[ka-Map-users] precache2.php bug

[Stephen Woodbridge]

OK, I think the fix is straight forward after reading the code a bit 
more. I changed it to look like this and it seems to be doing what it 
was expected to do before:

     $aszGroups = $oMap->getAllGroupNames();

     // get the default mapfile extents
     $minx = $oMap->extent->minx;
     $maxx = $oMap->extent->maxx;
     $miny = $oMap->extent->miny;
     $maxy = $oMap->extent->maxy;

     // modify map extent for max_extent metadata
     if($oMap->getMetaData('max_extents') != '') {
         $szMaxExtents = $oMap->getMetaData('max_extents');
         $aszMaxExtents = preg_split('/[\s,]+/', $szMaxExtents);
         if(count($aszMaxExtents) == 4) {
             $minx = min($aszMaxExtents[0], $aszMaxExtents[2]);
             $miny = min($aszMaxExtents[1], $aszMaxExtents[3]);
             $maxx = max($aszMaxExtents[0], $aszMaxExtents[2]);
             $maxy = max($aszMaxExtents[1], $aszMaxExtents[3]);
             $oMap->setExtent($minx, $miny, $maxx, $maxy);
         }
     }

     // modify map extents for extents as arguments
     if($_REQUEST['e']) {
         $aszMaxExtents = preg_split('/[\s,]+/', $_REQUEST['e']);
         if(count($aszMaxExtents) == 4) {
             $minx = min($aszMaxExtents[0], $aszMaxExtents[2]);
             $miny = min($aszMaxExtents[1], $aszMaxExtents[3]);
             $maxx = max($aszMaxExtents[0], $aszMaxExtents[2]);
             $maxy = max($aszMaxExtents[1], $aszMaxExtents[3]);
             $oMap->setExtent($minx, $miny, $maxx, $maxy);
         }
         else
             exit($usage);
     }

     // use these as the extents the we want to generate tiles over
     $dMinX = $minx;
     $dMaxX = $maxx;
     $dMinY = $miny;
     $dMaxY = $maxy;

     print "\nUsing adjusted extents of [$dMinX, $dMinY, $dMaxX, $dMaxY]\n";

-Steve

Stephen Woodbridge wrote:
> Hi Tim, Paul,
> 
> I think I have found a bug in precache2.php and I'm not sure of the best 
> way to fix it.
> 
> I added an argument -e <xmin ymin xmax ymax>  to limit cache creation to 
> extents so I could use this from then command line or URL instead of 
> modifing the mapfile. I modified the code to look like this:
> 
>     // modify map extent for max_extent metadata
>     if($oMap->getMetaData('max_extents') != '') {
>         $szMaxExtents = $oMap->getMetaData('max_extents');
>         $aszMaxExtents = preg_split('/[\s,]+/', $szMaxExtents);
>         if(count($aszMaxExtents) == 4) {
>             $minx = min($aszMaxExtents[0], $aszMaxExtents[2]);
>             $miny = min($aszMaxExtents[1], $aszMaxExtents[3]);
>             $maxx = max($aszMaxExtents[0], $aszMaxExtents[2]);
>             $maxy = max($aszMaxExtents[1], $aszMaxExtents[3]);
>             $oMap->setExtent($minx, $miny, $maxx, $maxy);
>         }
>     }
> 
>     // modify map extents for extents as arguments
>     if($_REQUEST['e']) {
>         $aszMaxExtents = preg_split('/[\s,]+/', $_REQUEST['e']);
>         if(count($aszMaxExtents) == 4) {
>             $minx = min($aszMaxExtents[0], $aszMaxExtents[2]);
>             $miny = min($aszMaxExtents[1], $aszMaxExtents[3]);
>             $maxx = max($aszMaxExtents[0], $aszMaxExtents[2]);
>             $maxy = max($aszMaxExtents[1], $aszMaxExtents[3]);
>             $oMap->setExtent($minx, $miny, $maxx, $maxy);
>         }
>         else
>             exit($usage);
>     }
> 
>     $dMinX = $oMap->extent->minx;
>     $dMaxX = $oMap->extent->maxx;
>     $dMinY = $oMap->extent->miny;
>     $dMaxY = $oMap->extent->maxy;
> 
>     print "\nUsing adjusted extents of [$dMinX, $dMinY, $dMaxX, $dMaxY]\n";
> 
> So basically, if the command line argument exists is over writes the 
> metadata values. This all works fine. I added the print, to see what I 
> was getting and to my surprise I got really wild values compared to what 
> I was expecting. So the URL and response is below.
> 
> http://localhost/ka-map/precache3.php?m=smap-01&s=4000000&e=-142+47+-50+74&f=1 
> 
> 
> Using adjusted extents of [-142, 14.5, -50, 106.5]
> 
>  Map: smap-01
>    Scale: 4000000
>      Meta tiles: 7 x 7 = 49
>      Tiles: 7 x 7 x 5 x 5 = 1225
>      Group: __base__
>  row: /u/data/tile-cache/smap-01/4000000/__base__/def/t-8960/l-3840, 
> rtime=3, rrate=11.7
>  row: /u/data/tile-cache/smap-01/4000000/__base__/def/t-7680/l-3840, 
> rtime=2, rrate=17.5
>  row: /u/data/tile-cache/smap-01/4000000/__base__/def/t-6400/l-3840, 
> rtime=3, rrate=11.7
>  row: /u/data/tile-cache/smap-01/4000000/__base__/def/t-5120/l-3840, 
> rtime=8, rrate=4.4
>  row: /u/data/tile-cache/smap-01/4000000/__base__/def/t-3840/l-3840, 
> rtime=128, rrate=0.3
>  row: /u/data/tile-cache/smap-01/4000000/__base__/def/t-2560/l-3840, 
> rtime=29, rrate=1.2
>  row: /u/data/tile-cache/smap-01/4000000/__base__/def/t-1280/l-3840, 
> rtime=2, rrate=17.5
>        MetaTile Rate = 0.3; Tile Rate = 7.0; Duration = 175 secs
> 
> So my analysis is that the code sets:
> 
>     $mapWidth = $metaWidth * $tileWidth;
>     $mapHeight = $metaHeight * $tileHeight;
>     $oMap->setSize($mapWidth, $mapHeight);
> 
> which is basically square. Then it gets the extents from the command 
> line does a:
> 
>             $oMap->setExtent($minx, $miny, $maxx, $maxy);
> 
> which does NOT set the extents entered, but adjusts the extents to be 
> the same aspect ratio of the square image set above. So if you request 
> extents 2 degrees high and 180 degrees wide you will generate a square 
> of tiles 180 x 180 degrees.
> 
> Is this analysis correct? Or did I miss something?
> 
> I seems the the max extents needs to be converted into correct $dMinX, 
> $dMinY, $dMaxX, $dMaxY, but it is not obvious how that should be done. 
> Got any thoughts on this?
> 
> -Steve
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