iteration 5

d2layouts/d2cycle/layout.go

@@ -14,27 +14,22 @@ const (
 	MIN_RADIUS      = 200
 	PADDING         = 20
 	MIN_SEGMENT_LEN = 10
-	ARC_STEPS       = 30 // high resolution for smooth arcs
+	ARC_STEPS       = 30
 )
 
-// Layout arranges nodes in a circle, ensures label/icon positions are set,
-// then routes edges with arcs that get clipped at node borders.
 func Layout(ctx context.Context, g *d2graph.Graph, layout d2graph.LayoutGraph) error {
 	objects := g.Root.ChildrenArray
 	if len(objects) == 0 {
 		return nil
 	}
 
-	// Ensure every object that has label/icon also has a default position
 	for _, obj := range g.Objects {
 		positionLabelsIcons(obj)
 	}
 
-	// Arrange objects in a circle
 	radius := calculateRadius(objects)
 	positionObjects(objects, radius)
 
-	// Create arcs for each edge
 	for _, edge := range g.Edges {
 		createCircularArc(edge)
 	}
@@ -49,22 +44,19 @@ func calculateRadius(objects []*d2graph.Object) float64 {
 		size := math.Max(obj.Box.Width, obj.Box.Height)
 		maxSize = math.Max(maxSize, size)
 	}
-	// Ensure enough radius to fit all objects
 	minRadius := (maxSize/2.0 + PADDING) / math.Sin(math.Pi/numObjects)
 	return math.Max(minRadius, MIN_RADIUS)
 }
 
 func positionObjects(objects []*d2graph.Object, radius float64) {
 	numObjects := float64(len(objects))
-	// Offset so i=0 is top-center
 	angleOffset := -math.Pi / 2
 
 	for i, obj := range objects {
-		angle := angleOffset + (2 * math.Pi * float64(i) / numObjects)
+		angle := angleOffset + (2*math.Pi*float64(i)/numObjects)
 		x := radius * math.Cos(angle)
 		y := radius * math.Sin(angle)
 
-		// Center the box at (x, y)
 		obj.TopLeft = geo.NewPoint(
 			x-obj.Box.Width/2,
 			y-obj.Box.Height/2,
@@ -72,9 +64,6 @@ func positionObjects(objects []*d2graph.Object, radius float64) {
 	}
 }
 
-// createCircularArc samples a smooth arc from center to center,
-// then forces the endpoints onto each shape's border by clamping them
-// using the box intersection helpers.
 func createCircularArc(edge *d2graph.Edge) {
 	if edge.Src == nil || edge.Dst == nil {
 		return
@@ -83,7 +72,6 @@ func createCircularArc(edge *d2graph.Edge) {
 	srcCenter := edge.Src.Center()
 	dstCenter := edge.Dst.Center()
 
-	// Compute angles from origin for both nodes
 	srcAngle := math.Atan2(srcCenter.Y, srcCenter.X)
 	dstAngle := math.Atan2(dstCenter.Y, dstCenter.X)
 	if dstAngle < srcAngle {
@@ -92,7 +80,6 @@ func createCircularArc(edge *d2graph.Edge) {
 
 	arcRadius := math.Hypot(srcCenter.X, srcCenter.Y)
 
-	// Sample points along the arc
 	path := make([]*geo.Point, 0, ARC_STEPS+1)
 	for i := 0; i <= ARC_STEPS; i++ {
 		t := float64(i) / float64(ARC_STEPS)
@@ -101,57 +88,42 @@ func createCircularArc(edge *d2graph.Edge) {
 		y := arcRadius * math.Sin(angle)
 		path = append(path, geo.NewPoint(x, y))
 	}
-	// Ensure endpoints start at the centers
 	path[0] = srcCenter
 	path[len(path)-1] = dstCenter
 
-	// Clamp the start point to the boundary of the source node
 	startIndex, newSrc := clampPointOutsideBox(edge.Src.Box, path, 0)
-	// Clamp the end point to the boundary of the destination node
 	endIndex, newDst := clampPointOutsideBoxReverse(edge.Dst.Box, path, len(path)-1)
 
-	// Update the endpoints with the clamped intersection points
 	path[0] = newSrc
 	path[len(path)-1] = newDst
 
