StrokeLine(l[0], l[1], l[2], l[3]);
        else
          m_oDC->DrawLine(l[0], l[1], l[2], l[3]);
      }
    }
 
//        glVertexPointer(2, GL_FLOAT, 2*sizeof(float), vertexes);
//        glDrawArrays(GL_LINES, 0, 2*count);
#endif
  }
}
 
#ifdef ocpnUSE_GL
//      Render a texture
//      x/y : origin in screen pixels of UPPER RIGHT corner of render rectangle
//      width/height : in screen pixels
void GRIBOverlayFactory::DrawSingleGLTexture(GribOverlay *pGO, GribRecord *pGR,
                                             double uv[], double x, double y,
                                             double width, double height) {
#if 1  // def __OCPN__ANDROID__
 
  glEnable(texture_format);
 
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
  glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_BLEND);
 
  float coords[8];
 
  coords[0] = -width;
  coords[1] = -height;
  coords[2] = 0;
  coords[3] = -height;
  coords[4] = 0;
  coords[5] = 0;
  coords[6] = -width;
  coords[7] = 0;
 
  extern int pi_texture_2D_shader_program;
  glUseProgram(pi_texture_2D_shader_program);
 
  // Get pointers to the attributes in the program.
  GLint mPosAttrib = glGetAttribLocation(pi_texture_2D_shader_program, "aPos");
  GLint mUvAttrib = glGetAttribLocation(pi_texture_2D_shader_program, "aUV");
 
  // Set up the texture sampler to texture unit 0
  GLint texUni = glGetUniformLocation(pi_texture_2D_shader_program, "uTex");
  glUniform1i(texUni, 0);
 
  // Disable VBO's (vertex buffer objects) for attributes.
  glBindBuffer(GL_ARRAY_BUFFER, 0);
  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 
  // Set the attribute mPosAttrib with the vertices in the screen coordinates...
  glVertexAttribPointer(mPosAttrib, 2, GL_FLOAT, GL_FALSE, 0, coords);
  // ... and enable it.
  glEnableVertexAttribArray(mPosAttrib);
 
  // Set the attribute mUvAttrib with the vertices in the GL coordinates...
  glVertexAttribPointer(mUvAttrib, 2, GL_FLOAT, GL_FALSE, 0, uv);
  // ... and enable it.
  glEnableVertexAttribArray(mUvAttrib);
 
  // Rotate
  float angle = 0;
  mat4x4 I, Q;
  mat4x4_identity(I);
  mat4x4_rotate_Z(Q, I, angle);
 
  // Translate
  Q[3][0] = x;
  Q[3][1] = y;
 
  GLint matloc =
      glGetUniformLocation(pi_texture_2D_shader_program, "TransformMatrix");
  glUniformMatrix4fv(matloc, 1, GL_FALSE, (const GLfloat *)Q);
 
  // Select the active texture unit.
  glActiveTexture(GL_TEXTURE0);
 
// Perform the actual drawing.
 
// For some reason, glDrawElements is busted on Android
// So we do this a hard ugly way, drawing two triangles...
#if 0
    GLushort indices1[] = {0,1,3,2};
    glDrawElements(GL_TRIANGLE_STRIP, 4, GL_UNSIGNED_SHORT, indices1);
#else
 
  float co1[8];
  co1[0] = coords[0];
  co1[1] = coords[1];
  co1[2] = coords[2];
  co1[3] = coords[3];
  co1[4] = coords[6];
  co1[5] = coords[7];
  co1[6] = coords[4];
  co1[7] = coords[5];
 
  float tco1[8];
  tco1[0] = uv[0];
  tco1[1] = uv[1];
  tco1[2] = uv[2];
  tco1[3] = uv[3];
  tco1[4] = uv[6];
  tco1[5] = uv[7];
  tco1[6] = uv[4];
  tco1[7] = uv[5];
 
  glVertexAttribPointer(mPosAttrib, 2, GL_FLOAT, GL_FALSE, 0, co1);
  glVertexAttribPointer(mUvAttrib, 2, GL_FLOAT, GL_FALSE, 0, tco1);
 
  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
  glDisable(GL_BLEND);
  glDisable(texture_format);
 
  // Restore identity matrix
  mat4x4_identity(I);
  glUniformMatrix4fv(matloc, 1, GL_FALSE, (const GLfloat *)I);
 
#endif
 
#else
 
  glColor4f(1, 1, 1, 1);
  glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_BLEND);
 
  if (texture_format != GL_TEXTURE_2D) {
    for (int i = 0; i < 4; i++) {
      uv[i * 2] *= pGR->getNi();
      uv[(i * 2) + 1] *= pGR->getNj();
    }
  }
 
  glBegin(GL_QUADS);
  glTexCoord2d(uv[0], uv[1]), glVertex2f(x - width, y - height);
  glTexCoord2d(uv[2], uv[3]), glVertex2f(x, y - height);
  glTexCoord2d(uv[4], uv[5]), glVertex2f(x, y);
  glTexCoord2d(uv[6], uv[7]), glVertex2f(x - width, y);
  glEnd();
 
