release: Linux files and checksums first, keep going when a Windows upload fails

- camera.NewService and SetAccessibility; AttachWorld wires the accessibility settings
- tests/camera: priorities, blends, cuts, zones, follow, bounds, outputs, shake, zero allocations, BrainStep benchmark
- integration: rewind restores the camera state across a zone change
- camera2d.Adjuster passes the view by value (no per-frame allocation), D304 updated
- modules/camera/module.mk: test-camera in CI, bench-camera

.dockerignore

@@ -5,3 +5,4 @@ site
 exports
 **/.aego
 *.test
+.claude

.github/workflows/ci.yml

@@ -3,6 +3,7 @@ name: ci
 on:
   push:
     branches: [master]
+    tags: ["v*"]
   pull_request:
 
 permissions:
@@ -111,4 +112,39 @@ jobs:
       - name: example project
         run: |
           /tmp/aego check examples/native-rotator
-          /tmp/aego run examples/native-rotator --headless --frames 60
+          /tmp/aego run examples/native-rotator --headless --frames 60
+
+  release:
+    needs: [checks, build]
+    if: github.event_name == 'push'
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: write
+    env:
+      CGO_ENABLED: "1"
+      GITEA_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      GITEA_API: ${{ github.server_url }}/api/v1/repos/${{ github.repository }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+      - name: linux packages
+        run: sudo apt-get update && sudo apt-get install -y $LINUX_PKGS
+      - uses: actions/cache@v4
+        continue-on-error: true
+        with:
+          path: .cache/native
+          key: native-linux_amd64-${{ hashFiles('third_party/sdl/version.txt', 'tools/bootstrap-native.sh') }}
+      - run: bash tools/bootstrap-native.sh
+      - name: windows tools
+        run: sudo apt-get install -y mingw-w64 nsis zip
+      - name: publish
+        env:
+          REQUIRE_WINDOWS: "1"
+          GITEA_RESOLVE: git.akarpov.ru:443:79.142.92.250
+        run: |
+          case "$GITHUB_REF" in
+          refs/tags/v*) sh tools/release/release.sh "$GITHUB_REF_NAME" ;;
+          refs/heads/master) sh tools/release/release.sh nightly ;;
+          esac

app/agent/cli_test.go

@@ -0,0 +1,85 @@
+package agent
+
+import (
+	"bytes"
+	"encoding/json"
+	"testing"
+)
+
+func mustFind(t *testing.T, name string) *Command {
+	t.Helper()
+	c, ok := Find(name)
+	if !ok {
+		t.Fatalf("no command %s", name)
+	}
+	return c
+}
+
+func TestParseArgs(t *testing.T) {
+	set := mustFind(t, "scene.set")
+	a, f, err := parseArgs(set, []string{"s.aescene", "--json", "Player", "--dry-run", "Body2D.mass", "-3"})
+	if err != nil || !f.json || a.Str("value") != "-3" || a.Str("node") != "Player" || !a.Bool("dry-run") {
+		t.Fatalf("flags after positionals: %v %+v %v", a, f, err)
+	}
+	add := mustFind(t, "scene.add-node")
+	for _, toks := range [][]string{{"s", "N", "--index=1"}, {"s", "N", "--index", "1"}} {
+		a, _, err := parseArgs(add, toks)
+		if n, _ := a.Int("index", -1); err != nil || n != 1 {
+			t.Fatalf("%v: %v %v", toks, a, err)
+		}
+	}
+	a, _, err = parseArgs(set, []string{"s", "--", "Player", "Body2D.mass", "--odd"})
+	if err != nil || a.Str("value") != "--odd" {
+		t.Fatalf("after --: %v %v", a, err)
+	}
+	if _, _, err := parseArgs(set, []string{"s", "--nope"}); err == nil {
+		t.Fatal("an unknown flag was accepted")
+	}
+	if _, _, err := parseArgs(set, []string{"s", "a", "b", "c", "d"}); err == nil {
+		t.Fatal("an extra positional was accepted")
+	}
+	var out, errw bytes.Buffer
+	if code := Main(nil, []string{"scene", "set", "s", "--nope"}, &out, &errw, Options{}); code != 2 {
+		t.Fatalf("unknown flag exit %d", code)
+	}
+	if code := Main(nil, []string{"scene", "set", "a", "b", "c", "d", "e"}, &out, &errw, Options{}); code != 2 {
+		t.Fatalf("extra positional exit %d", code)
+	}
+	if code := Main(nil, []string{"scene", "help"}, &out, &errw, Options{}); code != 0 {
+		t.Fatalf("help exit %d", code)
+	}
+}
+
+func TestSchemasAndToolNames(t *testing.T) {
+	seen := map[string]bool{}
+	for _, c := range Commands() {
+		if seen[c.Tool()] {
+			t.Fatalf("tool name %s is used twice", c.Tool())
+		}
+		seen[c.Tool()] = true
+		b, err := json.Marshal(c.Schema())
+		if err != nil {
+			t.Fatal(err)
+		}
+		var sch struct {
+			Type       string                    `json:"type"`
+			Properties map[string]map[string]any `json:"properties"`
+			Required   []string                  `json:"required"`
+		}
+		if err := json.Unmarshal(b, &sch); err != nil || sch.Type != "object" {
+			t.Fatalf("%s: %s", c.Name, b)
+		}
+		var want []string
+		for _, x := range c.AllArgs() {
+			if x.Required {
+				want = append(want, x.Name)
+			}
+			if _, ok := sch.Properties[x.Name]; !ok {
+				t.Fatalf("%s: no property %s", c.Name, x.Name)
+			}
+		}
+		if len(want) != len(sch.Required) {
+			t.Fatalf("%s: required %v, want %v", c.Name, sch.Required, want)
+		}
+	}
+}

