test(vulkan): pin the sceneDelta-seeded partial redraw at zero allocations

TestRenderSteadyStateAllocations replicates Render's partial sequence for a
new scene Seq with one of two windows moved, asserts the redraw is partial
and that building and clipping its draws allocates nothing.

commit: 8967242492da9807176f169f767457566f09db25
author: brice · 18d ago · 2026-10-04 20:34 UTC
committer: brice · 18d ago · 2026-10-04 20:57 UTC
parent: 185b931
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

1 file · +40 -1

M internal/adapters/vulkan/scene_perf_test.go +40 -1


@@ -12,7 +12,8 @@ import (
12	12		// on a normal and on a rotated output (orient works in place), and that
13	13		// building the draws of a scene with a moving window (a new Seq and window
14	14		// slice every frame, as an animation publishes) allocates nothing.
15		-	// TODO(A2): add the partial redraw seeded by sceneDelta once it is merged.
	15	+	// A new scene Seq with one of two windows moved is a partial redraw seeded by
	16	+	// sceneDelta and allocates nothing either.
16	17		func TestRenderSteadyStateAllocations(t *testing.T) {
17	18		for _, tc := range []struct {
18	19		name string

@@ -93,6 +94,44 @@ func TestRenderSteadyStateAllocations(t *testing.T) {
93	94		if allocs := testing.AllocsPerRun(50, partial); allocs != 0 {
94	95		t.Errorf("partial redraw draws: %.1f allocs/frame, want 0", allocs)
95	96		}
	97	+	// A new scene Seq with one window moved: the delta against the
	98	+	// scene the target holds seeds the partial redraw (A2). The
	99	+	// stand-in target holds the old scene and is never updated.
	100	+	half := tc.sceneW / 2
	101	+	content2 := solidContent(t, 8, 8, color.RGBA{G: 255, A: 255})
	102	+	content2.ID, content2.Surface, content2.Seq, content2.Version = 2, 2, 1, 1
	103	+	dcontents := map[ports.WindowID]ports.SurfaceContent{1: content, 2: content2}
	104	+	before := ports.Scene{Seq: 200, Transform: tc.transform, Scale: 1, Windows: []ports.SceneWindow{
	105	+	{ID: 1, Rect: ports.Rect{W: half, H: tc.sceneH}},
	106	+	{ID: 2, Rect: ports.Rect{X: half, W: tc.sceneW - half, H: tc.sceneH}},
	107	+	}}
	108	+	moved := before
	109	+	moved.Seq = 201
	110	+	moved.Windows = []ports.SceneWindow{before.Windows[0], {ID: 2, Rect: ports.Rect{X: half + 1, W: tc.sceneW - half - 1, H: tc.sceneH}}}
	111	+	full := image.Rect(0, 0, r.width, r.height)
	112	+	held = &target{valid: true, sceneSeq: before.Seq, scene: before, windows: map[ports.WindowID]heldWindow{
	113	+	1: {seq: 1, rect: image.Rect(0, 0, half, tc.sceneH)},
	114	+	2: {seq: 1, rect: image.Rect(half, 0, tc.sceneW, tc.sceneH)},
	115	+	}}
	116	+	seeded := func() {
	117	+	dmg := r.frameDamage(held, moved, bounds)
	118	+	ds := r.draws(moved, dcontents, dmg)
	119	+	dmg.finish()
	120	+	ds = append(ds, draw{})
	121	+	copy(ds[1:], ds[:len(ds)-1])
	122	+	ds[0] = r.fillDraw(dmg.area, parseColor(moved.Background))
	123	+	ds = dmg.clip(ds)
	124	+	r.scratchDraws = ds
	125	+	r.orient(ds, moved.Transform)
	126	+	area, whole = dmg.area, dmg.all()
	127	+	}
	128	+	seeded()
	129	+	if whole \|\| area.Empty() \|\| area.Dx()area.Dy() >= full.Dx()full.Dy() {
	130	+	t.Fatalf("sceneDelta did not seed a partial redraw: all %v, area %v of %v", whole, area, bounds)
	131	+	}
	132	+	if allocs := testing.AllocsPerRun(50, seeded); allocs != 0 {
	133	+	t.Errorf("sceneDelta-seeded partial redraw draws: %.1f allocs/frame, want 0", allocs)
	134	+	}
96	135		})
97	136		}
98	137		}


