Web export: the page build key covers the runtime and scripts, so a new engine gets new immutable URLs

README.md

@@ -0,0 +1,8 @@
+# Aego
+
+A 2D and 3D game engine with an editor, a scripting language and a web export, written in Go.
+
+- Documentation and the playground: <https://aego.akarpov.ru>
+- Installing and building from source: [engine/res/docs/install.md](engine/res/docs/install.md)
+- Contributing, check levels and rules for engine code: [docs/contributing.md](docs/contributing.md)
+- Architecture and decisions: [ARCHITECTURE.md](ARCHITECTURE.md)

app/agent/scene.go

@@ -2,6 +2,7 @@ package agent
 
 import (
 	"errors"
+	"maps"
 	"os"
 	"path"
 	"slices"
@@ -65,9 +66,8 @@ func sceneCommands() []*Command {
 		{Name: "scene.rename", Doc: "rename a node", Write: true, Args: []Arg{argFile, argNode, {Name: "name", Type: "string", Doc: "new name", Required: true, Pos: true}}, Run: func(s *Session, a Args) (*Output, error) {
 			return s.sceneTx(a, "Rename", mutate.Rename(a.Str("node"), a.Str("name")))
 		}},
-		{Name: "scene.add-comp", Doc: "add a component with its defaults", Write: true, Args: []Arg{argFile, argNode, {Name: "comp", Type: "string", Doc: "component name, full or a unique suffix (Body2D)", Required: true, Pos: true}}, Run: func(s *Session, a Args) (*Output, error) {
+		{Name: "scene.add-comp", Doc: "add a component with its defaults and the components it requires", Write: true, Args: []Arg{argFile, argNode, {Name: "comp", Type: "string", Doc: "component name, full or a unique suffix (Body2D)", Required: true, Pos: true},
-			return s.sceneTx(a, "Add Component", mutate.AddComp(a.Str("node"), a.Str("comp")))
+			{Name: "no-required", Type: "boolean", Doc: "add only this component; missing requirements stay as problems"}}, Run: (*Session).sceneAddComp},
-		}},
 		{Name: "scene.remove-comp", Doc: "remove a component", Write: true, Args: []Arg{argFile, argNode, {Name: "comp", Type: "string", Doc: "component name", Required: true, Pos: true}}, Run: func(s *Session, a Args) (*Output, error) {
 			return s.sceneTx(a, "Remove Component", mutate.RemoveComp(a.Str("node"), a.Str("comp")))
 		}},
@@ -93,6 +93,49 @@ func (s *Session) scene(a Args) (string, []byte, *mutate.Document, error) {
 	return rel, src, doc, err
 }
 
+// sceneAddComp adds a component and, unless no-required is set, the components it requires first, in one transaction (D144).
+func (s *Session) sceneAddComp(a Args) (*Output, error) {
+	rel, src, doc, err := s.scene(a)
+	if err != nil {
+		return nil, err
+	}
+	node, comp := a.Str("node"), a.Str("comp")
+	ops := []mutate.Op{mutate.AddComp(node, comp)}
+	var notes []string
+	if !a.Bool("no-required") {
+		td, err := doc.Component(comp)
+		if err != nil {
+			return nil, err
+		}
+		h, err := doc.Node(node)
+		if err != nil {
+			return nil, err
+		}
+		req, err := mutate.Required(doc.Scene, td, h)
+		if err != nil {
+			return nil, err
+		}
+		ops = ops[:0]
+		for _, r := range req {
+			ops = append(ops, mutate.AddComp(node, r.FullName))
+			notes = append(notes, "added "+label(r)+" (required by "+label(td)+")")
+		}
+		ops = append(ops, mutate.AddComp(node, td.FullName))
+	}
+	out, err := s.applyDoc(a, rel, src, doc, mutate.Tx{Label: "Add Component", Ops: ops})
+	if out != nil {
+		out.Notes = append(notes, out.Notes...)
+	}
+	return out, err
+}
+
+func label(td *schema.TypeDescriptor) string {
+	if td.DisplayName != "" {
+		return td.DisplayName
+	}
+	return td.FullName
+}
+
 func (s *Session) sceneTx(a Args, label string, ops ...mutate.Op) (*Output, error) {
 	rel, src, doc, err := s.scene(a)
 	if err != nil {
@@ -245,6 +288,9 @@ func (s *Session) sceneRun(a Args) (*Output, error) {
 	}
 	var b strings.Builder
 	b.WriteString("frames: " + strconv.Itoa(rep.Frames) + "\nhash: " + rep.Hash + "\n")
+	for _, k := range slices.Sorted(maps.Keys(rep.Counters)) {
+		b.WriteString(k + ": " + strconv.FormatUint(rep.Counters[k], 10) + "\n")
+	}
 	for _, l := range rep.Log {
 		b.WriteString(l + "\n")
 	}

app/agent/schema.go

@@ -1,6 +1,7 @@
 package agent
 
 import (
+	"aego/script/abi"
 	"errors"
 	"strings"
 
@@ -34,6 +35,14 @@ type TypeView struct {
 	Requires []string    `json:"requires,omitempty"`
 	Doc      string      `json:"doc,omitempty"`
 	Fields   []FieldView `json:"fields,omitempty"`
+	Methods  []CallView  `json:"methods,omitempty"`
+	Signals  []CallView  `json:"signals,omitempty"`
+}
+
+type CallView struct {
+	Name string `json:"name"`
+	Sig  string `json:"sig"`
+	Doc  string `json:"doc,omitempty"`
 }
 
 func schemaCommands() []*Command {
@@ -90,6 +99,7 @@ func (s *Session) lookupType(name string) (*schema.TypeDescriptor, error) {
 			found = append(found, td)
 		}
 	}
+	found = schema.PreferProject(found)
 	switch len(found) {
 	case 1:
 		return found[0], nil
@@ -162,5 +172,51 @@ func (s *Session) schemaShow(a Args) (*Output, error) {
 		}
 		b.WriteString("\n")
 	}
+	if s.kit != nil {
+		for _, cm := range s.kit.methods(td.FullName) {
+			v.Methods = append(v.Methods, CallView{Name: cm.Name, Sig: methodSig(cm.Sig, cm.Params), Doc: summary(cm.Doc)})
+		}
+	}
+	for _, sg := range td.Signals {
+		params := make([]string, len(sg.Params))
+		for i, p := range sg.Params {
+			params[i] = p
+			if i < len(sg.Names) && sg.Names[i] != "" {
+				params[i] = sg.Names[i] + " " + p
+			}
+		}
+		v.Signals = append(v.Signals, CallView{Name: sg.Name, Sig: "(" + strings.Join(params, ", ") + ")", Doc: summary(sg.Doc)})
+	}
+	for _, sec := range []struct {
+		title string
+		list  []CallView
+	}{{"methods", v.Methods}, {"signals", v.Signals}} {
+		if len(sec.list) == 0 {
+			continue
+		}
+		b.WriteString(sec.title + ":\n")
+		for _, c := range sec.list {
+			b.WriteString("  " + c.Name + c.Sig)
+			if c.Doc != "" {
+				b.WriteString("  — " + c.Doc)
+			}
+			b.WriteString("\n")
+		}
+	}
 	return &Output{Value: v, Text: b.String()}, nil
 }
+
+func methodSig(sig abi.Signature, names []string) string {
+	params := make([]string, len(sig.Params))
+	for i, p := range sig.Params {
+		params[i] = p.String()
+		if i < len(names) && names[i] != "" {
+			params[i] = names[i] + " " + params[i]
+		}
+	}
+	out := "(" + strings.Join(params, ", ") + ")"
+	if sig.Result.Kind != abi.Void {
+		out += " " + sig.Result.String()
+	}
+	return out
+}

