[Qgis-developer] Details of rendering GIS map data in QGis
Eric MSP Veith
eveith at wwweb-library.net
Fri Sep 30 11:45:30 EDT 2011
thank you for your friendly and helpful reply!
On Friday 30 September 2011, 17:02:22, Marco Hugentobler
<marco.hugentobler at sourcepole.ch> wrote:
> The class QgsMapToPixel (src/core/qgsmaptopixel.cpp/.h) contains the
> transformation from map to pixel coordinates. Is this what you are looking
I'm 98% positive that yes, this is what I was looking for. One last
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
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 836 bytes
Desc: This is a digitally signed message part.
Url : http://lists.osgeo.org/pipermail/qgis-developer/attachments/20110930/c3bf321f/attachment.bin
More information about the Qgis-developer