app/agent/project.go

@@ -0,0 +1,66 @@
+package agent
+
+import (
+	"strconv"
+
+	"aego/asset"
+	"aego/project/refs"
+	"aego/scene/mutate"
+)
+
+func projectCommands() []*Command {
+	return []*Command{
+		{Name: "project.validate", Doc: "missing assets and nodes, import errors, prefabs and scenes that do not load", Run: (*Session).projectValidate},
+	}
+}
+
+func (s *Session) projectValidate(Args) (*Output, error) {
+	out := &Output{}
+	add := func(err bool, node, msg string) {
+		out.Problems = append(out.Problems, mutate.Problem{Error: err, Node: node, Message: msg})
+	}
+	for _, m := range refs.MissingAssets(s.Project, s.Pipeline) {
+		add(true, "", "missing asset "+m.Label())
+	}
+	for _, m := range refs.MissingNodes(s.Pipeline) {
+		add(true, m.Scene+" "+m.Path, m.Owner+"."+m.Field+" references a node that is not in the scene")
+	}
+	if s.scriptErr != nil {
+		add(true, "", "script types: "+s.scriptErr.Error())
+	}
+	for _, e := range s.libErrs {
+		add(true, "", e.Error())
+	}
+	for _, x := range s.Pipeline.Assets() {
+		if x.Error != "" {
+			add(true, x.Path, x.Error)
+			continue
+		}
+		if x.Kind != asset.ArtScene && x.Kind != asset.ArtPrefab {
+			continue
+		}
+		src, err := s.read(x.Path)
+		if err != nil {
+			add(true, x.Path, err.Error())
+			continue
+		}
+		doc, err := mutate.Load(src, x.Path, s.env())
+		if err != nil {
+			add(true, x.Path, err.Error())
+			continue
+		}
+		for _, p := range doc.Problems {
+			add(p.Error, x.Path+" "+p.Node, p.Message)
+		}
+	}
+	errs, warns := 0, 0
+	for _, p := range out.Problems {
+		if p.Error {
+			errs++
+		} else {
+			warns++
+		}
+	}
+	out.Notes = []string{"project: " + strconv.Itoa(errs) + " error(s), " + strconv.Itoa(warns) + " warning(s)"}
+	return out, nil
+}

app/assembly/builtin/builtin.go

@@ -6,6 +6,7 @@ import (
 	"aego/engine/module"
 	"aego/modules/accessibility"
 	"aego/modules/audio"
+	"aego/modules/camera"
 	"aego/modules/dataasset"
 	"aego/modules/debug"
 	"aego/modules/display"
@@ -71,6 +72,10 @@ func tweenEntry() assembly.Entry {
 	return assembly.Entry{ID: tween.ID, Requires: []string{scripting.ID}, New: func(assembly.Options) module.Module { return tween.New() }}
 }
 
+func cameraEntry() assembly.Entry {
+	return assembly.Entry{ID: camera.ID, Requires: []string{scripting.ID}, New: func(assembly.Options) module.Module { return camera.New() }}
+}
+
 func dataEntry() assembly.Entry {
 	return assembly.Entry{ID: dataasset.ID, New: func(assembly.Options) module.Module { return dataasset.New() }}
 }
@@ -85,5 +90,5 @@ func savegameEntry() assembly.Entry {
 
 func Default() assembly.Catalog {
 	return assembly.Catalog{core(), dataEntry(), inputEntry(), render2dEntry(), render3dEntry(), scriptEntry(), physicsEntry(), debugEntry(),
-		displayEntry(), audioEntry(), accessibilityEntry(), settingsEntry(), tweenEntry(), spawnEntry(), savegameEntry()}
+		displayEntry(), audioEntry(), accessibilityEntry(), settingsEntry(), tweenEntry(), cameraEntry(), spawnEntry(), savegameEntry()}
 }

app/assembly/builtin/headless.go

@@ -3,5 +3,5 @@ package builtin
 import "aego/app/assembly"
 
 func Headless() assembly.Catalog {
-	return assembly.Catalog{core(), dataEntry(), inputEntry(), scriptEntry(), physicsEntry(), debugEntry(), displayEntry(), audioEntry(), accessibilityEntry(), settingsEntry(), tweenEntry(), spawnEntry(), savegameEntry()}
+	return assembly.Catalog{core(), dataEntry(), inputEntry(), scriptEntry(), physicsEntry(), debugEntry(), displayEntry(), audioEntry(), accessibilityEntry(), settingsEntry(), tweenEntry(), cameraEntry(), spawnEntry(), savegameEntry()}
 }

app/assembly/editors/editors.go

@@ -2,6 +2,8 @@ package editors
 
 import (
 	"aego/app/assembly"
+	"aego/modules/camera"
+	cameraeditor "aego/modules/camera/editor"
 	"aego/modules/debug"
 	debugeditor "aego/modules/debug/editor"
 	inputmod "aego/modules/input"
@@ -20,5 +22,6 @@ func With(c assembly.Catalog) assembly.Catalog {
 		With(render2d.ID, render2deditor.Hook).
 		With(render3d.ID, render3deditor.Hook).
 		With(physics.ID, physicseditor.Hook).
+		With(camera.ID, cameraeditor.Hook).
 		With(debug.ID, debugeditor.Hook)
 }

app/assembly/playground/playground.go

@@ -4,12 +4,16 @@ import (
 	"aego/app/assembly"
 	"aego/engine/base"
 	"aego/engine/module"
+	"aego/modules/camera"
 	"aego/modules/debug"
 	inputmod "aego/modules/input"
 	"aego/modules/physics"
 	"aego/modules/render2d"
+	"aego/modules/render3d"
 	"aego/modules/scripting"
+	"aego/modules/tween"
 	"aego/script/stdlib"
+	"aego/script/vm"
 )
 
 func Catalog() assembly.Catalog {
@@ -22,5 +26,18 @@ func Catalog() assembly.Catalog {
 		}},
 		{ID: physics.ID, New: func(assembly.Options) module.Module { return physics.New() }},
 		{ID: debug.ID, New: func(assembly.Options) module.Module { return debug.New() }},
+		{ID: tween.ID, Requires: []string{scripting.ID}, New: func(assembly.Options) module.Module { return tween.New() }},
+		{ID: camera.ID, Requires: []string{scripting.ID}, New: func(assembly.Options) module.Module { return camera.New() }},
+		{ID: render3d.ID, New: func(assembly.Options) module.Module { return render3d.New() }},
 	}
 }
+
+const (
+	SandboxBudget = 2_000_000
+	SandboxHeap   = 64 << 20
+	SandboxNodes  = 10_000
+)
+
+func SandboxVM() vm.Options {
+	return vm.Options{Budget: SandboxBudget, MaxHeap: SandboxHeap}
+}

