/// <summary>
/// Creates a node and either splits the objects recursively into sub-nodes, or stores them at the node depending on the heuristics.
/// Tree is built top->down
/// </summary>
/// <param name="objList">Geometries to index</param>
/// <param name="depth">Current depth of tree</param>
/// <param name="heurdata">Heuristics data</param>
public QuadTree(List <BoxObjects> objList, uint depth, Heuristic heurdata)
{
_depth = depth;
_box = objList[0].Box;
for (var i = 0; i < objList.Count; i++)
{
_box = _box.Join(objList[i].Box);
}
// test our build heuristic - if passes, make children
if (depth < heurdata.Maxdepth && objList.Count > heurdata.Mintricnt &&
(objList.Count > heurdata.Tartricnt || ErrorMetric(_box) > heurdata.Minerror))
{
var objBuckets = new List <BoxObjects> [2]; // buckets of geometries
objBuckets[0] = new List <BoxObjects>();
objBuckets[1] = new List <BoxObjects>();
var useXAxis = _box.Width > _box.Height; // longest axis
double geoAverage = 0; // geometric average - midpoint of ALL the objects
// go through all bbox and calculate the average of the midpoints
double fraction = 1.0f / objList.Count;
for (var i = 0; i < objList.Count; i++)
{
var centroid = useXAxis ? objList[i].Box.Centroid.X : objList[i].Box.Centroid.Y;
geoAverage += centroid * fraction;
}
// bucket bbox based on their midpoint's side of the geo average in the longest axis
for (var i = 0; i < objList.Count; i++)
{
var centroid = useXAxis ? objList[i].Box.Centroid.X : objList[i].Box.Centroid.Y;
objBuckets[geoAverage > centroid ? 1 : 0].Add(objList[i]);
}
//If objects couldn't be split, just store them at the leaf
//TODO: Try splitting on another axis
if (objBuckets[0].Count == 0 || objBuckets[1].Count == 0)
{
_child0 = null;
_child1 = null;
// copy object list
_objList = objList;
}
else
{
// create new children using the buckets
_child0 = new QuadTree(objBuckets[0], depth + 1, heurdata);
_child1 = new QuadTree(objBuckets[1], depth + 1, heurdata);
}
}
else
{
// otherwise the build heuristic failed, this is
// set the first child to null (identifies a leaf)
_child0 = null;
_child1 = null;
// copy object list
_objList = objList;
}
}
public void Draw(SKCanvas canvas, IReadOnlyViewport viewport, IWidget widget,
float layerOpacity)
{
var scaleBar = (ScaleBarWidget)widget;
if (!scaleBar.CanProject())
{
return;
}
// If this is the first time, we call this renderer, ...
if (_paintScaleBar == null)
{
// ... than create the paints
_paintScaleBar = CreateScaleBarPaint(SKPaintStyle.Fill);
_paintScaleBarStroke = CreateScaleBarPaint(SKPaintStyle.Stroke);
_paintScaleText = CreateTextPaint(SKPaintStyle.Fill);
_paintScaleTextStroke = CreateTextPaint(SKPaintStyle.Stroke);
}
// Update paints with new values
_paintScaleBar.Color = scaleBar.TextColor.ToSkia(layerOpacity);
_paintScaleBar.StrokeWidth = scaleBar.StrokeWidth * scaleBar.Scale;
_paintScaleBarStroke !.Color = scaleBar.Halo.ToSkia(layerOpacity);
_paintScaleBarStroke.StrokeWidth = scaleBar.StrokeWidthHalo * scaleBar.Scale;
_paintScaleText !.Color = scaleBar.TextColor.ToSkia(layerOpacity);
_paintScaleText.StrokeWidth = scaleBar.StrokeWidth * scaleBar.Scale;
_paintScaleText.Typeface = SKTypeface.FromFamilyName(scaleBar.Font?.FontFamily,
SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright);
_paintScaleText.TextSize = (float)(scaleBar.Font?.Size ?? 10) * scaleBar.Scale;
_paintScaleTextStroke !.Color = scaleBar.Halo.ToSkia(layerOpacity);