app/agent/session.go

@@ -28,6 +28,7 @@ import (
 	"aego/scene/sceneio"
 	"aego/schema"
 	"aego/script/bind"
+	"aego/script/bind/manifest"
 	"aego/script/reload"
 	"aego/script/runtime"
 	"aego/script/workspace"
@@ -48,6 +49,7 @@ type RunRequest struct {
 type RunReport struct {
 	Frames   int               `json:"frames"`
 	Hash     string            `json:"hash"`
+	Counters map[string]uint64 `json:"counters,omitempty"`
 	Log      []string          `json:"log,omitempty"`
 	Error    string            `json:"error,omitempty"`
 }
@@ -79,6 +81,25 @@ type Kit struct {
 	ws      *workspace.Workspace
 	binds   *bind.Registry
 	opt     Options
+	man     *manifest.Manifest
+}
+
+// methods lists the script methods the bindings give a component type, built once per kit.
+func (k *Kit) methods(comp string) []manifest.CompMethod {
+	if k.man == nil {
+		m, err := manifest.FromRegistry(k.binds, k.Types.Schema())
+		if err != nil {
+			return nil
+		}
+		k.man = m
+	}
+	var out []manifest.CompMethod
+	for _, cm := range k.man.CompMethods {
+		if cm.Comp == comp {
+			out = append(out, cm)
+		}
+	}
+	return out
 }
 
 func NewKit(p *project.Project, opt Options) (*Kit, error) {

app/assembly/builtin/builtin.go

@@ -10,6 +10,7 @@ import (
 	"aego/modules/dataasset"
 	"aego/modules/debug"
 	"aego/modules/display"
+	"aego/modules/gameplay"
 	inputmod "aego/modules/input"
 	"aego/modules/physics"
 	"aego/modules/render2d"
@@ -76,6 +77,10 @@ func cameraEntry() assembly.Entry {
 	return assembly.Entry{ID: camera.ID, Requires: []string{scripting.ID}, New: func(assembly.Options) module.Module { return camera.New() }}
 }
 
+func gameplayEntry() assembly.Entry {
+	return assembly.Entry{ID: gameplay.ID, Requires: []string{physics.ID, scripting.ID}, New: func(assembly.Options) module.Module { return gameplay.New() }}
+}
+
 func dataEntry() assembly.Entry {
 	return assembly.Entry{ID: dataasset.ID, New: func(assembly.Options) module.Module { return dataasset.New() }}
 }
@@ -90,5 +95,5 @@ func savegameEntry() assembly.Entry {
 
 func Default() assembly.Catalog {
 	return assembly.Catalog{core(), dataEntry(), inputEntry(), render2dEntry(), render3dEntry(), scriptEntry(), physicsEntry(), debugEntry(),
-		displayEntry(), audioEntry(), accessibilityEntry(), settingsEntry(), tweenEntry(), cameraEntry(), spawnEntry(), savegameEntry()}
+		displayEntry(), audioEntry(), accessibilityEntry(), settingsEntry(), tweenEntry(), cameraEntry(), gameplayEntry(), spawnEntry(), savegameEntry()}
 }

app/assembly/editors/editors.go

@@ -8,6 +8,8 @@ import (
 	cameraeditor "aego/modules/camera/editor"
 	"aego/modules/debug"
 	debugeditor "aego/modules/debug/editor"
+	"aego/modules/gameplay"
+	gameplayeditor "aego/modules/gameplay/editor"
 	inputmod "aego/modules/input"
 	inputeditor "aego/modules/input/editor"
 	"aego/modules/physics"
@@ -25,6 +27,7 @@ func With(c assembly.Catalog) assembly.Catalog {
 		With(render3d.ID, render3deditor.Hook).
 		With(physics.ID, physicseditor.Hook).
 		With(camera.ID, cameraeditor.Hook).
+		With(gameplay.ID, gameplayeditor.Hook).
 		With(audio.ID, audioeditor.Hook).
 		With(debug.ID, debugeditor.Hook)
 }

app/assembly/playground/playground.go

@@ -7,6 +7,7 @@ import (
 	"aego/modules/audio"
 	"aego/modules/camera"
 	"aego/modules/debug"
+	"aego/modules/gameplay"
 	inputmod "aego/modules/input"
 	"aego/modules/physics"
 	"aego/modules/render2d"
@@ -31,6 +32,7 @@ func Catalog() assembly.Catalog {
 		{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: gameplay.ID, Requires: []string{physics.ID, scripting.ID}, New: func(assembly.Options) module.Module { return gameplay.New() }},
 		{ID: render3d.ID, New: func(assembly.Options) module.Module { return render3d.New() }},
 		{ID: spawn.ID, New: func(assembly.Options) module.Module { return spawn.New() }},
 		{ID: savegame.ID, Requires: []string{scripting.ID, spawn.ID}, New: func(assembly.Options) module.Module { return savegame.New() }},

app/build.go

@@ -41,6 +41,7 @@ type Config struct {
 	Editor             bool
 	FailOnScriptErrors bool
 	Catalog            assembly.Catalog
+	Platform           platform.Platform
 	Profile            string
 	NoProfile          bool
 }
@@ -98,6 +99,9 @@ func (h *Host) build(cfg Config, mods []module.Module) error {
 		ecfg.LoopScope = cfg.LoopScope
 	}
 	builder := engine.NewBuilder(ecfg).WithLogger(lg).Use(rmod)
+	if cfg.Platform != nil {
+		builder.WithPlatform(cfg.Platform)
+	}
 	if h.Types, err = assembly.NewTypes(); err != nil {
 		return err
 	}
@@ -187,6 +191,7 @@ func (h *Host) build(cfg Config, mods []module.Module) error {
 	}
 	h.Settings.SetNames(h.Sections.Names)
 	h.Engine.SetService(settings.ServiceID, h.Settings)
+	h.Engine.OnClose(h.Modules.Shutdown)
 	if err = h.Modules.Init(&module.InitContext{Engine: h.Engine, Assets: h.Loader, Log: lg, Editor: cfg.Editor, Sections: h.Sections, Problems: h.Problems, Settings: h.Settings}); err != nil {
 		return err
 	}
@@ -227,9 +232,6 @@ func (h *Host) Close() {
 		return
 	}
 	h.closed = true
-	if h.Modules != nil {
-		h.Modules.Shutdown()
-	}
 	if h.Engine != nil {
 		h.Engine.Close()
 	}

