emulator: real gui — lift upstream v1.3.0 gui/ + wire Platform

The Phase 2 scaffolding boot screen is replaced with the actual
upstream v1.3.0 gui package running in browser. cmd/emulator now
calls gui.NewApp(plat, version) + drives a.Frame() in a goroutine.

Lifts:
  gui/                         (top-level UI + state machine)
  gui/assets                   (icons, fonts, 9-patch images)
  gui/layout                   (constraint-based UI layout)
  gui/op                       (drawing op primitives)
  gui/saver                    (screensaver + idle timeout)
  gui/text                     (text shaping)
  gui/widget                   (button/menu/keyboard widgets)
All 11 .go files lifted verbatim from seedhammer/seedhammer @ v1.3.0
(commit 2f071c1d...), import paths rewritten seedhammer.com → mineracks.

browserPlatform now implements gui.Platform (12 methods):
  Events(deadline)   — drains v1.Event chan, maps to gui.ButtonEvent
                       (gui.Button enum order matches platform/v1.Button,
                        so the conversion is a direct uint cast)
  Wakeup()           — no-op (no sleep state in browser)
  PlateSizes()       — backup.SquarePlate, backup.LargePlate
  Engraver()         — nullEngraver stub (browser can't punch metal)
  EngraverParams()   — copy of mjolnir.Params {StrokeWidth: 38,
                       Millimeter: 126}. Inlined because tarm/serial
                       (mjolnir's USB dep) doesn't compile to js/wasm.
  CameraFrame(size)  — emits FrameEvent{Error: stubbed} so QR-scan
                       screens fall through cleanly; real handoff
                       lands when SeedSigner sim wires up (Phase 2.5)
  Now()              — time.Now()
  DisplaySize()      — 240×240
  Dirty(r)           — records rect, resets chunk cursor
  NextChunk()        — one-shot: returns full sub-image once per
                       Dirty cycle, then flushes the whole frame
                       buffer to JS via emulatorPaint()
  ScanQR()           — returns nil decodes (stub)
  Debug()            — false

The Engraver interface is satisfied by nullEngraver — Engrave() returns
"engraver not connected" so the GUI's engrave flow fails cleanly
instead of looking like it's working.

WASM grows 2.7MB → 8.0MB (gui package + btcd + crypto deps + fonts
all linked in). Acceptable for the v1 emulator one-time cache.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

cmd/emulator/main.go

@@ -2,116 +2,250 @@
 
 // Command emulator is a browser-based SeedHammer v1 firmware runner.
 //
-// Phase 2 scaffolding stage. This binary boots a 240×240 canvas-backed
-// LCD mock and an 8-button input layer that maps keyboard events to the
-// v1's joystick + 3 keys. The real firmware GUI lift (upstream's gui/
-// package + its assets/layout/op/saver/text/widget subpackages) lands in
-// a follow-up commit; today this stage proves the build pipeline + the
-// platform/v1.Platform interface contract.
+// Loads the upstream v1.3.0 gui package and drives it through a
+// browser-side Platform implementation:
+//   - Display: a 240×240 canvas, painted from Go RGBA via JS callback
+//   - Input: keyboard + on-screen button events through gui.ButtonEvent
+//   - Engraver: a no-op stub (the browser doesn't drive real hardware)
+//   - Camera: stub that emits empty FrameEvents (real QR-scan handoff
+//     lands once the SeedSigner sim wiring lands in Phase 2.5)
 //
 // Build:
 //
 //	GOOS=js GOARCH=wasm go build -o ./web/emulator/emulator.wasm ./cmd/emulator
-//
-// The static shell (HTML/CSS/JS) lives under web/emulator/. JS exports
-// documented in web/emulator/app.js.
 package main
 
 import (
-	"fmt"
+	"errors"
 	"image"
 	"image/color"
 	"image/draw"
-	"strconv"
+	"sync"
 	"syscall/js"
+	"time"
 
-	"github.com/mineracks/seedhammer-v1-companion/platform/v1"
+	"github.com/mineracks/seedhammer-v1-companion/backup"
+	"github.com/mineracks/seedhammer-v1-companion/engrave"
+	"github.com/mineracks/seedhammer-v1-companion/gui"
+	v1 "github.com/mineracks/seedhammer-v1-companion/platform/v1"
 )
 
-const emulatorVersion = "v0.1-phase2-stub"
+const emulatorVersion = "v0.2-phase2-gui"
 
-// v1 hardware native LCD resolution.
 const (
 	lcdWidth  = 240
 	lcdHeight = 240
 )
 
-// browserPlatform implements v1.Platform against the JS host.
-//
-// Display() draws into an *image.RGBA buffer then ships it to JS via a
-// Uint8ClampedArray that the JS shell paints onto a <canvas>. Events()
-// returns a channel fed by exportPushEvent calls from JS.
+// browserPlatform implements gui.Platform against the JS host.
 type browserPlatform struct {
 	frame  *image.RGBA
 	events chan v1.Event
+
+	mu        sync.Mutex
+	pending   []gui.Event
+	dirtyRect image.Rectangle
+	chunkSent bool
 }
 
 func newBrowserPlatform() *browserPlatform {
 	return &browserPlatform{
 		frame:  image.NewRGBA(image.Rect(0, 0, lcdWidth, lcdHeight)),
-		events: make(chan v1.Event, 32),
+		events: make(chan v1.Event, 64),
 	}
 }
 
-func (p *browserPlatform) Events() <-chan v1.Event { return p.events }
+// ─── gui.Platform impl ────────────────────────────────────────────────────
 
-func (p *browserPlatform) Display(frame image.Image) {
-	draw.Draw(p.frame, p.frame.Bounds(), frame, frame.Bounds().Min, draw.Src)
-	// Convert RGBA buffer → JS Uint8ClampedArray and call back into JS.
+func (p *browserPlatform) Events(deadline time.Time) []gui.Event {
+	// Drain the v1.Event channel into gui.ButtonEvents. If no events
+	// pending, block (briefly) waiting for one or until deadline.
+	wait := time.Until(deadline)
+	if wait < 0 {
+		wait = 0
+	}
+	out := p.drainPending()
+	if len(out) > 0 {
+		return out
+	}
+	if wait == 0 {
+		return nil
+	}
+	timer := time.NewTimer(wait)
+	defer timer.Stop()
+	select {
+	case ev := <-p.events:
+		out = append(out, p.toGuiEvent(ev))
+	case <-timer.C:
+	}
+	// Drain any extras that piled up while we were waiting.
+	for {
+		select {
+		case ev := <-p.events:
+			out = append(out, p.toGuiEvent(ev))
+		default:
+			return out
+		}
+	}
+}
+
+func (p *browserPlatform) drainPending() []gui.Event {
+	p.mu.Lock()
+	out := p.pending
+	p.pending = nil
+	p.mu.Unlock()
+	return out
+}
+
+func (p *browserPlatform) toGuiEvent(ev v1.Event) gui.Event {
+	return gui.ButtonEvent{
+		Button:  gui.Button(ev.Button), // enum order matches by construction
+		Pressed: ev.Pressed,
+	}.Event()
+}
+
+// push is called from the JS bridge — feeds the buffered channel.
+func (p *browserPlatform) push(button v1.Button, pressed bool) {
+	select {
+	case p.events <- v1.Event{Button: button, Pressed: pressed}:
+	default:
+	}
+}
+
+func (p *browserPlatform) Wakeup() {
+	// no-op — JS-driven runtime; nothing to wake from.
+}
+
+func (p *browserPlatform) PlateSizes() []backup.PlateSize {
+	// Mirror what's defined in backup.PlateSize. v1.3.0 ships
+	// SquarePlate and LargePlate.
+	return []backup.PlateSize{backup.SquarePlate, backup.LargePlate}
+}
+
+func (p *browserPlatform) Engraver() (gui.Engraver, error) {
+	// The browser can't engrave anything. Return an Engraver that
+	// politely says "no" if the GUI ever tries to drive it.
+	return nullEngraver{}, nil
+}
+
+func (p *browserPlatform) EngraverParams() engrave.Params {
+	// Values copied from upstream driver/mjolnir.Params at v1.3.0.
+	// We can't import the mjolnir package here because it transitively
+	// pulls in tarm/serial, which doesn't compile to GOOS=js (uses
+	// OS-specific syscalls). The layout math doesn't need the serial
+	// driver — just these two constants.
+	return engrave.Params{
+		StrokeWidth: 38,
+		Millimeter:  126,
+	}
+}
+
+func (p *browserPlatform) CameraFrame(size image.Point) {
+	// Stub: no camera in the browser yet. Emit an error FrameEvent so
+	// the gui's QR-scan screen stays in its "no camera" state instead
+	// of waiting forever.
+	p.mu.Lock()
+	p.pending = append(p.pending, gui.FrameEvent{Error: errCameraStubbed}.Event())
+	p.mu.Unlock()
+}
+
+func (p *browserPlatform) Now() time.Time { return time.Now() }
+
+func (p *browserPlatform) DisplaySize() image.Point {
+	return image.Pt(lcdWidth, lcdHeight)
+}
+
+func (p *browserPlatform) Dirty(r image.Rectangle) error {
+	p.mu.Lock()
+	p.dirtyRect = r.Intersect(p.frame.Bounds())
+	p.chunkSent = false
+	p.mu.Unlock()
+	return nil
+}
+
+func (p *browserPlatform) NextChunk() (draw.RGBA64Image, bool) {
+	p.mu.Lock()
+	if p.chunkSent || p.dirtyRect.Empty() {
+		p.mu.Unlock()
+		// One-chunk model: we ship the whole frame to JS in a single
+		// JS callback when the gui completes a Dirty/NextChunk cycle.
+		p.flushFrame()
+		return nil, false
+	}
+	p.chunkSent = true
+	r := p.dirtyRect
+	p.mu.Unlock()
+	// gui writes into the returned RGBA64Image — sub-image of our frame
+	// for the dirty rect. Our buffer is RGBA which satisfies
+	// draw.RGBA64Image via the standard image package.
+	return p.frame.SubImage(r).(*image.RGBA), true
+}
+
+// flushFrame ships the current frame buffer to JS. Called after each
+// Dirty/NextChunk render cycle.
+func (p *browserPlatform) flushFrame() {
 	jsBuf := js.Global().Get("Uint8ClampedArray").New(len(p.frame.Pix))
 	js.CopyBytesToJS(jsBuf, p.frame.Pix)
 	js.Global().Call("emulatorPaint", jsBuf, lcdWidth, lcdHeight)
 }
 
