Function msDrawScalebar

mapscale.c:152–340

TODO : the will be msDrawScalebarGD */

/* TODO : the will be msDrawScalebarGD */
imageObj *msDrawScalebar(mapObj *map)
{
  int status;
  char label[32];
  double i, msx;
  int j;
  int isx, sx, sy, ox, oy, state, dsx;
  pointObj p;
  rectObj r;
  imageObj      *image = NULL;
  double fontWidth, fontHeight;
  outputFormatObj *format = NULL;
  strokeStyleObj strokeStyle;
  shapeObj shape;
  lineObj line;
  pointObj points[5];
  rendererVTableObj *renderer;

  strokeStyle.patternlength=0;
  
  if(map->units == -1) {
    msSetError(MS_MISCERR, "Map units not set.", "msDrawScalebar()");
    return(NULL);
  }

  renderer = MS_MAP_RENDERER(map);
  if(!renderer || !MS_MAP_RENDERER(map)->supports_pixel_buffer) {
	msSetError(MS_MISCERR, "Outputformat not supported for scalebar", "msDrawScalebar()");
	return(NULL);
  }
  
/*
 *  A string containing the ten decimal digits is rendered to compute an average cell size 
 *  for each number, which is used later to place labels on the scalebar.
 */
  
  if(msGetLabelSize(map,&map->scalebar.label,"0123456789",map->scalebar.label.size,&r,NULL) != MS_SUCCESS) {
	  return NULL;
  }
  fontWidth = (r.maxx-r.minx)/10.0;
  fontHeight = r.maxy -r.miny;

  map->cellsize = msAdjustExtent(&(map->extent), map->width, map->height);
  status = msCalculateScale(map->extent, map->units, map->width, map->height, map->resolution, &map->scaledenom);
  if(status != MS_SUCCESS)
  { 	
	return(NULL);
  }
  dsx = map->scalebar.width - 2*HMARGIN;
  do {
    msx = (map->cellsize * dsx)/(msInchesPerUnit(map->scalebar.units,0)/msInchesPerUnit(map->units,0));
    i = roundInterval(msx/map->scalebar.intervals);
    snprintf(label, sizeof(label), "%g", map->scalebar.intervals*i); /* last label */
    isx = MS_NINT((i/(msInchesPerUnit(map->units,0)/msInchesPerUnit(map->scalebar.units,0)))/map->cellsize);  
    sx = (map->scalebar.intervals*isx) + MS_NINT((1.5 + strlen(label)/2.0 + strlen(unitText[map->scalebar.units]))*fontWidth);

    if(sx <= (map->scalebar.width - 2*HMARGIN)) break; /* it will fit */