app/docstool/examples.go

@@ -0,0 +1,70 @@
+package docstool
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"aego/app/playground"
+	"aego/engine/docs"
+	"aego/engine/module"
+)
+
+// CheckExamples loads the example scene of every module code, validates it and runs it headless; the code must be among the problems it reports (D146).
+func CheckExamples(reg *docs.Registry, w io.Writer) int {
+	pg, err := playground.New()
+	if err != nil {
+		fmt.Fprintln(w, "examples: 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()
+		}
+	}()
+	bad := 0
+	for _, e := range reg.All() {
+		if e.Kind != docs.Code || e.Diag == nil || e.Diag.Example == "" {
+			continue
+		}
+		found, why := false, ""
+		code := ""
+		if e.Diag.ExampleScript != "" {
+			c, err := pg.TryCode(e.Diag.ExampleScript)
+			if err != nil {
+				fmt.Fprintf(w, "%s: error: example script does not compile: %v\n", e.ID, err)
+				bad++
+				continue
+			}
+			code = c
+		}
+		if res := pg.PlayScene("example-"+e.ID, []byte(e.Diag.Example), code, nil); !res.Started {
+			why = "does not load: " + res.Error
+		} else {
+			for _, d := range module.ValidateScene(pg.Game().Scene(), nil) {
+				found = found || d.Code == e.ID
+			}
+			if err := pg.Game().Step(tryFrames); err != nil {
+				why = "stops the engine: " + err.Error()
+			}
+		}
+		poll := pg.Poll()
+		for _, f := range poll.Faults {
+			found = found || f.Code == e.ID
+		}
+		for _, l := range poll.Log {
+			found = found || strings.Contains(l.Text, e.ID)
+		}
+		switch {
+		case why != "":
+			fmt.Fprintf(w, "%s: error: example %s %s\n", e.ID, e.Diag.ExampleFile, why)
+			bad++
+		case !found:
+			fmt.Fprintf(w, "%s: error: example of %s does not produce %s\n", e.ID, e.ID, e.ID)
+			bad++
+		}
+	}
+	pg.Stop()
+	return bad
+}

app/docstool/site.go

@@ -76,6 +76,9 @@ func (e *Env) Check(strict bool) int {
 	if CheckTry(reg, e.Stdout) > 0 && code == 0 {
 		code = 1
 	}
+	if CheckExamples(reg, e.Stdout) > 0 && code == 0 {
+		code = 1
+	}
 	return code
 }
 

app/docsview/bridge.go

@@ -19,6 +19,7 @@ type request struct {
 	Component string            `json:"component"`
 	Field     string            `json:"field"`
 	Value     float64           `json:"value"`
+	Node      string            `json:"node"`
 }
 
 type Reply struct {
@@ -27,6 +28,7 @@ type Reply struct {
 	Error  string            `json:"error,omitempty"`
 	State  *docsession.State `json:"state,omitempty"`
 	Log    []Line            `json:"log,omitempty"`
+	Pose   []float64         `json:"pose,omitempty"`
 }
 
 func (a *App) Call(method string, payload []byte) Reply {
@@ -64,6 +66,17 @@ func (a *App) Call(method string, payload []byte) Reply {
 	case "state":
 		st := s.State()
 		return Reply{State: &st}
+	case "pose":
+		sc := s.Controller().Scene()
+		if sc == nil {
+			return Reply{Error: "the scene is not running"}
+		}
+		h := sc.Find(sc.Root(), req.Node)
+		if h.IsZero() || !sc.IsAlive(h) {
+			return Reply{Error: "no node " + strconv.Quote(req.Node)}
+		}
+		p := sc.WorldPosition(h)
+		return Reply{Pose: []float64{float64(p.X), float64(p.Y)}}
 	case "log":
 		out := Reply{Log: a.lines}
 		a.lines = nil

app/edit/physics_test.go

@@ -179,7 +179,7 @@ func TestProfilerSectionsFollowPlay(t *testing.T) {
 		s.Step()
 	}
 	drawPanel(s, prof)
-	expectSections(t, prof.Sections(), "Frame", "Memory", "Game", "Scripts", "Physics", "Audio")
+	expectSections(t, prof.Sections(), "Frame", "Memory", "Game", "Scripts", "Physics", "Audio", "Camera", "Gameplay")
 	if _, err := ctx.Docs.Open("scenes/other.aescene"); err != nil {
 		t.Fatal(err)
 	}

app/edit/shots.go

@@ -7,8 +7,10 @@ import (
 	"os"
 	"path/filepath"
 
+	"aego/core/ids"
 	"aego/editor/core/command"
 	"aego/editor/core/context"
+	"aego/editor/core/vectors"
 	"aego/editor/core/workspace"
 	"aego/editor/panels/gameview"
 	"aego/editor/shell"
@@ -56,7 +58,60 @@ func (s *Session) shots(dir string) error {
 			}
 			return selectNamed(ctx, "Player")
 		}},
+		{name: "hitbox-gizmo", frames: 60, setup: func(s *Session) error {
+			sc := ctx.Scene()
+			var span []ids.NodeID
+			for _, n := range []string{"EnemyLeft", "PatrolA1", "PatrolB1"} {
+				span = append(span, sc.ID(sc.Find(sc.Root(), n)))
+			}
+			ctx.Select(span...)
+			if err := ctx.Commands.Run(command.SceneFrame); err != nil {
+				return err
+			}
+			for i := 0; i < 30; i++ {
+				s.Step()
+			}
+			return selectNamed(ctx, "EnemyLeft")
+		}},
+		{name: "camera-follow", frames: 60, setup: func(s *Session) error {
+			sc := ctx.Scene()
+			ctx.Select(sc.ID(sc.Find(sc.Root(), "Camera")), sc.ID(sc.Find(sc.Root(), "Player")))
+			if err := ctx.Commands.Run(command.SceneFrame); err != nil {
+				return err
+			}
+			for i := 0; i < 30; i++ {
+				s.Step()
+			}
+			return selectNamed(ctx, "Camera")
+		}},
+		{name: "camera-zone", frames: 60, setup: func(s *Session) error {
+			sc := ctx.Scene()
+			ctx.Select(sc.ID(sc.Find(sc.Root(), "ArenaZone")), sc.ID(sc.Find(sc.Root(), "PatrolA2")), sc.ID(sc.Find(sc.Root(), "PatrolB2")), sc.ID(sc.Find(sc.Root(), "GroundRight")))
+			if err := ctx.Commands.Run(command.SceneFrame); err != nil {
+				return err
+			}
+			for i := 0; i < 30; i++ {
+				s.Step()
+			}
+			return selectNamed(ctx, "ArenaZone")
+		}},
+		{name: "clip-inspector", frames: 60, setup: func(s *Session) error {
+			id, ok := s.Pipeline.Lookup("assets/audio/music.ogg")
+			if !ok {
+				return fmt.Errorf("no assets/audio/music.ogg")
+			}
+			s.App.Data().Inspect(id)
+			return nil
+		}},
+		{name: "add-required", frames: 30, setup: func(s *Session) error {
+			if err := selectNamed(ctx, "PatrolA1"); err != nil {
+				return err
+			}
+			s.App.Inspector().OpenAdd("follow")
+			return nil
+		}},
 		{name: "tags", frames: 60, setup: func(s *Session) error {
+			ctx.UI.CloseAllPopups()
 			return selectNamed(ctx, "Player")
 		}},
 		{name: "prefab", frames: 60, setup: func(s *Session) error {
@@ -83,12 +138,23 @@ func (s *Session) shots(dir string) error {
 			scene()
 			return ctx.Commands.Run(command.PlayStart)
 		}},
+		{name: "motion-play", frames: 30, setup: func(s *Session) error {
+			s.App.Workspace().Show(workspace.Inspector)
+			s.App.Inspector().ScrollTo("gameplay.Motion2D")
+			return selectNamed(ctx, "Player")
+		}},
+		{name: "mixer", frames: 120, setup: func(s *Session) error {
+			s.App.Workspace().Switch(workspace.Audio)
+			s.App.Workspace().Show(workspace.Mixer)
+			return nil
+		}},
 		{name: "physics-debug", frames: 30, setup: func(s *Session) error {
+			s.App.Workspace().Switch(workspace.Design)
 			ctx.Overlay.Set("physics.debug.contacts", true)
 			return ctx.Commands.Run(gameview.CommandOverlays)
 		}},
 		{name: "demo", frames: 60, inset: 2, bottom: 28, setup: func(s *Session) error {
-			for _, f := range []string{"physics.debug", "physics.debug.shapes", "physics.debug.contacts", "physics.debug.joints"} {
+			for _, f := range []string{gameview.CommandOverlays, vectors.CommandToggle} {
 				ctx.Overlay.Set(f, false)
 			}
 			return ctx.Commands.Run(shell.CommandFullscreenPlay)