#endif
}
 
void GRIBOverlayFactory::DrawGLTexture(GribOverlay *pGO, GribRecord *pGR,
                                       PlugIn_ViewPort *vp) {
  glEnable(texture_format);
  glBindTexture(texture_format, pGO->m_iTexture);
 
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
  double lat_min = pGR->getLatMin(), lon_min = pGR->getLonMin();
 
  bool repeat = pGR->getLonMin() == 0 && pGR->getLonMax() + pGR->getDi() == 360;
 
  // how to break screen up, because projections may not be linear
  // smaller values offer more precision but become irrelevant
  // at lower zoom levels and near poles, use smaller tiles
 
  // This formula is generally "good enough" but is not optimal,
  // certainly not for all projections, and may result in
  // more tiles than actually needed in some cases
 
  double pw = vp->view_scale_ppm * 1e6 / (pow(2, fabs(vp->clat) / 25));
  if (pw < 20)  // minimum 20 pixel to avoid too many tiles
    pw = 20;
 
  int xsquares = ceil(vp->pix_width / pw), ysquares = ceil(vp->pix_height / pw);
 
  // optimization for non-rotated mercator, since longitude is linear
  if (vp->rotation == 0 && vp->m_projection_type == PI_PROJECTION_MERCATOR)
    xsquares = 1;
 
  // It is possible to have only 1 square when the viewport covers more than
  // 180 longitudes but there is more logic needed.  This is simpler.
  //    if(vp->lon_max - vp->lon_min >= 180) {
  xsquares = wxMax(xsquares, 2);
  ysquares = wxMax(ysquares, 2);
  //    }
 
  double xs = vp->pix_width / double(xsquares),
         ys = vp->pix_height / double(ysquares);
  int i = 0, j = 0;
  typedef double mx[2][2];
 
  mx *lva = new mx[xsquares + 1];
  int tw = pGO->m_iTextureDim[0], th = pGO->m_iTextureDim[1];
  double latstep = fabs(pGR->getDj()) / (th - 2 - 1) * (pGR->getNj() - 1);
  double lonstep = pGR->getDi() / (tw - 2 * !repeat - 1) * (pGR->getNi() - 1);
 
  double potNormX = (double)pGO->m_iTexDataDim[0] / tw;
  double potNormY = (double)pGO->m_iTexDataDim[1] / th;
 
  double clon = (lon_min + pGR->getLonMax()) / 2;
 
  for (double y = 0; y < vp->pix_height + ys / 2; y += ys) {
    i = 0;
 
    for (double x = 0; x < vp->pix_width + xs / 2; x += xs) {
      double lat, lon;
      wxPoint p(x, y);
      GetCanvasLLPix(vp, p, &lat, &lon);
 
      if (!repeat) {
        if (clon - lon > 180)
          lon += 360;
        else if (lon - clon > 180)
          lon -= 360;
      }
 
      lva[i][j][0] =
          (((lon - lon_min) / lonstep - repeat + 1.5) / tw) * potNormX;
      lva[i][j][1] = (((lat - lat_min) / latstep + 1.5) / th) * potNormY;
 
      if (pGR->getDj() < 0) lva[i][j][1] = 1 - lva[i][j][1];
 
      if (x > 0 && y > 0) {
        double u0 = lva[i - 1][!j][0], v0 = lva[i - 1][!j][1];
        double u1 = lva[i][!j][0], v1 = lva[i][!j][1];
        double u2 = lva[i][j][0], v2 = lva[i][j][1];
        double u3 = lva[i - 1][j][0], v3 = lva[i - 1][j][1];
 
        if (repeat) { /* ensure all 4 texcoords are in the same phase */
          if (u1 - u0 > .5)
            u1--;
          else if (u0 - u1 > .5)
            u1++;
          if (u2 - u0 > .5)
            u2--;
          else if (u0 - u2 > .5)
            u2++;
          if (u3 - u0 > .5)
            u3--;
          else if (u0 - u3 > .5)
            u3++;
        }
 
        if ((repeat ||
             ((u0 >= 0 || u1 >= 0 || u2 >= 0 || u3 >= 0) &&  // optimzations
              (u0 <= 1 || u1 <= 1 || u2 <= 1 || u3 <= 1))) &&
            (v0 >= 0 || v1 >= 0 || v2 >= 0 || v3 >= 0) &&
            (v0 <= 1 || v1 <= 1 || v2 <= 1 || v3 <= 1)) {
          double uv[8];
          uv[0] = u0;
          uv[1] = v0;
          uv[2] = u1;
          uv[3] = v1;
          uv[4] = u2;
          uv[5] = v2;
          uv[6] = u3;
          uv[7] = v3;
 
          if (u1 > u0) {
            DrawSingleGLTexture(pGO, pGR, uv, x, y, xs, ys);
          }
        }
      }
 
      i++;
    }
    j = !j;
  }
  delete[] lva;
 
  glDisable(GL_BLEND);
  glDisable(texture_format);
}
#endif