SixLabors
/
Shapes
зеркало из https://github.com/SixLabors/Shapes.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность

reorganise clipper code some more.

This commit is contained in:
Scott Williams 2017-02-01 08:15:23 +00:00
Родитель c252e17ddc
Коммит d94db3503b
3 изменённых файлов: 139 добавлений и 91 удалений
Показать статистику Скачать Patch файл Скачать Diff файл Показать все файлы Свернуть все файлы

120
src/SixLabors.Shapes/PolygonClipper/Clipper.cs
Просмотреть файл

@ -21,8 +21,13 @@ namespace SixLabors.Shapes.PolygonClipper
/// The unassigned
/// </summary>
internal const int Unassigned = -1; // InitOptions that can be passed to the constructor ...
/// <summary>
/// The skip
/// </summary>
internal const int Skip = -2;
private const double HorizontalDeltaLimit = -3.4E+38;
private const int Skip = -2;
private static readonly IComparer<IntersectNode> IntersectNodeComparer = new IntersectNodeSort();
private readonly List<IntersectNode> intersectList = new List<IntersectNode>();
@ -574,12 +579,6 @@ namespace SixLabors.Shapes.PolygonClipper
val2 = tmp;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool IsHorizontal(Edge e)
{
return e.Delta.Y == 0;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool SlopesEqual(Edge e1, Edge e2)
{
@ -739,7 +738,7 @@ namespace SixLabors.Shapes.PolygonClipper
if (rb != null)
{
if (IsHorizontal(rb))
if (rb.IsHorizontal)
{
if (rb.NextInLML != null)
{
@ -760,7 +759,7 @@ namespace SixLabors.Shapes.PolygonClipper
}
// if output polygons share an Edge with a horizontal rb, they'll need joining later ...
if (op1 != null && IsHorizontal(rb) &&
if (op1 != null && rb.IsHorizontal &&
this.ghostJoins.Count > 0 && rb.WindingDelta != 0)
{
for (int i = 0; i < this.ghostJoins.Count; i++)
@ -1127,7 +1126,7 @@ namespace SixLabors.Shapes.PolygonClipper
{
OutPoint result;
Edge e, prevE;
if (IsHorizontal(e2) || (e1.Dx > e2.Dx))
if (e2.IsHorizontal || (e1.Dx > e2.Dx))
{
result = this.AddOutPt(e1, pt);
e2.OutIndex = e1.OutIndex;
@ -1695,16 +1694,12 @@ namespace SixLabors.Shapes.PolygonClipper
this.GetHorzDirection(horzEdge, out dir, out horzLeft, out horzRight);
Edge lastHorzEdge = horzEdge;
Edge lastHorzEdge = horzEdge.LastHorizonalEdge();
Edge maxPairEdge = null;
while (lastHorzEdge.NextInLML != null && IsHorizontal(lastHorzEdge.NextInLML))
{
lastHorzEdge = lastHorzEdge.NextInLML;
}
if (lastHorzEdge.NextInLML == null)
{
maxPairEdge = this.GetMaximaPair(lastHorzEdge);
maxPairEdge = lastHorzEdge?.GetMaximaPair();
}
Maxima currMax = this.maxima;
@ -1743,7 +1738,7 @@ namespace SixLabors.Shapes.PolygonClipper
while (true)
{
bool isLastHorz = horzEdge == lastHorzEdge;
Edge e = this.GetNextInAEL(horzEdge, dir);
Edge e = horzEdge.GetNextInAEL(dir);
while (e != null)
{
// this code block inserts extra coords into horizontal edges (in output
@ -1836,13 +1831,13 @@ namespace SixLabors.Shapes.PolygonClipper
this.IntersectEdges(e, horzEdge, pt);
}
Edge eNext = this.GetNextInAEL(e, dir);
Edge eNext = e.GetNextInAEL(dir);
this.SwapPositionsInAEL(horzEdge, e);
e = eNext;
} // end while(e != null)
// Break out of loop if HorzEdge.NextInLML is not also horizontal ...
if (horzEdge.NextInLML == null || !IsHorizontal(horzEdge.NextInLML))
if (horzEdge.NextInLML == null || !horzEdge.NextInLML.IsHorizontal)
{
break;
}
@ -1923,50 +1918,6 @@ namespace SixLabors.Shapes.PolygonClipper
}
}
private Edge GetNextInAEL(Edge e, Direction direction)
{