app/export/web.go

@@ -3,7 +3,9 @@ package export
 import (
 	"bytes"
 	"compress/gzip"
+	"crypto/sha256"
 	"embed"
+	"encoding/hex"
 	"encoding/json"
 	"html/template"
 	"io/fs"
@@ -141,6 +143,21 @@ func (j *job) webTitle() string {
 	return AppName(j.p)
 }
 
+// webBuild keys the page's ?v= URLs on the data, the runtime and both scripts, so a new engine gets new URLs under immutable caching.
+func (j *job) webBuild(scripts ...[]byte) (string, error) {
+	wasm, err := os.ReadFile(j.l.binary())
+	if err != nil {
+		return "", errs.Wrap(err, errs.VFSIO, "cannot read the web runtime")
+	}
+	h := sha256.New()
+	h.Write([]byte(j.rep.Hash))
+	h.Write(wasm)
+	for _, s := range scripts {
+		h.Write(s)
+	}
+	return hex.EncodeToString(h.Sum(nil))[:buildKeyLen], nil
+}
+
 func (j *job) packWeb() error {
 	src, err := wasmExecPath(j.goroot)
 	if err != nil {
@@ -176,9 +193,9 @@ func (j *job) packWeb() error {
 	if err := writeFile(filepath.Join(j.l.data, WebFiles), list, WebFiles); err != nil {
 		return err
 	}
-	build := j.rep.Hash
+	build, err := j.webBuild(exec, loader)
-	if len(build) > buildKeyLen {
+	if err != nil {
-		build = build[:buildKeyLen]
+		return err
 	}
 	var page bytes.Buffer
 	if err := webIndexTmpl.Execute(&page, webPage{Title: j.webTitle(), Build: build, Icon: j.icon != nil}); err != nil {

app/export/web/index.html

@@ -18,12 +18,14 @@ canvas { display: block; width: 100%; height: 100%; outline: none; touch-action:
 #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 { position: fixed; top: 10px; right: 10px; width: 36px; height: 36px; border: 0; border-radius: 6px; background: rgba(0, 0, 0, 0.45); color: #fff; padding: 0; cursor: pointer; opacity: 0.5; }
 #fullscreen:hover { opacity: 1; }
-#mute { position: fixed; top: 10px; right: 52px; width: 36px; height: 36px; border: 0; border-radius: 6px; background: rgba(0, 0, 0, 0.45); color: #fff; font-size: 16px; cursor: pointer; opacity: 0.5; }
+#mute { position: fixed; top: 10px; right: 52px; width: 36px; height: 36px; border: 0; border-radius: 6px; background: rgba(0, 0, 0, 0.45); color: #fff; padding: 0; cursor: pointer; opacity: 0.5; }
 #mute:hover { opacity: 1; }
+#fullscreen svg, #mute svg { display: block; width: 18px; height: 18px; margin: auto; }
+#mute .off, #mute.muted .on { display: none; }
+#mute.muted .off { display: inline; }
 </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>
@@ -33,8 +35,8 @@ canvas { display: block; width: 100%; height: 100%; outline: none; touch-action:
   <div id="status">Loading…</div>
   <pre id="error" hidden></pre>
 </div>
-<button id="fullscreen" type="button" title="Fullscreen" aria-label="Fullscreen" hidden>⛶</button>
+<button id="fullscreen" type="button" title="Fullscreen" aria-label="Fullscreen" hidden><svg viewBox="0 0 16 16" aria-hidden="true"><path fill="currentColor" d="M9.92 13.44L10.25 13.38L13.38 13.38L13.38 10.25L13.44 9.92L13.76 9.52L14.08 9.39L14.58 9.44L14.98 9.76L15.12 10.25L15.12 14.25L15.06 14.58L14.74 14.98L14.25 15.12L10.25 15.12L9.92 15.06L9.52 14.74L9.38 14.25L9.52 13.76ZM13.44 6.08L13.38 5.75L13.38 2.62L10.25 2.62L9.92 2.56L9.52 2.24L9.39 1.92L9.44 1.42L9.76 1.02L10.25 0.88L14.25 0.88L14.58 0.94L14.98 1.26L15.12 1.75L15.12 5.75L15.06 6.08L14.74 6.48L14.25 6.62L13.76 6.48ZM2.56 9.92L2.62 10.25L2.62 13.38L5.75 13.38L6.08 13.44L6.48 13.76L6.62 14.25L6.56 14.58L6.24 14.98L5.75 15.12L1.75 15.12L1.42 15.06L1.02 14.74L0.88 14.25L0.88 10.25L0.94 9.92L1.26 9.52L1.75 9.38L2.24 9.52ZM6.08 2.56L5.75 2.62L2.62 2.62L2.62 5.75L2.56 6.08L2.24 6.48L1.75 6.62L1.42 6.56L1.02 6.24L0.88 5.75L0.88 1.75L0.94 1.42L1.26 1.02L1.75 0.88L5.75 0.88L6.08 0.94L6.48 1.26L6.62 1.75L6.48 2.24Z"/></svg></button>
-<button id="mute" type="button" title="Mute" aria-label="Mute" hidden>🔊</button>
+<button id="mute" type="button" title="Mute" aria-label="Mute" hidden><svg viewBox="0 0 16 16" aria-hidden="true"><path fill="currentColor" d="M1.81 6.04L4 6L6.74 3.47L7.11 3.41L7.36 3.55L7.5 3.9L7.5 12.1L7.36 12.45L7.11 12.59L6.74 12.53L4 10L2 10L1.65 9.85L1.5 9.5L1.5 6.5L1.58 6.22Z"/><path class="on" fill="currentColor" d="M12.53 5.89L11.97 4.96L11.01 3.9L10.95 3.62L10.99 3.33L11.15 3.08L11.39 2.91L11.82 2.86L12.21 3.05L12.72 3.54L13.53 4.59L13.91 5.29L14.17 5.95L14.35 6.63L14.5 7.96L14.46 8.75L14.34 9.45L14.14 10.13L13.58 11.34L13.18 11.92L12.67 12.52L12.09 13.04L11.67 13.15L11.39 13.09L11.15 12.92L10.99 12.67L10.95 12.38L11.09 11.97L11.61 11.46L12.27 10.59L12.73 9.61L12.88 9.08L12.97 8.54L12.97 7.46L12.73 6.39ZM10.05 7.09L9.82 6.68L9.38 6.19L9.26 5.77L9.31 5.48L9.48 5.24L9.72 5.08L10.01 5.02L10.29 5.08L10.54 5.24L11.01 5.76L11.27 6.16L11.66 7.18L11.75 8.04L11.58 9.12L11.23 9.91L10.54 10.76L10.29 10.92L10.01 10.98L9.72 10.92L9.48 10.76L9.31 10.52L9.26 10.23L9.38 9.81L9.95 9.12L10.2 8.47L10.24 7.76Z"/><path class="off" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" d="M10.25 5.75l4.5 4.5M14.75 5.75l-4.5 4.5"/></svg></button>
 <script src="wasm_exec.js?v={{.Build}}"></script>
 <script src="loader.js?v={{.Build}}"></script>
 </body>