app/docstool/diagnostics.go

@@ -0,0 +1,33 @@
+package docstool
+
+import (
+	"aego/app/playground"
+	"aego/engine/docs"
+	"aego/script/diag"
+)
+
+func diagnoser(pg *playground.Playground) func(string, *docs.DiagInfo) {
+	return func(code string, d *docs.DiagInfo) {
+		got, err := pg.Reproduce(code)
+		if err != nil || got.Code == "" {
+			return
+		}
+		d.Severity, d.At, d.Message = got.Severity, got.File, got.Message
+		d.Line, d.Col, d.EndLine, d.EndCol = got.Line, got.Col, got.EndLine, got.EndCol
+	}
+}
+
+// DiagnosticProblems lists codes whose example is missing or no longer produces the code.
+func DiagnosticProblems() []docs.Problem {
+	pg, err := playground.New()
+	if err != nil {
+		return []docs.Problem{{ID: docs.DiagnosticsID, Error: true, Message: "cannot start the docs runtime: " + err.Error()}}
+	}
+	var out []docs.Problem
+	for _, c := range diag.Codes() {
+		if _, err := pg.Reproduce(c); err != nil {
+			out = append(out, docs.Problem{ID: c, Error: true, Message: err.Error()})
+		}
+	}
+	return out
+}

app/docstool/docstool_test.go

@@ -138,7 +138,7 @@ func TestF1Refs(t *testing.T) {
 	if err := os.WriteFile(path, []byte(probe), 0o644); err != nil {
 		t.Fatal(err)
 	}
-	reg, ws, err := build(p, nil)
+	reg, ws, err := build(p, nil, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -169,3 +169,17 @@ func TestF1Refs(t *testing.T) {
 		}
 	}
 }
+
+func TestDiagnosticExamplesExported(t *testing.T) {
+	if ps := DiagnosticProblems(); len(ps) > 0 {
+		t.Fatalf("diagnostics examples: %v", ps)
+	}
+	reg, err := ExportRegistry(nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	e, ok := reg.Get("AES2001")
+	if !ok || e.Diag == nil || e.Diag.Line == 0 || e.Diag.Severity != "error" || !strings.Contains(e.Diag.Message, "heigth") {
+		t.Fatalf("AES2001 example was not diagnosed: %+v", e.Diag)
+	}
+}

app/docstool/registry.go

@@ -9,6 +9,7 @@ import (
 
 	"aego/app/assembly"
 	"aego/app/assembly/builtin"
+	"aego/app/playground"
 	"aego/engine/docs"
 	"aego/engine/module"
 	scriptsystems "aego/modules/scripting/systems"
@@ -20,7 +21,7 @@ import (
 	"aego/script/workspace"
 )
 
-func build(p *project.Project, mods []module.Module) (*docs.Registry, *workspace.Workspace, error) {
+func build(p *project.Project, mods []module.Module, diagnose func(string, *docs.DiagInfo)) (*docs.Registry, *workspace.Workspace, error) {
 	types, err := assembly.NewTypes()
 	if err != nil {
 		return nil, nil, err
@@ -41,6 +42,7 @@ func build(p *project.Project, mods []module.Module) (*docs.Registry, *workspace
 		return nil, nil, err
 	}
 	src := docs.SourcesOf(bm, types.Schema(), man)
+	src.Diagnose = diagnose
 	var ws *workspace.Workspace
 	if p != nil {
 		ws, err = workspace.Open(workspace.Config{Root: p.Root, Module: p.Module, Scripts: p.ScriptsDir(), Bindings: reg.Table(), Docs: bm})
@@ -61,7 +63,17 @@ func build(p *project.Project, mods []module.Module) (*docs.Registry, *workspace
 }
 
 func Registry(p *project.Project, mods []module.Module) (*docs.Registry, error) {
-	r, _, err := build(p, mods)
+	r, _, err := build(p, mods, nil)
+	return r, err
+}
+
+// ExportRegistry is Registry with the diagnostics examples compiled for their messages and positions.
+func ExportRegistry(p *project.Project, mods []module.Module) (*docs.Registry, error) {
+	pg, err := playground.New()
+	if err != nil {
+		return nil, err
+	}
+	r, _, err := build(p, mods, diagnoser(pg))
 	return r, err
 }
 
@@ -84,9 +96,9 @@ func WriteExport(reg *docs.Registry, title, path string, w io.Writer) error {
 	return os.WriteFile(path, data, 0o644)
 }
 
-func Check(reg *docs.Registry, strict bool, w io.Writer) int {
+func Check(reg *docs.Registry, strict bool, w io.Writer, extra ...docs.Problem) int {
 	errs, warns := 0, 0
-	for _, p := range reg.Check(strict) {
+	for _, p := range append(reg.Check(strict), extra...) {
 		level := "warn "
 		if p.Error {
 			level = "error"

app/docstool/tool.go

@@ -21,7 +21,11 @@ func Tool(p *project.Project, args []string, stdout, stderr io.Writer, mods ...m
 	if err := fs.Parse(args[1:]); err != nil {
 		return 2
 	}
-	reg, err := Registry(p, mods)
+	build := Registry
+	if args[0] == "export" {
+		build = ExportRegistry
+	}
+	reg, err := build(p, mods)
 	if err != nil {
 		fmt.Fprintln(stderr, "aego:", err)
 		return 1
@@ -34,7 +38,7 @@ func Tool(p *project.Project, args []string, stdout, stderr io.Writer, mods ...m
 		}
 		return 0
 	case "check":
-		return Check(reg, *strict, stdout)
+		return Check(reg, *strict, stdout, DiagnosticProblems()...)
 	}
 	fmt.Fprintf(stderr, "unknown docs command %q\n", args[0])
 	return 2