@@ -12,7 +12,8 @@ import (
12		// on a normal and on a rotated output (orient works in place), and that	12		// on a normal and on a rotated output (orient works in place), and that
13		// building the draws of a scene with a moving window (a new Seq and window	13		// building the draws of a scene with a moving window (a new Seq and window
14		// slice every frame, as an animation publishes) allocates nothing.	14		// slice every frame, as an animation publishes) allocates nothing.
15	-	// TODO(A2): add the partial redraw seeded by sceneDelta once it is merged.	15	+	// A new scene Seq with one of two windows moved is a partial redraw seeded by
			16	+	// sceneDelta and allocates nothing either.
16		func TestRenderSteadyStateAllocations(t *testing.T) {	17		func TestRenderSteadyStateAllocations(t *testing.T) {
17		for _, tc := range []struct {	18		for _, tc := range []struct {
18		name string	19		name string

@@ -93,6 +94,44 @@ func TestRenderSteadyStateAllocations(t *testing.T) {
93		if allocs := testing.AllocsPerRun(50, partial); allocs != 0 {	94		if allocs := testing.AllocsPerRun(50, partial); allocs != 0 {
94		t.Errorf("partial redraw draws: %.1f allocs/frame, want 0", allocs)	95		t.Errorf("partial redraw draws: %.1f allocs/frame, want 0", allocs)
95		}	96		}
			97	+	// A new scene Seq with one window moved: the delta against the
			98	+	// scene the target holds seeds the partial redraw (A2). The
			99	+	// stand-in target holds the old scene and is never updated.
			100	+	half := tc.sceneW / 2
			101	+	content2 := solidContent(t, 8, 8, color.RGBA{G: 255, A: 255})
			102	+	content2.ID, content2.Surface, content2.Seq, content2.Version = 2, 2, 1, 1
			103	+	dcontents := map[ports.WindowID]ports.SurfaceContent{1: content, 2: content2}
			104	+	before := ports.Scene{Seq: 200, Transform: tc.transform, Scale: 1, Windows: []ports.SceneWindow{
			105	+	{ID: 1, Rect: ports.Rect{W: half, H: tc.sceneH}},
			106	+	{ID: 2, Rect: ports.Rect{X: half, W: tc.sceneW - half, H: tc.sceneH}},
			107	+	}}
			108	+	moved := before
			109	+	moved.Seq = 201
			110	+	moved.Windows = []ports.SceneWindow{before.Windows[0], {ID: 2, Rect: ports.Rect{X: half + 1, W: tc.sceneW - half - 1, H: tc.sceneH}}}
			111	+	full := image.Rect(0, 0, r.width, r.height)
			112	+	held = &target{valid: true, sceneSeq: before.Seq, scene: before, windows: map[ports.WindowID]heldWindow{
			113	+	1: {seq: 1, rect: image.Rect(0, 0, half, tc.sceneH)},
			114	+	2: {seq: 1, rect: image.Rect(half, 0, tc.sceneW, tc.sceneH)},
			115	+	}}
			116	+	seeded := func() {
			117	+	dmg := r.frameDamage(held, moved, bounds)
			118	+	ds := r.draws(moved, dcontents, dmg)
			119	+	dmg.finish()
			120	+	ds = append(ds, draw{})
			121	+	copy(ds[1:], ds[:len(ds)-1])
			122	+	ds[0] = r.fillDraw(dmg.area, parseColor(moved.Background))
			123	+	ds = dmg.clip(ds)
			124	+	r.scratchDraws = ds
			125	+	r.orient(ds, moved.Transform)
			126	+	area, whole = dmg.area, dmg.all()
			127	+	}
			128	+	seeded()
			129	+	if whole \|\| area.Empty() \|\| area.Dx()area.Dy() >= full.Dx()full.Dy() {
			130	+	t.Fatalf("sceneDelta did not seed a partial redraw: all %v, area %v of %v", whole, area, bounds)
			131	+	}
			132	+	if allocs := testing.AllocsPerRun(50, seeded); allocs != 0 {
			133	+	t.Errorf("sceneDelta-seeded partial redraw draws: %.1f allocs/frame, want 0", allocs)
			134	+	}
96		})	135		})
97		}	136		}
98		}	137		}