/**********************************************************************
 * $Id$
 *
 * Project:  MapServer
 * Purpose:  Graticule Renderer
 * Author:   John Novak, Novacell Technologies (jnovak@novacell.com)
 *
 **********************************************************************
 * Copyright (c) 2003, John Novak, Novacell Technologies
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies of this Software or works derived from this Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 ****************************************************************************/

#include "mapserver.h"
#include <assert.h>
#include "mapproject.h"

/**********************************************************************************************************************
 *
 */
typedef enum { posBottom = 1, posTop, posLeft, posRight } msGraticulePosition;

typedef enum {
  lpDefault = 0,
  lpDDMMSS = 1,
  lpDDMM,
  lpDD
} msLabelProcessingType;

void DefineAxis(int iTickCountTarget, double *Min, double *Max, double *Inc);
static int _AdjustLabelPosition(layerObj *pLayer, shapeObj *pShape,
                                msGraticulePosition ePosition);
static void _FormatLabel(layerObj *pLayer, shapeObj *pShape,
                         double dDataToFormat);

int msGraticuleLayerInitItemInfo(layerObj *layer);

#define MAPGRATICULE_ARC_SUBDIVISION_DEFAULT (256)
#define MAPGRATICULE_ARC_MINIMUM (16)
#define MAPGRATICULE_FORMAT_STRING_DEFAULT "%5.2g"
#define MAPGRATICULE_FORMAT_STRING_DDMMSS "%3d %02d %02d"
#define MAPGRATICULE_FORMAT_STRING_DDMM "%3d %02d"
#define MAPGRATICULE_FORMAT_STRING_DD "%3d"

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerOpen(layerObj *layer) {
  graticuleObj *pInfo = layer->grid;

  if (pInfo == NULL)
    return MS_FAILURE;

  pInfo->dincrementlatitude = 15.0;
  pInfo->dincrementlongitude = 15.0;
  pInfo->dwhichlatitude = -90.0;
  pInfo->dwhichlongitude = -180.0;
  pInfo->bvertical = 1;

  if (layer->numclasses == 0)
    msDebug("GRID layer has no classes, nothing will be rendered.\n");

  if (layer->numclasses > 0 && layer->class[0] -> numlabels > 0)
    pInfo->blabelaxes = 1;
  else
    pInfo->blabelaxes = 0;

  if (pInfo->labelformat == NULL) {
    pInfo->labelformat =
        (char *)msSmallMalloc(strlen(MAPGRATICULE_FORMAT_STRING_DEFAULT) + 1);
    pInfo->ilabeltype = (int)lpDefault;
    strcpy(pInfo->labelformat, MAPGRATICULE_FORMAT_STRING_DEFAULT);
  } else if (strcmp(pInfo->labelformat, "DDMMSS") == 0) {
    msFree(pInfo->labelformat);
    pInfo->labelformat =
        (char *)msSmallMalloc(strlen(MAPGRATICULE_FORMAT_STRING_DDMMSS) + 1);
    pInfo->ilabeltype = (int)lpDDMMSS;
    strcpy(pInfo->labelformat, MAPGRATICULE_FORMAT_STRING_DDMMSS);
  } else if (strcmp(pInfo->labelformat, "DDMM") == 0) {
    msFree(pInfo->labelformat);
    pInfo->labelformat =
        (char *)msSmallMalloc(strlen(MAPGRATICULE_FORMAT_STRING_DDMM) + 1);
    pInfo->ilabeltype = (int)lpDDMM;
    strcpy(pInfo->labelformat, MAPGRATICULE_FORMAT_STRING_DDMM);
  } else if (strcmp(pInfo->labelformat, "DD") == 0) {
    msFree(pInfo->labelformat);
    pInfo->labelformat =
        (char *)msSmallMalloc(strlen(MAPGRATICULE_FORMAT_STRING_DD) + 1);
    pInfo->ilabeltype = (int)lpDD;
    strcpy(pInfo->labelformat, MAPGRATICULE_FORMAT_STRING_DD);
  }

  return MS_SUCCESS;
}

/**********************************************************************************************************************
 * Return MS_TRUE if layer is open, MS_FALSE otherwise.
 */
int msGraticuleLayerIsOpen(layerObj *layer) {
  if (layer->grid)
    return MS_TRUE;

  return MS_FALSE;
}

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerClose(layerObj *layer) {
  (void)layer;
  return MS_SUCCESS;
}

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerWhichShapes(layerObj *layer, rectObj rect, int isQuery) {
  (void)isQuery;
  graticuleObj *pInfo = layer->grid;
  int iAxisTickCount = 0;
  rectObj rectMapCoordinates;

  if (msCheckParentPointer(layer->map, "map") == MS_FAILURE)
    return MS_FAILURE;

  pInfo->dstartlatitude = rect.miny;
  pInfo->dstartlongitude = rect.minx;
  pInfo->dendlatitude = rect.maxy;
  pInfo->dendlongitude = rect.maxx;
  pInfo->bvertical = 1;
  pInfo->extent = rect;

  if (pInfo->minincrement > 0.0) {
    pInfo->dincrementlongitude = pInfo->minincrement;
    pInfo->dincrementlatitude = pInfo->minincrement;
  } else if (pInfo->maxincrement > 0.0) {
    pInfo->dincrementlongitude = pInfo->maxincrement;
    pInfo->dincrementlatitude = pInfo->maxincrement;
  } else {
    pInfo->dincrementlongitude = 0;
    pInfo->dincrementlatitude = 0;
  }

  if (pInfo->maxarcs > 0)
    iAxisTickCount = (int)pInfo->maxarcs;
  else if (pInfo->minarcs > 0)
    iAxisTickCount = (int)pInfo->minarcs;

  DefineAxis(iAxisTickCount, &pInfo->dstartlongitude, &pInfo->dendlongitude,
             &pInfo->dincrementlongitude);
  DefineAxis(iAxisTickCount, &pInfo->dstartlatitude, &pInfo->dendlatitude,
             &pInfo->dincrementlatitude);

  pInfo->dwhichlatitude = pInfo->dstartlatitude;
  pInfo->dwhichlongitude = pInfo->dstartlongitude;

  if (pInfo->minincrement > 0.0 && pInfo->maxincrement > 0.0 &&
      pInfo->minincrement == pInfo->maxincrement) {
    pInfo->dincrementlongitude = pInfo->minincrement;
    pInfo->dincrementlatitude = pInfo->minincrement;
  } else if (pInfo->minincrement > 0.0) {
    pInfo->dincrementlongitude = pInfo->minincrement;
    pInfo->dincrementlatitude = pInfo->minincrement;
  } else if (pInfo->maxincrement > 0.0) {
    pInfo->dincrementlongitude = pInfo->maxincrement;
    pInfo->dincrementlatitude = pInfo->maxincrement;
  }

