Ellipse¶

Overview¶

Class

An ellipse.

Supertypes

GraphicalPrimitive

Attributes (data)

Name	Multiplicity	Type
Center	1	Point
FillStyle	1	FillStyle
HorizontalSemiAxis	1	Double
Rotation	1	Double
Stroke	1	Stroke
VerticalSemiAxis	1	Double

Geometry¶

The geometry of an Ellipse is characterized by its Center, its two axes (HorizontalSemiAxis and VerticalSemiAxis), and the Rotation of the HorizontalSemiAxis w.r.t. the x axis of the owner. The Rotation is measured clockwise and in degrees.

Example

We consider an Ellipse with

Center (10, 20),
HorizontalSemiAxis 110,
VerticalSemiAxis 50, and
Rotation 35.

The Ellipse will look like this:

Visual Center

The visual center of an Ellipse is its actual Center.

Mapping to SVG¶

An Ellipse corresponds to an svg:ellipse with these attributes:

transform describes both the Center \((c_x, c_y)\) and the Rotation \(r\) of the Ellipse.

transform = "translate( + str(\(c_x\)) + , + str(\(c_y\)) + ) rotate( + str(\(r\)) + )"
rx and ry are string representations of HorizontalSemiAxis and VerticalSemiAxis.
stroke, stroke-dasharray, stroke-dashoffset and stroke-width are set according to the SVG mapping rules for the Stroke of the Ellipse (see Stroke).
stroke-linecap = "round" and stroke-linejoin = "round" reflect the heuristic for line caps and line joins.
vector-effect = "non-scaling-stroke" reflects the heuristic for scaled symbols.
fill is set according to the SVG mapping rules for the FillStyle of the Ellipse (see FillStyle).

Implementation in Proteus Schema

An Ellipse is implemented using the Proteus element <Ellipse>. An Ellipse whose HorizontalSemiAxis equals its VerticalSemiAxis may alternatively be implemented using the Proteus element <Circle>>.

Example

We assume that the Stroke of the Ellipse above is 2mm #ff0000 Solid and that its FillStyle is Transparent.

<svg
  xmlns = "http://www.w3.org/2000/svg"
  width = "192mm"
  height = "154mm"
  viewBox = "-86 -57 192 154">
  <ellipse
    transform = "translate(10,20) rotate(35.0)"
    rx = "110"
    ry = "50"
    stroke = "#ff0000"
    stroke-dasharray = "none"
    stroke-dashoffset = "0mm"
    stroke-width = "2mm"
    stroke-linecap = "round"
    stroke-linejoin = "round"
    vector-effect = "non-scaling-stroke"
    fill = "none"/>
</svg>

Implementation in Proteus Schema

<Ellipse PrimaryAxis = "110" SecondaryAxis = "50">
  <Presentation
    LineType = "0"
    LineWeight = "2"
    R = "1"
    G = "0"
    B = "0"/>
  <Position>
    <Location X = "10" Y = "-20" Z = "0"/>
    <Axis X = "0" Y = "0" Z = "1"/>
    <Reference X = "0.819152044" Y = "-0.573576436" Z = "0"/>
  </Position>
</Ellipse>

Example

We consider the same Ellipse as in the previous example, except that the Stroke is 2mm #ff0000 LongDashShortDash.

<svg
  xmlns = "http://www.w3.org/2000/svg"
  width = "192mm"
  height = "154mm"
  viewBox = "-86 -57 192 154">
  <ellipse
    transform = "translate(10,20) rotate(35.0)"
    rx = "110"
    ry = "50"
    stroke = "#ff0000"
    stroke-dasharray = "22mm 26mm 4mm 26mm"
    stroke-dashoffset = "0mm"
    stroke-width = "2mm"
    stroke-linecap = "round"
    stroke-linejoin = "round"
    vector-effect = "non-scaling-stroke"
    fill = "none"/>
</svg>

Implementation in Proteus Schema

<Ellipse PrimaryAxis = "110" SecondaryAxis = "50">
  <Presentation
    LineType = "4"
    LineWeight = "2"
    R = "1"
    G = "0"
    B = "0"/>
  <Position>
    <Location X = "10" Y = "-20" Z = "0"/>
    <Axis X = "0" Y = "0" Z = "1"/>
    <Reference X = "0.819152044" Y = "-0.573576436" Z = "0"/>
  </Position>
</Ellipse>

Example

Finally, a variant with Stroke 2mm #ff0000 Solid and FillStyle Hatch.

<svg
  xmlns = "http://www.w3.org/2000/svg"
  width = "192mm"
  height = "154mm"
  viewBox = "-86 -57 192 154">
  <defs>
    <pattern
      id = "pattern-1"
      width = "10"
      height = "20"
      patternUnits = "userSpaceOnUse"
      patternTransform = "rotate(-35.0) scale(1.0,1.0) rotate(315) translate(-1.0,-1.0)">
      <polyline
        points = "0,1.0 10,1.0"
        stroke = "#ff0000"
        stroke-width = "2mm"
        vector-effect = "non-scaling-stroke"/>
    </pattern>
  </defs>
  <ellipse
    transform = "translate(10,20) rotate(35.0)"
    rx = "110"
    ry = "50"
    stroke = "#ff0000"
    stroke-dasharray = "none"
    stroke-dashoffset = "0mm"
    stroke-width = "2mm"
    stroke-linecap = "round"
    stroke-linejoin = "round"
    vector-effect = "non-scaling-stroke"
    fill = "url(#pattern-1)"/>
</svg>

Implementation in Proteus Schema

<Ellipse PrimaryAxis = "110" SecondaryAxis = "50" Filled = "Hatch">
  <Presentation
    LineType = "0"
    LineWeight = "2"
    R = "1"
    G = "0"
    B = "0"/>
  <Position>
    <Location X = "10" Y = "-20" Z = "0"/>
    <Axis X = "0" Y = "0" Z = "1"/>
    <Reference X = "0.819152044" Y = "-0.573576436" Z = "0"/>
  </Position>
</Ellipse>

Center¶

Attribute (data)

The center position of the Ellipse.

Multiplicity: 1

Type: Point

FillStyle¶

Attribute (data)

The fill style of the Ellipse.

Multiplicity: 1

Type: FillStyle

HorizontalSemiAxis¶

Attribute (data)

The length of the horizontal semi-axis of the Ellipse in mm.

Multiplicity: 1

Type: Double

Rotation¶

Attribute (data)

The rotation of the Ellipse around its center, measured clockwise and in degrees. The value must be in the inverval [0; 360).

Multiplicity: 1

Type: Double

Stroke¶

Attribute (data)

The stroke of the Ellipse.

Multiplicity: 1

Type: Stroke

VerticalSemiAxis¶

Attribute (data)

The length of the vertical semi-axis of the Ellipse in mm.

Multiplicity: 1

Type: Double