> Is this everything that QGis does to transform a POINT(long, lat) to a > Pixel- Point(x, y)? Because this is kind of what my naive approach (or > what I thought it was) looked like, i.e., scaling factor plus correction > of the counting direction.
Well, in case you apply on-the-fly reprojection (e.g. long / lat to meter system), a coordinate transformation is applied before the pixel transformation (done in class QgsCoordinateTransform). Regards, Marco Am Freitag, 30. September 2011, 17.45:30 schrieb Eric MSP Veith: > Hello Marco, > > thank you for your friendly and helpful reply! > > On Friday 30 September 2011, 17:02:22, Marco Hugentobler > > <[email protected]> wrote: > > The class QgsMapToPixel (src/core/qgsmaptopixel.cpp/.h) contains the > > transformation from map to pixel coordinates. Is this what you are > > looking for? > > I'm 98% positive that yes, this is what I was looking for. One last > confirmation, through: > > ---%<--- > QgsPoint QgsMapToPixel::toMapPoint( double x, double y ) const > { > double mx = x * mMapUnitsPerPixel + xMin; > double my = -1 * (( y - yMax ) * mMapUnitsPerPixel - yMin ); > return QgsPoint( mx, my ); > } > --->%--- > > Is this everything that QGis does to transform a POINT(long, lat) to a > Pixel- Point(x, y)? Because this is kind of what my naive approach (or > what I thought it was) looked like, i.e., scaling factor plus correction > of the counting direction. > > Eric _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