app/docstool/try.go

@@ -0,0 +1,70 @@
+package docstool
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"aego/app/playground"
+	"aego/engine/docs"
+)
+
+const tryFrames = 60
+
+func CheckTry(reg *docs.Registry, w io.Writer) int {
+	pg, err := playground.New()
+	if err != nil {
+		fmt.Fprintln(w, "try: cannot start the docs runtime:", err)
+		return 1
+	}
+	pg.SetGame(playground.GameConfig{Headless: true, FrameTime: 1.0 / 60})
+	defer func() {
+		if g := pg.Game(); g != nil {
+			g.Close()
+		}
+	}()
+	sandbox := map[string]bool{}
+	for _, e := range pg.TryScenes() {
+		sandbox[e.ID] = true
+	}
+	bad := 0
+	for _, e := range reg.All() {
+		if e.Try == "" {
+			continue
+		}
+		var msgs []string
+		add := func(msg string) {
+			for _, m := range msgs {
+				if m == msg || strings.Contains(m, msg) || strings.Contains(msg, m) {
+					return
+				}
+			}
+			msgs = append(msgs, msg)
+		}
+		switch res := pg.PlayScene(e.ID, []byte(e.Try)); {
+		case !sandbox[e.ID]:
+			add("belongs to a module the docs runtime does not include")
+		case !res.Started:
+			add("does not load: " + res.Error)
+		default:
+			if err := pg.Game().Step(tryFrames); err != nil {
+				add("stops the engine: " + err.Error())
+			}
+		}
+		poll := pg.Poll()
+		for _, l := range poll.Log {
+			if l.Level != "INFO" && l.Level != "DEBUG" {
+				add(l.Text)
+			}
+		}
+		for _, f := range poll.Faults {
+			add(f.Code + " " + f.Message)
+		}
+		for _, m := range msgs {
+			fmt.Fprintf(w, "%s: error: try scene %s\n", e.ID, m)
+		}
+		bad += len(msgs)
+	}
+	pg.Stop()
+	return bad
+}

app/docsview/bridge.go

@@ -0,0 +1,84 @@
+//go:build aego_editor
+
+package docsview
+
+import (
+	"encoding/json"
+	"strconv"
+
+	"aego/editor/core/docsession"
+	"aego/scene/sceneio"
+)
+
+type request struct {
+	Scene     string  `json:"scene"`
+	Select    string  `json:"select"`
+	Component string  `json:"component"`
+	Field     string  `json:"field"`
+	Value     float64 `json:"value"`
+}
+
+type Reply struct {
+	Text   string            `json:"text,omitempty"`
+	Values map[string]string `json:"values,omitempty"`
+	Error  string            `json:"error,omitempty"`
+	State  *docsession.State `json:"state,omitempty"`
+	Log    []Line            `json:"log,omitempty"`
+}
+
+func (a *App) Call(method string, payload []byte) Reply {
+	var req request
+	if len(payload) > 0 {
+		if err := json.Unmarshal(payload, &req); err != nil {
+			return Reply{Error: err.Error()}
+		}
+	}
+	s := a.session
+	var err error
+	switch method {
+	case "load":
+		err = s.Load([]byte(req.Scene), req.Select)
+	case "reset":
+		err = s.Reset()
+	case "text":
+	case "play":
+		s.TogglePause()
+	case "undo":
+		err = s.Undo()
+	case "redo":
+		err = s.Redo()
+	case "set":
+		err = s.Set(req.Component, req.Field, req.Value)
+	case "state":
+		st := s.State()
+		return Reply{State: &st}
+	case "log":
+		out := Reply{Log: a.lines}
+		a.lines = nil
+		return out
+	default:
+		return Reply{Error: "unknown method " + strconv.Quote(method)}
+	}
+	if err != nil {
+		return Reply{Error: err.Error()}
+	}
+	st := s.State()
+	return Reply{Text: string(s.Text()), Values: Values(s.Text()), State: &st}
+}
+
+// Values flattens a scene file into the field keys the docs scene tree uses.
+func Values(text []byte) map[string]string {
+	nodes, err := sceneio.Outline(text)
+	if err != nil {
+		return nil
+	}
+	return sceneio.OutlineValues(nodes)
+}
+
+func (a *App) Reply(method, payload string) string {
+	out, err := json.Marshal(a.Call(method, []byte(payload)))
+	if err != nil {
+		return `{"error":"cannot encode the reply"}`
+	}
+	return string(out)
+}

app/docsview/scripts.go

@@ -0,0 +1,70 @@
+//go:build aego_editor
+
+package docsview
+
+import (
+	playmods "aego/app/assembly/playground"
+	"aego/core/log"
+	"aego/editor/core/context"
+	"aego/engine"
+	"aego/engine/module"
+	"aego/scene"
+	"aego/script/bind"
+	"aego/script/bytecode"
+	scriptruntime "aego/script/runtime"
+)
+
+type scriptHost struct {
+	reg   *bind.Registry
+	types *scene.Types
+	man   *module.Manifest
+	log   *log.Logger
+	mods  []*bytecode.Module
+}
+
+func (h *scriptHost) Errors() int {
+	return 0
+}
+
+func (h *scriptHost) Attach(w *engine.World, s *scene.Scene) (func(), error) {
+	rt := scriptruntime.New(scriptruntime.Options{Bindings: h.reg, Schema: h.types.Schema(), Log: h.log, VM: playmods.SandboxVM()})
+	if err := rt.Link(h.mods); err != nil {
+		rt.Close()
+		return nil, err
+	}
+	w.SetService(scriptruntime.ServiceID, rt)
+	if err := rt.Instantiate(s); err != nil {
+		w.RemoveService(scriptruntime.ServiceID)
+		rt.Close()
+		return nil, err
+	}
+	detach, err := h.man.Attach(&module.AttachContext{World: w, Scene: s, Log: h.log, Editor: true, Play: true})
+	if err != nil {
+		w.RemoveService(scriptruntime.ServiceID)
+		rt.Close()
+		return nil, err
+	}
+	return func() {
+		detach()
+		w.RemoveService(scriptruntime.ServiceID)
+		rt.Close()
+	}, nil
+}
+
+func (h *scriptHost) Problems() ([]context.ScriptProblem, uint64) {
+	return nil, 0
+}
+
+func (h *scriptHost) Stats() (context.ScriptStats, bool) {
+	return context.ScriptStats{}, false
+}
+
+func (h *scriptHost) Status() (uint64, bool) {
+	return 0, false
+}
+
+func (h *scriptHost) Watch(*engine.World, scene.NodeHandle, string, string, int) (string, float64, bool, bool) {
+	return "", 0, false, false
+}
+
+var _ context.ScriptHost = (*scriptHost)(nil)

