also trace in elk

d2graph/layout.go

@@ -9,6 +9,8 @@ import (
 	"oss.terrastruct.com/d2/lib/shape"
 )
 
+const MIN_SEGMENT_LEN = 10
+
 func (obj *Object) MoveWithDescendants(dx, dy float64) {
 	obj.TopLeft.X += dx
 	obj.TopLeft.Y += dy
@@ -313,3 +315,72 @@ func (obj *Object) GetLabelTopLeft() *geo.Point {
 	)
 	return labelTL
 }
+
+func (edge *Edge) TraceToShape(points []*geo.Point, startIndex, endIndex int) (newStart, newEnd int) {
+	srcShape := edge.Src.ToShape()
+	dstShape := edge.Dst.ToShape()
+
+	// if an edge runs into an outside label, stop the edge at the label instead
+	overlapsOutsideLabel := false
+	if edge.Src.HasLabel() {
+		// assumes LabelPosition, LabelWidth, LabelHeight are all set if there is a label
+		labelPosition := label.Position(*edge.Src.LabelPosition)
+		if labelPosition.IsOutside() {
+			labelWidth := float64(edge.Src.LabelDimensions.Width)
+			labelHeight := float64(edge.Src.LabelDimensions.Height)
+			labelTL := labelPosition.GetPointOnBox(edge.Src.Box, label.PADDING, labelWidth, labelHeight)
+
+			startingSegment := geo.Segment{Start: points[startIndex+1], End: points[startIndex]}
+			labelBox := geo.NewBox(labelTL, labelWidth, labelHeight)
+			// add left/right padding to box
+			labelBox.TopLeft.X -= label.PADDING
+			labelBox.Width += 2 * label.PADDING
+			if intersections := labelBox.Intersections(startingSegment); len(intersections) > 0 {
+				overlapsOutsideLabel = true
+				// move starting segment to label intersection point
+				points[startIndex] = intersections[0]
+				startingSegment.End = intersections[0]
+				// if the segment becomes too short, just merge it with the next segment
+				if startIndex < len(points) && startingSegment.Length() < MIN_SEGMENT_LEN {
+					points[startIndex+1] = points[startIndex]
+					startIndex++
+				}
+			}
+		}
+	}
+	if !overlapsOutsideLabel {
+		// trace the edge to the specific shape's border
+		points[startIndex] = shape.TraceToShapeBorder(srcShape, points[startIndex], points[startIndex+1])
+	}
+	overlapsOutsideLabel = false
+	if edge.Dst.HasLabel() {
+		// assumes LabelPosition, LabelWidth, LabelHeight are all set if there is a label
+		labelPosition := label.Position(*edge.Dst.LabelPosition)
+		if labelPosition.IsOutside() {
+			labelWidth := float64(edge.Dst.LabelDimensions.Width)
+			labelHeight := float64(edge.Dst.LabelDimensions.Height)
+			labelTL := labelPosition.GetPointOnBox(edge.Dst.Box, label.PADDING, labelWidth, labelHeight)
+
+			endingSegment := geo.Segment{Start: points[endIndex-1], End: points[endIndex]}
+			labelBox := geo.NewBox(labelTL, labelWidth, labelHeight)
+			// add left/right padding to box
+			labelBox.TopLeft.X -= label.PADDING
+			labelBox.Width += 2 * label.PADDING
+			if intersections := labelBox.Intersections(endingSegment); len(intersections) > 0 {
+				overlapsOutsideLabel = true
+				// move ending segment to label intersection point
+				points[endIndex] = intersections[0]
+				endingSegment.End = intersections[0]
+				// if the segment becomes too short, just merge it with the previous segment
+				if endIndex-1 > 0 && endingSegment.Length() < MIN_SEGMENT_LEN {
+					points[endIndex-1] = points[endIndex]
+					endIndex--
+				}
+			}
+		}
+	}
+	if !overlapsOutsideLabel {
+		points[endIndex] = shape.TraceToShapeBorder(dstShape, points[endIndex], points[endIndex-1])
+	}
+	return startIndex, endIndex
+}

d2layouts/d2dagrelayout/layout.go

@@ -21,7 +21,6 @@ import (
 	"oss.terrastruct.com/d2/lib/geo"
 	"oss.terrastruct.com/d2/lib/label"
 	"oss.terrastruct.com/d2/lib/log"
-	"oss.terrastruct.com/d2/lib/shape"
 )
 