-// Push an event from JS into the events channel.
-func (p *browserPlatform) push(button v1.Button, pressed bool) {
-	select {
-	case p.events <- v1.Event{Button: button, Pressed: pressed}:
-	default:
-		// Drop on full — shouldn't happen with the modest buffer the
-		// firmware needs, but better than blocking the JS thread.
-	}
+func (p *browserPlatform) ScanQR(qr *image.Gray) ([][]byte, error) {
+	// Stub: no decodes. Real implementation lands when SeedSigner sim
+	// handoff wires up — the mock camera reads a sibling pane's canvas.
+	return nil, nil
 }
 
+func (p *browserPlatform) Debug() bool { return false }
+
+var errCameraStubbed = errors.New("camera not implemented in browser stub")
+
+// ─── nullEngraver ─────────────────────────────────────────────────────────
+
+type nullEngraver struct{}
+
+func (nullEngraver) Engrave(_ backup.PlateSize, _ engrave.Plan, _ <-chan struct{}) error {
+	return errors.New("engraver not connected (browser emulator)")
+}
+func (nullEngraver) Close() {}
+
+// ─── JS bridge ────────────────────────────────────────────────────────────
+
 var plat *browserPlatform
 
 func main() {
 	plat = newBrowserPlatform()
 
+	// Initial paint so the canvas isn't blank during gui bring-up.
+	clearBlack(plat.frame)
+	plat.flushFrame()
+
 	js.Global().Set("emulatorVersion", js.FuncOf(exportVersion))
 	js.Global().Set("emulatorPushEvent", js.FuncOf(exportPushEvent))
-	js.Global().Set("emulatorBootScreen", js.FuncOf(exportBootScreen))
 	js.Global().Set("emulatorLCDSize", js.ValueOf(map[string]any{
-		"w": lcdWidth,
-		"h": lcdHeight,
+		"w": lcdWidth, "h": lcdHeight,
 	}))
 
-	// Show the placeholder boot screen so the canvas isn't blank on load.
-	drawBootScreen(plat.frame)
-	plat.Display(plat.frame)
+	app, err := gui.NewApp(plat, emulatorVersion)
+	if err != nil {
+		js.Global().Get("console").Call("error", "gui.NewApp failed: "+err.Error())
+		select {}
+	}
 
-	// Future: wire plat to gui.Loop or whatever the lifted GUI exposes.
-	// For now, just consume events so the channel doesn't fill up.
+	// Drive frames in a goroutine. Each Frame call processes events
+	// and may render a new frame via Dirty + NextChunk.
 	go func() {
-		for ev := range plat.events {
-			// Echo to console for debugging; the real GUI will replace this.
-			js.Global().Get("console").Call("log",
-				fmt.Sprintf("emu: %s %s",
-					buttonName(ev.Button),
-					boolStr(ev.Pressed, "press", "release"),
-				),
-			)
+		for {
+			app.Frame()
 		}
 	}()
 
-	select {} // keep the runtime alive
+	select {}
 }
 
 func exportVersion(this js.Value, args []js.Value) any {
 	return emulatorVersion
 }
 
-// exportPushEvent: emulatorPushEvent(buttonId:number, pressed:boolean)
 func exportPushEvent(this js.Value, args []js.Value) any {
 	if len(args) != 2 {
 		return nil
@@ -125,66 +259,6 @@ func exportPushEvent(this js.Value, args []js.Value) any {
 	return nil
 }
 
-// exportBootScreen redraws the boot placeholder, useful for re-testing
-// after manual mucking.
-func exportBootScreen(this js.Value, args []js.Value) any {
-	drawBootScreen(plat.frame)
-	plat.Display(plat.frame)
-	return nil
-}
-
-// drawBootScreen fills the frame with a minimal welcome image so users see
-// SOMETHING the moment the WASM finishes loading. Future: this is replaced
-// by gui.Loop()'s first frame.
-func drawBootScreen(dst *image.RGBA) {
-	// Background.
-	draw.Draw(dst, dst.Bounds(), &image.Uniform{color.RGBA{0x12, 0x12, 0x12, 0xff}}, image.Point{}, draw.Src)
-
-	// Frame border to make the LCD area unambiguous.
-	border := color.RGBA{0xff, 0x88, 0x00, 0xff} // accent orange
-	for x := 0; x < lcdWidth; x++ {
-		dst.SetRGBA(x, 0, border)
-		dst.SetRGBA(x, lcdHeight-1, border)
-	}
-	for y := 0; y < lcdHeight; y++ {
-		dst.SetRGBA(0, y, border)
-		dst.SetRGBA(lcdWidth-1, y, border)
-	}
-
-	// Eight tick marks around the perimeter to show the button positions.
-	// Just a visual cue that this is real hardware-resolution rendering.
-	tick := color.RGBA{0xaa, 0xaa, 0xaa, 0xff}
-	for i := 0; i < 16; i++ {
-		dst.SetRGBA(lcdWidth/2-1+i-8, lcdHeight/2, tick)
-		dst.SetRGBA(lcdWidth/2, lcdHeight/2-1+i-8, tick)
-	}
-}
-
-func buttonName(b v1.Button) string {
-	switch b {
-	case v1.ButtonUp:
-		return "Up"
-	case v1.ButtonDown:
-		return "Down"
-	case v1.ButtonLeft:
-		return "Left"
-	case v1.ButtonRight:
-		return "Right"
-	case v1.ButtonCenter:
-		return "Center"
-	case v1.Button1:
-		return "Button1"
-	case v1.Button2:
-		return "Button2"
-	case v1.Button3:
-		return "Button3"
-	}
-	return "btn-" + strconv.Itoa(int(b))
-}
-
-func boolStr(b bool, t, f string) string {
-	if b {
-		return t
-	}
-	return f
+func clearBlack(dst *image.RGBA) {
+	draw.Draw(dst, dst.Bounds(), &image.Uniform{color.RGBA{0, 0, 0, 0xff}}, image.Point{}, draw.Src)
 }