  /*
   * If using PROJ, project rect back into map system, and generate rect corner
   * points in native system. These lines will be used when generating labels to
   * get correct placement at arc/rect edge intersections.
   */
  rectMapCoordinates = layer->map->extent;

  layer->project =
      msProjectionsDiffer(&(layer->projection), &(layer->map->projection));
  if (layer->project && strstr(layer->map->projection.args[0], "epsg:3857") &&
      msProjIsGeographicCRS(&(layer->projection))) {
    if (rectMapCoordinates.minx < -20037508)
      rectMapCoordinates.minx = -20037508;
    if (rectMapCoordinates.maxx > 20037508)
      rectMapCoordinates.maxx = 20037508;
  }

  msFree(pInfo->pboundinglines);
  pInfo->pboundinglines = (lineObj *)msSmallMalloc(sizeof(lineObj) * 4);
  msFree(pInfo->pboundingpoints);
  pInfo->pboundingpoints = (pointObj *)msSmallMalloc(sizeof(pointObj) * 8);

  {

    /*
     * top
     */
    pInfo->pboundinglines[0].numpoints = 2;
    pInfo->pboundinglines[0].point = &pInfo->pboundingpoints[0];
    pInfo->pboundinglines[0].point[0].x = rectMapCoordinates.minx;
    pInfo->pboundinglines[0].point[0].y = rectMapCoordinates.maxy;
    pInfo->pboundinglines[0].point[1].x = rectMapCoordinates.maxx;
    pInfo->pboundinglines[0].point[1].y = rectMapCoordinates.maxy;

    if (layer->project)
      msProjectLine(&layer->map->projection, &layer->projection,
                    &pInfo->pboundinglines[0]);

    /*
     * bottom
     */
    pInfo->pboundinglines[1].numpoints = 2;
    pInfo->pboundinglines[1].point = &pInfo->pboundingpoints[2];
    pInfo->pboundinglines[1].point[0].x = rectMapCoordinates.minx;
    pInfo->pboundinglines[1].point[0].y = rectMapCoordinates.miny;
    pInfo->pboundinglines[1].point[1].x = rectMapCoordinates.maxx;
    pInfo->pboundinglines[1].point[1].y = rectMapCoordinates.miny;

    if (layer->project)
      msProjectLine(&layer->map->projection, &layer->projection,
                    &pInfo->pboundinglines[1]);

    /*
     * left
     */
    pInfo->pboundinglines[2].numpoints = 2;
    pInfo->pboundinglines[2].point = &pInfo->pboundingpoints[4];
    pInfo->pboundinglines[2].point[0].x = rectMapCoordinates.minx;
    pInfo->pboundinglines[2].point[0].y = rectMapCoordinates.miny;
    pInfo->pboundinglines[2].point[1].x = rectMapCoordinates.minx;
    pInfo->pboundinglines[2].point[1].y = rectMapCoordinates.maxy;

    if (layer->project)
      msProjectLine(&layer->map->projection, &layer->projection,
                    &pInfo->pboundinglines[2]);

    /*
     * right
     */
    pInfo->pboundinglines[3].numpoints = 2;
    pInfo->pboundinglines[3].point = &pInfo->pboundingpoints[6];
    pInfo->pboundinglines[3].point[0].x = rectMapCoordinates.maxx;
    pInfo->pboundinglines[3].point[0].y = rectMapCoordinates.miny;
    pInfo->pboundinglines[3].point[1].x = rectMapCoordinates.maxx;
    pInfo->pboundinglines[3].point[1].y = rectMapCoordinates.maxy;

    if (layer->project)
      msProjectLine(&layer->map->projection, &layer->projection,
                    &pInfo->pboundinglines[3]);
  }

  return MS_SUCCESS;
}

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerNextShape(layerObj *layer, shapeObj *shape) {
  graticuleObj *pInfo = layer->grid;

  if (pInfo->minsubdivides <= 0.0 || pInfo->maxsubdivides <= 0.0)
    pInfo->minsubdivides = pInfo->maxsubdivides =
        MAPGRATICULE_ARC_SUBDIVISION_DEFAULT;

  shape->numlines = 1;
  shape->type = MS_SHAPE_LINE;
  shape->line = (lineObj *)msSmallMalloc(sizeof(lineObj));
  shape->line->numpoints = (int)pInfo->maxsubdivides;
  shape->line->point = NULL;

  /*
   * Subdivide and draw current arc, rendering the arc labels first
   */
  if (pInfo->bvertical) {
    int iPointIndex;
    double dArcDelta = (pInfo->dendlatitude - pInfo->dstartlatitude) /
                       (double)shape->line->numpoints;
    double dArcPosition = pInfo->dstartlatitude + dArcDelta;
    double dStartY, dDeltaX;

    switch (pInfo->ilabelstate) {
    case 0:
      if (!pInfo->blabelaxes) { /* Bottom */
        pInfo->ilabelstate++;
        msFreeShape(shape);
        return MS_SUCCESS;
      }

      dDeltaX = (pInfo->dwhichlongitude - pInfo->pboundinglines[1].point[0].x) /
                (pInfo->pboundinglines[1].point[1].x -
                 pInfo->pboundinglines[1].point[0].x);
      if (dDeltaX < 0)
        dDeltaX = dDeltaX * -1;

      dStartY = (pInfo->pboundinglines[1].point[1].y -
                 pInfo->pboundinglines[1].point[0].y) *
                    dDeltaX +
                pInfo->pboundinglines[1].point[0].y;
      shape->line->numpoints = (int)2;
      shape->line->point = (pointObj *)msSmallMalloc(sizeof(pointObj) * 2);

      shape->line->point[0].x = pInfo->dwhichlongitude;
      shape->line->point[0].y = dStartY;
      shape->line->point[1].x = pInfo->dwhichlongitude;
      shape->line->point[1].y = dStartY + dArcDelta;