app/edit/edit.go

@@ -154,6 +154,9 @@ func Run(p *project.Project, cfg Config, mods ...sdk.Module) error {
 			panic(rec)
 		}
 	}()
+	if dir := os.Getenv(EnvShots); dir != "" {
+		return s.shots(dir)
+	}
 	if err := s.Run(); err != nil {
 		return err
 	}

app/edit/edit_test.go

@@ -116,12 +116,8 @@ func TestPlayLeavesEditSceneByteIdentical(t *testing.T) {
 		t.Fatal("Spin is not registered")
 	}
 	speed, _ := td.Field("speed")
-	add := &commands.AddComponent{
-		Node:   spinner,
-		Type:   td.ID,
-		Name:   td.FullName,
-		Values: []commands.FieldValue{{Field: speed.ID, Value: schema.Float32(3)}},
-	}
+	add := commands.NewMutation("Add "+td.FullName, commands.EnvFor(es),
+		commands.AddComp(es, spinner, td, []commands.FieldValue{{Field: speed.ID, Value: schema.Float32(3)}}))
 	if err := d.History.Exec(add); err != nil {
 		t.Fatal(err)
 	}

app/edit/onadd_test.go

@@ -42,7 +42,7 @@ func TestColliderFitsSprite(t *testing.T) {
 	}
 	for _, name := range []string{"Crate", "Bare"} {
 		id := es.ID(es.Find(es.Root(), name))
-		if err := d.History.Exec(&commands.AddComponent{Node: id, Type: td.ID, Name: td.FullName, OnAdd: ctx.OnAdd(td)}); err != nil {
+		if err := d.History.Exec(commands.NewMutation("Add "+td.FullName, commands.WithOnAdd(commands.EnvFor(es), ctx.OnAdd), commands.AddComp(es, id, td, nil))); err != nil {
 			t.Fatal(err)
 		}
 	}

app/edit/play_test.go

@@ -51,12 +51,8 @@ func openSpinner(t *testing.T) *spinFixture {
 	}
 	fd, _ := td.Field("speed")
 	f.typ, f.speed = td.ID, fd.ID
-	add := &commands.AddComponent{
-		Node:   f.spinner,
-		Type:   td.ID,
-		Name:   td.FullName,
-		Values: []commands.FieldValue{{Field: fd.ID, Value: schema.Float32(3)}},
-	}
+	add := commands.NewMutation("Add "+td.FullName, commands.EnvFor(es),
+		commands.AddComp(es, f.spinner, td, []commands.FieldValue{{Field: fd.ID, Value: schema.Float32(3)}}))
 	if err := d.History.Exec(add); err != nil {
 		t.Fatal(err)
 	}

app/export/build.go

@@ -67,6 +67,17 @@ func (j *job) toolchain() error {
 	if _, err := exec.LookPath("go"); err != nil {
 		return errs.New(errs.BuildFailed, "export needs the Go toolchain on this machine; the exported game does not, see docs/export.md")
 	}
+	if j.t.Web() {
+		root, err := goRoot()
+		if err != nil {
+			return err
+		}
+		if _, err := wasmExecPath(root); err != nil {
+			return err
+		}
+		j.goroot = root
+		return nil
+	}
 	cc := j.cc()
 	if !j.t.Host() && cc == "" {
 		return errs.New(errs.BuildFailed, "exporting to "+j.t.String()+" from "+runtime.GOOS+"/"+runtime.GOARCH+
@@ -164,8 +175,12 @@ func (j *job) build() error {
 	args = append(args, pkg)
 	cmd := exec.Command("go", args...)
 	cmd.Dir = root
-	cmd.Env = append(os.Environ(), "GOOS="+j.t.OS, "GOARCH="+j.t.Arch, "CGO_ENABLED=1")
-	if cc := j.cc(); cc != "" {
+	cgo := "CGO_ENABLED=1"
+	if j.t.Web() {
+		cgo = "CGO_ENABLED=0"
+	}
+	cmd.Env = append(os.Environ(), "GOOS="+j.t.OS, "GOARCH="+j.t.Arch, cgo)
+	if cc := j.cc(); cc != "" && !j.t.Web() {
 		cmd.Env = append(cmd.Env, "CC="+cc)
 	}
 	if j.t.OS == "darwin" {

app/export/data.go

@@ -70,6 +70,7 @@ func (j *job) data() error {
 	var total int64
 	count := 0
 	var failed error
+	j.files = j.files[:0]
 	j.snap.idx.Each(func(e *asset.Entry) {
 		if failed != nil || e.Missing || e.Error != "" || exportSkip(e.Kind) {
 			return
@@ -98,6 +99,7 @@ func (j *job) data() error {
 				}
 				written[name] = true
 				names = append(names, name)
+				j.files = append(j.files, webFile{Path: bundle.ArtifactsDir + "/" + name, Size: int64(len(raw))})
 				s.Bytes += int64(len(raw))
 				total += int64(len(raw))
 			}
@@ -120,7 +122,9 @@ func (j *job) data() error {
 	if err := os.WriteFile(filepath.Join(j.l.data, bundle.ManifestFile), raw, 0o644); err != nil {
 		return errs.Wrap(err, errs.VFSIO, "cannot write the data manifest")
 	}
+	j.manifestSize = int64(len(raw))
 	slices.Sort(names)
+	slices.SortFunc(j.files, func(a, b webFile) int { return strings.Compare(a.Path, b.Path) })
 	h := sha256.New()
 	h.Write([]byte(strings.Join(names, "\n")))
 	h.Write(raw)
@@ -147,7 +151,7 @@ func (j *job) manifest() error {
 	p := j.p
 	x := &bundle.Export{
 		Engine: engine.Version, Game: p.Name, GameVersion: GameVersion(p), Module: p.Module,
-		Target: j.t.String(), Profile: j.profile, Binary: j.rep.Binary, BinarySize: j.rep.BinarySize,
+		Target: j.t.String(), Profile: j.profile, Binary: j.rep.Binary, BinarySize: j.rep.BinarySize, BinaryGzip: j.rep.BinaryGzip,
 		StartScene: p.MainScene, Modules: j.rep.Modules, Libs: j.libs(), Data: j.rep.Data,
 		DataSize: j.rep.DataSize, Artifacts: j.rep.Artifacts, Hash: j.rep.Hash,
 		BuildMillis: time.Since(j.start).Milliseconds(), Time: time.Now().UTC().Format(time.RFC3339),
@@ -169,19 +173,24 @@ func (j *job) sdlLicense() string {
 	return ""
 }
 