_paintScaleTextStroke.StrokeWidth = scaleBar.StrokeWidthHalo / 2 * scaleBar.Scale;
_paintScaleTextStroke.Typeface = SKTypeface.FromFamilyName(scaleBar.Font?.FontFamily,
SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright);
_paintScaleTextStroke.TextSize = (float)(scaleBar.Font?.Size ?? 10) * scaleBar.Scale;
float scaleBarLength1;
string?scaleBarText1;
float scaleBarLength2;
string?scaleBarText2;
(scaleBarLength1, scaleBarText1, scaleBarLength2, scaleBarText2) = scaleBar.GetScaleBarLengthAndText(viewport);
// Calc height of scale bar
var textSize = SKRect.Empty;
// Do this, because height of text changes sometimes (e.g. from 2 m to 1 m)
_paintScaleTextStroke.MeasureText("9999 m", ref textSize);
var scaleBarHeight = textSize.Height + (scaleBar.TickLength + scaleBar.StrokeWidthHalo * 0.5f + scaleBar.TextMargin) * scaleBar.Scale;
if (scaleBar.ScaleBarMode == ScaleBarMode.Both && scaleBar.SecondaryUnitConverter != null)
{
scaleBarHeight *= 2;
}
else
{
scaleBarHeight += scaleBar.StrokeWidthHalo * 0.5f * scaleBar.Scale;
}
scaleBar.Height = scaleBarHeight;
// Draw lines
// Get lines for scale bar
var points = scaleBar.GetScaleBarLinePositions(viewport, scaleBarLength1, scaleBarLength2, scaleBar.StrokeWidthHalo);
// Draw outline of scale bar
for (var i = 0; i < points.Count; i += 2)
{
canvas.DrawLine((float)points[i].X, (float)points[i].Y, (float)points[i + 1].X, (float)points[i + 1].Y, _paintScaleBarStroke);
}
// Draw scale bar
for (var i = 0; i < points.Count; i += 2)
{
canvas.DrawLine((float)points[i].X, (float)points[i].Y, (float)points[i + 1].X, (float)points[i + 1].Y, _paintScaleBar);
}
if (!points.Any())
{
throw new NotImplementedException($"A {nameof(ScaleBarWidget)} can not be drawn without line positions");
}
var envelop = new MRect(points.Select(p => p.MRect));
envelop = envelop.Grow(scaleBar.StrokeWidthHalo * 0.5f * scaleBar.Scale);
// Draw text
// Calc text height
var textSize1 = SKRect.Empty;
var textSize2 = SKRect.Empty;
scaleBarText1 ??= string.Empty;
_paintScaleTextStroke.MeasureText(scaleBarText1, ref textSize1);
if (scaleBar.ScaleBarMode == ScaleBarMode.Both && scaleBar.SecondaryUnitConverter != null)
{
// If there is SecondaryUnitConverter we need to calculate the size before passing it into GetScaleBarTextPositions
scaleBarText2 ??= string.Empty;
_paintScaleTextStroke.MeasureText(scaleBarText2, ref textSize2);
}
var(posX1, posY1, posX2, posY2) = scaleBar.GetScaleBarTextPositions(viewport, textSize.ToMRect(), textSize1.ToMRect(), textSize2.ToMRect(), scaleBar.StrokeWidthHalo);
// Now draw text
canvas.DrawText(scaleBarText1, posX1, posY1 - textSize1.Top, _paintScaleTextStroke);
canvas.DrawText(scaleBarText1, posX1, posY1 - textSize1.Top, _paintScaleText);
envelop = envelop?.Join(new MRect(posX1, posY1, posX1 + textSize1.Width, posY1 + textSize1.Height));
if (scaleBar.ScaleBarMode == ScaleBarMode.Both && scaleBar.SecondaryUnitConverter != null)
{
// Now draw second text
canvas.DrawText(scaleBarText2, posX2, posY2 - textSize2.Top, _paintScaleTextStroke);
canvas.DrawText(scaleBarText2, posX2, posY2 - textSize2.Top, _paintScaleText);
envelop = envelop?.Join(new MRect(posX2, posY2, posX2 + textSize2.Width, posY2 + textSize2.Height));
}
scaleBar.Envelope = envelop;
if (scaleBar.ShowEnvelop && envelop != null)
{
// Draw a rect around the scale bar for testing
var tempPaint = _paintScaleTextStroke;
canvas.DrawRect(new SKRect((float)envelop.MinX, (float)envelop.MinY, (float)envelop.MaxX, (float)envelop.MaxY), tempPaint);
}
}