      _FormatLabel(layer, shape, shape->line->point[0].x);
      if (_AdjustLabelPosition(layer, shape, posBottom) != MS_SUCCESS) {
        msFreeShape(shape);
        pInfo->ilabelstate++;
        return MS_SUCCESS;
      }

      pInfo->ilabelstate++;
      return MS_SUCCESS;

    case 1:
      if (!pInfo->blabelaxes) { /* Top */
        pInfo->ilabelstate++;
        msFreeShape(shape);
        return MS_SUCCESS;
      }

      dDeltaX = (pInfo->dwhichlongitude - pInfo->pboundinglines[0].point[0].x) /
                (pInfo->pboundinglines[0].point[1].x -
                 pInfo->pboundinglines[0].point[0].x);
      if (dDeltaX < 0)
        dDeltaX = dDeltaX * -1;

      dStartY = (pInfo->pboundinglines[0].point[1].y -
                 pInfo->pboundinglines[0].point[0].y) *
                    dDeltaX +
                pInfo->pboundinglines[0].point[1].y;
      shape->line->numpoints = (int)2;
      shape->line->point = (pointObj *)msSmallMalloc(sizeof(pointObj) * 2);

      shape->line->point[0].x = pInfo->dwhichlongitude;
      shape->line->point[0].y = dStartY - dArcDelta;
      shape->line->point[1].x = pInfo->dwhichlongitude;
      shape->line->point[1].y = dStartY;

      _FormatLabel(layer, shape, shape->line->point[0].x);
      if (_AdjustLabelPosition(layer, shape, posTop) != MS_SUCCESS) {
        msFreeShape(shape);
        pInfo->ilabelstate++;
        return MS_SUCCESS;
      }

      pInfo->ilabelstate++;
      return MS_SUCCESS;

    case 2:
      shape->line->numpoints = (int)shape->line->numpoints + 1;
      shape->line->point =
          (pointObj *)msSmallMalloc(sizeof(pointObj) * shape->line->numpoints);

      shape->line->point[0].x = pInfo->dwhichlongitude;
      shape->line->point[0].y = pInfo->dstartlatitude;

      for (iPointIndex = 1; iPointIndex < shape->line->numpoints;
           iPointIndex++) {
        shape->line->point[iPointIndex].x = pInfo->dwhichlongitude;
        shape->line->point[iPointIndex].y = dArcPosition;

        dArcPosition += dArcDelta;
      }

      pInfo->ilabelstate = 0;

      pInfo->dwhichlongitude += pInfo->dincrementlongitude;
      break;

    default:
      pInfo->ilabelstate = 0;
      break;
    }

  } else { /*horizontal*/
    int iPointIndex;
    double dArcDelta = (pInfo->dendlongitude - pInfo->dstartlongitude) /
                       (double)shape->line->numpoints;
    double dArcPosition = pInfo->dstartlongitude + dArcDelta;
    double dStartX, dDeltaY;

    switch (pInfo->ilabelstate) {
    case 0:
      if (!pInfo->blabelaxes) { /* Left side */
        pInfo->ilabelstate++;
        msFreeShape(shape);
        return MS_SUCCESS;
      }

      dDeltaY = (pInfo->dwhichlatitude - pInfo->pboundinglines[2].point[0].y) /
                (pInfo->pboundinglines[2].point[1].y -
                 pInfo->pboundinglines[2].point[0].y);
      if (dDeltaY < 0)
        dDeltaY = dDeltaY * -1;

      dStartX = (pInfo->pboundinglines[2].point[1].x -
                 pInfo->pboundinglines[2].point[0].x) *
                    dDeltaY +
                pInfo->pboundinglines[2].point[0].x;
      shape->line->numpoints = (int)2;
      shape->line->point = (pointObj *)msSmallMalloc(sizeof(pointObj) * 2);

      shape->line->point[0].x = dStartX;
      shape->line->point[0].y = pInfo->dwhichlatitude;
      shape->line->point[1].x = dStartX + dArcDelta;
      shape->line->point[1].y = pInfo->dwhichlatitude;

      _FormatLabel(layer, shape, shape->line->point[0].y);
      if (_AdjustLabelPosition(layer, shape, posLeft) != MS_SUCCESS) {
        msFreeShape(shape);
        pInfo->ilabelstate++;
        return MS_SUCCESS;
      }

      pInfo->ilabelstate++;
      return MS_SUCCESS;

    case 1:
      if (!pInfo->blabelaxes) { /* Right side */
        pInfo->ilabelstate++;
        msFreeShape(shape);
        return MS_SUCCESS;
      }

      dDeltaY = (pInfo->dwhichlatitude - pInfo->pboundinglines[3].point[0].y) /
                (pInfo->pboundinglines[3].point[1].y -
                 pInfo->pboundinglines[3].point[0].y);
      if (dDeltaY < 0)
        dDeltaY = dDeltaY * -1;

      dStartX = (pInfo->pboundinglines[3].point[1].x -
                 pInfo->pboundinglines[3].point[0].x) *
                    dDeltaY +
                pInfo->pboundinglines[3].point[0].x;
      shape->line->numpoints = (int)2;
      shape->line->point = (pointObj *)msSmallMalloc(sizeof(pointObj) * 2);

      shape->line->point[0].x = dStartX - dArcDelta;
      shape->line->point[0].y = pInfo->dwhichlatitude;
      shape->line->point[1].x = dStartX;
      shape->line->point[1].y = pInfo->dwhichlatitude;

