From f7b4cc602b9a646fbc66f3f17d6bb9c20efc3ead Mon Sep 17 00:00:00 2001 From: jaseg Date: Sun, 24 Jan 2021 18:44:56 +0100 Subject: Initial commit --- .../ClipperLib/Classes/PolyTree/Methods/Clear.htm | 73 ++++++++ .../Classes/PolyTree/Methods/GetFirst.htm | 77 +++++++++ .../Classes/PolyTree/Properties/Total.htm | 74 ++++++++ .../Units/ClipperLib/Classes/PolyTree/_Body.htm | 189 +++++++++++++++++++++ 4 files changed, 413 insertions(+) create mode 100644 upstream/clipper-6.4.2/Documentation/Docs/Units/ClipperLib/Classes/PolyTree/Methods/Clear.htm create mode 100644 upstream/clipper-6.4.2/Documentation/Docs/Units/ClipperLib/Classes/PolyTree/Methods/GetFirst.htm create mode 100644 upstream/clipper-6.4.2/Documentation/Docs/Units/ClipperLib/Classes/PolyTree/Properties/Total.htm create mode 100644 upstream/clipper-6.4.2/Documentation/Docs/Units/ClipperLib/Classes/PolyTree/_Body.htm (limited to 'upstream/clipper-6.4.2/Documentation/Docs/Units/ClipperLib/Classes/PolyTree') diff --git a/upstream/clipper-6.4.2/Documentation/Docs/Units/ClipperLib/Classes/PolyTree/Methods/Clear.htm b/upstream/clipper-6.4.2/Documentation/Docs/Units/ClipperLib/Classes/PolyTree/Methods/Clear.htm new file mode 100644 index 0000000..d30fb15 --- /dev/null +++ b/upstream/clipper-6.4.2/Documentation/Docs/Units/ClipperLib/Classes/PolyTree/Methods/Clear.htm @@ -0,0 +1,73 @@ + + + + + + + + + + + + + + + + + + + + Clear + + + + + + + + + + + + + + + + + + + + + + +

PolyTree.Clear

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Del.» procedure Clear;

+ +

C++ » void Clear();

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C# » public void Clear();

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+ + +

This method clears any PolyNode children contained by PolyTree the object.

Clear does not need to be called explicitly. The Clipper.Execute method that accepts a PolyTree parameter will automatically clear the PolyTree object before propagating it with new PolyNodes. Likewise, PolyTree's destructor will also automatically clear any contained PolyNodes.

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PolyTree.GetFirst

+ + +

Del.» function GetFirst: TPolyNode;

+ +

C++ » PolyNode* GetFirst();

+ +

C# » public PolyNode GetFirst();

+ + +

This method returns the first outer polygon contour if any, otherwise a null pointer.

This function is almost equivalent to calling Childs[0] except that when a PolyTree object is empty (has no children), calling Childs[0] would raise an out of range exception.

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PolyTree.Total

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Del.» property Total: Integer; //read only

+ +

C++ » Total(); //read only

+ +

C# » public int Total; //read only

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+ +

Returns the total number of PolyNodes (polygons) contained within the PolyTree. This value is not to be confused with ChildCount which returns the number of immediate children only (Childs) contained by PolyTree.

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PolyTree

Hierarchy

PolyNode

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+ +

PolyTree is intended as a read-only data structure that should only be used to receive solutions from clipping and offsetting operations. It's an alternative to the Paths data structure which also receives these solutions. PolyTree's two major advantages over the Paths structure are: it properly represents the parent-child relationships of the returned polygons; it differentiates between open and closed paths. However, since PolyTree is a more complex structure than the Paths structure, and since it's more computationally expensive to process (the Execute method being roughly 5-10% slower), it should used only be when parent-child polygon relationships are needed, or when open paths are being 'clipped'.

An empty PolyTree object can be passed as the solution parameter in Clipper.Execute and in ClipperOffset.Execute. Once the clipping or offseting operation is completed, the method returns with the PolyTree structure filled with data representing the solution.

A PolyTree object is a container for any number of PolyNode children, with each contained PolyNode representing a single polygon contour (either an outer or hole polygon). PolyTree itself is a specialized PolyNode whose immediate children represent the top-level outer polygons of the solution. (Its own Contour property is always empty.) The contained top-level PolyNodes may contain their own PolyNode children representing hole polygons that may also contain children representing nested outer polygons etc. Children of outers will always be holes, and children of holes will always be outers.

PolyTrees can also contain open paths. Open paths will always be represented by top level PolyNodes. Two functions are provided to quickly separate out open and closed paths from a polytree - OpenPathsFromPolyTree and ClosedPathsFromPolyTree.

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+
+    polytree: 
+    Contour = ()
+    ChildCount = 1
+    Childs[0]: 
+        Contour = ((10,10),(100,10),(100,100),(10,100))
+        IsHole = False
+        ChildCount = 1
+        Childs[0]: 
+            Contour = ((20,20),(20,90),(90,90),(90,20))
+            IsHole = True
+            ChildCount = 2
+            Childs[0]: 
+                Contour = ((30,30),(50,30),(50,50),(30,50))
+                IsHole = False
+                ChildCount = 0
+            Childs[1]: 
+                Contour = ((60,60),(80,60),(80,80),(60,80))
+                IsHole = False
+                ChildCount = 0
+
+

+ +

Reference

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Fields +	Methods +	Properties +
In PolyTree: +
+	Clear +	Total +
+	GetFirst +	+
In PolyNode: +
+	GetNext +	ChildCount +
+	+	Childs +
+	+	Contour +
+	+	IsHole +
+	+	IsOpen +
+	+	Parent +

PolyTree.Clear

See Also

PolyTree.GetFirst

See Also

PolyTree.Total

See Also

PolyTree

Hierarchy

Reference

See Also