-func (j *job) libs() []bundle.Lib {
-	lib := bundle.Lib{Name: "SDL3", Link: "static"}
-	src := j.sdlLicense()
+func (j *job) license(lib bundle.Lib, src, name string) bundle.Lib {
 	if src == "" {
-		return []bundle.Lib{lib}
+		return lib
 	}
 	data, err := os.ReadFile(src)
 	if err != nil {
-		return []bundle.Lib{lib}
+		return lib
 	}
-	dst := filepath.Join(j.out, "licenses", "SDL3.txt")
+	dst := filepath.Join(j.out, "licenses", name)
 	if os.MkdirAll(filepath.Dir(dst), 0o755) == nil && os.WriteFile(dst, data, 0o644) == nil {
-		lib.License = "licenses/SDL3.txt"
+		lib.License = "licenses/" + name
 	}
-	return []bundle.Lib{lib}
+	return lib
+}
+
+func (j *job) libs() []bundle.Lib {
+	if j.t.Web() {
+		return []bundle.Lib{j.license(bundle.Lib{Name: "Go wasm_exec.js", Link: "script", File: webExec}, filepath.Join(j.goroot, "LICENSE"), "Go.txt")}
+	}
+	return []bundle.Lib{j.license(bundle.Lib{Name: "SDL3", Link: "static"}, j.sdlLicense(), "SDL3.txt")}
 }

app/export/pack.go

@@ -21,6 +21,8 @@ func (j *job) pack() error {
 		return j.packLinux()
 	case "darwin":
 		return j.packDarwin()
+	case "js":
+		return j.packWeb()
 	}
 	return nil
 }

app/export/report.go

@@ -24,6 +24,7 @@ type Report struct {
 	Out         string                `json:"out"`
 	Binary      string                `json:"binary,omitempty"`
 	BinarySize  int64                 `json:"binarySize"`
+	BinaryGzip  int64                 `json:"binaryGzip,omitempty"`
 	Data        []bundle.Size         `json:"data"`
 	DataSize    int64                 `json:"dataSize"`
 	Artifacts   int                   `json:"artifacts"`
@@ -70,7 +71,11 @@ func Bytes(n int64) string {
 func (r *Report) Lines() [][2]string {
 	out := [][2]string{{"Target", r.Target}, {"Profile", r.Profile}, {"Output", r.Out}}
 	if r.Binary != "" {
-		out = append(out, [2]string{"Binary", r.Binary + " (" + Bytes(r.BinarySize) + ")"})
+		s := r.Binary + " (" + Bytes(r.BinarySize)
+		if r.BinaryGzip > 0 {
+			s += ", gzip " + Bytes(r.BinaryGzip)
+		}
+		out = append(out, [2]string{"Binary", s + ")"})
 	}
 	if r.Artifacts > 0 {
 		out = append(out, [2]string{"Data", Bytes(r.DataSize) + " in " + strconv.Itoa(r.Artifacts) + " artifacts"})

app/export/web/index.html

@@ -0,0 +1,38 @@
+<!doctype html>
+<html lang="en" data-build="{{.Build}}">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1">
+<title>{{.Title}}</title>
+{{if .Icon}}<link rel="icon" href="favicon.png">{{else}}<link rel="icon" href="data:,">{{end}}
+<style>
+html, body { margin: 0; height: 100%; background: #0d0e10; color: #e4e3df; overflow: hidden; font: 14px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif; }
+canvas { display: block; width: 100%; height: 100%; outline: none; touch-action: none; }
+.loader { position: fixed; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 12px; background: #0d0e10; transition: opacity 0.25s; }
+.loader.done { opacity: 0; pointer-events: none; }
+.loader .title { font-size: 20px; font-weight: 600; }
+.progress { width: min(360px, 80vw); height: 6px; border-radius: 3px; background: #2d3036; overflow: hidden; }
+#bar { width: 0; height: 100%; background: #6e9bf5; transition: width 0.1s; }
+#bar.indeterminate { width: 30%; animation: slide 1s ease-in-out infinite alternate; }
+@keyframes slide { from { margin-left: 0; } to { margin-left: 70%; } }
+#status { color: #9a9890; font-size: 13px; }
+.loader.failed #bar { background: #f0776c; }
+#error { max-width: min(640px, 90vw); max-height: 40vh; overflow: auto; margin: 0; padding: 10px 12px; white-space: pre-wrap; color: #f0776c; background: #1d1f23; border-radius: 6px; font: 12px/1.5 ui-monospace, Menlo, Consolas, monospace; }
+#fullscreen { position: fixed; top: 10px; right: 10px; width: 36px; height: 36px; border: 0; border-radius: 6px; background: rgba(0, 0, 0, 0.45); color: #fff; font-size: 18px; cursor: pointer; opacity: 0.5; }
+#fullscreen:hover { opacity: 1; }
+</style>
+<link rel="preload" href="game.wasm?v={{.Build}}" as="fetch" type="application/wasm" crossorigin>
+</head>
+<body>
+<canvas id="game" data-aego tabindex="0" aria-label="{{.Title}}"></canvas>
+<div id="loader" class="loader" role="status" aria-live="polite">
+  <div class="title">{{.Title}}</div>
+  <div class="progress"><div id="bar"></div></div>
+  <div id="status">Loading…</div>
+  <pre id="error" hidden></pre>
+</div>
+<button id="fullscreen" type="button" title="Fullscreen" aria-label="Fullscreen" hidden>⛶</button>
+<script src="wasm_exec.js?v={{.Build}}"></script>
+<script src="loader.js?v={{.Build}}"></script>
+</body>
+</html>

