static void test_point_interpolate(void)
{
POINT4D p, q, r;
int rv = 0;
p.x = 10.0;
p.y = 20.0;
p.z = 30.0;
p.m = 40.0;
q.x = 20.0;
q.y = 30.0;
q.z = 40.0;
q.m = 50.0;
rv = point_interpolate(&p, &q, &r, 1, 1, 'Z', 35.0);
CU_ASSERT_EQUAL( rv, LW_SUCCESS );
CU_ASSERT_EQUAL( r.x, 15.0);
rv = point_interpolate(&p, &q, &r, 1, 1, 'M', 41.0);
CU_ASSERT_EQUAL( rv, LW_SUCCESS );
CU_ASSERT_EQUAL( r.y, 21.0);
rv = point_interpolate(&p, &q, &r, 1, 1, 'M', 50.0);
CU_ASSERT_EQUAL( rv, LW_SUCCESS );
CU_ASSERT_EQUAL( r.y, 30.0);
rv = point_interpolate(&p, &q, &r, 1, 1, 'M', 40.0);
CU_ASSERT_EQUAL( rv, LW_SUCCESS );
CU_ASSERT_EQUAL( r.y, 20.0);
}
/**
* Take in a LINESTRING and return a MULTILINESTRING of those portions of the
* LINESTRING between the from/to range for the specified ordinate (XYZM)
*/
LWCOLLECTION*
lwline_clip_to_ordinate_range(const LWLINE *line, char ordinate, double from, double to)
{
POINTARRAY *pa_in = NULL;
LWCOLLECTION *lwgeom_out = NULL;
POINTARRAY *dp = NULL;
int i, rv;
int added_last_point = 0;
POINT4D *p = NULL, *q = NULL, *r = NULL;
double ordinate_value_p = 0.0, ordinate_value_q = 0.0;
char hasz = lwgeom_has_z(lwline_as_lwgeom(line));
char hasm = lwgeom_has_m(lwline_as_lwgeom(line));
char dims = FLAGS_NDIMS(line->flags);
/* Null input, nothing we can do. */
if ( ! line )
{
lwerror("Null input geometry.");
return NULL;
}
/* Ensure 'from' is less than 'to'. */
if ( to < from )
{
double t = from;
from = to;
to = t;
}
LWDEBUGF(4, "from = %g, to = %g, ordinate = %c", from, to, ordinate);
LWDEBUGF(4, "%s", lwgeom_to_ewkt((LWGEOM*)line));
/* Asking for an ordinate we don't have. Error. */
if ( (ordinate == 'Z' && ! hasz) || (ordinate == 'M' && ! hasm) )
{
lwerror("Cannot clip on ordinate %d in a %d-d geometry.", ordinate, dims);
return NULL;
}
/* Prepare our working point objects. */
p = lwalloc(sizeof(POINT4D));
q = lwalloc(sizeof(POINT4D));
r = lwalloc(sizeof(POINT4D));
/* Construct a collection to hold our outputs. */
lwgeom_out = lwcollection_construct_empty(MULTILINETYPE, line->srid, hasz, hasm);
/* Get our input point array */
pa_in = line->points;
for ( i = 0; i < pa_in->npoints; i++ )
{
LWDEBUGF(4, "Point #%d", i);
LWDEBUGF(4, "added_last_point %d", added_last_point);
if ( i > 0 )
{
*q = *p;
ordinate_value_q = ordinate_value_p;
}
rv = getPoint4d_p(pa_in, i, p);
ordinate_value_p = lwpoint_get_ordinate(p, ordinate);
LWDEBUGF(4, " ordinate_value_p %g (current)", ordinate_value_p);
LWDEBUGF(4, " ordinate_value_q %g (previous)", ordinate_value_q);
/* Is this point inside the ordinate range? Yes. */
if ( ordinate_value_p >= from && ordinate_value_p <= to )
{
LWDEBUGF(4, " inside ordinate range (%g, %g)", from, to);
if ( ! added_last_point )
{
LWDEBUG(4," new ptarray required");
/* We didn't add the previous point, so this is a new segment.
* Make a new point array. */
dp = ptarray_construct_empty(hasz, hasm, 32);
/* We're transiting into the range so add an interpolated
* point at the range boundary.