      _FormatLabel(layer, shape, shape->line->point[0].y);
      if (_AdjustLabelPosition(layer, shape, posRight) != MS_SUCCESS) {
        msFreeShape(shape);
        pInfo->ilabelstate++;
        return MS_SUCCESS;
      }

      pInfo->ilabelstate++;
      return MS_SUCCESS;

    case 2:
      shape->line->numpoints = (int)shape->line->numpoints + 1;
      shape->line->point =
          (pointObj *)msSmallMalloc(sizeof(pointObj) * shape->line->numpoints);

      shape->line->point[0].x = pInfo->dstartlongitude;
      shape->line->point[0].y = pInfo->dwhichlatitude;

      for (iPointIndex = 1; iPointIndex < shape->line->numpoints;
           iPointIndex++) {
        shape->line->point[iPointIndex].x = dArcPosition;
        shape->line->point[iPointIndex].y = pInfo->dwhichlatitude;

        dArcPosition += dArcDelta;
      }

      pInfo->ilabelstate = 0;
      pInfo->dwhichlatitude += pInfo->dincrementlatitude;
      break;

    default:
      pInfo->ilabelstate = 0;
      break;
    }
  }

  /*
   * Increment and move to next arc
   */

  if (pInfo->bvertical && pInfo->dwhichlongitude > pInfo->dendlongitude) {
    pInfo->dwhichlatitude = pInfo->dstartlatitude;
    pInfo->bvertical = 0;
  }

  if (pInfo->dwhichlatitude > pInfo->dendlatitude) {
    /* free the lineObj and pointObj that have been erroneously allocated
     * beforehand */
    msFreeShape(shape);
    return MS_DONE;
  }

  return MS_SUCCESS;
}

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerGetItems(layerObj *layer) {
  char **ppItemName = (char **)msSmallMalloc(sizeof(char *));

  *ppItemName = (char *)msSmallMalloc(64); /* why is this necessary? */
  strcpy(*ppItemName, "Graticule");

  layer->numitems = 1;
  layer->items = ppItemName;

  return MS_SUCCESS;
}

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerInitItemInfo(layerObj *layer) {
  (void)layer;
  return MS_SUCCESS;
}

/**********************************************************************************************************************
 *
 */
void msGraticuleLayerFreeItemInfo(layerObj *layer) { (void)layer; }

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerGetShape(layerObj *layer, shapeObj *shape,
                             resultObj *record) {
  (void)layer;
  (void)shape;
  (void)record;
  return MS_FAILURE;
}

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerGetExtent(layerObj *layer, rectObj *extent) {
  graticuleObj *pInfo = layer->grid;

  if (pInfo) {
    *extent = pInfo->extent;
    return MS_SUCCESS;
  }

  return MS_FAILURE;
}

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerGetAutoStyle(mapObj *map, layerObj *layer, classObj *c,
                                 shapeObj *shape) {
  (void)map;
  (void)layer;
  (void)c;
  (void)shape;
  return MS_SUCCESS;
}

/************************************************************************/
/*                  msGraticuleLayerFreeIntersectionPoints              */
/*                                                                      */
/*      Free intersection object.                                       */
/************************************************************************/
void msGraticuleLayerFreeIntersectionPoints(graticuleIntersectionObj *psValue) {
  if (psValue) {
    for (int i = 0; i < psValue->nTop; i++)
      msFree(psValue->papszTopLabels[i]);
    msFree(psValue->papszTopLabels);
    msFree(psValue->pasTop);

    for (int i = 0; i < psValue->nBottom; i++)
      msFree(psValue->papszBottomLabels[i]);
    msFree(psValue->papszBottomLabels);
    msFree(psValue->pasBottom);

    for (int i = 0; i < psValue->nLeft; i++)
      msFree(psValue->papszLeftLabels[i]);
    msFree(psValue->papszLeftLabels);
    msFree(psValue->pasLeft);

    for (int i = 0; i < psValue->nRight; i++)
      msFree(psValue->papszRightLabels[i]);
    msFree(psValue->papszRightLabels);
    msFree(psValue->pasRight);

    msFree(psValue);
  }
}

/************************************************************************/
/*                  msGraticuleLayerInitIntersectionPoints              */
/*                                                                      */
/*      init intersection object.                                       */
/************************************************************************/
static void
msGraticuleLayerInitIntersectionPoints(graticuleIntersectionObj *psValue) {
  if (psValue) {
    psValue->nTop = 0;
    psValue->pasTop = NULL;
    psValue->papszTopLabels = NULL;
    psValue->nBottom = 0;
    psValue->pasBottom = NULL;
    psValue->papszBottomLabels = NULL;
    psValue->nLeft = 0;
    psValue->pasLeft = NULL;
    psValue->papszLeftLabels = NULL;
    psValue->nRight = 0;
    psValue->pasRight = NULL;
    psValue->papszRightLabels = NULL;
  }
}

/************************************************************************/
/*                  msGraticuleLayerGetIntersectionPoints               */
/*                                                                      */
/*      Utility function thar returns all intersection positions and    */
/*      labels (4 sides of the map) for a grid layer.                   */
/************************************************************************/
graticuleIntersectionObj *
msGraticuleLayerGetIntersectionPoints(mapObj *map, layerObj *layer) {

  shapeObj shapegrid, tmpshape;
  rectObj searchrect;
  int status;
  pointObj oFirstPoint;
  pointObj oLastPoint;
  lineObj oLineObj;
  rectObj cliprect;
  graticuleObj *pInfo = NULL;
  double dfTmp;
  int i = 0;

  if (layer->connectiontype != MS_GRATICULE)
    return NULL;

  pInfo = layer->grid;

  /*set cellsize if bnot already set*/
  if (map->cellsize == 0)
    map->cellsize = msAdjustExtent(&(map->extent), map->width, map->height);

  if (layer->transform == MS_TRUE)
    searchrect = map->extent;
  else {
    searchrect.minx = searchrect.miny = 0;
    searchrect.maxx = map->width - 1;
    searchrect.maxy = map->height - 1;
  }

  if ((map->projection.numargs > 0) && (layer->projection.numargs > 0))
    msProjectRect(&map->projection, &layer->projection,
                  &searchrect); /* project the searchrect to source coords */

  status = msLayerOpen(layer);
  if (status != MS_SUCCESS)
    return NULL;

  status = msLayerWhichShapes(layer, searchrect, MS_FALSE);
  if (status == MS_DONE) { /* no overlap */
    msLayerClose(layer);
    return NULL;
  } else if (status != MS_SUCCESS) {
    msLayerClose(layer);
    return NULL;
  }

  /* step through the target shapes */
  msInitShape(&shapegrid);
  cliprect.minx = map->extent.minx - map->cellsize;
  cliprect.miny = map->extent.miny - map->cellsize;
  cliprect.maxx = map->extent.maxx + map->cellsize;
  cliprect.maxy = map->extent.maxy + map->cellsize;