 //go:embed setup.js
@@ -31,9 +30,8 @@ var setupJS string
 var dagreJS string
 
 const (
-	MIN_SEGMENT_LEN = 10
+	MIN_RANK_SEP   = 60
-	MIN_RANK_SEP    = 60
+	EDGE_LABEL_GAP = 20
-	EDGE_LABEL_GAP  = 20
 )
 
 type ConfigurableOpts struct {
@@ -433,7 +431,7 @@ func Layout(ctx context.Context, g *d2graph.Graph, opts *ConfigurableOpts) (err
 		// to fix this, we try extending the previous segment into the shape instead of having a very short segment
 		if !start.Equals(points[0]) && startIndex+2 < len(points) {
 			newStartingSegment := *geo.NewSegment(start, points[startIndex+1])
-			if newStartingSegment.Length() < MIN_SEGMENT_LEN {
+			if newStartingSegment.Length() < d2graph.MIN_SEGMENT_LEN {
 				// we don't want a very short segment right next to the source because it will mess up the arrowhead
 				// instead we want to extend the next segment into the shape border if possible
 				nextStart := points[startIndex+1]
@@ -442,30 +440,32 @@ func Layout(ctx context.Context, g *d2graph.Graph, opts *ConfigurableOpts) (err
 				// Note: in other direction to extend towards source
 				nextSegment := *geo.NewSegment(nextStart, nextEnd)
 				v := nextSegment.ToVector()
-				extendedStart := nextEnd.ToVector().Add(v.AddLength(MIN_SEGMENT_LEN)).ToPoint()
+				extendedStart := nextEnd.ToVector().Add(v.AddLength(d2graph.MIN_SEGMENT_LEN)).ToPoint()
 				extended := *geo.NewSegment(nextEnd, extendedStart)
 
 				if intersections := edge.Src.Box.Intersections(extended); len(intersections) > 0 {
-					start = intersections[0]
+					startIndex++
-					startIndex += 1
+					points[startIndex] = intersections[0]
+					start = points[startIndex]
 				}
 			}
 		}
 		if !end.Equals(points[len(points)-1]) && endIndex-2 >= 0 {
 			newEndingSegment := *geo.NewSegment(end, points[endIndex-1])
-			if newEndingSegment.Length() < MIN_SEGMENT_LEN {
+			if newEndingSegment.Length() < d2graph.MIN_SEGMENT_LEN {
 				// extend the prev segment into the shape border if possible
 				prevStart := points[endIndex-2]
 				prevEnd := points[endIndex-1]
 
 				prevSegment := *geo.NewSegment(prevStart, prevEnd)
 				v := prevSegment.ToVector()
-				extendedEnd := prevStart.ToVector().Add(v.AddLength(MIN_SEGMENT_LEN)).ToPoint()
+				extendedEnd := prevStart.ToVector().Add(v.AddLength(d2graph.MIN_SEGMENT_LEN)).ToPoint()
 				extended := *geo.NewSegment(prevStart, extendedEnd)
 
 				if intersections := edge.Dst.Box.Intersections(extended); len(intersections) > 0 {
-					end = intersections[0]
+					endIndex--
-					endIndex -= 1
+					points[endIndex] = intersections[0]
+					end = points[endIndex]
 				}
 			}
 		}
@@ -489,72 +489,7 @@ func Layout(ctx context.Context, g *d2graph.Graph, opts *ConfigurableOpts) (err
 			}
 		}
 