return direction == Direction.LeftToRight ? e.NextInAEL : e.PreviousInAEL;
}
private bool IsMaxima(Edge e, double y)
{
return e != null && e.Top.Y == y && e.NextInLML == null;
}
private bool IsIntermediate(Edge e, double y)
{
return e.Top.Y == y && e.NextInLML != null;
}
private Edge GetMaximaPair(Edge e)
{
if ((e.NextEdge.Top == e.Top) && e.NextEdge.NextInLML == null)
{
return e.NextEdge;
}
else if ((e.PreviousEdge.Top == e.Top) && e.PreviousEdge.NextInLML == null)
{
return e.PreviousEdge;
}
else
{
return null;
}
}
private Edge GetMaximaPairEx(Edge e)
{
// as above but returns null if MaxPair isn't in AEL (unless it's horizontal)
Edge result = this.GetMaximaPair(e);
if (result == null || result.OutIndex == Skip ||
((result.NextInAEL == result.PreviousInAEL) && !IsHorizontal(result)))
{
return null;
}
return result;
}
private bool ProcessIntersections(float topY)
{
if (this.activeEdges == null)
@ -2138,7 +2089,7 @@ namespace SixLabors.Shapes.PolygonClipper
if (edge1.Delta.X == 0)
{
ip.X = edge1.Bottom.X;
if (IsHorizontal(edge2))
if (edge2.IsHorizontal)
{
ip.Y = edge2.Bottom.Y;
}
@ -2151,7 +2102,7 @@ namespace SixLabors.Shapes.PolygonClipper
else if (edge2.Delta.X == 0)
{
ip.X = edge2.Bottom.X;
if (IsHorizontal(edge1))
if (edge1.IsHorizontal)
{
ip.Y = edge1.Bottom.Y;
}
@ -2222,12 +2173,12 @@ namespace SixLabors.Shapes.PolygonClipper
{
// 1. process maxima, treating them as if they're 'bent' horizontal edges,
// but exclude maxima with horizontal edges. nb: e can't be a horizontal.
bool isMaximaEdge = this.IsMaxima(e, topY);
bool isMaximaEdge = e.IsMaxima(topY);
if (isMaximaEdge)
{
Edge eMaxPair = this.GetMaximaPairEx(e);
isMaximaEdge = eMaxPair == null || !IsHorizontal(eMaxPair);
Edge eMaxPair = e.GetMaximaPairEx();
isMaximaEdge = eMaxPair == null || !eMaxPair.IsHorizontal;
}
if (isMaximaEdge)
@ -2246,7 +2197,7 @@ namespace SixLabors.Shapes.PolygonClipper
else
{
// 2. promote horizontal edges, otherwise update Curr.X and Curr.Y ...
if (this.IsIntermediate(e, topY) && IsHorizontal(e.NextInLML))
if (e.IsIntermediate(topY) && e.NextInLML.IsHorizontal)
{
this.UpdateEdgeIntoAEL(ref e);
if (e.OutIndex >= 0)
@ -2273,7 +2224,7 @@ namespace SixLabors.Shapes.PolygonClipper
e = this.activeEdges;
while (e != null)
{
if (this.IsIntermediate(e, topY))
if (e.IsIntermediate(topY))
{
OutPoint op = null;
if (e.OutIndex >= 0)
@ -2312,7 +2263,7 @@ namespace SixLabors.Shapes.PolygonClipper
private void DoMaxima(Edge e)
{
Edge eMaxPair = this.GetMaximaPairEx(e);
Edge eMaxPair = e?.GetMaximaPairEx();
if (eMaxPair == null)
{
if (e.OutIndex >= 0)
@ -2353,24 +2304,6 @@ namespace SixLabors.Shapes.PolygonClipper
}
}
private int PointCount(OutPoint pts)
{
if (pts == null)
{
return 0;
}
int result = 0;
OutPoint p = pts;
do
{
result++;
p = p.Next;
}
while (p != pts);
return result;
}
private ImmutableArray<IShape> BuildResult()
{
List<IShape> shapes = new List<IShape>(this.polyOuts.Count);
@ -2379,7 +2312,12 @@ namespace SixLabors.Shapes.PolygonClipper
for (int i = 0; i < this.polyOuts.Count; i++)
{
OutRec outRec = this.polyOuts[i];
int cnt = this.PointCount(outRec.Points);
if (outRec.Points == null)
{
continue;
}
int cnt = outRec.Points.Count();
if ((outRec.IsOpen && cnt < 2) ||
(!outRec.IsOpen && cnt < 3))
{
@ -3255,7 +3193,7 @@ namespace SixLabors.Shapes.PolygonClipper
e.Current = e.Bottom;
e.PreviousInAEL = aelPrev;
e.NextInAEL = aelNext;
if (!IsHorizontal(e))
if (!e.IsHorizontal)
{
this.InsertScanbeam(e.Top.Y);
}

