Add RenderPriority to objects and edges

d2exporter/export.go

@@ -8,6 +8,7 @@ import (
 	"oss.terrastruct.com/d2/d2target"
 	"oss.terrastruct.com/d2/d2themes"
 	"oss.terrastruct.com/d2/d2themes/d2themescatalog"
+	"oss.terrastruct.com/d2/lib/go2"
 )
 
 func Export(ctx context.Context, g *d2graph.Graph, themeID int64) (*d2target.Diagram, error) {
@@ -16,13 +17,16 @@ func Export(ctx context.Context, g *d2graph.Graph, themeID int64) (*d2target.Dia
 	diagram := d2target.NewDiagram()
 
 	diagram.Shapes = make([]d2target.Shape, len(g.Objects))
+	highestObjectPriority := 0
 	for i := range g.Objects {
 		diagram.Shapes[i] = toShape(g.Objects[i], &theme)
+		highestObjectPriority = go2.IntMax(highestObjectPriority, diagram.Shapes[i].RenderPriority)
 	}
 
+	edgeDefaultRenderPriority := highestObjectPriority + 1
 	diagram.Connections = make([]d2target.Connection, len(g.Edges))
 	for i := range g.Edges {
-		diagram.Connections[i] = toConnection(g.Edges[i], &theme)
+		diagram.Connections[i] = toConnection(g.Edges[i], &theme, edgeDefaultRenderPriority)
 	}
 
 	return diagram, nil
@@ -88,13 +92,17 @@ func toShape(obj *d2graph.Object, theme *d2themes.Theme) d2target.Shape {
 	shape := d2target.BaseShape()
 	shape.SetType(obj.Attributes.Shape.Value)
 	shape.ID = obj.AbsID()
+	if obj.RenderPriority == nil {
+		shape.RenderPriority = int(obj.Level())
+	} else {
+		shape.RenderPriority = *obj.RenderPriority
+	}
 	shape.Pos = d2target.NewPoint(int(obj.TopLeft.X), int(obj.TopLeft.Y))
 	shape.Width = int(obj.Width)
 	shape.Height = int(obj.Height)
 
 	text := obj.Text()
 	shape.FontSize = text.FontSize
-	shape.Level = int(obj.Level())
 
 	applyStyles(shape, obj)
 	applyTheme(shape, obj, theme)
@@ -130,9 +138,14 @@ func toShape(obj *d2graph.Object, theme *d2themes.Theme) d2target.Shape {
 	return *shape
 }
 
-func toConnection(edge *d2graph.Edge, theme *d2themes.Theme) d2target.Connection {
+func toConnection(edge *d2graph.Edge, theme *d2themes.Theme, defaultRenderPriotity int) d2target.Connection {
 	connection := d2target.BaseConnection()
 	connection.ID = edge.AbsID()
+	if edge.RenderPriority == nil {
+		connection.RenderPriority = defaultRenderPriotity
+	} else {
+		connection.RenderPriority = *edge.RenderPriority
+	}
 	// edge.Edge.ID = go2.StringToIntHash(connection.ID)
 	text := edge.Text()
 

d2graph/d2graph.go

@@ -78,6 +78,8 @@ type Object struct {
 	ChildrenArray []*Object          `json:"-"`
 
 	Attributes Attributes `json:"attributes"`
+
+	RenderPriority *int `json:"renderPriority",omitempty`
 }
 
 type Attributes struct {
@@ -630,6 +632,8 @@ type Edge struct {
 
 	References []EdgeReference `json:"references,omitempty"`
 	Attributes Attributes      `json:"attributes"`
+
+	RenderPriority *int `json:"renderPriority,omitempty"`
 }
 
 type EdgeReference struct {

d2renderers/d2svg/d2svg.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"hash/fnv"
 	"io"
+	"sort"
 	"strings"
 
 	"math"
@@ -983,25 +984,31 @@ func Render(diagram *d2target.Diagram) ([]byte, error) {
 	// SVG has no notion of z-index. The z-index is effectively the order it's drawn.
 	// So draw from the least nested to most nested
 	idToShape := make(map[string]d2target.Shape)
-	highest := 1
+	allObjects := make([]d2target.DiagramObject, 0, len(diagram.Shapes)+len(diagram.Connections))
 	for _, s := range diagram.Shapes {
-		highest = go2.Max(highest, s.Level)
 		idToShape[s.ID] = s
+		allObjects = append(allObjects, s)
 	}
-	for i := 1; i <= highest; i++ {
-		for _, s := range diagram.Shapes {
-			if s.Level == i {
-				err := drawShape(buf, s)
-				if err != nil {
-					return nil, err
-				}
-			}
-		}
+	for _, c := range diagram.Connections {
+		allObjects = append(allObjects, c)
 	}
 
+	sort.SliceStable(allObjects, func(i, j int) bool {
+		return allObjects[i].GetPriority() < allObjects[j].GetPriority()
+	})
+
 	markers := map[string]struct{}{}
-	for _, c := range diagram.Connections {
-		drawConnection(buf, c, markers, idToShape)
+	for _, obj := range allObjects {
+		if c, is := obj.(d2target.Connection); is {
+			drawConnection(buf, c, markers, idToShape)
+		} else if s, is := obj.(d2target.Shape); is {
+			err := drawShape(buf, s)
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			return nil, fmt.Errorf("unknow object of type %t", obj)
+		}
 	}
 
 	embedFonts(buf)

d2target/d2target.go

@@ -17,6 +17,10 @@ const (
 	MAX_ICON_SIZE     = 64
 )
 
+type DiagramObject interface {
+	GetPriority() int
+}
+
 type Diagram struct {
 	Name        string `json:"name"`
 	Description string `json:"description,omitempty"`
@@ -91,7 +95,6 @@ type Shape struct {
 	Pos    Point `json:"pos"`
 	Width  int   `json:"width"`
 	Height int   `json:"height"`
-	Level  int   `json:"level"`
 
 	Opacity     float64 `json:"opacity"`
 	StrokeDash  float64 `json:"strokeDash"`
@@ -117,6 +120,8 @@ type Shape struct {
 	Text
 
 	LabelPosition string `json:"labelPosition,omitempty"`
+
+	RenderPriority int `json:"renderPriority"`
 }
 
 func (s *Shape) SetType(t string) {
@@ -130,6 +135,10 @@ func (s *Shape) SetType(t string) {
 	s.Type = strings.ToLower(t)
 }
 
+func (s Shape) GetPriority() int {
+	return s.RenderPriority
+}
+
 type Text struct {
 	Label      string `json:"label"`
 	FontSize   int    `json:"fontSize"`
@@ -183,6 +192,8 @@ type Connection struct {
 	Animated bool     `json:"animated"`
 	Tooltip  string   `json:"tooltip"`
 	Icon     *url.URL `json:"icon"`
+
+	RenderPriority int `json:"renderPriority"`
 }
 
 func BaseConnection() *Connection {
@@ -210,6 +221,10 @@ func (c *Connection) GetLabelTopLeft() *geo.Point {
 	)
 }
 
+func (c Connection) GetPriority() int {
+	return c.RenderPriority
+}
+
 type Arrowhead string
 
 const (