app/export/web/loader.js

@@ -2,6 +2,7 @@
 
 (function () {
     const build = document.documentElement.dataset.build || "";
+    if (document.documentElement.dataset.sound === "off") globalThis.aegoSoundDefault = false;
     const canvas = document.getElementById("game");
     const loader = document.getElementById("loader");
     const bar = document.getElementById("bar");
@@ -12,7 +13,7 @@
 
     function syncMute() {
         const on = globalThis.aegoAudioMute();
-        mute.textContent = on ? "🔇" : "🔊";
+        mute.classList.toggle("muted", on);
         mute.title = on ? "Unmute" : "Mute";
         mute.setAttribute("aria-label", mute.title);
     }
@@ -70,9 +71,22 @@
         status.textContent = `${mb(got)} of ${mb(total)}`;
     }
 
-    async function read(url) {
+    // A request that delivers nothing for STALL ms is aborted and made again past the HTTP cache; a stuck cache entry must not leave the page on "Loading…".
-        const resp = await fetch(url);
+    const STALL = 8000;
+    const TRIES = 3;
+
+    async function readOnce(url, cache) {
+        const ctl = new AbortController();
+        let timer = setTimeout(() => ctl.abort(), STALL);
+        const kick = () => {
+            clearTimeout(timer);
+            timer = setTimeout(() => ctl.abort(), STALL);
+        };
+        let counted = 0;
+        try {
+            const resp = await fetch(url, { signal: ctl.signal, cache });
             if (!resp.ok) throw new Error(`${url}: HTTP ${resp.status}`);
+            kick();
             if (!resp.body) {
                 const all = new Uint8Array(await resp.arrayBuffer());
                 progress(all.byteLength);
@@ -84,8 +98,10 @@
             for (;;) {
                 const { done, value } = await reader.read();
                 if (done) break;
+                kick();
                 parts.push(value);
                 size += value.byteLength;
+                counted += value.byteLength;
                 progress(value.byteLength);
             }
             const out = new Uint8Array(size);
@@ -95,6 +111,26 @@
                 at += p.byteLength;
             }
             return out;
+        } catch (e) {
+            got -= counted;
+            throw e;
+        } finally {
+            clearTimeout(timer);
+        }
+    }
+
+    async function read(url) {
+        for (let i = 0; ; i++) {
+            try {
+                return await readOnce(url, i === 0 ? "default" : "reload");
+            } catch (e) {
+                if (!(e && e.name === "AbortError") || i + 1 >= TRIES) throw e;
+            }
+        }
+    }
+
+    async function readJSON(url) {
+        return JSON.parse(new TextDecoder().decode(await read(url)));
     }
 
     async function each(items, fn) {
@@ -106,9 +142,8 @@
     }
 
     async function start() {
-        const resp = await fetch(`data/files.json?v=${build}`);
+        const list = await readJSON(`data/files.json?v=${build}`);
-        if (!resp.ok) throw new Error(`data/files.json: HTTP ${resp.status}`);
+        got = 0;
-        const list = await resp.json();
         total = list.wasm + list.manifest.size + list.files.reduce((s, f) => s + f.size, 0);
         const wasm = read(`game.wasm?v=${build}`);
         const manifest = read(`data/${list.manifest.path}?v=${build}`);

app/export/web_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"testing"
 
@@ -60,9 +61,16 @@ func TestPackWeb(t *testing.T) {
 	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"`) {
+	key := regexp.MustCompile(`data-build="([0-9a-f]{12})"`).FindStringSubmatch(string(page))
+	if key == nil {
 		t.Fatal("the build key is missing")
 	}
+	if err := os.WriteFile(j.l.binary(), append(wasm, '!'), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if again, err := j.webBuild(); err != nil || again == key[1] {
+		t.Fatalf("a new runtime kept the build key %s (%v)", again, err)
+	}
 	raw, err := os.ReadFile(filepath.Join(j.l.data, WebFiles))
 	if err != nil {
 		t.Fatal(err)

app/playground/game.go

@@ -198,6 +198,11 @@ func (g *Game) Engine() *engine.Engine {
 	return g.e
 }
 
+// Scene is the scene Play loaded, nil before the first Play or after Stop.
+func (g *Game) Scene() *scene.Scene {
+	return g.scene
+}
+
 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, VM: playmods.SandboxVM()})

app/run/agent.go

@@ -9,6 +9,10 @@ import (
 	"aego/app/agent"
 	"aego/core/log"
 	"aego/core/rewind"
+	"aego/engine/recorder"
+	"aego/modules/audio"
+	"aego/modules/camera"
+	"aego/modules/gameplay"
 	"aego/project"
 	"aego/sdk"
 )
@@ -45,6 +49,7 @@ func AgentRunner(mods ...sdk.Module) agent.Runner {
 		}
 		sum, _, _ := WorldHash(a.Engine.MainWorld(), rewind.NewHasher())
 		rep.Hash = hex.EncodeToString(sum[:])
+		rep.Counters = counters(a)
 		a.Close()
 		rep.Log = logLines(buf.String())
 		return rep, nil
@@ -63,3 +68,27 @@ func logLines(s string) []string {
 	}
 	return out
 }
+
+// counters sums what the modules counted during the run, for scene run and run_headless.
+func counters(a *App) map[string]uint64 {
+	out := map[string]uint64{}
+	w := a.Engine.MainWorld()
+	if s := gameplay.Of(w); s != nil {
+		st := s.Stats()
+		out["gameplay.steps"], out["gameplay.casts"], out["gameplay.hits"] = st.Steps, st.Casts, st.Hits
+		out["gameplay.deaths"], out["gameplay.respawns"], out["gameplay.pickups"] = st.Deaths, st.Respawns, st.Pickups
+	}
+	if c := camera.Of(w); c != nil {
+		c.Outputs(func(camera.OutputInfo) { out["camera.outputs"]++ })
+	}
+	if m := audio.ModuleOf(a.Engine); m != nil {
+		c, st := m.Counts(), m.Stats()
+		out["audio.finished"], out["audio.stolen"], out["audio.rejected"], out["audio.starved"] = c.Finished, c.Stolen, c.Rejected, c.Starved
+		out["audio.underruns"] = st.Underruns
+	}
+	if r := w.Recorder; r != nil {
+		counts := r.Counts()
+		out["events.audio"], out["events.gameplay"] = counts[recorder.Audio], counts[recorder.Gameplay]
+	}
+	return out
+}