  /* clip using the layer projection */
  /* msProjectRect(&map->projection , &layer->projection,  &cliprect); */

  graticuleIntersectionObj *psValues =
      (graticuleIntersectionObj *)msSmallMalloc(
          sizeof(graticuleIntersectionObj));
  msGraticuleLayerInitIntersectionPoints(psValues);

  while ((status = msLayerNextShape(layer, &shapegrid)) == MS_SUCCESS) {
    /*don't really need a class here*/
    /*
      shapegrid.classindex = msShapeGetClass(layer, &shapegrid, map->scaledenom,
    NULL, 0); if((shapegrid.classindex == -1) ||
    (layer->class[shapegrid.classindex]->status == MS_OFF)) {
    msFreeShape(&shapegrid);
    continue;
    }
    */

    msInitShape(&tmpshape);
    msCopyShape(&shapegrid, &tmpshape);
    /* status = msDrawShape(map, layer, &tmpshape, image, -1); */

    if (layer->project) {
      if (layer->reprojectorLayerToMap == NULL) {
        layer->reprojectorLayerToMap =
            msProjectCreateReprojector(&layer->projection, &map->projection);
      }
      if (layer->reprojectorLayerToMap)
        msProjectShapeEx(layer->reprojectorLayerToMap, &shapegrid);
    }

    msClipPolylineRect(&shapegrid, cliprect);

    msTransformShapeToPixelRound(&shapegrid, map->extent, map->cellsize);

    if (shapegrid.numlines <= 0 ||
        shapegrid.line[0].numpoints <
            2) { /* once clipped the shape didn't need to be drawn */
      msFreeShape(&shapegrid);
      msFreeShape(&tmpshape);
      continue;
    }

    {
      int iTmpLine = 0;
      int nNumPoints = 0;
      /*grid code seems to retunr lines that can double cross the extenst??*/
      /*creating a more than one clipped shape. Take the shape that has the most
        points, which should be the most likley to be correct*/

      if (shapegrid.numlines > 1) {
        for (i = 0; i < shapegrid.numlines; i++) {
          if (shapegrid.line[i].numpoints > nNumPoints) {
            nNumPoints = shapegrid.line[i].numpoints;
            iTmpLine = i;
          }
        }
      }
      /* get the first and last point*/
      oFirstPoint.x = shapegrid.line[iTmpLine].point[0].x;
      oFirstPoint.y = shapegrid.line[iTmpLine].point[0].y;
      oLineObj = shapegrid.line[iTmpLine];
      oLastPoint.x = oLineObj.point[oLineObj.numpoints - 1].x;
      oLastPoint.y = oLineObj.point[oLineObj.numpoints - 1].y;

      if (pInfo->bvertical) { /*vertical*/
        /*SHAPES ARE DRAWN FROM BOTTOM TO TOP.*/
        /*Normally lines are drawn FROM BOTTOM TO TOP but not always for some
        reason, so make sure that firstpoint < lastpoint in y, We are in pixel
        coordinates so y increases as we we go down*/
        if (oFirstPoint.y < oLastPoint.y) {
          dfTmp = oFirstPoint.x;
          oFirstPoint.x = oLastPoint.x;
          oLastPoint.x = dfTmp;
          dfTmp = oFirstPoint.y;
          oFirstPoint.y = oLastPoint.y;
          oLastPoint.y = dfTmp;
        }

        /*first point should cross the BOTTOM base where y== map->height*/

        if (abs((int)oFirstPoint.y - map->height) <= 1) {
          char *pszLabel = NULL;
          oFirstPoint.y = map->height;

          /*validate point is in map width/height*/
          if (oFirstPoint.x < 0 || oFirstPoint.x > map->width)
            continue;

          /*validate point is in map width/height*/
          if (oLastPoint.x < 0 || oLastPoint.x > map->width)
            continue;

          if (shapegrid.text)
            pszLabel = msStrdup(shapegrid.text);
          else {
            _FormatLabel(
                layer, &tmpshape,
                tmpshape.line[0].point[tmpshape.line[0].numpoints - 1].x);
            if (tmpshape.text)
              pszLabel = msStrdup(tmpshape.text);
            else
              pszLabel = msStrdup("unknown");
          }
          /*validate that the  value is not already in the array*/
          if (psValues->nBottom > 0) {
            /* if (psValues->pasBottom[psValues->nBottom-1].x == oFirstPoint.x)
                 continue; */

            for (i = 0; i < psValues->nBottom; i++) {
              if (psValues->pasBottom[i].x == oFirstPoint.x)
                break;
            }
            if (i < psValues->nBottom) {
              msFree(pszLabel);
              continue;
            }
          }
          if (psValues->pasBottom == NULL) {
            psValues->pasBottom = (pointObj *)msSmallMalloc(sizeof(pointObj));
            psValues->papszBottomLabels =
                (char **)msSmallMalloc(sizeof(char *));
            psValues->nBottom = 1;
          } else {
            psValues->nBottom++;
            psValues->pasBottom = (pointObj *)msSmallRealloc(
                psValues->pasBottom, sizeof(pointObj) * psValues->nBottom);
            psValues->papszBottomLabels =
                (char **)msSmallRealloc(psValues->papszBottomLabels,
                                        sizeof(char *) * psValues->nBottom);
          }

          psValues->pasBottom[psValues->nBottom - 1].x = oFirstPoint.x;
          psValues->pasBottom[psValues->nBottom - 1].y = oFirstPoint.y;
          psValues->papszBottomLabels[psValues->nBottom - 1] = pszLabel;
        }
        /*first point should cross the TOP base where y==0*/
        if (abs((int)oLastPoint.y) <= 1) {
          char *pszLabel = NULL;
          oLastPoint.y = 0;

