repo_description: D2 is a modern diagram scripting language that turns text to diagrams.
repo_topics: developer-tools diagramming diagrams go golang software-architecture text-to-diagram
code: package shape
  
  import (
  	"math"
  
  	"oss.terrastruct.com/d2/lib/geo"
  	"oss.terrastruct.com/d2/lib/svg"
  	"oss.terrastruct.com/util-go/go2"
  )
  
  type shapeQueue struct {
  	*baseShape
  }
  
  func NewQueue(box *geo.Box) Shape {
  	shape := shapeQueue{
  		baseShape: &baseShape{
  			Type: QUEUE_TYPE,
  			Box:  box,
  		},
  	}
  	shape.FullShape = go2.Pointer(Shape(shape))
  	return shape
  }
  
  func getArcWidth(box *geo.Box) float64 {
  	arcWidth := defaultArcDepth
  	// Note: box width should always be larger than 3*default
  	// this just handles after collaping into an oval
  	if box.Width < arcWidth*2 {
  		arcWidth = box.Width / 2.0
  	}
  	return arcWidth
  }
  
  func (s shapeQueue) GetInnerBox() *geo.Box {
  	width := s.Box.Width
  	tl := s.Box.TopLeft.Copy()
  	arcWidth := getArcWidth(s.Box)
  	width -= 3 * arcWidth
  	tl.X += arcWidth
  	return geo.NewBox(tl, width, s.Box.Height)
  }
  
  func queueOuterPath(box *geo.Box) *svg.SvgPathContext {
  	arcWidth := getArcWidth(box)
  	multiplier := 0.45
  	pc := svg.NewSVGPathContext(box.TopLeft, 1, 1)
  	pc.StartAt(pc.Absolute(arcWidth, 0))
  	pc.H(true, box.Width-2*arcWidth)
  	pc.C(false, box.Width, 0, box.Width, box.Height*multiplier, box.Width, box.Height/2.0)
  	pc.C(false, box.Width, box.Height-box.Height*multiplier, box.Width, box.Height, box.Width-arcWidth, box.Height)
  	pc.H(true, -1*(box.Width-2*arcWidth))
  	pc.C(false, 0, box.Height, 0, box.Height-box.Height*multiplier, 0, box.Height/2.0)
  	pc.C(false, 0, box.Height*multiplier, 0, 0, arcWidth, 0)
  	pc.Z()
  	return pc
  }
  
  func queueInnerPath(box *geo.Box) *svg.SvgPathContext {
  	arcWidth := getArcWidth(box)
  	multiplier := 0.45
  	pc := svg.NewSVGPathContext(box.TopLeft, 1, 1)
  	pc.StartAt(pc.Absolute(box.Width-arcWidth, 0))
  	pc.C(false, box.Width-2*arcWidth, 0, box.Width-2*arcWidth, box.Height*multiplier, box.Width-2*arcWidth, box.Height/2.0)
  	pc.C(false, box.Width-2*arcWidth, box.Height-box.Height*multiplier, box.Width-2*arcWidth, box.Height, box.Width-arcWidth, box.Height)
  	return pc
  }
  
  func (s shapeQueue) Perimeter() []geo.Intersectable {
  	return queueOuterPath(s.Box).Path
  }
  
  func (s shapeQueue) GetSVGPathData() []string {
  	return []string{
  		queueOuterPath(s.Box).PathData(),
  		queueInnerPath(s.Box).PathData(),
  	}
  }
  
  func (s shapeQueue) GetDimensionsToFit(width, height, paddingX, paddingY float64) (float64, float64) {
  	// 1 arc left, width+ padding, 2 arcs right
  	totalWidth := 3*defaultArcDepth + width + paddingX
  	return math.Ceil(totalWidth), math.Ceil(height + paddingY)
  }
  
  func (s shapeQueue) GetDefaultPadding() (paddingX, paddingY float64) {
  	return defaultPadding / 2, defaultPadding
  }
  