Merge pull request #1940 from alixander/opacity-label-mask

renderer: dont render label & icon unnecessarily with opacity 0

ci/release/changelogs/next.md

@@ -2,6 +2,8 @@
 
 #### Improvements 🧹
 
+- Opacity 0 shapes no longer have a label mask which made any segment of connections going through them lower opacity [#1940](https://github.com/terrastruct/d2/pull/1940)
+
 #### Bugfixes ⛑️
 
 - Local relative icons are relative to the d2 file instead of CLI invoke path [#1924](https://github.com/terrastruct/d2/pull/1924)

d2renderers/d2svg/d2svg.go

@@ -1213,7 +1213,7 @@ func drawShape(writer, appendixWriter io.Writer, diagramHash string, targetShape
 	// Closes the class=shape
 	fmt.Fprint(writer, `</g>`)
 
-	if targetShape.Icon != nil && targetShape.Type != d2target.ShapeImage {
+	if targetShape.Icon != nil && targetShape.Type != d2target.ShapeImage && targetShape.Opacity != 0 {
 		iconPosition := label.FromString(targetShape.IconPosition)
 		var box *geo.Box
 		if iconPosition.IsOutside() {
@@ -1234,7 +1234,7 @@ func drawShape(writer, appendixWriter io.Writer, diagramHash string, targetShape
 		)
 	}
 
-	if targetShape.Label != "" {
+	if targetShape.Label != "" && targetShape.Opacity != 0 {
 		labelPosition := label.FromString(targetShape.LabelPosition)
 		var box *geo.Box
 		if labelPosition.IsOutside() {

e2etests/testdata/txtar.txt

@@ -213,3 +213,21 @@ ok: {
   }
   dog1 -> dog3
 }
+
+-- opacity-zero-route --
+grid: {
+  *.style.opacity: 0
+  grid-columns: 3
+  a
+  b
+  c
+  d
+  e
+  f
+  g
+  h
+
+  d.style.opacity: 1
+}
+
+out -> grid.d