gui/assets/embed.go

@@ -0,0 +1,276 @@
+// Code generated by gui/assets/gen.go; DO NOT EDIT.
+package assets
+
+import (
+	_ "embed"
+	"unsafe"
+
+	"github.com/mineracks/seedhammer-v1-companion/image/ninepatch"
+	"github.com/mineracks/seedhammer-v1-companion/image/paletted"
+)
+
+var (
+	ArrowDown = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(ArrowDownData[:135]), len(ArrowDownData[:135])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 15, MaxY: 9},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(ArrowDownData[135:]), len(ArrowDownData[135:]))),
+	}
+	//go:embed arrow-down.bin
+	ArrowDownData string
+
+	ArrowLeft = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(ArrowLeftData[:135]), len(ArrowLeftData[:135])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 9, MaxY: 15},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(ArrowLeftData[135:]), len(ArrowLeftData[135:]))),
+	}
+	//go:embed arrow-left.bin
+	ArrowLeftData string
+
+	ArrowRight = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(ArrowRightData[:135]), len(ArrowRightData[:135])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 9, MaxY: 15},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(ArrowRightData[135:]), len(ArrowRightData[135:]))),
+	}
+	//go:embed arrow-right.bin
+	ArrowRightData string
+
+	ArrowUp = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(ArrowUpData[:135]), len(ArrowUpData[:135])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 15, MaxY: 9},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(ArrowUpData[135:]), len(ArrowUpData[135:]))),
+	}
+	//go:embed arrow-up.bin
+	ArrowUpData string
+
+	ButtonFocused = ninepatch.New(&paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(ButtonFocusedData[:850]), len(ButtonFocusedData[:850])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 34, MaxY: 25},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(ButtonFocusedData[850:]), len(ButtonFocusedData[850:]))),
+	})
+	//go:embed button-focused.bin
+	ButtonFocusedData string
+
+	CameraCorners = ninepatch.New(&paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(CameraCornersData[:3249]), len(CameraCornersData[:3249])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 57, MaxY: 57},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(CameraCornersData[3249:]), len(CameraCornersData[3249:]))),
+	})
+	//go:embed camera-corners.bin
+	CameraCornersData string
+
+	CircleFilled = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(CircleFilledData[:169]), len(CircleFilledData[:169])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 13, MaxY: 13},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(CircleFilledData[169:]), len(CircleFilledData[169:]))),
+	}
+	//go:embed circle-filled.bin
+	CircleFilledData string
+
+	Circle = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(CircleData[:169]), len(CircleData[:169])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 13, MaxY: 13},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(CircleData[169:]), len(CircleData[169:]))),
+	}
+	//go:embed circle.bin
+	CircleData string
+
+	Hammer = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(HammerData[:14760]), len(HammerData[:14760])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 120, MaxY: 123},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(HammerData[14760:]), len(HammerData[14760:]))),
+	}
+	//go:embed hammer.bin
+	HammerData string
+
+	IconBack = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconBackData[:270]), len(IconBackData[:270])),
+		Rect:    paletted.Rectangle{MinX: 8, MinY: 10, MaxX: 26, MaxY: 25},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconBackData[270:]), len(IconBackData[270:]))),
+	}
+	//go:embed icon-back.bin
+	IconBackData string
+
+	IconBackspace = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconBackspaceData[:260]), len(IconBackspaceData[:260])),
+		Rect:    paletted.Rectangle{MinX: 7, MinY: 11, MaxX: 27, MaxY: 24},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconBackspaceData[260:]), len(IconBackspaceData[260:]))),
+	}
+	//go:embed icon-backspace.bin
+	IconBackspaceData string
+
+	IconCheckmark = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconCheckmarkData[:414]), len(IconCheckmarkData[:414])),
+		Rect:    paletted.Rectangle{MinX: 6, MinY: 8, MaxX: 29, MaxY: 26},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconCheckmarkData[414:]), len(IconCheckmarkData[414:]))),
+	}
+	//go:embed icon-checkmark.bin
+	IconCheckmarkData string
+
+	IconDiscard = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconDiscardData[:460]), len(IconDiscardData[:460])),
+		Rect:    paletted.Rectangle{MinX: 7, MinY: 6, MaxX: 27, MaxY: 29},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconDiscardData[460:]), len(IconDiscardData[460:]))),
+	}
+	//go:embed icon-discard.bin
+	IconDiscardData string
+
+	IconDot = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconDotData[:121]), len(IconDotData[:121])),
+		Rect:    paletted.Rectangle{MinX: 12, MinY: 12, MaxX: 23, MaxY: 23},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconDotData[121:]), len(IconDotData[121:]))),
+	}
+	//go:embed icon-dot.bin
+	IconDotData string
+
+	IconEdit = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconEditData[:441]), len(IconEditData[:441])),
+		Rect:    paletted.Rectangle{MinX: 7, MinY: 7, MaxX: 28, MaxY: 28},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconEditData[441:]), len(IconEditData[441:]))),
+	}
+	//go:embed icon-edit.bin
+	IconEditData string
+
+	IconFlip = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconFlipData[:360]), len(IconFlipData[:360])),
+		Rect:    paletted.Rectangle{MinX: 8, MinY: 9, MaxX: 28, MaxY: 27},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconFlipData[360:]), len(IconFlipData[360:]))),
+	}
+	//go:embed icon-flip.bin
+	IconFlipData string
+
+	IconHammer = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconHammerData[:506]), len(IconHammerData[:506])),
+		Rect:    paletted.Rectangle{MinX: 6, MinY: 7, MaxX: 29, MaxY: 29},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconHammerData[506:]), len(IconHammerData[506:]))),
+	}
+	//go:embed icon-hammer.bin
+	IconHammerData string
+
+	IconInfo = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconInfoData[:152]), len(IconInfoData[:152])),
+		Rect:    paletted.Rectangle{MinX: 14, MinY: 8, MaxX: 22, MaxY: 27},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconInfoData[152:]), len(IconInfoData[152:]))),
+	}
+	//go:embed icon-info.bin
+	IconInfoData string
+
+	IconLeft = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconLeftData[:270]), len(IconLeftData[:270])),
+		Rect:    paletted.Rectangle{MinX: 8, MinY: 10, MaxX: 26, MaxY: 25},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconLeftData[270:]), len(IconLeftData[270:]))),
+	}
+	//go:embed icon-left.bin
+	IconLeftData string
+
+	IconProgress = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconProgressData[:529]), len(IconProgressData[:529])),
+		Rect:    paletted.Rectangle{MinX: 6, MinY: 6, MaxX: 29, MaxY: 29},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconProgressData[529:]), len(IconProgressData[529:]))),
+	}
+	//go:embed icon-progress.bin
+	IconProgressData string
+
+	IconRight = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconRightData[:270]), len(IconRightData[:270])),
+		Rect:    paletted.Rectangle{MinX: 9, MinY: 10, MaxX: 27, MaxY: 25},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconRightData[270:]), len(IconRightData[270:]))),
+	}
+	//go:embed icon-right.bin
+	IconRightData string
+
+	IconSkip = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(IconSkipData[:270]), len(IconSkipData[:270])),
+		Rect:    paletted.Rectangle{MinX: 8, MinY: 10, MaxX: 26, MaxY: 25},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(IconSkipData[270:]), len(IconSkipData[270:]))),
+	}
+	//go:embed icon-skip.bin
+	IconSkipData string
+
+	KeyActive = ninepatch.New(&paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(KeyActiveData[:112]), len(KeyActiveData[:112])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 8, MaxY: 14},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(KeyActiveData[112:]), len(KeyActiveData[112:]))),
+	})
+	//go:embed key-active.bin
+	KeyActiveData string
+
+	KeyBackspace = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(KeyBackspaceData[:187]), len(KeyBackspaceData[:187])),
+		Rect:    paletted.Rectangle{MinX: 2, MinY: 0, MaxX: 19, MaxY: 11},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(KeyBackspaceData[187:]), len(KeyBackspaceData[187:]))),
+	}
+	//go:embed key-backspace.bin
+	KeyBackspaceData string
+
+	Key = ninepatch.New(&paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(KeyData[:112]), len(KeyData[:112])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 8, MaxY: 14},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(KeyData[112:]), len(KeyData[112:]))),
+	})
+	//go:embed key.bin
+	KeyData string
+
+	LogoSmall = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(LogoSmallData[:441]), len(LogoSmallData[:441])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 21, MaxY: 21},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(LogoSmallData[441:]), len(LogoSmallData[441:]))),
+	}
+	//go:embed logo-small.bin
+	LogoSmallData string
+
+	NavBtnPrimary = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(NavBtnPrimaryData[:1225]), len(NavBtnPrimaryData[:1225])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 35, MaxY: 35},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(NavBtnPrimaryData[1225:]), len(NavBtnPrimaryData[1225:]))),
+	}
+	//go:embed nav-btn-primary.bin
+	NavBtnPrimaryData string
+
+	NavBtnSecondary = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(NavBtnSecondaryData[:1225]), len(NavBtnSecondaryData[:1225])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 35, MaxY: 35},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(NavBtnSecondaryData[1225:]), len(NavBtnSecondaryData[1225:]))),
+	}
+	//go:embed nav-btn-secondary.bin
+	NavBtnSecondaryData string
+
+	ProgressCircle = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(ProgressCircleData[:16384]), len(ProgressCircleData[:16384])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 128, MaxY: 128},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(ProgressCircleData[16384:]), len(ProgressCircleData[16384:]))),
+	}
+	//go:embed progress-circle.bin
+	ProgressCircleData string
+
+	Sh02 = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(Sh02Data[:5720]), len(Sh02Data[:5720])),
+		Rect:    paletted.Rectangle{MinX: 1, MinY: 0, MaxX: 89, MaxY: 65},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(Sh02Data[5720:]), len(Sh02Data[5720:]))),
+	}
+	//go:embed sh02.bin
+	Sh02Data string
+
+	Sh03 = &paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(Sh03Data[:5720]), len(Sh03Data[:5720])),
+		Rect:    paletted.Rectangle{MinX: 1, MinY: 0, MaxX: 89, MaxY: 65},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(Sh03Data[5720:]), len(Sh03Data[5720:]))),
+	}
+	//go:embed sh03.bin
+	Sh03Data string
+
+	WarningBoxBg = ninepatch.New(&paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(WarningBoxBgData[:405]), len(WarningBoxBgData[:405])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 27, MaxY: 15},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(WarningBoxBgData[405:]), len(WarningBoxBgData[405:]))),
+	})
+	//go:embed warning-box-bg.bin
+	WarningBoxBgData string
+
+	WarningBoxBorder = ninepatch.New(&paletted.Image{
+		Pix:     unsafe.Slice(unsafe.StringData(WarningBoxBorderData[:405]), len(WarningBoxBorderData[:405])),
+		Rect:    paletted.Rectangle{MinX: 0, MinY: 0, MaxX: 27, MaxY: 15},
+		Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(WarningBoxBorderData[405:]), len(WarningBoxBorderData[405:]))),
+	})
+	//go:embed warning-box-border.bin
+	WarningBoxBorderData string
+)