          /*validate point is in map width/height*/
          if (oLastPoint.x < 0 || oLastPoint.x > map->width)
            continue;

          if (shapegrid.text)
            pszLabel = msStrdup(shapegrid.text);
          else {
            _FormatLabel(
                layer, &tmpshape,
                tmpshape.line[0].point[tmpshape.line[0].numpoints - 1].x);
            if (tmpshape.text)
              pszLabel = msStrdup(tmpshape.text);
            else
              pszLabel = msStrdup("unknown");
          }
          /*validate if same value is not already there*/
          if (psValues->nTop > 0) {
            /* if (psValues->pasTop[psValues->nTop-1].x == oLastPoint.x)
                 continue; */

            for (i = 0; i < psValues->nTop; i++) {
              if (psValues->pasTop[i].x == oLastPoint.x ||
                  strcasecmp(pszLabel, psValues->papszTopLabels[i]) == 0)
                break;
            }
            if (i < psValues->nTop) {
              msFree(pszLabel);
              continue;
            }
          }

          if (psValues->pasTop == NULL) {
            psValues->pasTop = (pointObj *)msSmallMalloc(sizeof(pointObj));
            psValues->papszTopLabels = (char **)msSmallMalloc(sizeof(char *));
            psValues->nTop = 1;
          } else {
            psValues->nTop++;
            psValues->pasTop = (pointObj *)msSmallRealloc(
                psValues->pasTop, sizeof(pointObj) * psValues->nTop);
            psValues->papszTopLabels = (char **)msSmallRealloc(
                psValues->papszTopLabels, sizeof(char *) * psValues->nTop);
          }

          psValues->pasTop[psValues->nTop - 1].x = oLastPoint.x;
          psValues->pasTop[psValues->nTop - 1].y = oLastPoint.y;
          psValues->papszTopLabels[psValues->nTop - 1] = pszLabel;
        }
      } else { /*horzontal*/
        /*Normally lines are drawn from left to right but not always for some
          reason, so make sure that firstpoint < lastpoint in x*/
        if (oFirstPoint.x > oLastPoint.x) {

          dfTmp = oFirstPoint.x;
          oFirstPoint.x = oLastPoint.x;
          oLastPoint.x = dfTmp;
          dfTmp = oFirstPoint.y;
          oFirstPoint.y = oLastPoint.y;
          oLastPoint.y = dfTmp;
        }
        /*first point should cross the LEFT base where x=0 axis*/
        if (abs((int)oFirstPoint.x) <= 1) {
          char *pszLabel = NULL;
          oFirstPoint.x = 0;

          /*validate point is in map width/height*/
          if (oFirstPoint.y < 0 || oFirstPoint.y > map->height)
            continue;

          if (shapegrid.text)
            pszLabel = msStrdup(shapegrid.text);
          else {
            _FormatLabel(
                layer, &tmpshape,
                tmpshape.line[0].point[tmpshape.line[0].numpoints - 1].y);
            if (tmpshape.text)
              pszLabel = msStrdup(tmpshape.text);
            else
              pszLabel = msStrdup("unknown");
          }

          /*validate that the previous value is not the same*/
          if (psValues->nLeft > 0) {
            /* if (psValues->pasLeft[psValues->nLeft-1].y == oFirstPoint.y)
                 continue; */

            for (i = 0; i < psValues->nLeft; i++) {
              if (psValues->pasLeft[i].y == oFirstPoint.y)
                break;
            }
            if (i < psValues->nLeft) {
              msFree(pszLabel);
              continue;
            }
          }
          if (psValues->pasLeft == NULL) {
            psValues->pasLeft = (pointObj *)msSmallMalloc(sizeof(pointObj));
            psValues->papszLeftLabels = (char **)msSmallMalloc(sizeof(char *));
            psValues->nLeft = 1;
          } else {
            psValues->nLeft++;
            psValues->pasLeft = (pointObj *)msSmallRealloc(
                psValues->pasLeft, sizeof(pointObj) * psValues->nLeft);
            psValues->papszLeftLabels = (char **)msSmallRealloc(
                psValues->papszLeftLabels, sizeof(char *) * psValues->nLeft);
          }

          psValues->pasLeft[psValues->nLeft - 1].x = oFirstPoint.x;
          psValues->pasLeft[psValues->nLeft - 1].y = oFirstPoint.y;
          psValues->papszLeftLabels[psValues->nLeft - 1] =
              pszLabel; /* takes ownership of allocated pszLabel */
        }
        /*first point should cross the RIGHT base where x=map=>width axis*/
        if (abs((int)oLastPoint.x - map->width) <= 1) {
          char *pszLabel = NULL;
          oLastPoint.x = map->width;

          /*validate point is in map width/height*/
          if (oLastPoint.y < 0 || oLastPoint.y > map->height)
            continue;

          if (shapegrid.text)
            pszLabel = msStrdup(shapegrid.text);
          else {
            _FormatLabel(
                layer, &tmpshape,
                tmpshape.line[0].point[tmpshape.line[0].numpoints - 1].y);
            if (tmpshape.text)
              pszLabel = msStrdup(tmpshape.text);
            else
              pszLabel = msStrdup("unknown");
          }

          /*validate that the previous value is not the same*/
          if (psValues->nRight > 0) {
            /* if (psValues->pasRight[psValues->nRight-1].y == oLastPoint.y)
                 continue; */
            for (i = 0; i < psValues->nRight; i++) {
              if (psValues->pasRight[i].y == oLastPoint.y)
                break;
            }
            if (i < psValues->nRight) {
              msFree(pszLabel);
              continue;
            }
          }
          if (psValues->pasRight == NULL) {
            psValues->pasRight = (pointObj *)msSmallMalloc(sizeof(pointObj));
            psValues->papszRightLabels = (char **)msSmallMalloc(sizeof(char *));
            psValues->nRight = 1;
          } else {
            psValues->nRight++;
            psValues->pasRight = (pointObj *)msSmallRealloc(
                psValues->pasRight, sizeof(pointObj) * psValues->nRight);
            psValues->papszRightLabels = (char **)msSmallRealloc(
                psValues->papszRightLabels, sizeof(char *) * psValues->nRight);
          }

          psValues->pasRight[psValues->nRight - 1].x = oLastPoint.x;
          psValues->pasRight[psValues->nRight - 1].y = oLastPoint.y;
          psValues->papszRightLabels[psValues->nRight - 1] = pszLabel;
        }
      }
      msFreeShape(&shapegrid);
      msFreeShape(&tmpshape);
    }
    msInitShape(&shapegrid);
  }
  msLayerClose(layer);
  return psValues;
}