* If we're on a boundary and crossing from the far side,
* we also need an interpolated point. */
if ( i > 0 && ( /* Don't try to interpolate if this is the first point */
( ordinate_value_p > from && ordinate_value_p < to ) || /* Inside */
( ordinate_value_p == from && ordinate_value_q > to ) || /* Hopping from above */
( ordinate_value_p == to && ordinate_value_q < from ) ) ) /* Hopping from below */
{
double interpolation_value;
(ordinate_value_q > to) ? (interpolation_value = to) : (interpolation_value = from);
rv = point_interpolate(q, p, r, hasz, hasm, ordinate, interpolation_value);
rv = ptarray_append_point(dp, r, LW_FALSE);
LWDEBUGF(4, "[0] interpolating between (%g, %g) with interpolation point (%g)", ordinate_value_q, ordinate_value_p, interpolation_value);
}
}
/* Add the current vertex to the point array. */
rv = ptarray_append_point(dp, p, LW_FALSE);
if ( ordinate_value_p == from || ordinate_value_p == to )
{
added_last_point = 2; /* Added on boundary. */
}
else
{
added_last_point = 1; /* Added inside range. */
}
}
/* Is this point inside the ordinate range? No. */
else
{
LWDEBUGF(4, " added_last_point (%d)", added_last_point);
if ( added_last_point == 1 )
{
/* We're transiting out of the range, so add an interpolated point
* to the point array at the range boundary. */
double interpolation_value;
(ordinate_value_p > to) ? (interpolation_value = to) : (interpolation_value = from);
rv = point_interpolate(q, p, r, hasz, hasm, ordinate, interpolation_value);
rv = ptarray_append_point(dp, r, LW_FALSE);
LWDEBUGF(4, " [1] interpolating between (%g, %g) with interpolation point (%g)", ordinate_value_q, ordinate_value_p, interpolation_value);
}
else if ( added_last_point == 2 )
{
/* We're out and the last point was on the boundary.
* If the last point was the near boundary, nothing to do.
* If it was the far boundary, we need an interpolated point. */
if ( from != to && (
(ordinate_value_q == from && ordinate_value_p > from) ||
(ordinate_value_q == to && ordinate_value_p < to) ) )
{
double interpolation_value;
(ordinate_value_p > to) ? (interpolation_value = to) : (interpolation_value = from);
rv = point_interpolate(q, p, r, hasz, hasm, ordinate, interpolation_value);
rv = ptarray_append_point(dp, r, LW_FALSE);
LWDEBUGF(4, " [2] interpolating between (%g, %g) with interpolation point (%g)", ordinate_value_q, ordinate_value_p, interpolation_value);
}
}
else if ( i && ordinate_value_q < from && ordinate_value_p > to )
{
/* We just hopped over the whole range, from bottom to top,
* so we need to add *two* interpolated points! */
dp = ptarray_construct(hasz, hasm, 2);
/* Interpolate lower point. */
rv = point_interpolate(p, q, r, hasz, hasm, ordinate, from);
ptarray_set_point4d(dp, 0, r);
/* Interpolate upper point. */
rv = point_interpolate(p, q, r, hasz, hasm, ordinate, to);
ptarray_set_point4d(dp, 1, r);
}
else if ( i && ordinate_value_q > to && ordinate_value_p < from )
{
/* We just hopped over the whole range, from top to bottom,
* so we need to add *two* interpolated points! */
dp = ptarray_construct(hasz, hasm, 2);
/* Interpolate upper point. */
rv = point_interpolate(p, q, r, hasz, hasm, ordinate, to);
ptarray_set_point4d(dp, 0, r);
/* Interpolate lower point. */
rv = point_interpolate(p, q, r, hasz, hasm, ordinate, from);
ptarray_set_point4d(dp, 1, r);
}
/* We have an extant point-array, save it out to a multi-line. */
if ( dp )
{
LWDEBUG(4, "saving pointarray to multi-line (1)");
/* Only one point, so we have to make an lwpoint to hold this
* and set the overall output type to a generic collection. */
if ( dp->npoints == 1 )
{
LWPOINT *opoint = lwpoint_construct(line->srid, NULL, dp);
lwgeom_out->type = COLLECTIONTYPE;
lwgeom_out = lwcollection_add_lwgeom(lwgeom_out, lwpoint_as_lwgeom(opoint));
}
else
{
LWLINE *oline = lwline_construct(line->srid, NULL, dp);
lwgeom_out = lwcollection_add_lwgeom(lwgeom_out, lwline_as_lwgeom(oline));
}
/* Pointarray is now owned by lwgeom_out, so drop reference to it */
dp = NULL;
}
added_last_point = 0;
}
}
/* Still some points left to be saved out. */
if ( dp && dp->npoints > 0 )
{
LWDEBUG(4, "saving pointarray to multi-line (2)");
LWDEBUGF(4, "dp->npoints == %d", dp->npoints);
LWDEBUGF(4, "lwgeom_out->ngeoms == %d", lwgeom_out->ngeoms);
if ( dp->npoints == 1 )
{
LWPOINT *opoint = lwpoint_construct(line->srid, NULL, dp);
lwgeom_out->type = COLLECTIONTYPE;
lwgeom_out = lwcollection_add_lwgeom(lwgeom_out, lwpoint_as_lwgeom(opoint));
}
else
{
LWLINE *oline = lwline_construct(line->srid, NULL, dp);
lwgeom_out = lwcollection_add_lwgeom(lwgeom_out, lwline_as_lwgeom(oline));
}
/* Pointarray is now owned by lwgeom_out, so drop reference to it */
dp = NULL;
}
lwfree(p);
lwfree(q);
lwfree(r);
if ( lwgeom_out->ngeoms > 0 )
{
lwgeom_drop_bbox((LWGEOM*)lwgeom_out);
lwgeom_add_bbox((LWGEOM*)lwgeom_out);
}
return lwgeom_out;
}