gui/assets/gen.go

@@ -0,0 +1,3 @@
+package assets
+
+//go:generate go run generator.go

gui/assets/generator.go

@@ -0,0 +1,151 @@
+//go:build ignore
+
+// gen converts the PNG assets to embedded image literals.
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/format"
+	"image"
+	"image/color"
+	"image/draw"
+	_ "image/png"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"unicode"
+
+	simage "github.com/mineracks/seedhammer-v1-companion/image"
+	"github.com/mineracks/seedhammer-v1-companion/image/rgb565"
+)
+
+func main() {
+	pngs, err := filepath.Glob("*.png")
+	if err != nil {
+		log.Fatal(err)
+	}
+	// out is the generated embed.go file.
+	out := new(bytes.Buffer)
+	// data is the binary embed.bin containing image data.
+	fmt.Fprintf(out, "// Code generated by gui/assets/gen.go; DO NOT EDIT.\n")
+	fmt.Fprintf(out, "package assets\n\n")
+	fmt.Fprintf(out, "import (\n")
+	fmt.Fprintf(out, "_ \"embed\"\n")
+	fmt.Fprintf(out, "\"unsafe\"\n\n")
+	fmt.Fprintf(out, "\"github.com/mineracks/seedhammer-v1-companion/image/ninepatch\"\n")
+	fmt.Fprintf(out, "\"github.com/mineracks/seedhammer-v1-companion/image/paletted\"\n\n")
+	fmt.Fprintf(out, ")\n\n")
+	fmt.Fprintf(out, "var (\n")
+	for _, p := range pngs {
+		r, err := os.Open(p)
+		if err != nil {
+			log.Fatal(err)
+		}
+		img, _, err := image.Decode(r)
+		r.Close()
+		if err != nil {
+			log.Fatal(err)
+		}
+		// Convert RGBA images to image.Paletted.
+		if nrgba, ok := img.(*image.NRGBA); ok {
+			// Convert to alpha pre-multiplied RGBA.
+			rgba := image.NewRGBA(nrgba.Bounds())
+			draw.Draw(rgba, rgba.Bounds(), nrgba, nrgba.Bounds().Min, draw.Src)
+			paletteMap := make(map[color.RGBA64]uint8)
+			b := rgba.Bounds()
+			index := uint8(0)
+			for y := b.Min.Y; y < b.Max.Y; y++ {
+				for x := b.Min.X; x < b.Max.X; x++ {
+					c := rgba.RGBA64At(x, y)
+					idx, ok := paletteMap[c]
+					if !ok {
+						idx = index
+						paletteMap[c] = idx
+						index++
+						if index < idx {
+							log.Fatalf("too many colors in %q:", p)
+						}
+					}
+				}
+			}
+			palette := make([]color.Color, len(paletteMap))
+			for col, idx := range paletteMap {
+				palette[idx] = col
+			}
+			pimg := image.NewPaletted(rgba.Bounds(), palette)
+			for y := b.Min.Y; y < b.Max.Y; y++ {
+				for x := b.Min.X; x < b.Max.X; x++ {
+					c := rgba.RGBA64At(x, y)
+					idx := paletteMap[c]
+					pimg.SetColorIndex(x, y, idx)
+				}
+			}
+			img = pimg
+		}
+		name := p[:len(p)-len(filepath.Ext(p))]
+		ninePatchPrefix, ninePatchSuffix := "", ""
+		if ext := filepath.Ext(name); ext == ".9" {
+			name = name[:len(name)-len(ext)]
+			ninePatchPrefix, ninePatchSuffix = "ninepatch.New(", ")"
+		}
+		goName := filenameToGoName(name)
+		fmt.Fprintf(out, "%s = %s&", goName, ninePatchPrefix)
+		data := new(bytes.Buffer)
+		switch img := img.(type) {
+		case *image.Paletted:
+			r := simage.Crop(img)
+			crop := image.NewPaletted(r, img.Palette)
+			draw.Draw(crop, crop.Rect, img, crop.Rect.Min, draw.Src)
+			img = crop
+			data.Write(img.Pix)
+			start := data.Len()
+			// Write palette.
+			for _, c := range img.Palette {
+				r, g, b, a := c.RGBA()
+				rgb565 := rgb565.RGB888ToRGB565(uint8(r>>8), uint8(g>>8), uint8(b>>8))
+				data.Write([]byte{rgb565[0], rgb565[1], uint8(a >> 8)})
+			}
+			b := img.Rect
+			fmt.Fprintf(out, "paletted.Image{\n")
+			fmt.Fprintf(out, "Pix: unsafe.Slice(unsafe.StringData(%sData[:%d]), len(%[1]sData[:%[2]d])),\n", goName, start)
+			fmt.Fprintf(out, "Rect: paletted.Rectangle{MinX: %d, MinY: %d, MaxX: %d, MaxY: %d},\n", b.Min.X, b.Min.Y, b.Max.X, b.Max.Y)
+			fmt.Fprintf(out, "Palette: paletted.Palette(unsafe.Slice(unsafe.StringData(%sData[%d:]), len(%[1]sData[%[2]d:]))),\n", goName, start)
+		default:
+			log.Fatalf("unsupported image format for %q: %T\n", p, img)
+		}
+		fmt.Fprintf(out, "}%s\n", ninePatchSuffix)
+		binName := fmt.Sprintf("%s.bin", name)
+		fmt.Fprintf(out, "//go:embed %s\n", binName)
+		fmt.Fprintf(out, "%sData string\n\n", goName)
+		if err := os.WriteFile(binName, data.Bytes(), 0o644); err != nil {
+			log.Fatal(err)
+		}
+	}
+	fmt.Fprintf(out, ")\n\n")
+	src, err := format.Source(out.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+	if err := os.WriteFile("embed.go", src, 0o644); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func filenameToGoName(n string) string {
+	var name strings.Builder
+	toTitle := true
+	for _, ch := range n {
+		if !unicode.IsLetter(ch) && !unicode.IsDigit(ch) {
+			toTitle = true
+			continue
+		}
+		if toTitle {
+			toTitle = false
+			ch = unicode.ToTitle(ch)
+		}
+		name.WriteRune(ch)
+	}
+	return name.String()
+}

gui/doc.go

@@ -1,22 +0,0 @@
-// Package gui is the v1 controller's on-device UI — screen drawing, menu
-// navigation, page state machine.
-//
-// Self-contained, hardware-abstracted: it talks to platform/ for input
-// events and frame output. That abstraction lets the same gui run on a
-// real Pi (via driver/wshat + driver/drm) and in the browser emulator
-// (via platform/v1 + canvas).
-//
-// Screen flow follows the v1 controller's existing conventions:
-//
-//   - Joystick (Up/Down/Left/Right/Center) = navigation
-//   - Button1 = back
-//   - Button2 = secondary action (hold-to-arm dry-run)
-//   - Button3 = primary confirm (hold-to-engrave)
-//
-// Hold-to-confirm distinguishes Pressed from Click with a confirmDelay
-// timer (see gui.go in upstream).
-//
-// Status: STUB — to be lifted from upstream seedhammer/seedhammer at v1.3.0.
-// Browser-emulator-specific tweaks (mock camera, keyboard event source)
-// live in platform/v1, NOT in this package.
-package gui

