使用PathGeometry.Widen（）

Question

我正在使用SharpDX在.NET WinForms上绘制折线。 这些折线代表钣金件的轮廓。

组成PathGeometry对象，定义折线：

'reset m_pathGeometry (the core geometry of this sheetmetal profile)
m_pathGeometry = New PathGeometry(D2DCanvas.canvas_factory2D)

' pointsRef = collection of points showing the segments & bends in this sheetmetal profile
Dim pointsRef As List(Of Vector2) = calculateSegmentsPoints()

' Add lines to m_pathGeometry using our points collection
Using sink As SimplifiedGeometrySink = m_pathGeometry.Open()
    sink.BeginFigure(pointsRef.First(), FigureBegin.Filled)
    sink.AddLines(pointsRef.ToArray)
    sink.EndFigure(FigureEnd.Open)
    sink.Close()
End Using

在被绘制到屏幕之前，我应用了一个转换（考虑到转换和扩展）：

' update m_fillTransformedGeometry based on m_pathGeometry & the current transform matrix3x2,
m_fillTransformedGeometry = New TransformedGeometry(D2DCanvas.canvas_factory2D, m_pathGeometry, Matrix3x2.Rotation(m_rotation, InsertPoint) * _transformMatrix)

' to draw the polyline
D2DCanvas.canvas_renderTarget2D.DrawGeometry(m_fillTransformedGeometry, m_fillBrush, plaatdikte * _transformMatrix.ScaleVector(1), m_strokeStyle)

使用描边样式，圆角线连接和平顶端

绘制折线

With m_strokeStyleProps
   .LineJoin = LineJoin.Round
   .EndCap = CapStyle.Flat
   .StartCap = CapStyle.Flat
End With

结果有点苍白，可以使用笔画：

第一个想法是用更深的颜色绘制相同的折线，稍微宽一点的StrokeWidth：

' First draw a wider stroke
D2DCanvas.canvas_renderTarget2D.DrawGeometry(m_fillTransformedGeometry, m_strokeBrush, (plaatdikte + 0.2) * _transformMatrix.ScaleVector(1), m_strokeStyle)

' Then draw the fill
D2DCanvas.canvas_renderTarget2D.DrawGeometry(m_fillTransformedGeometry, m_fillBrush, plaatdikte * _transformMatrix.ScaleVector(1), m_strokeStyle)

结果很好，但是这样的结束时不会中风：

第二个想法是通过在原始折线-PathGeometry上调用 Widen（）方法为笔划本身创建一个（略微加宽的）PathGeometry。

'define m_widenedPathGeometry (makes op the outline/stroke of this sheetmetal profile)
m_widenedPathGeometry = New PathGeometry(D2DCanvas.canvas_factory2D)
Using sink As SimplifiedGeometrySink = m_widenedPathGeometry.Open()
    m_pathGeometry.Widen(0.2, sink)
    sink.Close()
End Using

在绘制“填充”（两者都使用相同的StrokeStyle！）之前，这个加宽的几何体被绘制（考虑转换）为“笔划”：

' update m_transGeom based on m_widenedPathGeometry & the current transform matrix3x2,
m_transGeom = New TransformedGeometry(D2DCanvas.canvas_factory2D, m_widenedPathGeometry, Matrix3x2.Rotation(m_rotation, InsertPoint) * _transformMatrix)
'   to draw the stroke of the Polyline
D2DCanvas.canvas_renderTarget2D.DrawGeometry(m_transGeom, m_strokeBrush, plaatdikte * _transformMatrix.ScaleVector(1), m_strokeStyle)

' update m_fillTransformedGeometry based on m_pathGeometry & the current transform matrix3x2,
m_fillTransformedGeometry = New TransformedGeometry(D2DCanvas.canvas_factory2D, m_pathGeometry, Matrix3x2.Rotation(m_rotation, InsertPoint) * _transformMatrix)
' to draw the fill of the PolyLine
D2DCanvas.canvas_renderTarget2D.DrawGeometry(m_fillTransformedGeometry, m_fillBrush, plaatdikte * _transformMatrix.ScaleVector(1), m_strokeStyle)

这会对End-Caps产生不良影响： （圆角，未在StrokeStyle中定义，或介于两者之间）

当我将已使用的StrokeStyle重新定义为具有“圆形”端盖时，此笔划/填充方法可正常工作：

但是'扁平'的封顶真的是我所追求的。

为什么会发生这种情况，或者我如何解决这个问题？

干杯！

Answer 1

发现这里出了什么问题！

为可能遇到类似内容的其他人写下来。

在创建加宽的几何体时，我添加了'FigureEnd'属性设置为'Open'，这可以防止在自身上创建“闭环”的几何体，从而导致这些伪影。

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