audio/mix/mix.go

@@ -80,6 +80,7 @@ type bus struct {
 	target  float32
 	delta   float32
 	ramp    int
+	live    bool
 	acc     []float32
 	peak    atomic.Uint32
 	rms     atomic.Uint32

audio/mix/mix_test.go

@@ -441,3 +441,87 @@ func TestVoicePositionAndKill(t *testing.T) {
 		t.Fatalf("kill: %+v, live %v", ev, m.Live(id))
 	}
 }
+
+func directPair(tb testing.TB, mem *Memory, loop bool) (*Mixer, voice, voice) {
+	m := newMixer(tb)
+	m.Play(PlayParams{Memory: mem, Gain: 0.7, Pan: 0.3, Loop: loop, FadeIn: 0.005})
+	buf := make([]float32, 64*2)
+	m.Mix(buf)
+	for i := range m.voices {
+		if m.voices[i].state == voicePlaying {
+			return m, m.voices[i], m.voices[i]
+		}
+	}
+	tb.Fatal("no playing voice")
+	return nil, voice{}, voice{}
+}
+
+// The direct path for pitch 1 gives the same samples, position, gain and end as Hermite, through fades, loops and the stop ramp.
+func TestDirectPathMatchesHermite(t *testing.T) {
+	for _, ch := range []int{1, 2} {
+		for _, loop := range []bool{false, true} {
+			mem := sine(440, rate/20, ch, 0.5)
+			if loop {
+				mem.LoopStart, mem.LoopEnd = 100, mem.Frames()-50
+			}
+			m, a, b := directPair(t, mem, loop)
+			if b.step != 1 {
+				t.Fatalf("step %v, the direct path needs 1", b.step)
+			}
+			const n = 256
+			accA, accB := make([]float32, n*2), make([]float32, n*2)
+			for block := 0; block < 40; block++ {
+				if block == 20 {
+					a.rampTo(0, 300)
+					b.rampTo(0, 300)
+					a.stopping, b.stopping = true, true
+				}
+				clear(accA)
+				clear(accB)
+				da := m.renderMemory(&a, accA, n)
+				db := m.renderMemoryDirect(&b, accB, n)
+				if da != db || a.pos != b.pos || a.gain != b.gain {
+					t.Fatalf("ch=%d loop=%v block %d: done %v/%v pos %v/%v gain %v/%v", ch, loop, block, da, db, a.pos, b.pos, a.gain, b.gain)
+				}
+				for i := range accA {
+					if accA[i] != accB[i] {
+						t.Fatalf("ch=%d loop=%v block %d sample %d: %v != %v", ch, loop, block, i, accA[i], accB[i])
+					}
+				}
+				if da {
+					break
+				}
+			}
+		}
+	}
+}
+
+func loadedPitch1(tb testing.TB) (*Mixer, []float32) {
+	m := newMixer(tb)
+	mem := sine(440, rate/10, 1, 0.5)
+	for i := 0; i < 64; i++ {
+		m.Play(PlayParams{Memory: mem, Gain: 0.1, Pan: float32(i%3 - 1), Pitch: 1, Loop: true})
+	}
+	buf := make([]float32, 512*2)
+	m.Mix(buf)
+	if m.Active() != 64 {
+		tb.Fatalf("%d active voices", m.Active())
+	}
+	return m, buf
+}
+
+func TestMixPitch1Allocs(t *testing.T) {
+	m, buf := loadedPitch1(t)
+	if n := testing.AllocsPerRun(200, func() { m.Mix(buf) }); n != 0 {
+		t.Fatalf("Mix allocates %v times per call", n)
+	}
+}
+
+func BenchmarkMix64Pitch1(b *testing.B) {
+	m, buf := loadedPitch1(b)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for b.Loop() {
+		m.Mix(buf)
+	}
+}

audio/pump/pump.go

@@ -141,7 +141,7 @@ func (p *Pump) Start() {
 
 func (p *Pump) run(stop, done chan struct{}) {
 	defer close(done)
-	period := time.Duration(float64(p.cfg.Block) / float64(p.cfg.SampleRate) / 2 * float64(time.Second))
+	period := time.Duration(float64(p.cfg.Block*p.cfg.Target) / float64(p.cfg.SampleRate) / 6 * float64(time.Second))
 	t := time.NewTicker(max(period, time.Millisecond))
 	defer t.Stop()
 	for {

cmd/aego/agent_test.go

@@ -102,3 +102,33 @@ func TestAgentSceneTreeJSON(t *testing.T) {
 		t.Fatalf("output %v:\n%s", err, out)
 	}
 }
+
+// The top-down example needs no native module, so the CLI can run it from a copy.
+func TestAgentSceneRunCounters(t *testing.T) {
+	dir := copyProject(t, "topdown")
+	r, w, err := os.Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	stdout := os.Stdout
+	os.Stdout = w
+	code := dispatch([]string{"scene", "run", "scenes/main.aescene", "--frames", "300", "--json", "--project", dir})
+	os.Stdout = stdout
+	w.Close()
+	out, _ := io.ReadAll(r)
+	if code != 0 {
+		t.Fatalf("exit %d:\n%s", code, out)
+	}
+	var v struct {
+		Value struct {
+			Counters map[string]uint64 `json:"counters"`
+		} `json:"value"`
+	}
+	if err := json.Unmarshal(out, &v); err != nil {
+		t.Fatalf("output %v:\n%s", err, out)
+	}
+	c := v.Value.Counters
+	if c["gameplay.steps"] == 0 || c["camera.outputs"] != 1 {
+		t.Fatalf("counters %v, want gameplay steps and one camera output", c)
+	}
+}

contracts/physics2d/physics2d.go

@@ -10,7 +10,9 @@ const ServiceID = "physics2d.queries"
 type QueryFilter struct {
 	LayerMask       uint32
 	IncludeTriggers bool
+	SkipDynamic     bool
 	ExcludeNode     scene.NodeHandle
+	ExcludeBody     scene.NodeHandle
 }
 
 type RayHit struct {
@@ -21,6 +23,16 @@ type RayHit struct {
 	ColliderNode scene.NodeHandle
 }
 