gui/gui_test.go

@@ -0,0 +1,960 @@
+package gui
+
+import (
+	"errors"
+	"fmt"
+	"image"
+	"image/draw"
+	"io"
+	"reflect"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/btcsuite/btcd/btcutil/hdkeychain"
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/kortschak/qr"
+	"github.com/mineracks/seedhammer-v1-companion/backup"
+	"github.com/mineracks/seedhammer-v1-companion/bc/urtypes"
+	"github.com/mineracks/seedhammer-v1-companion/bip32"
+	"github.com/mineracks/seedhammer-v1-companion/bip39"
+	"github.com/mineracks/seedhammer-v1-companion/driver/mjolnir"
+	"github.com/mineracks/seedhammer-v1-companion/engrave"
+	"github.com/mineracks/seedhammer-v1-companion/font/constant"
+	"github.com/mineracks/seedhammer-v1-companion/gui/op"
+	"github.com/mineracks/seedhammer-v1-companion/nonstandard"
+	"github.com/mineracks/seedhammer-v1-companion/seedqr"
+)
+
+func TestDescriptorScreenError(t *testing.T) {
+	dupDesc := urtypes.OutputDescriptor{
+		Script:    urtypes.P2WSH,
+		Type:      urtypes.SortedMulti,
+		Threshold: 2,
+		Keys:      make([]urtypes.KeyDescriptor, 2),
+	}
+	dupMnemonic := fillDescriptor(t, dupDesc, dupDesc.Script.DerivationPath(), 12, 0)
+	dupDesc.Keys[1] = dupDesc.Keys[0]
+	smallDesc := urtypes.OutputDescriptor{
+		Script:    urtypes.P2WSH,
+		Type:      urtypes.SortedMulti,
+		Threshold: 2,
+		Keys:      make([]urtypes.KeyDescriptor, 5),
+	}
+	smallMnemonic := fillDescriptor(t, smallDesc, smallDesc.Script.DerivationPath(), 12, 0)
+	okDesc := urtypes.OutputDescriptor{
+		Script:    urtypes.P2WSH,
+		Type:      urtypes.SortedMulti,
+		Threshold: 3,
+		Keys:      make([]urtypes.KeyDescriptor, 5),
+	}
+	okMnemonic := fillDescriptor(t, okDesc, okDesc.Script.DerivationPath(), 12, 0)
+	tests := []struct {
+		name     string
+		desc     urtypes.OutputDescriptor
+		mnemonic bip39.Mnemonic
+		ok       bool
+	}{
+		{"duplicate key", dupDesc, dupMnemonic, false},
+		{"small threshold", smallDesc, smallMnemonic, false},
+		{"ok descriptor", okDesc, okMnemonic, true},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			scr := &DescriptorScreen{
+				Descriptor: test.desc,
+				Mnemonic:   test.mnemonic,
+			}
+			ctx := NewContext(newPlatform())
+			// Ok descriptor, ok error message, back.
+			ctxButton(ctx, Button3, Button3, Button1)
+			quit := runUI(ctx, func() {
+				if _, ok := scr.Confirm(ctx, op.Ctx{}, &descriptorTheme); ok != test.ok {
+					t.Fatalf("DescriptorScreen.Confirm returned %v, expected %v", ok, test.ok)
+				}
+			})
+			defer quit()
+		})
+	}
+}
+
+func TestValidateDescriptor(t *testing.T) {
+	// Duplicate key.
+	dup := urtypes.OutputDescriptor{
+		Script:    urtypes.P2WSH,
+		Threshold: 1,
+		Type:      urtypes.SortedMulti,
+		Keys:      make([]urtypes.KeyDescriptor, 2),
+	}
+	fillDescriptor(t, dup, dup.Script.DerivationPath(), 12, 0)
+	dup.Keys[1] = dup.Keys[0]
+
+	// Threshold too small.
+	smallDesc := urtypes.OutputDescriptor{
+		Script:    urtypes.P2WSH,
+		Threshold: 2,
+		Type:      urtypes.SortedMulti,
+		Keys:      make([]urtypes.KeyDescriptor, 5),
+	}
+	fillDescriptor(t, smallDesc, smallDesc.Script.DerivationPath(), 12, 0)
+
+	tests := []struct {
+		name string
+		desc urtypes.OutputDescriptor
+		err  error
+	}{
+		{"duplicate key", dup, new(errDuplicateKey)},
+		{"threshold too small", smallDesc, backup.ErrDescriptorTooLarge},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			err := validateDescriptor(mjolnir.Params, test.desc)
+			if err == nil {
+				t.Fatal("validateDescriptor accepted an unsupported descriptor")
+			}
+			if !errors.Is(err, test.err) {
+				t.Fatalf("validateDescriptor returned %v, expected %v", err, test.err)
+			}
+		})
+	}
+}
+
+func runUI(ctx *Context, f func()) func() {
+	token := new(int)
+	frameCh := make(chan struct{})
+	closed := make(chan struct{})
+	frames := 0
+	ctx.Frame = func() {
+		frames++
+		if frames > 1000 {
+			panic("UI is not making progress")
+		}
+		frameCh <- struct{}{}
+		select {
+		case <-frameCh:
+		case <-closed:
+		}
+	}
+	go func() {
+		defer func() {
+			if v := recover(); v != nil && v != token {
+				panic(v)
+			}
+		}()
+		defer close(closed)
+		<-frameCh
+		f()
+	}()
+	quit := func() {
+		ctx.Frame = func() {
+			panic(token)
+		}
+		close(frameCh)
+		<-closed
+		ctx.Frame = nil
+	}
+	return quit
+}
+
+func resetOps(ops *op.Ops, f func()) func() {
+	return func() {
+		ops.Reset()
+		f()
+	}
+}
+
+func opsContains(ops *op.Ops, str string) bool {
+	clip := image.Rectangle{Max: image.Pt(testDisplayDim, testDisplayDim)}
+	str = strings.ToLower(str)
+	txt := strings.Join(ops.ExtractText(clip), " ")
+	return strings.Index(strings.ToLower(txt), str) != -1
+}
+
+func TestMainScreen(t *testing.T) {
+	p := newPlatform()
+	ctx := NewContext(p)
+
+	ops := new(op.Ops)
+	quit := runUI(ctx, func() {
+		mainFlow(ctx, ops.Context())
+	})
+	defer quit()
+	frame := resetOps(ops, ctx.Frame)
+	// Test sd card warning.
+	ctxButton(ctx, Button3)
+	frame()
+	if !opsContains(ops, "Remove SD") {
+		t.Fatal("MainScreen ignored SD card present")
+	}
+	ctx.EmptySDSlot = true
+	frame()
+	if opsContains(ops, "Remove SD") {
+		t.Fatal("MainScreen ignored SD card ejected")
+	}
+	// Input method camera
+	ctxButton(ctx, Down, Button3)
+	// Scan xpub as descriptor.
+	ctxQR(t, ctx, p, "xpub6F148LnjUhGrHfEN6Pa8VkwF8L6FJqYALxAkuHfacfVhMLVY4MRuUVMxr9pguAv67DHx1YFxqoKN8s4QfZtD9sR2xRCffTqi9E8FiFLAYk8")
+	frame()
+	if !opsContains(ops, "Invalid Seed") {
+		t.Fatal("MainScreen accepted invalid data for a Seed")
+	}
+}
+
+func TestNonParticipatingSeed(t *testing.T) {
+	// Enter seed not part of the descriptor.
+	mnemonic := make(bip39.Mnemonic, 12)
+	for i := range mnemonic {
+		mnemonic[i] = bip39.RandomWord()
+	}
+	mnemonic = mnemonic.FixChecksum()
+	scr := &DescriptorScreen{
+		Mnemonic:   mnemonic,
+		Descriptor: twoOfThree.Descriptor,
+	}
+	ctx := NewContext(newPlatform())
+
+	// Accept descriptor.
+	ctxButton(ctx, Button3)
+
+	ops := new(op.Ops)
+	quit := runUI(ctx, func() {
+		if _, ok := scr.Confirm(ctx, ops.Context(), &descriptorTheme); ok {
+			t.Fatal("a non-participating seed was accepted")
+		}
+	})
+	defer quit()
+	ctx.Frame()
+	if !opsContains(ops, "Unknown Wallet") {
+		t.Fatal("a non-participating seed was accepted")
+	}
+}
+
+func newTestEngraveScreen(t *testing.T, ctx *Context) *EngraveScreen {
+	desc := twoOfThree.Descriptor
+	const keyIdx = 0
+	plate, err := engravePlate(plateSizes, mjolnir.Params, desc, keyIdx, twoOfThree.Mnemonic)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return NewEngraveScreen(
+		ctx,
+		plate,
+	)
+}
+
+func TestEngraveScreenCancel(t *testing.T) {
+	p := newPlatform()
+	ctx := NewContext(p)
+	scr := newTestEngraveScreen(t, ctx)
+
+	// Back.
+	ctxButton(ctx, Button1)
+	// Hold confirm.
+	ctxPress(ctx, Button3)
+	var cancelled bool
+	quit := runUI(ctx, func() {
+		cancelled = !scr.Engrave(ctx, op.Ctx{}, &engraveTheme)
+	})
+	defer quit()
+	ctx.Frame()
+	if cancelled {
+		t.Error("exited screen without confirmation")
+	}
+	p.timeOffset += confirmDelay
+	ctx.Frame()
+	if !cancelled {
+		t.Error("failed to exit screen")
+	}
+}
+
+func TestEngraveError(t *testing.T) {
+	nonstdPath := []uint32{
+		hdkeychain.HardenedKeyStart + 86,
+		hdkeychain.HardenedKeyStart + 0,
+		hdkeychain.HardenedKeyStart + 0,
+	}
+	tests := []struct {
+		name      string
+		threshold int
+		keys      int
+		path      []uint32
+		err       error
+	}{
+		{"threshold too small", 1, 5, nonstdPath, backup.ErrDescriptorTooLarge},
+	}
+	for i, test := range tests {
+		name := fmt.Sprintf("%d-%d-of-%d", i, test.threshold, test.keys)
+		t.Run(name, func(t *testing.T) {
+			desc := urtypes.OutputDescriptor{
+				Script:    urtypes.P2WSH,
+				Threshold: test.threshold,
+				Type:      urtypes.SortedMulti,
+				Keys:      make([]urtypes.KeyDescriptor, test.keys),
+			}
+			mnemonic := fillDescriptor(t, desc, test.path, 12, 0)
+			_, err := engravePlate(plateSizes, mjolnir.Params, desc, 0, mnemonic)
+			if err == nil {
+				t.Fatal("invalid descriptor succeeded")
+			}
+			if !errors.Is(err, test.err) {
+				t.Fatalf("got error %v, expected %v", err, test.err)
+			}
+		})
+	}
+}
+
+func TestEngraveScreenConnectionError(t *testing.T) {
+	p := newPlatform()
+	p.engrave.closed = make(chan []mjolnir.Cmd, 1)
+	p.engrave.connErr = errors.New("failed to connect")
+	ctx := NewContext(p)
+	scr := newTestEngraveScreen(t, ctx)
+	ops := new(op.Ops)
+	quit := runUI(ctx, func() {
+		scr.Engrave(ctx, ops.Context(), &engraveTheme)
+	})
+	defer quit()
+	frame := resetOps(ops, ctx.Frame)
+	// Press next until connect is reached.
+	for scr.instructions[scr.step].Type != ConnectInstruction {
+		ctxButton(ctx, Button3)
+		ctx.Frame()
+	}
