[gdal-dev] geospatialPDF DPI and EXTRA_IMAGES
even.rouault at spatialys.com
Thu May 26 08:23:05 PDT 2016
On Thursday 26 May 2016 09:38:21 Luca Delucchi wrote:
> On 25 May 2016 at 17:12, Even Rouault <even.rouault at spatialys.com> wrote:
> > The following extract from the driver should hopefully answer your
> more or less yes, now I understood a little bit more but..
> > double dfUserUnit = dfDPI * USER_UNIT_IN_INCH;
> > double dfWidthInUserUnit = nWidth / dfUserUnit + sMargins.nLeft +
> > sMargins.nRight; double dfHeightInUserUnit = nHeight / dfUserUnit +
> > sMargins.nBottom + sMargins.nTop;>
> > --> nWidth and nHeight are the dimensions of the source raster in pixel.
> if I have no raster how can I found this two values?
Ah ok, so you create a vector dataset then ?
Here's the relevant code in pdfwritabledataset.cpp:
double dfRatio = (sGlobalExtent.MaxY - sGlobalExtent.MinY) /
(sGlobalExtent.MaxX - sGlobalExtent.MinX);
int nWidth, nHeight;
if (dfRatio < 1)
nWidth = 1024;
nHeight = static_cast<int>(nWidth * dfRatio);
nHeight = 1024;
nWidth = static_cast<int>(nHeight / dfRatio);
where sGlobalExtent is the georeferenced extent of the vectors added in the
PDF vector layer.
Spatialys - Geospatial professional services
More information about the gdal-dev