+type CastHit struct {
+	Point        mathx.Vec2
+	Normal       mathx.Vec2
+	Fraction     float32
+	Depth        float32
+	Node         scene.NodeHandle
+	ColliderNode scene.NodeHandle
+	Initial      bool
+}
+
 type Queries interface {
 	Raycast(origin, dir mathx.Vec2, maxDist float32, f QueryFilter) (RayHit, bool)
 	RaycastAll(origin, dir mathx.Vec2, maxDist float32, f QueryFilter, out []RayHit) int
@@ -28,4 +40,15 @@ type Queries interface {
 	OverlapCircle(c mathx.Vec2, r float32, f QueryFilter, out []scene.NodeHandle) int
 	OverlapBox(c, half mathx.Vec2, angle float32, f QueryFilter, out []scene.NodeHandle) int
 	BodyAt(p mathx.Vec2, f QueryFilter) (scene.NodeHandle, bool)
+	CastCircle(c mathx.Vec2, r float32, delta mathx.Vec2, f QueryFilter) (CastHit, bool)
+	CastBox(c, half mathx.Vec2, angle float32, delta mathx.Vec2, f QueryFilter) (CastHit, bool)
+	CastCapsule(a, b mathx.Vec2, r float32, delta mathx.Vec2, f QueryFilter) (CastHit, bool)
+	CastBody(body scene.NodeHandle, offset, delta mathx.Vec2, f QueryFilter) (CastHit, bool)
+	Penetration(body scene.NodeHandle, f QueryFilter, out []CastHit) int
+	BodyPose(body scene.NodeHandle) (mathx.Vec2, float32, bool)
+	BodyVelocity(body scene.NodeHandle) (mathx.Vec2, float32, bool)
+	MoveKinematic(body scene.NodeHandle, p mathx.Vec2, angle, dt float32) error
+	Teleport(body scene.NodeHandle, p mathx.Vec2, angle float32) error
+	ApplyImpulse(body scene.NodeHandle, j mathx.Vec2) error
+	Gravity() mathx.Vec2
 }

contracts/scriptcall/scriptcall.go

@@ -0,0 +1,22 @@
+package scriptcall
+
+import (
+	"aego/scene"
+	"aego/script/vm"
+)
+
+const ServiceID = "script.call"
+
+// Ref names a plain method of one script instance; a new program generation makes it stale.
+type Ref struct {
+	Node     scene.NodeHandle
+	Instance vm.InstanceID
+	Index    int32
+	Gen      uint64
+}
+
+type Caller interface {
+	Method(node scene.NodeHandle, name string, params int) (Ref, bool)
+	Call(ref *Ref, args []vm.Value) bool
+	Generation() uint64
+}

docs/contributing.md

@@ -0,0 +1,37 @@
+# Contributing
+
+## Build and run
+
+```sh
+bash tools/bootstrap-native.sh
+make cli
+.cache/bin/aego edit examples/platformer
+```
+
+`make res` regenerates icons, previews and ES shaders; `make golden-update` rewrites golden images after an intended UI change.
+
+## Check levels
+
+| Level | When | Command |
+|---|---|---|
+| 1 | after an edit | `make quick`: build and short tests of the packages your change touches and everything that imports them |
+| 2 | before a commit | `make affected`, plus `make check-camera`, `check-audio`, `check-gameplay`, `check-mutate`, `check-editor`, `check-web` or `check-docs` for the areas you touched, and `make golden` after UI changes |
+| 3 | before a push or a tag | `make ci` |
+
+`tools/affected.sh [base]` lists the affected packages (default base `origin/master`, uncommitted files included). The CI server always runs the full `make ci`.
+
+## Rules for engine code
+
+- **Modules talk through contracts.** A module never imports another module: shared types and services live in `contracts/` (`physics2d`, `camera2d`, `scriptcall`, `signals`, `debugdraw`, …). `tools/depcheck` enforces the import rules; an exception goes into `tools/depcheck/exceptions.txt` with its file and reason.
+- **Kernel stays neutral.** Kernel, editor and `sdk` never name a built-in module, its components or its diagnostic codes in string literals; names come from the module catalog.
+- **Every component has a Try it scene.** It lives at `res/docs/try/<Component>.aescene` (with `<Component>.aes` and prefabs next to it when needed), shows the component's own effect and runs without warnings; `aego docs check` fails without it.
+- **Internal state is not a component.** Controller state lives in unexported fields of the component it belongs to or in a world service. A component that exists only to carry state for a service is registered `Hidden`: it is not in Create, Add Component, Try it or the docs.
+- **Requirements add, they do not block.** Declare `Requires`; Add Component, `scene add-comp`, Paste and presets add the missing components in the same undo step.
+- **Every diagnostic code has a page with an example.** Component codes (`CAM`, `AUD`, `GMP`, `PHY`, …) also have an example scene that produces the code; `aego docs check` fails without one. Asset codes say `scope: asset`, codes that only an edit during Play produces say `scope: play`.
+- **Nodes are labelled, not pathed.** UI shows nodes with `props.NodeLabel` (icon and name, the path in the tooltip).
+- **Editor edits go through history.** Every edit is a history command, normally `commands.Mutation`, so Undo, the Play changes diff and agents see it.
+- **Hot paths do not allocate.** Systems, mixers and controllers allocate nothing per frame; add `testing.AllocsPerRun` checks and a benchmark next to new hot code.
+
+## Commits
+
+One commit per sub-stage, named `Stage <n><x>: <what>`; decisions go into `ARCHITECTURE.md` as `D<number>` in the same commit.

docs/extensions.md

@@ -97,6 +97,16 @@ sdk.Component[Wind](r, sdk.Name("weather.Wind")).
 
 `engine/problems` collects `sdk.Diagnostic{Owner, Code, Severity, Message, Subject, BlocksPlay}` from sources with a revision; the service rebuilds the list only when a revision changes. `sdk.Diagnostics(ctx)` in `Init` returns the service; a module adds runtime diagnostics as a `sdk.ProblemSource` from `AttachWorld` and removes it in `DetachWorld`. The Problems panel shows them with the owner as category; an error with `BlocksPlay` stops Play (D210).
 
+Every code a module reports is listed in `Info.Codes` and has a page `res/docs/diagnostics/<CODE>.md` with front matter `code`, `title`, `severity` (`error`, `warning` or `info`) and either `example: <CODE>.aescene`, a scene next to the page that produces the code (with `<CODE>.aes` next to it when a script has to act, as for PHY007), `scope: asset` for codes that come from importing or checking an asset, or `scope: play` for codes that only an edit during Play produces (PHY006). `aego docs check` fails on a declared code without a page, a page whose code is not declared, a component code without an example, and an example that does not produce its code after `module.ValidateScene` and 60 headless frames. The pages appear under Reference → Diagnostics next to the script codes (D146, D316).
+
+### Contracts between modules
+
+A module never imports another module. What two modules share lives in `contracts/<name>` as plain types, a service ID and an interface; the provider registers the service in its world, the consumer looks it up with `engine.ServiceOf` and works without it.
+
+- **Provisions.** A value handed over at load time, keyed by a kind. `camera2d.AccessibilityKind` (`"camera2d.accessibility"`) carries the IDs of the Screen Shake and Reduce Motion settings: the settings module provides them with `r.Provide(camera2d.AccessibilityKind, camera2d.Accessibility{...})`, the camera module reads `ctx.Provided(camera2d.AccessibilityKind)` in `Init` and scales shake by them every frame.
+- **`physics2d.Queries`** (`physics2d.ServiceID`). Ray, point, circle and box queries; shape casts `CastCircle`, `CastBox`, `CastCapsule` and `CastBody`, which sweeps every non-trigger collider of a body and returns the first hit with its fraction, normal and, when the shapes already overlap, `Initial` and `Depth`; `Penetration` lists the overlaps of a body for depenetration; `BodyPose`, `BodyVelocity`, `MoveKinematic` (moves a kinematic body so contacts see its velocity), `Teleport`, `ApplyImpulse` and `Gravity`. `QueryFilter` selects layers and triggers; `SkipDynamic` ignores dynamic bodies, and `ExcludeNode` and `ExcludeBody` skip the caller's own collider or body. The gameplay controller is written only against this interface.
+- **`scriptcall.Caller`** (`scriptcall.ServiceID`). `Method(node, name, params)` finds a plain method by name in the scripts on a node and returns a `Ref`; `Call(&ref, args)` runs it. A hot reload starts a new `Generation`, which makes every older `Ref` stale: look the method up again when `Ref.Gen` differs. The State Machine finds its hooks this way.
+
 ### Resources
 
