mapObj.zoomRectangle from Java Mapscript.

[Umberto Nicoletti]

Howard's version is the right one, only the error message is still
wrong, it should say:

msSetError(MS_MISCERR, "image rectangle maxy >= miny",

and this confuses both users and developers...

There is an issue in bugzilla, but unfortunately I can't view it
because bugzilla is slow/down at the moment.

Umberto

On 12/11/06, Tamas Szekeres <szekerest at gmail.com> wrote:
> Hi All,
>
> Going through the CVS History of mapzoom.i I can see that umberto has
> addressed this issue in ver1.3 (2006 05 30) but hobu has reverted the
> changes in ver1.4 (2006 07 04)
>
> So the developers should agree with the desired action.
>
> I would vote +1 to correct this issue as logical, that is:
>
> mapzoom.i (282)
>
>   if (poPixRect->miny >= poPixRect->maxy)
>         {
>             msSetError(MS_MISCERR, "image rectangle miny >= maxy",
>                        "mapscript::mapObj::zoomRectangle()");
>             return MS_FAILURE;
>         }
>
> However it will break the existing code and should be noted as a
> backward incompatible change.
>
> Best Regards,
>
> Tamas Szekeres
>
>
>
>
>
> 2006/12/11, Rodrigo Del C. Andrade <rodrigo.andrade at digitro.com.br>:
> >
> >
> >      Hello Javier, thanks for the info.
> >
> >      We have been struggling for some time now with the zoomRectangle and
> > every piece of info is appreciated.
> >      Concerning the swap of MinY with MaxY in your code, I gotta say this
> > caught me off guard.
> >       I couldn't get past a "miny >= maxy" error while trying to  use
> > zoomRectangle before and went as far as changing and recompiling mapzoom.i
> > where there is a consistency check that looks like:
> >  if (poPixRect->maxy >= poPixRect->miny) { -- insert nasty error here -- }
> >
> >
> >      thinking I found a bug. I got past the error after that change, however
> > the zoom behavior was what could best be described as "all over the place".
> > Like zooming to the wrong hemisphere and the like.
> >      So I changed mapzoom.i back to the original code and swapped the order
> > of arguments on my code following your example, and it worked better than
> > the last behavior, however the zoom isn't still quite working in a
> > predictable manner.
> >      Sometimes when zooming the map will remain at the same zoom factor, and
> > just pan a little to the sides or actually zooming out instead of going
> > zooming to the passed coordinates. I am running out of ideas as to what
> > could be causing this behavior.
> >      Here is what I am doing:
> >
> >        //Current map geo extent
> >        String[] extents = ((String) params.get("extent")).split(" ");
> >         rectObj extent = new rectObj(Double.parseDouble(extents[0]),
> > Double.parseDouble(extents[1]),
> >                                       Double.parseDouble(extents[2]),
> > Double.parseDouble(extents[3]), mapscript.MS_FALSE);
> >         mapa.setExtent(extent);
> >
> >          //rectangle Pic coords
> >          String[] pxCoordZoom = ((String) params.get("coordenadas")).split("
> > ");
> >          Double minx = Double.parseDouble(pxCoordZoom[0]);
> >          Double miny = Double.parseDouble(pxCoordZoom[1]);
> >          Double maxy = Double.parseDouble(pxCoordZoom[2]);
> >          Double maxx = Double.parseDouble(pxCoordZoom[3]);
> >
> >         /*We are using a cropper javascript class and the order the
> > rectangle coordinates where being passed was kind of unpredictable and
> > causing errors                while trying to create the rectangle with the
> > eventual minX > maxX /*
> >          double transport;
> >          if(minx > maxx){
> >              transport = minx;
> >              minx = maxx;
> >              maxx = transport;
> >          }
> >          if(miny > maxy){
> >              transport = miny;
> >              miny = maxy;
> >              maxy = transport;
> >          }
> >
> >          rectObj zoomArea = new rectObj(minx, maxy, maxx, miny,
> > mapscript.MS_TRUE);   //with MaxY and MinY swapped
> >          mapa.zoomRectangle(zoomArea, mapa.getWidth(), mapa.getHeight(),
> > extent, getMaxGeorefExtent(mapa));
> >
> >      Do you see any glaring mistakes that could cause the zoom to behave
> > wrongly?
> >      What confuses me is the fact that you mentioned that the rectangle
> > should be constructed with bottom-left and top-right defined, but isn't the
> > MinX and MaxY pair actually top-left?
> >
> >      Thanks in advance, any scrap of information helps immensely.
> >
> >      Rod.
> >
> >  --
> >
> >
> >  Rodrigo Del C. Andrade
> >  Estagiário Nível Superior
> >  SIC - SSE - Soluções Segurança Pública
> >
> >  DÍGITRO TECNOLOGIA
> >  E-mail: rodrigo.andrade at digitro.com.br
> >  Fone: +55 48 3281- / +55 48 3281-7000
> >  Fax: +55 48 3281-7299
> >  Site: www.digitro.com
> >
> >
> >  Javier Caicedo wrote:
> >  According to the Mapscript API mapObj.zoomRectangle first parameter must
> > be in image coordinates, so you should set the last parameter of the
> > rectObj constructor to TRUE. Here goes an example from my current project:
> >
> >  //vMap is an instance of mapObj
> >  rectObj rect = vMap.getExtent(); //map coordinates
> >  String [] box =
> > getCurrentRequest().getParameter("box").split(" ");
> >  //box is something like this: 10 10 200 200
> >  //0,0 is at top left, so box defines top left and bottom right corners
> >  double mx = Double.parseDouble(box[0]);
> >  double my = Double.parseDouble(box[1]);
> >  double mxx = Double.parseDouble(box[2]);
> >  double mxy = Double.parseDouble(box[3]);
> >
> >  //bunch of validation code ommitted
> >
> >  rectObj rbox = new rectObj(mx,mxy,mxx,my,mapscriptConstants.MS_TRUE);
> >  //notice the switch of mxy and my
> >  //rectObj constructor requires you define bottom left and top right
> >  //corners. rbox is in image coordinates
> >  vMap.zoomRectangle(rbox,w,h,rect,null);
> >
> > Hopefully this will help you out a little.
> >
> > Regards,
> > Javier Caicedo Espinoza
> > CTI - ESPOL
> > Guayaquil, Ecuador
> >
> >
> >
> >
> >
> >
> >
> >
>