// Before placing a new label we need to see if the label overlaps over
// previously placed labels. This algorithm will be refactored a bit to try
// NE SE SW NW placements in the future.
void
try_and_insert_placement(simplet_lithograph_t *litho, PangoLayout *layout, double x, double y){
int width, height;
// Find the computed width and height of a layout in image pixels
pango_layout_get_pixel_size(layout, &width, &height);
simplet_bounds_t *bounds = simplet_bounds_new();
if(!bounds) return;
// Create a bounds to test for intersection
simplet_bounds_extend(bounds, floor(x - width / 2), floor(y - height / 2));
simplet_bounds_extend(bounds, floor(x + width / 2), floor(y + height / 2));
// Iterate through the list of already placed labels and check for overlaps.
simplet_listiter_t *iter = simplet_get_list_iter(litho->placements);
placement_t *placement;
while((placement = (placement_t *) simplet_list_next(iter))){
if(simplet_bounds_intersects(placement->bounds, bounds)){
simplet_bounds_free(bounds);
g_object_unref(layout);
simplet_list_iter_free(iter);
return;
}
}
// If we get here we can create and insert a new placement.
placement_t *plc = placement_new(layout, bounds);
if(!plc) {
simplet_bounds_free(bounds);
g_object_unref(layout);
return;
}
simplet_list_push(litho->placements, (void *)plc);
}
// Create a bounds from the Convex Hull of an OGR Geometry.
simplet_bounds_t*
simplet_bounds_from_ogr(OGRGeometryH geom){
OGRGeometryH hull;
// Grab the Convex Hull
if(!(hull = OGR_G_ConvexHull(geom)))
return NULL;
// Create the bounds.
simplet_bounds_t *bounds;
if(!(bounds = simplet_bounds_new())){
OGR_G_DestroyGeometry(hull);
return NULL;
}
// Extend the bounds by adding the points from the Convex Hull.
double x, y;
for(int i = 0; i < OGR_G_GetGeometryCount(hull); i++){
OGRGeometryH subgeom = OGR_G_GetGeometryRef(hull, i);
if(subgeom == NULL)
continue;
for(int j = 0; j < OGR_G_GetPointCount(subgeom); j++){
OGR_G_GetPoint(subgeom, j, &x, &y, NULL);
simplet_bounds_extend(bounds, x, y);
}
}
OGR_G_DestroyGeometry(hull);
return bounds;
}