+	// Hold connect.
+	ctxPress(ctx, Button3)
+	frame()
+	p.timeOffset += confirmDelay
+	frame()
+	if !opsContains(ops, p.engrave.connErr.Error()) {
+		t.Fatal("engraver error did not propagate to screen")
+	}
+	// Dismiss error.
+	ctxButton(ctx, Button3)
+	// Successfully connect, but fail during engraving.
+	p.engrave.connErr = nil
+	p.engrave.ioErr = errors.New("error during engraving")
+	delivered := make(chan struct{})
+	p.engrave.ioErrDelivered = delivered
+	// Hold connect.
+	ctxPress(ctx, Button3)
+	frame()
+	p.timeOffset += confirmDelay
+	frame()
+	if opsContains(ops, "error") {
+		t.Fatal("screen reported error for connection success")
+	}
+	<-delivered
+	for {
+		frame()
+		if opsContains(ops, p.engrave.ioErr.Error()) {
+			// t.Fatal("screen didn't report engraver error")
+			break
+		}
+	}
+	// Dismiss error and verify screen exits.
+	ctxButton(ctx, Button3)
+	frame()
+	if opsContains(ops, "error") {
+		t.Fatal("screen didn't exit after fatal engraver error")
+	}
+	// Verify device was closed.
+	<-p.engrave.closed
+}
+
+func TestScanScreenConnectError(t *testing.T) {
+	p := newPlatform()
+	// Fail on connect.
+	ctx := NewContext(p)
+	scr := &ScanScreen{}
+	camErr := errors.New("failed to open camera")
+	ctx.events = append(ctx.events, FrameEvent{Error: camErr}.Event())
+	ops := new(op.Ops)
+	quit := runUI(ctx, func() {
+		scr.Scan(ctx, ops.Context())
+	})
+	defer quit()
+	frame := resetOps(ops, ctx.Frame)
+	frame()
+	if !opsContains(ops, camErr.Error()) {
+		t.Fatal("initial camera error not reported")
+	}
+}
+
+func TestScanScreenStreamError(t *testing.T) {
+	p := newPlatform()
+	ctx := NewContext(p)
+	// Fail during streaming.
+	scr := &ScanScreen{}
+	// Connect.
+	camErr := errors.New("error during streaming")
+	ctx.events = append(ctx.events, FrameEvent{Error: camErr}.Event())
+	ops := new(op.Ops)
+	quit := runUI(ctx, func() {
+		scr.Scan(ctx, ops.Context())
+	})
+	defer quit()
+	ctx.Frame()
+	if !opsContains(ops, camErr.Error()) {
+		t.Fatal("streaming camera error not reported")
+	}
+}
+
+func TestWordKeyboardScreen(t *testing.T) {
+	ctx := NewContext(newPlatform())
+	for i := bip39.Word(0); i < bip39.NumWords; i++ {
+		w := bip39.LabelFor(i)
+		ctxString(ctx, strings.ToUpper(w))
+		ctxButton(ctx, Button2)
+		m := make(bip39.Mnemonic, 1)
+		inputWordsFlow(ctx, op.Ctx{}, &descriptorTheme, m, 0)
+		if got := bip39.LabelFor(m[0]); got != w {
+			t.Errorf("keyboard mapped %q to %q", w, got)
+		}
+	}
+}
+
+func ctxMnemonic(ctx *Context, m bip39.Mnemonic) {
+	for _, word := range m {
+		ctxString(ctx, strings.ToUpper(bip39.LabelFor(word)))
+		ctxButton(ctx, Button2)
+	}
+}
+
+func ctxQR(t *testing.T, ctx *Context, p *testPlatform, qrs ...string) {
+	t.Helper()
+	for _, qr := range qrs {
+		ctx.events = append(ctx.events, qrFrame(t, p, qr).Event())
+	}
+}
+
+func TestSeedScreenScan(t *testing.T) {
+	p := newPlatform()
+	ctx := NewContext(p)
+	// Select camera.
+	ctxButton(ctx, Down, Button3)
+	want, err := bip39.ParseMnemonic("attack pizza motion avocado network gather crop fresh patrol unusual wild holiday candy pony ranch winter theme error hybrid van cereal salon goddess expire")
+	if err != nil {
+		t.Fatal(err)
+	}
+	ctxQR(t, ctx, p, string(seedqr.QR(want)))
+	got, ok := newMnemonicFlow(ctx, op.Ctx{}, &descriptorTheme)
+	if !ok {
+		t.Errorf("no mnemonic from scanned seed")
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("scanned %v, want %v", got, want)
+	}
+}
+
+func TestSeedScreenScanInvalid(t *testing.T) {
+	p := newPlatform()
+	ctx := NewContext(p)
+	// Select camera.
+	ctxButton(ctx, Down, Button3)
+	ctxQR(t, ctx, p, "UR:CRYPTO-SEED/OYADGDIYWLAMAEJSZSWDWYTLTIFEENFTLNMNWKBDHNSSRO")
+	ops := new(op.Ops)
+	quit := runUI(ctx, func() {
+		newMnemonicFlow(ctx, ops.Context(), &descriptorTheme)
+	})
+	defer quit()
+	ctx.Frame()
+	if !opsContains(ops, "invalid seed") {
+		t.Error("invalid seed accepted")
+	}
+}
+
+func TestSeedScreenInvalidSeed(t *testing.T) {
+	p := newPlatform()
+	ctx := NewContext(p)
+	m := append(bip39.Mnemonic{}, twoOfThree.Mnemonic...)
+	// Invalidate seed.
+	m[0] = 0
+	// Accept seed.
+	ctxButton(ctx, Button3)
+	scr := new(SeedScreen)
+	var confirmed bool
+	ops := new(op.Ops)
+	var exited bool
+	quit := runUI(ctx, func() {
+		scr.Confirm(ctx, ops.Context(), &singleTheme, m)
+		exited = true
+	})
+	defer quit()
+	frame := resetOps(ops, ctx.Frame)
+	frame()
+	if confirmed || !opsContains(ops, "invalid seed") {
+		t.Fatal("invalid seed accepted")
+	}
+	// Dismiss error.
+	ctxButton(ctx, Button3)
+
+	// Back.
+	ctxButton(ctx, Button1)
+	// Hold confirm.
+	ctxPress(ctx, Button3)
+	frame()
+	if exited {
+		t.Error("exited screen without confirmation")
+	}
+	p.timeOffset += confirmDelay
+	frame()
+	if !exited {
+		t.Error("failed to exit screen")
+	}
+}
+
+func TestXpubMasterFingerprintSinglesig(t *testing.T) {
+	const mnemonic = "upset toe sheriff cotton vibrant shock torch waste congress innocent company review"
+	const descriptor = "zpub6qiC7jMrWkhNEu7YamFTWx8YHQaDFynLYQCUmxjCWpBiLQ4Qp6c6PEwpZpkN27XmUtBjX7hVLyyBKa7zhgaB5B2qvdckaP21ADwx7oYgYD6"
+
+	m, err := bip39.ParseMnemonic(mnemonic)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	p := newPlatform()
+	ctx := NewContext(p)
+	ops := new(op.Ops)
+	ctxQR(t, ctx, p, descriptor)
+	ctxButton(ctx, Button3)
+	got, parsed := inputDescriptorFlow(ctx, ops.Context(), &descriptorTheme, m)
+
+	if !parsed {
+		t.Error("failed to parse descriptor")
+	}
+
+	want, err := nonstandard.OutputDescriptor([]byte(descriptor))
+	if err != nil {
+		t.Fatal(err)
+	}
+	mfp, err := masterFingerprintFor(m, &chaincfg.MainNetParams)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want.Keys[0].MasterFingerprint = mfp
+	if !reflect.DeepEqual(want, *got) {
+		t.Error("descriptors don't match")
+	}
+}
+
+func TestSeed(t *testing.T) {
+	p := newPlatform()
+	ctx := NewContext(p)
+
+	const mnemonic = "doll clerk nice coast caught valid shallow taxi buyer economy lunch roof"
+	m, err := bip39.ParseMnemonic(mnemonic)
+	if err != nil {
+		t.Fatal(err)
+	}
+	mk, ok := deriveMasterKey(m, &chaincfg.MainNetParams)
+	if !ok {
+		t.Fatal("failed to derive master key")
+	}
+	mfp, _, err := bip32.Derive(mk, urtypes.Path{0})
+	if err != nil {
+		t.Fatal(err)
+	}
+	seedDesc := backup.Seed{
+		KeyIdx:            0,
+		Mnemonic:          m,
+		Keys:              1,
+		MasterFingerprint: mfp,
+		Font:              constant.Font,
+		Size:              backup.SquarePlate,
+	}
+	side, err := backup.EngraveSeed(p.EngraverParams(), seedDesc)
+	if err != nil {
+		t.Fatal(err)
+	}
+	plate := Plate{
+		Sides:             []engrave.Plan{side},
+		Size:              backup.SquarePlate,
+		MasterFingerprint: mfp,
+	}
+
+	var completed bool
+	scr := NewEngraveScreen(ctx, plate)
+	quit := runUI(ctx, func() {
+		completed = scr.Engrave(ctx, op.Ctx{}, &engraveTheme)
+	})
+	defer quit()
+
+	testEngraving(t, p, ctx, scr, side)
+	for !completed {
+		ctxButton(ctx, Button3)
+		ctx.Frame()
+	}
+}
+
+func TestMulti(t *testing.T) {
+	const oneOfTwoDesc = "wsh(sortedmulti(1,[94631f99/48h/0h/0h/2h]xpub6ENfRaMWq2UoFy5FrLRMwiEkdgFdMgjEoikR34RBGzhsx8JzAkn7fyQeR5odirEwERvmxhSEv7rsmV7nuzjSKKKJHBP2aQZVu3R2d5ERgcw,[4bbaa801/48h/0h/0h/2h]xpub6E8mpiqJiVKuJZqxtu5SbHQnwUWWPQpZEy9CVtvfU1gxXZnbb9DG2AvZyMHvyVRtUPAEmu6BuRCy4LK2rKMeNr7jQKXsCyFfr1osgFCMYpc))"
+	mnemonics := []string{
+		"doll clerk nice coast caught valid shallow taxi buyer economy lunch roof",
+		"road lend lyrics shift rabbit amazing fetch impulse provide reopen sphere network",
+	}
+
+	for i, mnemonic := range mnemonics {
+		p := newPlatform()
+		ctx := NewContext(p)
+
+		m, err := bip39.ParseMnemonic(mnemonic)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		oneOfTwo, err := nonstandard.OutputDescriptor([]byte(oneOfTwoDesc))
+		if err != nil {
+			t.Fatal(err)
+		}
+		const size = backup.LargePlate
+		descPlate := backup.Descriptor{
+			Descriptor: oneOfTwo,
+			KeyIdx:     i,
+			Font:       constant.Font,
+			Size:       size,
+		}
+		descSide, err := backup.EngraveDescriptor(p.EngraverParams(), descPlate)
+		if err != nil {
+			t.Fatal(err)
+		}
+		seedDesc := backup.Seed{
+			Title:             oneOfTwo.Title,
+			KeyIdx:            i,
+			Mnemonic:          m,
+			Keys:              len(oneOfTwo.Keys),
+			MasterFingerprint: oneOfTwo.Keys[i].MasterFingerprint,
+			Font:              constant.Font,
+			Size:              size,
+		}
+		seedSide, err := backup.EngraveSeed(p.EngraverParams(), seedDesc)
+		if err != nil {
+			t.Fatal(err)
+		}
+		plate := Plate{
+			Size:  size,
+			Sides: []engrave.Plan{descSide, seedSide},
+		}
+		var completed bool
+		scr := NewEngraveScreen(ctx, plate)
+		quit := runUI(ctx, func() {
