Function msGraticuleLayerGetIntersectionPoints

mapgraticule.c:623–1011

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

/*      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;
    graticuleIntersectionObj *psValues = NULL;
    int i=0;

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

    pInfo  = (graticuleObj *) layer->layerinfo;

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

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

    if(layer->transform == MS_TRUE)
    searchrect = map->extent;
    else {
      searchrect.minx = searchrect.miny = 0;
      searchrect.maxx = map->width-1;
      searchrect.maxy = map->height-1;
    }
  
#ifdef USE_PROJ
    if((map->projection.numargs > 0) && (layer->projection.numargs > 0))
      msProjectRect(&map->projection, &layer->projection, &searchrect); /* project the searchrect to source coords */
#endif
 
    msLayerOpen(layer);
   
    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;