app/export/web_test.go

@@ -0,0 +1,85 @@
+package export
+
+import (
+	"bytes"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"aego/project"
+	"aego/runtime/bundle"
+)
+
+var webTarget = Target{OS: "js", Arch: "wasm"}
+
+func TestParseWeb(t *testing.T) {
+	for _, s := range []string{"web", "WEB", "js/wasm", "wasm"} {
+		tg, err := ParseTarget(s)
+		if err != nil || !tg.Web() || tg.String() != "web" {
+			t.Fatalf("%s: %+v %v", s, tg, err)
+		}
+	}
+}
+
+func TestWebLayout(t *testing.T) {
+	p := &project.Project{Name: "My Game", Root: t.TempDir()}
+	l := layoutFor(webTarget, "/out", p)
+	if l.binary() != filepath.Join("/out", WebWasm) || l.data != filepath.Join("/out", bundle.DataDir) {
+		t.Fatalf("layout %+v", l)
+	}
+	if !strings.HasSuffix(DefaultOut(p, webTarget, bundle.Release), "web-"+bundle.Release) {
+		t.Fatal(DefaultOut(p, webTarget, bundle.Release))
+	}
+}
+
+func TestPackWeb(t *testing.T) {
+	root, err := goRoot()
+	if err != nil {
+		t.Skip(err)
+	}
+	out := t.TempDir()
+	wasm := bytes.Repeat([]byte("wasm"), 4096)
+	j := &job{
+		p: &project.Project{Name: `<Game & "Co">`, Module: "game"}, t: webTarget, out: out, goroot: root,
+		rep:   &Report{Hash: strings.Repeat("ab", 32), BinarySize: int64(len(wasm))},
+		files: []webFile{{Path: "artifacts/a.tex", Size: 3}}, manifestSize: 8,
+	}
+	j.l = layoutFor(webTarget, out, j.p)
+	if err := os.MkdirAll(j.l.data, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(j.l.binary(), wasm, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := j.packWeb(); err != nil {
+		t.Fatal(err)
+	}
+	page, _ := os.ReadFile(filepath.Join(out, webIndex))
+	if !strings.Contains(string(page), "&lt;Game &amp;") || strings.Contains(string(page), "<Game") {
+		t.Fatal("the title is not escaped")
+	}
+	if !strings.Contains(string(page), `data-build="abababababab"`) {
+		t.Fatal("the build key is missing")
+	}
+	raw, err := os.ReadFile(filepath.Join(j.l.data, WebFiles))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var list webList
+	if err := json.Unmarshal(raw, &list); err != nil {
+		t.Fatal(err)
+	}
+	if list.Wasm != int64(len(wasm)) || list.Manifest.Size != 8 || len(list.Files) != 1 || list.Files[0].Path != "artifacts/a.tex" {
+		t.Fatalf("files.json %+v", list)
+	}
+	for _, f := range []string{webExec, webLoader, WebWasm + ".gz"} {
+		if _, err := os.Stat(filepath.Join(out, f)); err != nil {
+			t.Errorf("%s is missing", f)
+		}
+	}
+	if j.rep.BinaryGzip <= 0 || j.rep.BinaryGzip >= j.rep.BinarySize {
+		t.Fatalf("wasm gzip size %d of %d", j.rep.BinaryGzip, j.rep.BinarySize)
+	}
+}

app/playground/check_test.go

@@ -0,0 +1,31 @@
+package playground
+
+import (
+	"testing"
+
+	"aego/app/assembly/builtin"
+)
+
+func TestCheckSnippetsCompile(t *testing.T) {
+	p, err := NewWith(builtin.Default())
+	if err != nil {
+		t.Fatal(err)
+	}
+	n := 0
+	for _, e := range p.docs.All() {
+		for _, s := range e.Snippets {
+			if !s.Check || s.Lang != "aes" {
+				continue
+			}
+			n++
+			for _, d := range p.Compile(map[string]string{"main.aes": s.Code}) {
+				if d.Severity == "error" {
+					t.Errorf("%s (line %d of its page): %d:%d %s %s", e.ID, s.Line, d.Line, d.Col, d.Code, d.Message)
+				}
+			}
+		}
+	}
+	if n == 0 {
+		t.Fatal("no aes check blocks in the documentation")
+	}
+}

app/playground/diagnose.go

@@ -0,0 +1,65 @@
+package playground
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"aego/script/diag"
+)
+
+const exampleFrames = 3
+
+// Reproduce runs the diagnostics example of code and returns what its broken version reports.
+func (p *Playground) Reproduce(code string) (Diagnostic, error) {
+	ex, ok := diag.Example(code)
+	if !ok {
+		return Diagnostic{}, errors.New("no example in script/diag/examples.go")
+	}
+	if ex.Why != "" {
+		return Diagnostic{}, nil
+	}
+	if ex.Bad == "" || ex.Good == "" {
+		return Diagnostic{}, errors.New("the example needs both a broken and a fixed version")
+	}
+	bad := reports(p.Run(ex.Sources(false), exampleFrames))
+	var found *Diagnostic
+	for i := range bad {
+		if bad[i].Code == code {
+			found = &bad[i]
+			break
+		}
+	}
+	if found == nil {
+		return Diagnostic{}, fmt.Errorf("the broken example does not report %s, it reports %s", code, list(bad))
+	}
+	var wrong []Diagnostic
+	for _, d := range reports(p.Run(ex.Sources(true), exampleFrames)) {
+		if d.Code == code || d.Severity == "error" {
+			wrong = append(wrong, d)
+		}
+	}
+	if len(wrong) > 0 {
+		return *found, fmt.Errorf("the fixed example still reports %s", list(wrong))
+	}
+	return *found, nil
+}
+
+func reports(res Result) []Diagnostic {
+	out := append([]Diagnostic(nil), res.Diagnostics...)
+	for _, f := range res.Faults {
+		out = append(out, Diagnostic{File: f.File, Line: f.Line, Code: f.Code, Severity: "error", Message: f.Message})
+	}
+	return out
+}
+
+func list(ds []Diagnostic) string {
+	if len(ds) == 0 {
+		return "nothing"
+	}
+	parts := make([]string, len(ds))
+	for i, d := range ds {
+		parts[i] = strings.TrimSpace(d.Code + " " + d.Message)
+	}
+	return strings.Join(parts, "; ")
+}