-		srcShape := edge.Src.ToShape()
+		startIndex, endIndex = edge.TraceToShape(points, startIndex, endIndex)
-		dstShape := edge.Dst.ToShape()
-
-		// if an edge runs into an outside label, stop the edge at the label instead
-		overlapsOutsideLabel := false
-		if edge.Src.HasLabel() {
-			// assumes LabelPosition, LabelWidth, LabelHeight are all set if there is a label
-			labelPosition := label.Position(*edge.Src.LabelPosition)
-			if labelPosition.IsOutside() {
-				labelWidth := float64(edge.Src.LabelDimensions.Width)
-				labelHeight := float64(edge.Src.LabelDimensions.Height)
-				labelTL := labelPosition.GetPointOnBox(edge.Src.Box, label.PADDING, labelWidth, labelHeight)
-
-				startingSegment := geo.Segment{Start: points[startIndex+1], End: points[startIndex]}
-				labelBox := geo.NewBox(labelTL, labelWidth, labelHeight)
-				// add left/right padding to box
-				labelBox.TopLeft.X -= label.PADDING
-				labelBox.Width += 2 * label.PADDING
-				if intersections := labelBox.Intersections(startingSegment); len(intersections) > 0 {
-					overlapsOutsideLabel = true
-					// move starting segment to label intersection point
-					points[startIndex] = intersections[0]
-					startingSegment.End = intersections[0]
-					// if the segment becomes too short, just merge it with the next segment
-					if startIndex < len(points) && startingSegment.Length() < MIN_SEGMENT_LEN {
-						points[startIndex+1] = points[startIndex]
-						startIndex++
-					}
-				}
-			}
-		}
-		if !overlapsOutsideLabel {
-			// trace the edge to the specific shape's border
-			points[startIndex] = shape.TraceToShapeBorder(srcShape, start, points[startIndex+1])
-		}
-
-		overlapsOutsideLabel = false
-		if edge.Dst.HasLabel() {
-			// assumes LabelPosition, LabelWidth, LabelHeight are all set if there is a label
-			labelPosition := label.Position(*edge.Dst.LabelPosition)
-			if labelPosition.IsOutside() {
-				labelWidth := float64(edge.Dst.LabelDimensions.Width)
-				labelHeight := float64(edge.Dst.LabelDimensions.Height)
-				labelTL := labelPosition.GetPointOnBox(edge.Dst.Box, label.PADDING, labelWidth, labelHeight)
-
-				endingSegment := geo.Segment{Start: points[endIndex-1], End: points[endIndex]}
-				labelBox := geo.NewBox(labelTL, labelWidth, labelHeight)
-				// add left/right padding to box
-				labelBox.TopLeft.X -= label.PADDING
-				labelBox.Width += 2 * label.PADDING
-				if intersections := labelBox.Intersections(endingSegment); len(intersections) > 0 {
-					overlapsOutsideLabel = true
-					// move ending segment to label intersection point
-					points[endIndex] = intersections[0]
-					endingSegment.End = intersections[0]
-					// if the segment becomes too short, just merge it with the previous segment
-					if endIndex-1 > 0 && endingSegment.Length() < MIN_SEGMENT_LEN {
-						points[endIndex-1] = points[endIndex]
-						endIndex--
-					}
-				}
-			}
-		}
-		if !overlapsOutsideLabel {
-			points[endIndex] = shape.TraceToShapeBorder(dstShape, end, points[endIndex-1])
-		}
 		points = points[startIndex : endIndex+1]
 
 		// build a curved path from the dagre route

d2layouts/d2elklayout/layout.go

@@ -501,12 +501,8 @@ func Layout(ctx context.Context, g *d2graph.Graph, opts *ConfigurableOpts) (err
 			}
 		}
 
-		srcShape := edge.Src.ToShape()
+		startIndex, endIndex = edge.TraceToShape(points, startIndex, endIndex)
-		dstShape := edge.Dst.ToShape()
+		points = points[startIndex : endIndex+1]
-
-		// trace the edge to the specific shape's border
-		points[startIndex] = shape.TraceToShapeBorder(srcShape, points[startIndex], points[startIndex+1])
-		points[endIndex] = shape.TraceToShapeBorder(dstShape, points[endIndex], points[endIndex-1])
 
 		if edge.Label.Value != "" {
 			edge.LabelPosition = go2.Pointer(string(label.InsideMiddleCenter))