/**********************************************************************************************************************
 *
 */
int msGraticuleLayerInitializeVirtualTable(layerObj *layer) {
  assert(layer != NULL);
  assert(layer->vtable != NULL);

  layer->vtable->LayerInitItemInfo =
      msGraticuleLayerInitItemInfo; /* should use defaults for item info
                                       functions */
  layer->vtable->LayerFreeItemInfo = msGraticuleLayerFreeItemInfo;
  layer->vtable->LayerOpen = msGraticuleLayerOpen;
  layer->vtable->LayerIsOpen = msGraticuleLayerIsOpen;
  layer->vtable->LayerWhichShapes = msGraticuleLayerWhichShapes;
  layer->vtable->LayerNextShape = msGraticuleLayerNextShape;
  /* layer->vtable->LayerResultsGetShape, use default */
  layer->vtable->LayerGetShape = msGraticuleLayerGetShape;
  /* layer->vtable->LayerGetShapeCount, use default */
  layer->vtable->LayerClose = msGraticuleLayerClose;
  layer->vtable->LayerGetItems = msGraticuleLayerGetItems;
  layer->vtable->LayerGetExtent = msGraticuleLayerGetExtent;
  layer->vtable->LayerGetAutoStyle = msGraticuleLayerGetAutoStyle;
  /* layer->vtable->LayerCloseConnection, use default */;
  layer->vtable->LayerSetTimeFilter = msLayerMakePlainTimeFilter;
  /* layer->vtable->LayerApplyFilterToLayer, use default */
  /* layer->vtable->LayerCreateItems, use default */
  /* layer->vtable->LayerGetNumFeatures, use default */

  return MS_SUCCESS;
}

/**********************************************************************************************************************
 *
 */
static void _FormatLabel(layerObj *pLayer, shapeObj *pShape,
                         double dDataToFormat) {
  graticuleObj *pInfo = pLayer->grid;
  char cBuffer[32];
  int iDegrees, iMinutes;

  switch (pInfo->ilabeltype) {
  case lpDDMMSS:
    iDegrees = (int)dDataToFormat;
    dDataToFormat = fabs(dDataToFormat - (double)iDegrees);
    iMinutes = (int)(dDataToFormat * 60.0);
    dDataToFormat = dDataToFormat - (((double)iMinutes) / 60.0);
    sprintf(cBuffer, pInfo->labelformat, iDegrees, iMinutes,
            (int)(dDataToFormat * 3600.0));
    break;
  case lpDDMM:
    iDegrees = (int)dDataToFormat;
    dDataToFormat = fabs(dDataToFormat - (double)iDegrees);
    sprintf(cBuffer, pInfo->labelformat, iDegrees, (int)(dDataToFormat * 60.0));
    break;
  case lpDD:
    iDegrees = (int)dDataToFormat;
    sprintf(cBuffer, pInfo->labelformat, iDegrees);
    break;
  case lpDefault:
  default:
    sprintf(cBuffer, pInfo->labelformat, dDataToFormat);
  }

  pShape->text = msStrdup(cBuffer);
}

/**********************************************************************************************************************
 *
 *  Move label position into display area by adjusting underlying shape line.
 */
static int _AdjustLabelPosition(layerObj *pLayer, shapeObj *pShape,
                                msGraticulePosition ePosition) {
  graticuleObj *pInfo = pLayer->grid;
  rectObj rectLabel;
  pointObj ptPoint;
  double size = -1;
  char *labeltxt;

  if (pInfo == NULL || pShape == NULL) {
    msSetError(MS_MISCERR,
               "Assertion failed: Null shape or non-configured grid!, ",
               "_AdjustLabelPosition()");
    return MS_FAILURE;
  }

  assert(pLayer->class[0] -> numlabels >= 1);

  if (msCheckParentPointer(pLayer->map, "map") == MS_FAILURE)
    return MS_FAILURE;

  ptPoint = pShape->line->point[0];

  if (pLayer->project) {
    if (pLayer->reprojectorLayerToMap == NULL) {
      pLayer->reprojectorLayerToMap = msProjectCreateReprojector(
          &pLayer->projection, &pLayer->map->projection);
    }
    if (pLayer->reprojectorLayerToMap)
      msProjectShapeEx(pLayer->reprojectorLayerToMap, pShape);

    /* Poor man detection of reprojection failure */
    if (msProjIsGeographicCRS(&(pLayer->projection)) !=
        msProjIsGeographicCRS(&(pLayer->map->projection))) {
      if (ptPoint.x == pShape->line->point[0].x &&
          ptPoint.y == pShape->line->point[0].y) {
        return MS_FAILURE;
      }
    }
  }

  if (pLayer->transform) {
    msTransformShapeToPixelRound(pShape, pLayer->map->extent,
                                 pLayer->map->cellsize);
  }

  size = pLayer->class[0]
             ->labels[0]
             ->size; /* TODO someday: adjust minsize/maxsize/resolution*/
  /* We only use the first label as there's no use (yet) in defining multiple
   lables for GRID layers, as the only label to represent is the longitude or
   latitude */
  labeltxt =
      msShapeGetLabelAnnotation(pLayer, pShape, pLayer->class[0] -> labels[0]);
  assert(labeltxt);
  if (msGetStringSize(pLayer->map, pLayer->class[0] -> labels[0], size,
                      labeltxt, &rectLabel) != MS_SUCCESS) {
    free(labeltxt);
    return MS_FAILURE; /* msSetError already called */
  }
  free(labeltxt);

  switch (ePosition) {
  case posBottom:
    pShape->line->point[1].y = pLayer->map->height;
    pShape->line->point[0].y =
        pLayer->map->height - (fabs(rectLabel.maxy - rectLabel.miny) * 2 + 5);
    break;
  case posTop:
    pShape->line->point[1].y = 0;
    pShape->line->point[0].y = fabs(rectLabel.maxy - rectLabel.miny) * 2 + 5;
    break;
  case posLeft:
    pShape->line->point[0].x = 0;
    pShape->line->point[1].x = fabs(rectLabel.maxx - rectLabel.minx) * 2 + 5;
    break;
  case posRight:
    pShape->line->point[1].x = pLayer->map->width;
    pShape->line->point[0].x =
        pLayer->map->width - (fabs(rectLabel.maxx - rectLabel.minx) * 2 + 5);
    break;
  }

  if (pLayer->transform)
    msTransformPixelToShape(pShape, pLayer->map->extent, pLayer->map->cellsize);

