/// <summary> /// Updates info on the longest horizontal span that crosses this polygon (used /// by <see cref="GetLabelPosition"/>) /// </summary> /// <param name="y">The Y-value of the scan line.</param> /// <param name="minx">The X-value for the western end of the scan line.</param> /// <param name="maxx">The X-value for the eastern end of the scan line.</param> /// <param name="weight">Weighting factor to use when comparing span lengths versus /// the initial best length.</param> /// <param name="beststart">The position of the start of the best span.</param> /// <param name="bestend">The position of the end of the best span.</param> /// <param name="bestlen">The weighted length of the best span. This is what defines /// the meaning of "best".</param> void GetLabelSpan(double y, double minx, double maxx, double weight, ref IPosition beststart, ref IPosition bestend, ref double bestlen) { // Define scan line. ITerminal sloc = new FloatingTerminal(minx, y); ITerminal eloc = new FloatingTerminal(maxx, y); SegmentGeometry seg = new SegmentGeometry(sloc, eloc); // Intersect with the map IntersectionFinder xseg = new IntersectionFinder(seg, true); // Arrange intersections along the scan line. IntersectionResult xres = new IntersectionResult(xseg); xres.Sort(true); // Define start of the first span IPosition start = sloc; IPosition end = null; // Go through each successive intersection, to locate spans // that run through the interior of the polygon. foreach (IntersectionData d in xres.Intersections) { // If the intersection is a graze if (d.IsGraze) { // Just define the end of the graze as the end point (there's // no point in trying to locate a label along the graze). end = d.P2; } else { // Simple intersection... // Get the next intersection end = d.P1; // Get the midpoint of the span. IPosition mid = Position.CreateMidpoint(start, end); // If the midpoint really falls inside this polygon, see whether the span // length is bigger than what we already have (if anything). if (this.IsEnclosing(mid)) { double len = (end.X - start.X) / weight; if (len > bestlen) { bestlen = len; beststart = start; bestend = end; } } } start = end; } }
/// <summary> /// Does any edge of this closed shape intersect a line segment? /// </summary> /// <param name="ps">The start of the segment</param> /// <param name="pe">The end of the segment</param> /// <returns>True if any edge of this shape intersects the segment</returns> bool IsOverlap(IPointGeometry ps, IPointGeometry pe) { Window segwin = new Window(ps, pe); if (!m_Extent.IsOverlap(segwin)) { return(false); } // Define the test segment. ITerminal ts = new FloatingTerminal(ps); ITerminal te = new FloatingTerminal(pe); SegmentGeometry seg = new SegmentGeometry(ts, te); return(IsIntersect(seg)); }
/// <summary> /// Does any edge of this closed shape intersect a line segment? /// </summary> /// <param name="ps">The start of the segment</param> /// <param name="pe">The end of the segment</param> /// <returns>True if any edge of this shape intersects the segment</returns> bool IsOverlap(IPointGeometry ps, IPointGeometry pe) { Window segwin = new Window(ps, pe); if (!m_Extent.IsOverlap(segwin)) return false; // Define the test segment. ITerminal ts = new FloatingTerminal(ps); ITerminal te = new FloatingTerminal(pe); SegmentGeometry seg = new SegmentGeometry(ts, te); return IsIntersect(seg); }
/// <summary> /// Updates info on the longest horizontal span that crosses this polygon (used /// by <see cref="GetLabelPosition"/>) /// </summary> /// <param name="y">The Y-value of the scan line.</param> /// <param name="minx">The X-value for the western end of the scan line.</param> /// <param name="maxx">The X-value for the eastern end of the scan line.</param> /// <param name="weight">Weighting factor to use when comparing span lengths versus /// the initial best length.</param> /// <param name="beststart">The position of the start of the best span.</param> /// <param name="bestend">The position of the end of the best span.</param> /// <param name="bestlen">The weighted length of the best span. This is what defines /// the meaning of "best".</param> void GetLabelSpan(double y, double minx, double maxx, double weight, ref IPosition beststart, ref IPosition bestend, ref double bestlen) { // Define scan line. ITerminal sloc = new FloatingTerminal(minx, y); ITerminal eloc = new FloatingTerminal(maxx, y); SegmentGeometry seg = new SegmentGeometry(sloc, eloc); // Intersect with the map IntersectionFinder xseg = new IntersectionFinder(seg, true); // Arrange intersections along the scan line. IntersectionResult xres = new IntersectionResult(xseg); xres.Sort(true); // Define start of the first span IPosition start = sloc; IPosition end = null; // Go through each successive intersection, to locate spans // that run through the interior of the polygon. foreach (IntersectionData d in xres.Intersections) { // If the intersection is a graze if (d.IsGraze) { // Just define the end of the graze as the end point (there's // no point in trying to locate a label along the graze). end = d.P2; } else { // Simple intersection... // Get the next intersection end = d.P1; // Get the midpoint of the span. IPosition mid = Position.CreateMidpoint(start, end); // If the midpoint really falls inside this polygon, see whether the span // length is bigger than what we already have (if anything). if (this.IsEnclosing(mid)) { double len = (end.X - start.X)/weight; if (len>bestlen) { bestlen = len; beststart = start; bestend = end; } } } start = end; } }