iteration 3

d2layouts/d2cycle/layout.go

@@ -255,7 +255,7 @@ import (
 const (
 	MIN_RADIUS = 200
 	PADDING    = 20
-	ARC_STEPS  = 60 // High resolution for perfect circles
+	ARC_STEPS  = 60
 )
 
 func Layout(ctx context.Context, g *d2graph.Graph, layout d2graph.LayoutGraph) error {
@@ -268,17 +268,19 @@ func Layout(ctx context.Context, g *d2graph.Graph, layout d2graph.LayoutGraph) e
 		positionLabelsIcons(obj)
 	}
 
-	baseRadius := calculateBaseRadius(objects)
+	// Calculate layout parameters
+	baseRadius, maxNodeSize := calculateLayoutParams(objects)
 	positionObjects(objects, baseRadius)
 
+	// Create edges with boundary-perfect arcs
 	for _, edge := range g.Edges {
-		createPerfectArc(edge, baseRadius)
+		createBoundaryArc(edge, baseRadius, maxNodeSize)
 	}
 
 	return nil
 }
 
-func calculateBaseRadius(objects []*d2graph.Object) float64 {
+func calculateLayoutParams(objects []*d2graph.Object) (float64, float64) {
 	numNodes := float64(len(objects))
 	maxSize := 0.0
 	for _, obj := range objects {
@@ -286,7 +288,7 @@ func calculateBaseRadius(objects []*d2graph.Object) float64 {
 		maxSize = math.Max(maxSize, size)
 	}
 	minRadius := (maxSize/2 + PADDING) / math.Sin(math.Pi/numNodes)
-	return math.Max(minRadius, MIN_RADIUS)
+	return math.Max(minRadius, MIN_RADIUS), maxSize
 }
 
 func positionObjects(objects []*d2graph.Object, radius float64) {
@@ -298,6 +300,7 @@ func positionObjects(objects []*d2graph.Object, radius float64) {
 		x := radius * math.Cos(angle)
 		y := radius * math.Sin(angle)
 		
+		// Center object at calculated position
 		obj.TopLeft = geo.NewPoint(
 			x-obj.Width/2,
 			y-obj.Height/2,
@@ -305,21 +308,24 @@ func positionObjects(objects []*d2graph.Object, radius float64) {
 	}
 }
 
-func createPerfectArc(edge *d2graph.Edge, baseRadius float64) {
+func createBoundaryArc(edge *d2graph.Edge, baseRadius, maxNodeSize float64) {
 	if edge.Src == nil || edge.Dst == nil || edge.Src == edge.Dst {
 		return
 	}
 
+	// Calculate arc radius outside node boundaries
+	arcRadius := baseRadius + maxNodeSize/2 + PADDING
+
 	srcCenter := edge.Src.Center()
 	dstCenter := edge.Dst.Center()
 	layoutCenter := geo.NewPoint(0, 0)
 
-	// Calculate angles with proper wrapping
+	// Calculate angles with shortest path
 	startAngle := math.Atan2(srcCenter.Y-layoutCenter.Y, srcCenter.X-layoutCenter.X)
 	endAngle := math.Atan2(dstCenter.Y-layoutCenter.Y, dstCenter.X-layoutCenter.X)
-	
-	// Calculate angular distance taking shortest path
 	angleDiff := endAngle - startAngle
+
+	// Normalize angle difference
 	if angleDiff < 0 {
 		angleDiff += 2 * math.Pi
 	}
@@ -327,24 +333,23 @@ func createPerfectArc(edge *d2graph.Edge, baseRadius float64) {
 		angleDiff -= 2 * math.Pi
 	}
 
-	// Generate perfect circular arc
+	// Generate arc points
 	path := make([]*geo.Point, 0, ARC_STEPS+1)
 	for i := 0; i <= ARC_STEPS; i++ {
 		t := float64(i) / ARC_STEPS
-		currentAngle := startAngle + t*angleDiff
-		x := layoutCenter.X + baseRadius*math.Cos(currentAngle)
-		y := layoutCenter.Y + baseRadius*math.Sin(currentAngle)
+		angle := startAngle + t*angleDiff
+		x := layoutCenter.X + arcRadius*math.Cos(angle)
+		y := layoutCenter.Y + arcRadius*math.Sin(angle)
 		path = append(path, geo.NewPoint(x, y))
 	}
 
-	// Clip to shape boundaries while preserving arc properties
+	// Clip to actual node boundaries
 	edge.Route = path
 	startIdx, endIdx := edge.TraceToShape(edge.Route, 0, len(edge.Route)-1)
 
 	// Maintain smooth arc after clipping
 	if startIdx < endIdx {
 		edge.Route = edge.Route[startIdx : endIdx+1]
-		
 		// Ensure minimal points for smooth rendering
 		if len(edge.Route) < 3 {
 			edge.Route = []*geo.Point{path[0], path[len(path)-1]}
@@ -354,28 +359,6 @@ func createPerfectArc(edge *d2graph.Edge, baseRadius float64) {
 	edge.IsCurve = true
 }
 
-// Keep existing helper functions (positionLabelsIcons, boxContains, boxIntersections)
-// Helper if your geo.Box doesn’t implement Contains()
-func boxContains(b *geo.Box, p *geo.Point) bool {
-	// typical bounding-box check
-	return p.X >= b.TopLeft.X &&
-		p.X <= b.TopLeft.X+b.Width &&
-		p.Y >= b.TopLeft.Y &&
-		p.Y <= b.TopLeft.Y+b.Height
-}
-
-// Helper if your geo.Box doesn’t implement Intersections(geo.Segment) yet
-func boxIntersections(b *geo.Box, seg geo.Segment) []*geo.Point {
-	// We'll assume d2's standard geo.Box has a built-in Intersections(*Segment) method.
-	// If not, implement manually. For example, checking each of the 4 edges:
-	//   left, right, top, bottom
-	// For simplicity, if you do have b.Intersections(...) you can just do:
-	//     return b.Intersections(seg)
-	return b.Intersections(seg)
-	// If you don't have that, you'd code the line-rect intersection yourself.
-}
-
-// positionLabelsIcons is basically your logic that sets default label/icon positions if needed
 func positionLabelsIcons(obj *d2graph.Object) {
 	// If there's an icon but no icon position, give it a default
 	if obj.Icon != nil && obj.IconPosition == nil {
@@ -415,6 +398,17 @@ func positionLabelsIcons(obj *d2graph.Object) {
 		}
 	}
 }
+
+func boxContains(b *geo.Box, p *geo.Point) bool {
+	return p.X >= b.TopLeft.X &&
+		p.X <= b.TopLeft.X+b.Width &&
+		p.Y >= b.TopLeft.Y &&
+		p.Y <= b.TopLeft.Y+b.Height
+}
+
+func boxIntersections(b *geo.Box, seg geo.Segment) []*geo.Point {
+	return b.Intersections(seg)
+}
 // package d2cycle
 
 // import (