// internal test to see if regions don't intersect (optimization)
bool LLRegion::NoIntersection(const LLRegion& region) const
{
if(Empty() || region.Empty())
return true;
LLBBox box = GetBox(), rbox = region.GetBox();
return box.IntersectOut(rbox) || NoIntersection(rbox) || region.NoIntersection(box);
}
LLRegion ViewPort::GetLLRegion( const OCPNRegion ®ion )
{
// todo: for these projecetions, improve this calculation by using the
// method in SetBoxes here
#ifndef ocpnUSE_GL
return LLRegion(GetBBox());
#else
if(!glChartCanvas::CanClipViewport(*this))
return LLRegion(GetBBox());
OCPNRegionIterator it( region );
LLRegion r;
while( it.HaveRects() ) {
wxRect rect = it.GetRect();
int x1 = rect.x, y1 = rect.y, x2 = x1 + rect.width, y2 = y1 + rect.height;
int p[8] = {x1, y1, x2, y1, x2, y2, x1, y2};
double pll[8];
for(int i=0; i<8; i+=2)
GetLLFromPix(wxPoint(p[i], p[i+1]), pll+i, pll+i+1);
// resolve (this works even if rectangle crosses both 0 and 180)
//if(LLRegion::PointsCCW(4, pll))
for(int i=0; i<8; i+=2) {
if(pll[i+1] <= clon - 180)
pll[i+1] += 360;
else if(pll[i+1] >= clon + 180)
pll[i+1] -= 360;
}
r.Union(LLRegion(4, pll));
it.NextRect();
}
return r;
#endif
}
LLRegion ViewPort::GetLLRegion( const OCPNRegion ®ion )
{
// todo: for these projecetions, improve this calculation by using the
// method in SetBoxes here
#ifndef ocpnUSE_GL
return LLRegion(GetBBox());
#else
if(!glChartCanvas::CanClipViewport(*this))
return LLRegion(GetBBox());
OCPNRegionIterator it( region );
LLRegion r;
while( it.HaveRects() ) {
wxRect rect = it.GetRect();
int x1 = rect.x, y1 = rect.y, x2 = x1 + rect.width, y2 = y1 + rect.height;
int p[8] = {x1, y1, x2, y1, x2, y2, x1, y2};
double pll[540];
int j;
/* if the viewport is rotated, we must split the segments as straight lines in lat/lon
coordinates map to curves in projected coordinate space */
if(fabs( rotation ) >= 0.0001) {
j=0;
double lastlat, lastlon;
int li = 6;
GetLLFromPix(wxPoint(p[li], p[li+1]), &lastlat, &lastlon);
for(int i=0; i<8; i+=2) {
double lat, lon;
GetLLFromPix(wxPoint(p[i], p[i+1]), &lat, &lon);
// use 2 degree grid
double grid = 2;
int lat_splits = floor(fabs(lat-lastlat) / grid);
double lond = fabs(lon-lastlon);
int lon_splits = floor((lond > 180 ? 360-lond : lond) / grid);
int splits = wxMax(lat_splits, lon_splits) + 1;
for(int k = 1; k<splits; k++) {
float d = (float)k / splits;
GetLLFromPix(wxPoint((1-d)*p[li] + d*p[i], (1-d)*p[li+1] + d*p[i+1]), pll+j, pll+j+1);
j += 2;
}
pll[j++] = lat;
pll[j++] = lon;
li = i;
lastlat = lat, lastlon = lon;
}
} else {
j=8;
for(int i=0; i<j; i+=2)
GetLLFromPix(wxPoint(p[i], p[i+1]), pll+i, pll+i+1);
}
// resolve (this works even if rectangle crosses both 0 and 180)
for(int i=0; i<j; i+=2) {
if(pll[i+1] <= clon - 180)
pll[i+1] += 360;
else if(pll[i+1] >= clon + 180)
pll[i+1] -= 360;
}
r.Union(LLRegion(j/2, pll));
it.NextRect();
}
return r;
#endif
}