+			completed = scr.Engrave(ctx, op.Ctx{}, &engraveTheme)
+		})
+		defer quit()
+		for _, side := range plate.Sides {
+			testEngraving(t, p, ctx, scr, side)
+		}
+		for !completed {
+			ctxButton(ctx, Button3)
+			ctx.Frame()
+		}
+	}
+}
+
+func fillDescriptor(t *testing.T, desc urtypes.OutputDescriptor, path urtypes.Path, seedlen int, keyIdx int) bip39.Mnemonic {
+	var mnemonic bip39.Mnemonic
+	for i := range desc.Keys {
+		m := make(bip39.Mnemonic, seedlen)
+		for j := range m {
+			m[j] = bip39.Word(i*seedlen + j)
+		}
+		m = m.FixChecksum()
+		seed := bip39.MnemonicSeed(m, "")
+		network := &chaincfg.MainNetParams
+		mk, err := hdkeychain.NewMaster(seed, network)
+		if err != nil {
+			t.Fatal(err)
+		}
+		mfp, xpub, err := bip32.Derive(mk, path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		pub, err := xpub.ECPubKey()
+		if err != nil {
+			t.Fatal(err)
+		}
+		desc.Keys[i] = urtypes.KeyDescriptor{
+			Network:           network,
+			MasterFingerprint: mfp,
+			DerivationPath:    path,
+			KeyData:           pub.SerializeCompressed(),
+			ChainCode:         xpub.ChainCode(),
+			ParentFingerprint: xpub.ParentFingerprint(),
+		}
+		if i == keyIdx {
+			mnemonic = m
+		}
+	}
+	return mnemonic
+}
+
+type testPlatform struct {
+	events []Event
+
+	engrave struct {
+		closed         chan []mjolnir.Cmd
+		connErr        error
+		ioErr          error
+		ioErrDelivered chan<- struct{}
+	}
+
+	timeOffset time.Duration
+	qrImages   map[*uint8][]byte
+}
+
+func (t *testPlatform) ScanQR(img *image.Gray) ([][]byte, error) {
+	if content, ok := t.qrImages[&img.Pix[0]]; ok {
+		return [][]byte{content}, nil
+	}
+	return nil, errors.New("no QR code")
+}
+
+const testDisplayDim = 240
+
+func (*testPlatform) DisplaySize() image.Point {
+	return image.Pt(testDisplayDim, testDisplayDim)
+}
+
+func (*testPlatform) Dirty(r image.Rectangle) error {
+	return nil
+}
+
+func (*testPlatform) NextChunk() (draw.RGBA64Image, bool) {
+	return nil, false
+}
+
+func (t *testPlatform) Now() time.Time {
+	return time.Now().Add(t.timeOffset)
+}
+
+func (*testPlatform) Debug() bool {
+	return false
+}
+
+func ctxString(ctx *Context, str string) {
+	for _, r := range str {
+		ctx.Events(
+			ButtonEvent{
+				Button:  Rune,
+				Rune:    r,
+				Pressed: true,
+			}.Event(),
+		)
+	}
+}
+
+func ctxPress(ctx *Context, bs ...Button) {
+	for _, b := range bs {
+		ctx.Events(
+			ButtonEvent{
+				Button:  b,
+				Pressed: true,
+			}.Event(),
+		)
+	}
+}
+
+func ctxButton(ctx *Context, bs ...Button) {
+	for _, b := range bs {
+		ctx.Events(
+			ButtonEvent{
+				Button:  b,
+				Pressed: true,
+			}.Event(),
+			ButtonEvent{
+				Button:  b,
+				Pressed: false,
+			}.Event(),
+		)
+	}
+}
+
+func (p *testPlatform) Wakeup() {
+}
+
+func (p *testPlatform) Events(deadline time.Time) []Event {
+	evts := p.events
+	p.events = nil
+	return evts
+}
+
+type wrappedEngraver struct {
+	dev            *mjolnir.Simulator
+	closed         chan<- []mjolnir.Cmd
+	ioErr          error
+	ioErrDelivered chan<- struct{}
+}
+
+func (w *wrappedEngraver) Read(p []byte) (int, error) {
+	n, err := w.dev.Read(p)
+	if err == nil && w.ioErr != nil {
+		err = w.ioErr
+		w.ioErr = nil
+		close(w.ioErrDelivered)
+	}
+	return n, err
+}
+
+func (w *wrappedEngraver) Write(p []byte) (int, error) {
+	n, err := w.dev.Write(p)
+	if err == nil && w.ioErr != nil {
+		err = w.ioErr
+		w.ioErr = nil
+		close(w.ioErrDelivered)
+	}
+	return n, err
+}
+
+func (w *wrappedEngraver) Close() error {
+	if w.closed != nil {
+		w.closed <- w.dev.Cmds
+	}
+	return w.dev.Close()
+}
+
+func (p *testPlatform) EngraverParams() engrave.Params {
+	return mjolnir.Params
+}
+
+var plateSizes = []backup.PlateSize{backup.SquarePlate, backup.LargePlate}
+
+func (p *testPlatform) PlateSizes() []backup.PlateSize {
+	return plateSizes
+}
+
+func (p *testPlatform) Engraver() (Engraver, error) {
+	if err := p.engrave.connErr; err != nil {
+		return nil, err
+	}
+	sim := mjolnir.NewSimulator()
+	return &engraver{
+		dev: &wrappedEngraver{sim, p.engrave.closed, p.engrave.ioErr, p.engrave.ioErrDelivered},
+	}, nil
+}
+
+type engraver struct {
+	dev io.ReadWriteCloser
+}
+
+func (e *engraver) Engrave(sz backup.PlateSize, plan engrave.Plan, quit <-chan struct{}) error {
+	return mjolnir.Engrave(e.dev, mjolnir.Options{}, plan, quit)
+}
+
+func (e *engraver) Close() {
+	e.dev.Close()
+}
+
+func (p *testPlatform) CameraFrame(dims image.Point) {
+}
+
+func newPlatform() *testPlatform {
+	return &testPlatform{}
+}
+
+func qrFrame(t *testing.T, p *testPlatform, content string) FrameEvent {
+	qr, err := qr.Encode(content, qr.L)
+	if err != nil {
+		t.Fatal(err)
+	}
+	qrImg := qr.Image()
+	b := qrImg.Bounds()
+	frameImg := image.NewYCbCr(b, image.YCbCrSubsampleRatio420)
+	for y := b.Min.Y; y < b.Max.Y; y++ {
+		for x := b.Min.X; x < b.Max.X; x++ {
+			off := frameImg.YOffset(x, y)
+			r, _, _, _ := qrImg.At(x, y).RGBA()
+			frameImg.Y[off] = uint8(r >> 8)
+		}
+	}
+	if p.qrImages == nil {
+		p.qrImages = make(map[*byte][]byte)
+	}
+	p.qrImages[&frameImg.Y[0]] = []byte(content)
+	return FrameEvent{
+		Image: frameImg,
+	}
+}
+
+func testEngraving(t *testing.T, p *testPlatform, ctx *Context, scr *EngraveScreen, side engrave.Plan) {
+	p.engrave.closed = make(chan []mjolnir.Cmd)
+done:
+	for {
+		switch scr.instructions[scr.step].Type {
+		case EngraveInstruction:
+			break done
+		case ConnectInstruction:
+			// Hold connect.
+			ctxPress(ctx, Button3)
+			ctx.Frame()
+			p.timeOffset += confirmDelay
+			ctx.Frame()
+		default:
+			ctxButton(ctx, Button3)
+			ctx.Frame()
+		}
+	}
+	got := <-p.engrave.closed
+	// Verify the step is advanced after engrave completion.
+	for scr.instructions[scr.step].Type == EngraveInstruction {
+		ctx.Frame()
+	}
+	want := simEngrave(t, side)
+	if !reflect.DeepEqual(want, got) {
+		t.Fatalf("engraver commands mismatch for side %v", side)
+	}
+}
+
+func simEngrave(t *testing.T, plate engrave.Plan) []mjolnir.Cmd {
+	sim := mjolnir.NewSimulator()
+	defer sim.Close()
+	if err := mjolnir.Engrave(sim, mjolnir.Options{}, plate, nil); err != nil {
+		t.Fatal(err)
+	}
+	return sim.Cmds
+}
+
+func mnemonicFor(phrase string) bip39.Mnemonic {
+	m, err := bip39.ParseMnemonic(phrase)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
+var twoOfThree = struct {
+	Descriptor urtypes.OutputDescriptor
+	Mnemonic   bip39.Mnemonic
+}{
+	Mnemonic: mnemonicFor("flip begin artist fringe online release swift genre wool general transfer arm"),
+	Descriptor: urtypes.OutputDescriptor{
+		Script:    urtypes.P2WSH,
+		Threshold: 2,
+		Type:      urtypes.SortedMulti,
+		Keys: []urtypes.KeyDescriptor{
+			{
+				Network:           &chaincfg.MainNetParams,
+				MasterFingerprint: 0x5a0804e3,
+				DerivationPath:    urtypes.Path{0x80000030, 0x80000000, 0x80000000, 0x80000002},
+				KeyData:           []byte{0x3, 0xa9, 0x39, 0x4a, 0x2f, 0x1a, 0x4f, 0x99, 0x61, 0x3a, 0x71, 0x69, 0x56, 0xc8, 0x54, 0xf, 0x6d, 0xba, 0x6f, 0x18, 0x93, 0x1c, 0x26, 0x39, 0x10, 0x72, 0x21, 0xb2, 0x67, 0xd7, 0x40, 0xaf, 0x23},
+				ChainCode:         []byte{0xdb, 0xe8, 0xc, 0xbb, 0x4e, 0xe, 0x41, 0x8b, 0x6, 0xf4, 0x70, 0xd2, 0xaf, 0xe7, 0xa8, 0xc1, 0x7b, 0xe7, 0x1, 0xab, 0x20, 0x6c, 0x59, 0xa6, 0x5e, 0x65, 0xa8, 0x24, 0x1, 0x6a, 0x6c, 0x70},
+				ParentFingerprint: 0xc7bce7a8,
+			},
+			{
+				Network:           &chaincfg.MainNetParams,
+				MasterFingerprint: 0xdd4fadee,
+				DerivationPath:    urtypes.Path{0x80000030, 0x80000000, 0x80000000, 0x80000002},
+				KeyData:           []byte{0x2, 0x21, 0x96, 0xad, 0xc2, 0x5f, 0xde, 0x16, 0x9f, 0xe9, 0x2e, 0x70, 0x76, 0x90, 0x59, 0x10, 0x22, 0x75, 0xd2, 0xb4, 0xc, 0xc9, 0x87, 0x76, 0xea, 0xab, 0x92, 0xb8, 0x2a, 0x86, 0x13, 0x5e, 0x92},
+				ChainCode:         []byte{0x43, 0x8e, 0xff, 0x7b, 0x3b, 0x36, 0xb6, 0xd1, 0x1a, 0x60, 0xa2, 0x2c, 0xcb, 0x93, 0x6, 0xee, 0xa3, 0x5, 0xb0, 0x43, 0x9f, 0x1e, 0xa0, 0x9d, 0x59, 0x28, 0x1, 0x5d, 0xe3, 0x73, 0x81, 0x16},
+				ParentFingerprint: 0x22969377,
+			},
+			{
+				Network:           &chaincfg.MainNetParams,
+				MasterFingerprint: 0x9bacd5c0,
+				DerivationPath:    urtypes.Path{0x80000030, 0x80000000, 0x80000000, 0x80000002},
+				KeyData:           []byte{0x2, 0xfb, 0x72, 0x50, 0x7f, 0xc2, 0xd, 0xdb, 0xa9, 0x29, 0x91, 0xb1, 0x7c, 0x4b, 0xb4, 0x66, 0x13, 0xa, 0xd9, 0x3a, 0x88, 0x6e, 0x73, 0x17, 0x50, 0x33, 0xbb, 0x43, 0xe3, 0xbc, 0x78, 0x5a, 0x6d},
+				ChainCode:         []byte{0x95, 0xb3, 0x49, 0x13, 0x93, 0x7f, 0xa5, 0xf1, 0xc6, 0x20, 0x5b, 0x52, 0x5b, 0xb5, 0x7d, 0xe1, 0x51, 0x76, 0x25, 0xe0, 0x45, 0x86, 0xb5, 0x95, 0xbe, 0x68, 0xe7, 0x13, 0x62, 0xd3, 0xed, 0xc5},
+				ParentFingerprint: 0x97ec38f9,
+			},
+		},
+	},
+}

