perf(drm): keep a float on the overlay plane over the lines painted under it

commit: 8f14070c0e59e602e50d9cc12ab7f53f1987acef
author: brice · 14d ago · 2026-10-08 19:50 UTC
parent: b0baaac
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

2 files · +50 -2

M internal/adapters/drm/overlay.go +22 -2


@@ -73,6 +73,7 @@ func overlayCandidate(s ports.Scene, surfaces map[ports.WindowID]ports.SurfaceCo
73	73		scale = 1
74	74		}
75	75		var pick *ports.SceneWindow
	76	+	var pickAt int
76	77		var mode colorMode
77	78		for i := range s.Windows {
78	79		w := &s.Windows[i]

@@ -95,7 +96,7 @@ func overlayCandidate(s ports.Scene, surfaces map[ports.WindowID]ports.SurfaceCo
95	96		// lift; an overview preview is drawn smaller than its buffer.
96	97		if w.Dim <= 0 && w.Fade <= 0 && w.Zoom <= 0 && w.FocusEffect <= 0 && w.Preview <= 0 && c.DMABuf != nil && !isYUVFormat(c.DMABuf.Format) && c.Opaque && len(c.Children) == 0 && c.Transform == 0 && !cropped(c) && (kept == nil \|\| !kept(w.ID)) {
97	98		if m, why := planeColor(c.Color, c.DMABuf.Format, c.Opaque, hdrOn, pipeline); why == "" {
98		-	pick, mode = w, m
	99	+	pick, pickAt, mode = w, i, m
99	100		continue
100	101		}
101	102		}

@@ -143,7 +144,7 @@ func overlayCandidate(s ports.Scene, surfaces map[ports.WindowID]ports.SurfaceCo
143	144		return ports.SceneWindow{}, ports.SurfaceContent{}, colorBypass, "border"
144	145		}
145	146		for _, sep := range s.Separators {
146		-	if sep.Rect.Overlaps(pick.Rect) {
	147	+	if sep.Rect.Overlaps(pick.Rect) && !linesUnder(s, sep, pick, pickAt) {
147	148		// The overlay shows the buffer alone; the lines would go
148	149		// under it.
149	150		return ports.SceneWindow{}, ports.SurfaceContent{}, colorBypass, "border"

@@ -170,6 +171,25 @@ func overlayCandidate(s ports.Scene, surfaces map[ports.WindowID]ports.SurfaceCo
170	171		return *pick, c, mode, ""
171	172		}
172	173
	174	+	// linesUnder reports whether sep is painted before the candidate at index
	175	+	// pickAt, so stays composed under the plane: the tile lines and the lines
	176	+	// of windows listed before it, when the candidate is a float drawn above
	177	+	// the tiles.
	178	+	func linesUnder(s ports.Scene, sep ports.Separator, pick *ports.SceneWindow, pickAt int) bool {
	179	+	if !pick.Floating \|\| pick.Below {
	180	+	return false
	181	+	}
	182	+	if sep.Window == 0 {
	183	+	return true
	184	+	}
	185	+	for _, w := range s.Windows[:pickAt] {
	186	+	if w.ID == sep.Window {
	187	+	return true
	188	+	}
	189	+	}
	190	+	return false
	191	+	}
	192	+
173	193		// overlayProps puts ov on the overlay plane, or turns it off.
174	194		func (o Output) overlayProps(req atomicReq, ov overlayWin) {
175	195		p := o.overlay

 		scale = 1
 	}
 	var pick *ports.SceneWindow
+	var pickAt int
 	var mode colorMode
 	for i := range s.Windows {
 		w := &s.Windows[i]
 		// lift; an overview preview is drawn smaller than its buffer.
 		if w.Dim <= 0 && w.Fade <= 0 && w.Zoom <= 0 && w.FocusEffect <= 0 && w.Preview <= 0 && c.DMABuf != nil && !isYUVFormat(c.DMABuf.Format) && c.Opaque && len(c.Children) == 0 && c.Transform == 0 && !cropped(c) && (kept == nil || !kept(w.ID)) {
 			if m, why := planeColor(c.Color, c.DMABuf.Format, c.Opaque, hdrOn, pipeline); why == "" {
-				pick, mode = w, m
+				pick, pickAt, mode = w, i, m
 				continue
 			}
 		}
 			return ports.SceneWindow{}, ports.SurfaceContent{}, colorBypass, "border"
 		}
 		for _, sep := range s.Separators {
-			if sep.Rect.Overlaps(pick.Rect) {
+			if sep.Rect.Overlaps(pick.Rect) && !linesUnder(s, sep, pick, pickAt) {
 				// The overlay shows the buffer alone; the lines would go
 				// under it.
 				return ports.SceneWindow{}, ports.SurfaceContent{}, colorBypass, "border"
 	return *pick, c, mode, ""
 }
+// linesUnder reports whether sep is painted before the candidate at index
+// pickAt, so stays composed under the plane: the tile lines and the lines
+// of windows listed before it, when the candidate is a float drawn above
+// the tiles.
+func linesUnder(s ports.Scene, sep ports.Separator, pick *ports.SceneWindow, pickAt int) bool {
+	if !pick.Floating || pick.Below {
+		return false
+	}
+	if sep.Window == 0 {
+		return true
+	}
+	for _, w := range s.Windows[:pickAt] {
+		if w.ID == sep.Window {
+			return true
+		}
+	}
+	return false
+}
 // overlayProps puts ov on the overlay plane, or turns it off.
 func (o *Output) overlayProps(req *atomicReq, ov overlayWin) {
 	p := o.overlay

