SVN commit 1160337 by hdevalence:
Filter away points below the horizon in Equatorial mode.
We don't call EquatorialToHorizontal first because it is
expensive and has usually already been called.
Ideally there would be a way to know whether or not
the given SkyPoint had its two sets of coordinates syncronized,
but it doesn't seem that there is a way to do this.
Instead, we add the proviso that the points must have already
had EquatorialToHorizontal called on them.
CCMAIL:kstars-devel at kde.org
M +2 -2 projector.cpp
M +10 -1 projector.h
--- branches/kstars/hdevalence/kstars/kstars/projections/projector.cpp #1160336:1160337
@@ -196,8 +196,8 @@
p->EquatorialToHorizontal( m_data->lst(), m_data->geo()->lat() );
if( p->alt().Degrees() < -1.0 ) return false;
}
- */
- if( m_vp.fillGround && m_vp.useAltAz && p->alt().Degrees() < -1.0 ) return false;
+ */ //Here we hope that the point has already been 'synchronized'
+ if( m_vp.fillGround /*&& m_vp.useAltAz*/ && p->alt().Degrees() < -1.0 ) return false;
if ( m_vp.useAltAz ) {
dY = fabs( p->altRefracted().Degrees() - m_vp.focus->alt().Degrees() );
--- branches/kstars/hdevalence/kstars/kstars/projections/projector.h #1160336:1160337
@@ -138,7 +138,14 @@
* absolutely essential that checkVisibility() is significantly faster than
* the computations required to draw the object to the screen.
*
- * The function first checks the difference between the Declination/Altitude
+ * If the ground is to be filled, the function first checks whether the point is
+ * below the horizon, because they will be covered by the ground anyways.
+ * Importantly, it does not call the expensive EquatorialToHorizontal function.
+ * This means that the horizontal coordinates MUST BE CORRECT! The vast majority
+ * of points are already synchronized, so recomputing the horizontal coordinates is
+ * a waste.
+ *
+ * The function then checks the difference between the Declination/Altitude
* coordinate of the Focus position, and that of the point p. If the absolute
* value of this difference is larger than fov, then the function returns false.
* For most configurations of the sky map window, this simple check is enough to
@@ -165,6 +172,8 @@
* @return true if the point p was found to be inside the Sky map window.
* @see SkyMap::setMapGeometry()
* @see SkyMap::fov()
+ * @note If you are creating skypoints using equatorial coordinates, then
+ * YOU MUST CALL EQUATORIALTOHORIZONTAL BEFORE THIS FUNCTION!
*/
bool checkVisibility( SkyPoint *p ) const;