func GetXYOnSurface(g Geom) (float64, float64) {
pt := C.GEOSGetCentroid(g.geom)
var x C.double
var y C.double
coord := C.GEOSGeom_getCoordSeq(pt)
err := C.GEOSCoordSeq_getX(coord, 0, &x)
if err == -1 {
panic(err)
}
err = C.GEOSCoordSeq_getY(coord, 0, &y)
if err == -1 {
panic(err)
}
return float64(x), float64(y)
}
func (this *Geom) Bounds() Bounds {
geom := C.GEOSEnvelope(this.v)
if geom == nil {
return NilBounds
}
extRing := C.GEOSGetExteriorRing(geom)
if extRing == nil {
return NilBounds
}
cs := C.GEOSGeom_getCoordSeq(extRing)
var csLen C.uint
C.GEOSCoordSeq_getSize(cs, &csLen)
minx := 1.e+20
maxx := -1e+20
miny := 1.e+20
maxy := -1e+20
var temp C.double
for i := 0; i < int(csLen); i++ {
C.GEOSCoordSeq_getX(cs, C.uint(i), &temp)
x := float64(temp)
if x < minx {
minx = x
}
if x > maxx {
maxx = x
}
C.GEOSCoordSeq_getY(cs, C.uint(i), &temp)
y := float64(temp)
if y < miny {
miny = y
}
if y > maxy {
maxy = y
}
}
return Bounds{minx, miny, maxx, maxy}
}