bool Polygon::covers(PointRef& ref) const
{
GEOSCoordSequence* coords = GEOSCoordSeq_create_r(m_ctx, 1, 3);
if (!coords)
throw pdal_error("Unable to allocate coordinate sequence");
const double x = ref.getFieldAs<double>(Dimension::Id::X);
const double y = ref.getFieldAs<double>(Dimension::Id::Y);
const double z = ref.getFieldAs<double>(Dimension::Id::Z);
if (!GEOSCoordSeq_setX_r(m_ctx, coords, 0, x))
throw pdal_error("unable to set x for coordinate sequence");
if (!GEOSCoordSeq_setY_r(m_ctx, coords, 0, y))
throw pdal_error("unable to set y for coordinate sequence");
if (!GEOSCoordSeq_setZ_r(m_ctx, coords, 0, z))
throw pdal_error("unable to set z for coordinate sequence");
GEOSGeometry* p = GEOSGeom_createPoint_r(m_ctx, coords);
if (!p)
throw pdal_error("unable to allocate candidate test point");
bool covers = (bool)(GEOSPreparedCovers_r(m_ctx, m_prepGeom, p));
GEOSGeom_destroy_r(m_ctx, p);
return covers;
}
State get_state(const Point &point, const GEOSPreparedGeometry *gp_domain,
GEOSContextHandle_t handle)
{
State state;
if (isfinite(point.x) && isfinite(point.y))
{
// TODO: Avoid create-destroy
GEOSCoordSequence *coords = GEOSCoordSeq_create_r(handle, 1, 2);
GEOSCoordSeq_setX_r(handle, coords, 0, point.x);
GEOSCoordSeq_setY_r(handle, coords, 0, point.y);
GEOSGeometry *g_point = GEOSGeom_createPoint_r(handle, coords);
state = GEOSPreparedCovers_r(handle, gp_domain, g_point) ? POINT_IN : POINT_OUT;
GEOSGeom_destroy_r(handle, g_point);
}
else
{
state = POINT_NAN;
}
return state;
}
/*
* Return whether the given line segment is suitable as an
* approximation of the projection of the source line.
*
* t_start: Interpolation parameter for the start point.
* p_start: Projected start point.
* t_end: Interpolation parameter for the end point.
* p_start: Projected end point.
* interpolator: Interpolator for current source line.
* threshold: Lateral tolerance in target projection coordinates.
* handle: Thread-local context handle for GEOS.
* gp_domain: Prepared polygon of target map domain.
* inside: Whether the start point is within the map domain.
*/
bool straightAndDomain(double t_start, const Point &p_start,
double t_end, const Point &p_end,
Interpolator *interpolator, double threshold,
GEOSContextHandle_t handle,
const GEOSPreparedGeometry *gp_domain,
bool inside)
{
// Straight and in-domain (de9im[7] == 'F')
bool valid;
// This could be optimised out of the loop.
if (!(isfinite(p_start.x) && isfinite(p_start.y)))
{
valid = false;
}
else if (!(isfinite(p_end.x) && isfinite(p_end.y)))
{
valid = false;
}
else
{
// TODO: Re-use geometries, instead of create-destroy!
// Create a LineString for the current end-point.
GEOSCoordSequence *coords = GEOSCoordSeq_create_r(handle, 2, 2);
GEOSCoordSeq_setX_r(handle, coords, 0, p_start.x);
GEOSCoordSeq_setY_r(handle, coords, 0, p_start.y);
GEOSCoordSeq_setX_r(handle, coords, 1, p_end.x);
GEOSCoordSeq_setY_r(handle, coords, 1, p_end.y);
GEOSGeometry *g_segment = GEOSGeom_createLineString_r(handle, coords);
// Find the projected mid-point
double t_mid = (t_start + t_end) * 0.5;
Point p_mid = interpolator->interpolate(t_mid);
// Make it into a GEOS geometry
coords = GEOSCoordSeq_create_r(handle, 1, 2);
GEOSCoordSeq_setX_r(handle, coords, 0, p_mid.x);
GEOSCoordSeq_setY_r(handle, coords, 0, p_mid.y);
GEOSGeometry *g_mid = GEOSGeom_createPoint_r(handle, coords);
double along = GEOSProjectNormalized_r(handle, g_segment, g_mid);
if(isnan(along))
{
valid = true;
}
else
{
valid = 0.0 < along && along < 1.0;
if (valid)
{
double separation;
GEOSDistance_r(handle, g_segment, g_mid, &separation);
if (inside)
{
// Scale the lateral threshold by the distance from
// the nearest end. I.e. Near the ends the lateral
// threshold is much smaller; it only has its full
// value in the middle.
valid = separation <= threshold * 2.0 *
(0.5 - fabs(0.5 - along));
}
else
{
// Check if the mid-point makes less than ~11 degree
// angle with the straight line.
// sin(11') => 0.2
// To save the square-root we just use the square of
// the lengths, hence:
// 0.2 ^ 2 => 0.04
double hypot_dx = p_mid.x - p_start.x;
double hypot_dy = p_mid.y - p_start.y;
double hypot = hypot_dx * hypot_dx + hypot_dy * hypot_dy;
valid = ((separation * separation) / hypot) < 0.04;
}
}
}
if (valid)
{
if(inside)
valid = GEOSPreparedCovers_r(handle, gp_domain, g_segment);
else
valid = GEOSPreparedDisjoint_r(handle, gp_domain, g_segment);
}
GEOSGeom_destroy_r(handle, g_segment);
GEOSGeom_destroy_r(handle, g_mid);
}
return valid;
}