-	// Update the route to only include the valid segment between the clamped indices
 	edge.Route = path[startIndex : endIndex+1]
 	edge.IsCurve = true
 }
 
-// clampPointOutsideBox walks forward from 'startIdx' until the path segment
-// leaves the bounding box. Then it sets path[startIdx] to the intersection.
-// If no intersection is found, it returns the original point.
 func clampPointOutsideBox(box *geo.Box, path []*geo.Point, startIdx int) (int, *geo.Point) {
 	if startIdx >= len(path)-1 {
 		return startIdx, path[startIdx]
 	}
-	// If the current point is already outside, no clamping is needed.
 	if !boxContains(box, path[startIdx]) {
 		return startIdx, path[startIdx]
 	}
 
-	// Walk forward until we leave the box.
 	for i := startIdx + 1; i < len(path); i++ {
 		if boxContains(box, path[i]) {
 			continue
 		}
-		// Crossing from inside to outside between path[i-1] and path[i]
 		seg := geo.NewSegment(path[i-1], path[i])
 		inters := boxIntersections(box, *seg)
 		if len(inters) > 0 {
 			return i, inters[0]
 		}
-		// Fallback if no intersection found
 		return i, path[i]
 	}
-	// If the entire remaining path is inside, return the last point.
 	last := len(path) - 1
 	return last, path[last]
 }
 
-// clampPointOutsideBoxReverse scans backward from endIdx while path[j] is in the box.
-// When an outside-to-inside crossing is detected, it returns the intersection.
 func clampPointOutsideBoxReverse(box *geo.Box, path []*geo.Point, endIdx int) (int, *geo.Point) {
 	if endIdx <= 0 {
 		return endIdx, path[endIdx]
@@ -164,7 +136,6 @@ func clampPointOutsideBoxReverse(box *geo.Box, path []*geo.Point, endIdx int) (i
 		if boxContains(box, path[j]) {
 			continue
 		}
-		// Crossing from outside to inside between path[j] and path[j+1]
 		seg := geo.NewSegment(path[j], path[j+1])
 		inters := boxIntersections(box, *seg)
 		if len(inters) > 0 {
@@ -172,11 +143,9 @@ func clampPointOutsideBoxReverse(box *geo.Box, path []*geo.Point, endIdx int) (i
 		}
 		return j, path[j]
 	}
-	// If the entire path is inside, return the first point.
 	return 0, path[0]
 }
 
-// boxContains performs a typical bounding-box check.
 func boxContains(b *geo.Box, p *geo.Point) bool {
 	return p.X >= b.TopLeft.X &&
 		p.X <= b.TopLeft.X+b.Width &&
@@ -184,15 +153,11 @@ func boxContains(b *geo.Box, p *geo.Point) bool {
 		p.Y <= b.TopLeft.Y+b.Height
 }
 
-// boxIntersections returns the intersection points between a box and a segment.
-// This assumes that geo.Box implements an Intersections method.
 func boxIntersections(b *geo.Box, seg geo.Segment) []*geo.Point {
 	return b.Intersections(seg)
 }
 
-// positionLabelsIcons sets default positions for icons and labels if not already specified.
 func positionLabelsIcons(obj *d2graph.Object) {
-	// Set default icon position if an icon exists and none is specified.
 	if obj.Icon != nil && obj.IconPosition == nil {
 		if len(obj.ChildrenArray) > 0 {
 			obj.IconPosition = go2.Pointer(label.OutsideTopLeft.String())
@@ -207,7 +172,6 @@ func positionLabelsIcons(obj *d2graph.Object) {
 		}
 	}
 
-	// Set default label position if a label exists and none is specified.
 	if obj.HasLabel() && obj.LabelPosition == nil {
 		if len(obj.ChildrenArray) > 0 {
 			obj.LabelPosition = go2.Pointer(label.OutsideTopCenter.String())
@@ -219,7 +183,6 @@ func positionLabelsIcons(obj *d2graph.Object) {
 			obj.LabelPosition = go2.Pointer(label.InsideMiddleCenter.String())
 		}
 
-		// If the label dimensions exceed the object's size, fallback to an outside position.
 		if float64(obj.LabelDimensions.Width) > obj.Width ||
 			float64(obj.LabelDimensions.Height) > obj.Height {
 			if len(obj.ChildrenArray) > 0 {