app/playground/diagnose_test.go

@@ -0,0 +1,27 @@
+package playground
+
+import (
+	"testing"
+
+	"aego/script/diag"
+)
+
+func TestDiagnosticExamples(t *testing.T) {
+	p := open(t)
+	var skipped []string
+	for _, code := range diag.Codes() {
+		d, err := p.Reproduce(code)
+		if err != nil {
+			t.Errorf("%s: %v", code, err)
+			continue
+		}
+		if d.Code == "" {
+			skipped = append(skipped, code)
+			continue
+		}
+		t.Logf("%s %s:%d:%d-%d:%d %s %s", code, d.File, d.Line, d.Col, d.EndLine, d.EndCol, d.Severity, d.Message)
+	}
+	if len(skipped) > 10 {
+		t.Errorf("%d codes are not reproducible: %v", len(skipped), skipped)
+	}
+}

app/playground/game.go

@@ -1,8 +1,11 @@
 package playground
 
 import (
+	"fmt"
 	"strings"
 
+	playmods "aego/app/assembly/playground"
+
 	"aego/asset"
 	"aego/asset/loader"
 	"aego/core/log"
@@ -99,6 +102,7 @@ type Game struct {
 	bench    bench
 	running  bool
 	looping  bool
+	overflow bool
 }
 
 type driver struct {
@@ -195,7 +199,7 @@ func (g *Game) Engine() *engine.Engine {
 
 func (g *Game) Play(name string, src []byte, mods []*bytecode.Module) error {
 	g.Stop()
-	rt := scriptruntime.New(scriptruntime.Options{Bindings: g.reg, Schema: g.types.Schema(), Log: g.log})
+	rt := scriptruntime.New(scriptruntime.Options{Bindings: g.reg, Schema: g.types.Schema(), Log: g.log, VM: playmods.SandboxVM()})
 	if err := rt.Link(mods); err != nil {
 		rt.Close()
 		return err
@@ -225,7 +229,7 @@ func (g *Game) Play(name string, src []byte, mods []*bytecode.Module) error {
 		return err
 	}
 	g.detach = d
-	g.example, g.running, g.faults = name, true, 0
+	g.example, g.running, g.faults, g.overflow = name, true, 0, false
 	g.start()
 	return nil
 }
@@ -272,6 +276,10 @@ func (g *Game) update(dt float64) {
 		g.frameMs += (ft - g.frameMs) * statsAlpha
 	}
 	g.bench.t += dt
+	if g.scene != nil && !g.overflow && g.scene.Stats().Alive > playmods.SandboxNodes {
+		g.overflow = true
+		g.clog.Error(fmt.Sprintf("the scene grew past %d nodes, the game was stopped", playmods.SandboxNodes))
+	}
 }
 
 func hue(i, n int) mathx.Color {
@@ -351,6 +359,10 @@ func (g *Game) newFaults() []Fault {
 }
 
 func (g *Game) Poll() Poll {
+	if g.overflow {
+		g.overflow = false
+		g.Stop()
+	}
 	p := Poll{Log: g.lines, Faults: g.newFaults()}
 	g.lines = nil
 	s := &p.Stats

app/playground/play.go

@@ -109,3 +109,14 @@ func (p *Playground) Poll() Poll {
 func (p *Playground) LoseContext(lose bool) bool {
 	return p.game != nil && p.game.LoseContext(lose)
 }
+
+func (p *Playground) PlayScene(name string, src []byte) PlayResult {
+	g, err := p.host()
+	if err != nil {
+		return PlayResult{Error: err.Error()}
+	}
+	if err := g.Play(name, src, nil); err != nil {
+		return PlayResult{Error: err.Error()}
+	}
+	return PlayResult{Started: true}
+}

app/playground/sandbox_test.go

@@ -0,0 +1,86 @@
+package playground
+
+import (
+	"strings"
+	"testing"
+
+	"aego/script/vm"
+)
+
+const loopKick = `package boxes
+
+script Kick {
+	func Update(dt float) {
+		n := 0
+		for n >= 0 {
+			n++
+		}
+	}
+}
+`
+
+const heapKick = `package boxes
+
+script Kick {
+	func Update(dt float) {
+		s := "ab"
+		for s != "" {
+			s = s + s
+		}
+	}
+}
+`
+
+const saveScript = `package demo
+
+import "aego/save"
+
+script S {
+	func Ready() {
+		save.Save("slot")
+	}
+}
+`
+
+func faultOf(t *testing.T, p *Playground, code string) Fault {
+	t.Helper()
+	res := p.Play(ScenePrefix+"boxes", map[string]string{"main.aes": code})
+	if !res.Started {
+		t.Fatalf("did not start: %s %+v", res.Error, res.Diagnostics)
+	}
+	if err := p.Game().Step(3); err != nil {
+		t.Fatal(err)
+	}
+	for _, f := range p.Poll().Faults {
+		if f.Code == vm.CodeBudget {
+			return f
+		}
+	}
+	t.Fatal("the script was not stopped by the sandbox")
+	return Fault{}
+}
+
+func TestSandboxInstructionBudget(t *testing.T) {
+	p := newHeadless(t)
+	faultOf(t, p, loopKick)
+	if !p.Poll().Stats.Running {
+		t.Fatal("the game stopped with the script")
+	}
+}
+
+func TestSandboxHeapLimit(t *testing.T) {
+	p := newHeadless(t)
+	if f := faultOf(t, p, heapKick); !strings.Contains(f.Message, "heap") {
+		t.Fatalf("fault %+v", f)
+	}
+}
+
+func TestSandboxHasNoSaves(t *testing.T) {
+	p := newHeadless(t)
+	for _, d := range p.Compile(map[string]string{"main.aes": saveScript}) {
+		if d.Severity == "error" {
+			return
+		}
+	}
+	t.Fatal("aego/save compiled in the sandbox")
+}