  if (pLayer->project) {
    /* Clamp coordinates into the validity area of the projection, in the */
    /* particular case of EPSG:3857 (WebMercator) to longlat reprojection */
    if (strstr(pLayer->map->projection.args[0], "epsg:3857") &&
        msProjIsGeographicCRS(&(pLayer->projection))) {
      if (!pLayer->map->projection.gt.need_geotransform &&
          ePosition == posLeft && pShape->line->point[0].x < -20037508) {
        pShape->line->point[1].x =
            -20037508 + (pShape->line->point[1].x - pShape->line->point[0].x);
        pShape->line->point[0].x = -20037508;
      } else if (pLayer->map->projection.gt.need_geotransform &&
                 ePosition == posLeft &&
                 pLayer->map->projection.gt.geotransform[0] +
                         pShape->line->point[0].x *
                             pLayer->map->projection.gt.geotransform[1] +
                         pShape->line->point[0].y *
                             pLayer->map->projection.gt.geotransform[2] <
                     -20037508) {
        double y_tmp;
        double width = pShape->line->point[1].x - pShape->line->point[0].x;

        y_tmp = pLayer->map->projection.gt.geotransform[3] +
                pShape->line->point[0].x *
                    pLayer->map->projection.gt.geotransform[4] +
                pShape->line->point[0].y *
                    pLayer->map->projection.gt.geotransform[5];
        pShape->line->point[0].x =
            pLayer->map->projection.gt.invgeotransform[0] +
            -20037508 * pLayer->map->projection.gt.invgeotransform[1] +
            y_tmp * pLayer->map->projection.gt.invgeotransform[2];
        pShape->line->point[1].x = pShape->line->point[0].x + width;
      }

      if (!pLayer->map->projection.gt.need_geotransform &&
          ePosition == posRight && pShape->line->point[1].x > 20037508) {
        pShape->line->point[0].x =
            20037508 - (pShape->line->point[1].x - pShape->line->point[0].x);
        pShape->line->point[1].x = 20037508;
      } else if (pLayer->map->projection.gt.need_geotransform &&
                 ePosition == posRight &&
                 pLayer->map->projection.gt.geotransform[0] +
                         pShape->line->point[1].x *
                             pLayer->map->projection.gt.geotransform[1] +
                         pShape->line->point[1].y *
                             pLayer->map->projection.gt.geotransform[2] >
                     20037508) {
        double y_tmp;
        double width = pShape->line->point[1].x - pShape->line->point[0].x;

        y_tmp = pLayer->map->projection.gt.geotransform[3] +
                pShape->line->point[1].x *
                    pLayer->map->projection.gt.geotransform[4] +
                pShape->line->point[1].y *
                    pLayer->map->projection.gt.geotransform[5];
        pShape->line->point[1].x =
            pLayer->map->projection.gt.invgeotransform[0] +
            20037508 * pLayer->map->projection.gt.invgeotransform[1] +
            y_tmp * pLayer->map->projection.gt.invgeotransform[2];
        pShape->line->point[0].x = pShape->line->point[1].x - width;
      }
    }

    if (pLayer->reprojectorMapToLayer == NULL) {
      pLayer->reprojectorMapToLayer = msProjectCreateReprojector(
          &pLayer->map->projection, &pLayer->projection);
    }
    if (pLayer->reprojectorMapToLayer)
      msProjectShapeEx(pLayer->reprojectorMapToLayer, pShape);
  }

  switch (ePosition) {
  case posBottom:
  case posTop:
    pShape->line->point[1].x = ptPoint.x;
    pShape->line->point[0].x = ptPoint.x;
    break;
  case posLeft:
  case posRight:
    pShape->line->point[1].y = ptPoint.y;
    pShape->line->point[0].y = ptPoint.y;
    break;
  }

  return MS_SUCCESS;
}

/**********************************************************************************************************************
 **********************************************************************************************************************
 * DefineAxes - Copyright (c) 2000, Michael P.D. Bramley.
 *
 * Permission is granted to use this code without restriction as long as
 * this copyright notice appears in all source files.
 *
 * Minor tweaks to incrment calculations - jnovak
 */
void DefineAxis(int iTickCountTarget, double *Min, double *Max, double *Inc) {
  /* define local variables... */

  double Test_inc,         /* candidate increment value */
      Test_min,            /* minimum scale value */
      Test_max,            /* maximum scale value */
      Range = *Max - *Min; /* range of data */

  int i = 0; /* counter */

  /* don't create problems -- solve them */

  if (Range < 0) {
    *Inc = 0;
    return;
  }

  /* handle special case of repeated values */

  else if (Range == 0) {
    *Min = ceil(*Max) - 1;
    *Max = *Min + 1;
    *Inc = 1;
    return;
  }

  /* compute candidate for increment */

  Test_inc = pow(10.0, ceil(log10(Range / 10)));
  if (*Inc > 0 && (Test_inc < *Inc || Test_inc > *Inc))
    Test_inc = *Inc;

  /* establish maximum scale value... */
  Test_max = ((long)(*Max / Test_inc)) * Test_inc;

  if (Test_max < *Max)
    Test_max += Test_inc;

  /* establish minimum scale value... */
  Test_min = Test_max;
  do {
    ++i;
    Test_min -= Test_inc;
  } while (Test_min > *Min);

  /* subtracting small values can screw up the scale limits, */
  /* eg: if DefineAxis is called with (min,max)=(0.01, 0.1), */
  /* then the calculated scale is 1.0408E17 TO 0.05 BY 0.01. */
  /* the following if statment corrects for this... */

  /* if(fabs(Test_min) < 1E-10) */
  /* Test_min = 0 ; */

  /* adjust for too few tick marks */

  if (iTickCountTarget <= 0)
    iTickCountTarget = MAPGRATICULE_ARC_MINIMUM;

  while (i < iTickCountTarget) {
    Test_inc /= 2;
    i *= 2;
  }

  if (i < 6 && 0) {
    Test_inc /= 2;
    if ((Test_min + Test_inc) <= *Min)
      Test_min += Test_inc;
    if ((Test_max - Test_inc) >= *Max)
      Test_max -= Test_inc;
  }

  /* pass back axis definition to caller */

  *Min = Test_min;
  *Max = Test_max;
  *Inc = Test_inc;
}

/**********************************************************************************************************************
 **********************************************************************************************************************/