93
src/SixLabors.Shapes/PolygonClipper/Edge.cs
Просмотреть файл

@ -155,6 +155,14 @@ namespace SixLabors.Shapes.PolygonClipper
/// </summary>
public Edge NextInSEL { get; set; }
/// <summary>
/// Gets a value indicating whether this instance is horizontal.
/// </summary>
/// <value>
/// <c>true</c> if this instance is horizontal; otherwise, <c>false</c>.
/// </value>
public bool IsHorizontal => this.Delta.Y == 0;
/// <summary>
/// Gets or sets the previous in sel.
/// </summary>
@ -176,5 +184,90 @@ namespace SixLabors.Shapes.PolygonClipper
this.Current = pt;
this.OutIndex = Clipper.Unassigned;
}
/// <summary>
/// Lasts the horizonal edge.
/// </summary>
/// <returns>The last horizontal edge</returns>
public Edge LastHorizonalEdge()
{
var lastHorzEdge = this;
while (lastHorzEdge.NextInLML != null && lastHorzEdge.NextInLML.IsHorizontal)
{
lastHorzEdge = lastHorzEdge.NextInLML;
}
return lastHorzEdge;
}
/// <summary>
/// Gets the next in ael.
/// </summary>
/// <param name="direction">The direction.</param>
/// <returns>the next edge based on direction</returns>
public Edge GetNextInAEL(Direction direction)
{
return direction == Direction.LeftToRight ? this.NextInAEL : this.PreviousInAEL;
}
/// <summary>
/// Determines whether the edge is Maxima in relation to y.
/// </summary>
/// <param name="y">The y.</param>
/// <returns>
/// <c>true</c> if the specified y is maxima; otherwise, <c>false</c>.
/// </returns>
public bool IsMaxima(double y)
{
return this.Top.Y == y && this.NextInLML == null;
}
/// <summary>
/// Gets the maxima pair.
/// </summary>
/// <returns>The maxima pair for this edge</returns>
public Edge GetMaximaPair()
{
if ((this.NextEdge.Top == this.Top) && this.NextEdge.NextInLML == null)
{
return this.NextEdge;
}
if ((this.PreviousEdge.Top == this.Top) && this.PreviousEdge.NextInLML == null)
{
return this.PreviousEdge;
}
return null;
}
/// <summary>
/// Determines whether the specified intermediate in relation to y.
/// </summary>
/// <param name="y">The y.</param>
/// <returns>
/// <c>true</c> if the specified y is intermediate; otherwise, <c>false</c>.
/// </returns>
public bool IsIntermediate(double y)
{
return this.Top.Y == y && this.NextInLML != null;
}
/// <summary>
/// Gets the maxima pair ex.
/// </summary>
/// <returns>The maxima pair for this edge unless it should be skipped</returns>
public Edge GetMaximaPairEx()
{
// as above but returns null if MaxPair isn't in AEL (unless it's horizontal)
Edge result = this.GetMaximaPair();
if (result == null || result.OutIndex == Clipper.Skip ||
((result.NextInAEL == result.PreviousInAEL) && !result.IsHorizontal))
{
return null;
}
return result;
}
}
}

17
src/SixLabors.Shapes/PolygonClipper/OutPoint.cs
Просмотреть файл

@ -35,5 +35,22 @@ namespace SixLabors.Shapes.PolygonClipper
/// Gets or sets the previous <see cref="OutPoint"/>
/// </summary>
public OutPoint Previous { get; set; }
/// <summary>
/// Counts this instance.
/// </summary>
/// <returns>count the number of points in this set</returns>
public int Count()
{
int result = 0;
OutPoint p = this;
do
{
result++;
p = p.Next;
}
while (p != this);
return result;
}
}
}