M internal/adapters/drm/overlay_test.go +28 -0


@@ -271,6 +271,34 @@ func TestOverlayPopupAndBorder(t *testing.T) {
271	271		}
272	272		}
273	273
	274	+	// A float above the tiles covers the tile lines and the lines of windows
	275	+	// listed before it; its own lines and those of later windows still block
	276	+	// the overlay.
	277	+	func TestOverlayFloatOverLines(t *testing.T) {
	278	+	for _, tc := range []struct {
	279	+	name string
	280	+	sep ports.WindowID
	281	+	below bool
	282	+	reason string
	283	+	}{
	284	+	{"tile line", 0, false, ""},
	285	+	{"earlier window line", 1, false, ""},
	286	+	{"own line", 2, false, "border"},
	287	+	{"later window line", 3, false, "border"},
	288	+	{"tile line over a below float", 0, true, "border"},
	289	+	} {
	290	+	t.Run(tc.name, func(t *testing.T) {
	291	+	s, c := overlayScene()
	292	+	s.Windows[1].Floating, s.Windows[1].Below = true, tc.below
	293	+	s.Windows = append(s.Windows, ports.SceneWindow{ID: 3, Floating: true, Rect: ports.Rect{W: 10, H: 10}})
	294	+	s.Separators = []ports.Separator{{Rect: ports.Rect{X: 150, W: 2, H: 100}, Window: tc.sep}}
	295	+	if _, _, _, reason := overlayCandidate(s, c, false, nil, nil); reason != tc.reason {
	296	+	t.Fatalf("reason %q, want %q", reason, tc.reason)
	297	+	}
	298	+	})
	299	+	}
	300	+	}
	301	+
274	302		// What is drawn elsewhere on screen stays composed on the primary plane: a
275	303		// bar, a popup, another window's lines or a window that do not touch the
276	304		// candidate leave it on the overlay.


@@ -271,6 +271,34 @@ func TestOverlayPopupAndBorder(t *testing.T) {
271	}	271		}
272	}	272		}
273		273
		274	+	// A float above the tiles covers the tile lines and the lines of windows
		275	+	// listed before it; its own lines and those of later windows still block
		276	+	// the overlay.
		277	+	func TestOverlayFloatOverLines(t *testing.T) {
		278	+	for _, tc := range []struct {
		279	+	name string
		280	+	sep ports.WindowID
		281	+	below bool
		282	+	reason string
		283	+	}{
		284	+	{"tile line", 0, false, ""},
		285	+	{"earlier window line", 1, false, ""},
		286	+	{"own line", 2, false, "border"},
		287	+	{"later window line", 3, false, "border"},
		288	+	{"tile line over a below float", 0, true, "border"},
		289	+	} {
		290	+	t.Run(tc.name, func(t *testing.T) {
		291	+	s, c := overlayScene()
		292	+	s.Windows[1].Floating, s.Windows[1].Below = true, tc.below
		293	+	s.Windows = append(s.Windows, ports.SceneWindow{ID: 3, Floating: true, Rect: ports.Rect{W: 10, H: 10}})
		294	+	s.Separators = []ports.Separator{{Rect: ports.Rect{X: 150, W: 2, H: 100}, Window: tc.sep}}
		295	+	if _, _, _, reason := overlayCandidate(s, c, false, nil, nil); reason != tc.reason {
		296	+	t.Fatalf("reason %q, want %q", reason, tc.reason)
		297	+	}
		298	+	})
		299	+	}
		300	+	}
		301	+
274	// What is drawn elsewhere on screen stays composed on the primary plane: a	302		// What is drawn elsewhere on screen stays composed on the primary plane: a
275	// bar, a popup, another window's lines or a window that do not touch the	303		// bar, a popup, another window's lines or a window that do not touch the
276	// candidate leave it on the overlay.	304		// candidate leave it on the overlay.