vertex_hashtable* vertex_hashtable_new(int table_size) {
vertex_hashtable* ht = malloc(sizeof(vertex_hashtable));
ht->items = malloc( sizeof(vertex_bucket) * table_size );
ht->table_size = table_size;
for(int i = 0; i < ht->table_size; i++) {
ht->items[i].keys = vertex_list_new();
ht->items[i].values = int_list_new();
}
return ht;
}
static void
inscribed_discs_and_friends(gdouble *inscrdrvalues,
gdouble *inscrdxvalues,
gdouble *inscrdyvalues,
gdouble *edmeanvalues,
const gdouble *xvalues,
const gdouble *yvalues,
const guint *grains,
const guint *sizes,
guint ngrains,
const GwyMaskField *mask,
gdouble dx, gdouble dy)
{
enum { NCAND_MAX = 15 };
g_return_if_fail(grains);
g_return_if_fail(sizes);
g_return_if_fail(xvalues);
g_return_if_fail(yvalues);
g_return_if_fail(GWY_IS_MASK_FIELD(mask));
g_return_if_fail(inscrdrvalues || inscrdxvalues || inscrdyvalues
|| edmeanvalues);
const GwyFieldPart *bbox = gwy_mask_field_grain_bounding_boxes(mask);
guint xres = mask->xres;
gdouble qgeom = sqrt(dx*dy);
gboolean nodiscs = !inscrdrvalues && !inscrdxvalues && !inscrdyvalues;
guint *grain = NULL, *workspace = NULL;
guint grainsize = 0;
IntList *inqueue = int_list_new(0);
IntList *outqueue = int_list_new(0);
GArray *candidates = g_array_new(FALSE, FALSE, sizeof(FooscribedDisc));
GArray *vertices = g_array_new(FALSE, FALSE, sizeof(guint));
EdgeList edges = { 0, 0, NULL };
/*
* For each grain:
* Extract it, find all boundary pixels.
* Use (octagnoal) erosion to find disc centre candidate(s).
* For each candidate:
* Find maximum disc that fits with this centre.
* By expanding/moving try to find a larger disc until we cannot
* improve it.
*/
for (guint gno = 1; gno <= ngrains; gno++) {
guint w = bbox[gno].width, h = bbox[gno].height;
gdouble xoff = dx*bbox[gno].col, yoff = dy*bbox[gno].row;
/* If the grain is rectangular, calculate the properties directly.
* Large rectangular grains are rare but the point is to catch
* grains with width or height of 1 here. */
if (sizes[gno] == w*h) {
gdouble sdx = 0.5*w*dx, sdy = 0.5*h*dy;
gdouble Lmax = fmax(sdx, sdy), Lmin = fmin(sdx, sdy);
if (inscrdrvalues)
inscrdrvalues[gno] = 0.999999*Lmin;
if (inscrdxvalues)
inscrdxvalues[gno] = sdx + xoff;
if (inscrdyvalues)
inscrdyvalues[gno] = sdy + yoff;
if (edmeanvalues)
edmeanvalues[gno] = Lmin/6.0*(3.0 - Lmin/Lmax);
continue;
}
/* Upsampling twice combined with octagonal erosion has the nice
* property that we get candidate pixels in places such as corners
* or junctions of one-pixel thin lines. */
guint width, height, wspsize = grainsize;
grain = extract_upsampled_square_pixel_grain(grains, xres, gno,
bbox + gno,
grain, &grainsize,
&width, &height,
dx, dy);
workspace = grain_maybe_realloc(workspace, width, height, &wspsize);
g_assert(wspsize == grainsize);
/* Size of upsampled pixel in original squeezed pixel coordinates.
* Normally equal to 1/2 and always approximately 1:1. */
gdouble sdx = w*(dx/qgeom)/width;
gdouble sdy = h*(dy/qgeom)/height;
/* Grain centre in squeezed pixel coordinates within the bbox. */
gdouble centrex = (xvalues[gno] + 0.5)*(dx/qgeom);
gdouble centrey = (yvalues[gno] + 0.5)*(dy/qgeom);
_gwy_distance_transform_raw(grain, workspace, width, height, TRUE,
inqueue, outqueue);
if (edmeanvalues) {
edmeanvalues[gno] = mean_euclidean_distance(grain, width*height,
w*dx/width,
h*dy/height);
}
if (nodiscs)
continue;
#if 0
g_printerr("Grain #%u, orig %ux%u, resampled to %ux%u\n",
gno, bbox[gno].width, bbox[gno].height, width, height);
for (guint i = 0; i < height; i++) {
for (guint j = 0; j < width; j++) {
if (!grain[i*width + j])
g_printerr("..");
else
g_printerr("%02u", grain[i*width + j]);
g_printerr("%c", j == width-1 ? '\n' : ' ');
}
}
#endif
double dist = find_disc_centre_candidates(candidates, NCAND_MAX,
grain, width, height,
sdx, sdy,
centrex, centrey);
find_all_edges(&edges, vertices, grains, xres, gno, bbox + gno,
dx/qgeom, dy/qgeom);
/* Try a few first candidates for the inscribed disc centre. */
FooscribedDisc *cand;
for (guint i = 0; i < candidates->len; i++) {
cand = &g_array_index(candidates, FooscribedDisc, i);
improve_inscribed_disc(cand, &edges, dist);
}
cand = &g_array_index(candidates, FooscribedDisc, 0);
for (guint i = 1; i < candidates->len; i++) {
if (g_array_index(candidates, FooscribedDisc, i).R2 > cand->R2)
cand = &g_array_index(candidates, FooscribedDisc, i);
}
if (inscrdrvalues)
inscrdrvalues[gno] = sqrt(cand->R2)*qgeom;
if (inscrdxvalues)
inscrdxvalues[gno] = cand->x*qgeom + xoff;
if (inscrdyvalues)
inscrdyvalues[gno] = cand->y*qgeom + yoff;
//g_printerr("[%u] %g %g %g\n", gno, sqrt(cand->R2)*qgeom, cand->x*qgeom + xoff, cand->y*qgeom + yoff);
}
g_free(workspace);
g_free(grain);
int_list_free(inqueue);
int_list_free(outqueue);
g_free(edges.edges);
g_array_free(vertices, TRUE);
g_array_free(candidates, TRUE);
}
