Package com.inductiveautomation.rm.graphics

Class RMDoubleStroke

java.lang.Object
com.inductiveautomation.rm.base.RMListenerList
com.inductiveautomation.rm.base.RMObject
com.inductiveautomation.rm.graphics.RMFill
com.inductiveautomation.rm.graphics.RMStroke
com.inductiveautomation.rm.graphics.RMDoubleStroke
All Implemented Interfaces:
Archivable, RMPropertyChanger, Cloneable
public class RMDoubleStroke extends RMStroke
Strokes a path with 2 lines of different widths, with an arbitrary separation (d) between them.

This works by taking the input path and creating 'offset curves'. The offset curve is defined as being parallel to the original curve at every point.

For a given parametric curve C(t)={x(t),y(t)}, the slope of the curve at t is given by mC(t)=(dy/dt) / (dx/dt) = y'(t)/x'(t) and the the normal is therefore NC(t)=Normalize({-x'(t), y'(t)})

An offset curve for a cubic bezier can not be represented by a single bezier. Therefore, we need to find a set of n curves OffC0,OffC1,...OffCn that fits, as closely as possible, the following points: OffsetPoint(t)=C(t)+d*NC(t)

One possibility is to calculate a million OffsetPoints for the range t->{0,1} and run the curve fit code.

In order to preserve continuity of the different bezier segments, it should also be required that mOffC0(0) = mC(0) and mOffCn(1) = mC(1) That is, the slopes at the beginning and end of the curve should the same in the offset curve as it is in the original curve. Also, since the offset points are obtained by walking along the normal vector for the original curve, the slope of the offset curve at offsetpoint(t) should be the same as mC(t). The curve fit code does not currently take into account the slope of the curve at a given input point, but it's something to look into. Knowing this may provide enough additional information to speed up the curve fit and/or reduce the number of input points needed for an accurate fit.

  • Field Details

  • Constructor Details

    • RMDoubleStroke

      public RMDoubleStroke()
      Creates a new plain double stroke.

    • RMDoubleStroke

      public RMDoubleStroke(RMColor col, float w)
      Creates a new double stroke.

    • RMDoubleStroke

      public RMDoubleStroke(RMColor col, float outerW, float innerW, float separation, int positions)
      Creates a new double stroke.

  • Method Details

    • getRulePositions

      public int getRulePositions()
      Returns the double stroke rule positions.

    • setRulePositions

      public void setRulePositions(int _rulePositions)

    • getInnerRuleWidth

      public float getInnerRuleWidth()
      Returns the inner rule width.

    • setInnerRuleWidth

      public void setInnerRuleWidth(float _innerRuleWidth)

    • getOuterRuleWidth

      public float getOuterRuleWidth()
      Returns the outer rule width.

    • setOuterRuleWidth

      public void setOuterRuleWidth(float _outerRuleWidth)

    • getOuterStroke

      public RMStroke getOuterStroke()
      Return the stroke used on the outside of a clockwise path

    • getInnerStroke

      public RMStroke getInnerStroke()
      Return the stroke used on the inside of a clockwise path

    • getRuleSeparation

      public float getRuleSeparation()

    • setRuleSeparation

      public void setRuleSeparation(float _ruleSeparation)

    • getBounds

      public RMRect getBounds(RMShape aShape)
      Returns the bounds required to render this fill for this shape.
      Overrides:
      getBounds in class RMStroke

    • paint

      public void paint(RMShapePainter aPntr, RMShape aShape)
      Override to paint inner and outer strokes.
      Overrides:
      paint in class RMStroke

    • equals

      public boolean equals(Object anObj)
      Standard equals implementation.
      Overrides:
      equals in class RMStroke

    • clone

      public RMDoubleStroke clone()
      Standard clone implementation.
      Overrides:
      clone in class RMStroke

    • toXML

      public RXElement toXML(RXArchiver anArchiver)
      XML archival.
      Specified by:
      toXML in interface Archivable
      Overrides:
      toXML in class RMStroke

    • fromXML

      public Object fromXML(RXArchiver anArchiver, RXElement e)
      XML unarchival.
      Specified by:
      fromXML in interface Archivable
      Overrides:
      fromXML in class RMStroke

    • readAttributes

      protected void readAttributes(RXElement e)
      Overrides:
      readAttributes in class RMStroke