 Module icons are named `<owner>.*` or `cat.<owner>`; a clash with the engine atlas or another module is a build error. Built-in modules list their icon sources through `IconDir()`. Docs registered with `Registry.Docs` carry the module as owner and are left out of runtime builds (D211).
@@ -169,4 +179,6 @@ A panel gets a fresh `Frame` every draw (`UI`, drag and drop, time, focus). Anyt
 
 A module can give any of its components a live example on the documentation site: put a scene in `res/docs/try/<Component>.aescene`, named after the last part of the component ID (`try/Body2D.aescene` for `physics.Body2D`). The page of that component gets a Try it block that runs the scene in the browser with the Inspector, selecting the first node that has the component; a guide page can show a scene with `try: try/name.aescene` and `try_select: module.Component` in its front matter.
 
-Try scenes run on the sandbox catalog (core, input, render2d, scripting, physics, debug) with builtin assets only and no scripts. `aego docs check` loads each one, runs it for 60 frames and fails on a load error, a warning or a fault, and on a scene of a module outside the sandbox. Keep the scene to what the component needs, put the documented node first, and add a camera.
+Try scenes run on the docs runtime catalog (core, input, render2d, render3d, scripting, physics, debug, tween, cameras, gameplay, spawn, savegame and audio) with builtin assets only. A script `<Component>.aes` and prefabs `<Component>.<name>.aeprefab` (with their `.meta`) next to the scene are compiled and mounted with it. `aego docs check` loads each one, runs it for 60 frames and fails on a load error, a warning or a fault, and on a scene of a module outside the catalog. Keep the scene to what the component needs, put the documented node first, and add a camera.
+
+Every visible component needs one. A component registered `Hidden`, which only carries state for a service, has none and is left out of Create, Add Component, Try it and the docs. The rules for engine code, including these, are in [contributing.md](contributing.md).

docs/icons.md

@@ -17,6 +17,7 @@ Sources are `<id>.svg` files in `engine/res/icons/src` and `modules/<id>/res/ico
 | `cat.audio` | engine | 16 | Documentation: Audio group and module | ok |
 | `cat.camera` | engine | 24 | New Project: template 2.5d | ok |
 | `cat.game` | engine | 16 | Inspector and Add Component: components of a project module without an icon of their own | ok |
+| `cat.gameplay` | engine | 16 | template menu Gameplay | ok |
 | `cat.node` | engine | 24 | New Project: template empty; Search: node results | ok |
 | `cat.physics` | engine | 16 | template menu Physics | ok |
 | `cat.rendering` | engine | 24 | New Project: template 2d; Search: mesh assets | ok |
@@ -60,8 +61,10 @@ Sources are `<id>.svg` files in `engine/res/icons/src` and `modules/<id>/res/ico
 | `edit.paste` | engine | 16 | Paste (nodes, assets, inspector field) | ok |
 | `edit.rename` | engine | 16 | Rename (nodes, assets, workspace) | ok |
 | `edit.select_all` | engine | 16 | Edit → Select All | ok |
+| `file.audio` | engine | 16 | Documentation: sound clips page | ok |
 | `file.autosave` | engine | 16 | File → Autosave Scripts | ok |
 | `file.data` | engine | 24 | Assets: data asset tiles | ok |
+| `file.download` | engine | 16 | Documentation: Install and run page | ok |
 | `file.folder` | engine | 24 | Assets: folders | ok |
 | `file.mesh` | engine | 24 | Assets: mesh tiles | ok |
 | `file.open` | engine | 16 | Assets menu: Open | ok |
@@ -75,6 +78,16 @@ Sources are `<id>.svg` files in `engine/res/icons/src` and `modules/<id>/res/ico
 | `file.table` | engine | 24 | Assets: table tiles | ok |
 | `file.texture` | engine | 24 | Assets: texture tiles | ok |
 | `file.unknown` | engine | 24 | Assets: tiles of other kinds | ok |
+| `gameplay.checkpoint` | engine | 16 | component gameplay.Checkpoint2D; template gameplay.checkpoint | ok |
+| `gameplay.fsm` | engine | 16 | component gameplay.StateMachine | ok |
+| `gameplay.health` | engine | 16 | component gameplay.Health | ok |
+| `gameplay.hitbox` | engine | 16 | component gameplay.Hitbox2D; template gameplay.enemy | ok |
+| `gameplay.hurtbox` | engine | 16 | component gameplay.Hurtbox2D | ok |
+| `gameplay.killzone` | engine | 16 | component gameplay.KillZone2D; template gameplay.killzone | ok |
+| `gameplay.lifetime` | engine | 16 | component gameplay.Lifetime | ok |
+| `gameplay.motion` | engine | 16 | component gameplay.Motion2D; template gameplay.platform; template gameplay.platformer; template gameplay.topdown | ok |
+| `gameplay.pickup` | engine | 16 | component gameplay.Pickup2D; template gameplay.pickup | ok |
+| `gameplay.respawn` | engine | 16 | component gameplay.Respawn | ok |
 | `help.about` | engine | 16 | Help → About Aego | ok |
 | `help.book` | engine | 16 | Documentation tab | ok |
 | `log.error` | engine | 16 | Console: errors | ok |
@@ -123,6 +136,7 @@ Sources are `<id>.svg` files in `engine/res/icons/src` and `modules/<id>/res/ico
 | `prefab.variant` | engine | 16 | Assets menu: Create Variant | ok |
 | `shape.cube` | engine | 16 | template render3d.cube | ok |
 | `shape.cylinder` | engine | 16 | template render3d.cylinder | ok |
+| `shape.dice` | engine | 16 | Documentation: random numbers module | ok |
 | `shape.plane` | engine | 16 | template render3d.plane | ok |
 | `shape.sphere` | engine | 16 | template render3d.sphere | ok |
 | `status.busy` | engine | 14 | Task Center: running task | ok |
@@ -140,6 +154,7 @@ Sources are `<id>.svg` files in `engine/res/icons/src` and `modules/<id>/res/ico
 | `ui.chevron_down` | engine | 16 | trees, combos and drop-downs | ok |
 | `ui.chevron_right` | engine | 16 | trees and submenus | ok |
 | `ui.close` | engine | 16 | tabs, chips and dialogs | ok |
+| `ui.curve` | engine | 16 | Documentation: curves module | ok |
 | `ui.lock` | engine | 16 | Inspector: locked | ok |
 | `ui.minus` | engine | 16 | list editors: remove | ok |
 | `ui.more` | engine | 16 | card menus | ok |