gui/layout/layout.go

@@ -0,0 +1,160 @@
+package layout
+
+import (
+	"image"
+)
+
+type Rectangle image.Rectangle
+
+func (r Rectangle) Shrink(top, end, bottom, start int) Rectangle {
+	r2 := Rectangle{
+		Min: r.Min.Add(image.Pt(start, top)),
+		Max: r.Max.Sub(image.Pt(end, bottom)),
+	}
+	if r2.Min.X > r.Max.X {
+		r2.Min.X = r.Max.X
+	}
+	if r2.Max.X < r.Min.X {
+		r2.Max.X = r.Min.X
+	}
+	if r2.Min.Y > r.Max.Y {
+		r2.Min.Y = r.Max.Y
+	}
+	if r2.Max.Y < r.Min.Y {
+		r2.Max.Y = r.Min.Y
+	}
+	return r2
+}
+
+func (r Rectangle) Center(sz image.Point) image.Point {
+	off := r.Size().Sub(sz).Div(2)
+	return r.Min.Add(off)
+}
+
+func (r Rectangle) E(sz image.Point) image.Point {
+	return image.Point{
+		X: r.Max.X - sz.X,
+		Y: (r.Max.Y + r.Min.Y - sz.Y) / 2,
+	}
+}
+
+func (r Rectangle) N(sz image.Point) image.Point {
+	return image.Point{
+		X: (r.Max.X + r.Min.X - sz.X) / 2,
+		Y: r.Min.Y,
+	}
+}
+
+func (r Rectangle) W(sz image.Point) image.Point {
+	return image.Point{
+		X: r.Min.X,
+		Y: (r.Max.Y + r.Min.Y - sz.Y) / 2,
+	}
+}
+
+func (r Rectangle) S(sz image.Point) image.Point {
+	return image.Point{
+		X: (r.Max.X + r.Min.X - sz.X) / 2,
+		Y: r.Max.Y - sz.Y,
+	}
+}
+
+func (r Rectangle) NW(sz image.Point) image.Point {
+	return r.Min
+}
+
+func (r Rectangle) NE(sz image.Point) image.Point {
+	return image.Point{
+		X: r.Max.X - sz.X,
+		Y: r.Min.Y,
+	}
+}
+
+func (r Rectangle) SW(sz image.Point) image.Point {
+	return image.Point{
+		X: r.Min.X,
+		Y: r.Max.Y - sz.Y,
+	}
+}
+
+func (r Rectangle) SE(sz image.Point) image.Point {
+	return r.Max.Sub(sz)
+}
+
+func (r Rectangle) Dx() int {
+	return image.Rectangle(r).Dx()
+}
+
+func (r Rectangle) Dy() int {
+	return image.Rectangle(r).Dy()
+}
+
+func (r Rectangle) Size() image.Point {
+	return image.Rectangle(r).Size()
+}
+
+func (r Rectangle) CutTop(height int) (top Rectangle, bottom Rectangle) {
+	cuty := r.Min.Y + height
+	if cuty > r.Max.Y {
+		cuty = r.Max.Y
+	}
+	return r.cutY(cuty)
+}
+
+func (r Rectangle) CutBottom(height int) (top Rectangle, bottom Rectangle) {
+	cuty := r.Max.Y - height
+	if cuty < r.Min.Y {
+		cuty = r.Min.Y
+	}
+	return r.cutY(cuty)
+}
+
+func (r Rectangle) cutY(cuty int) (top Rectangle, bottom Rectangle) {
+	top = Rectangle(image.Rect(r.Min.X, r.Min.Y, r.Max.X, cuty))
+	bottom = Rectangle(image.Rect(r.Min.X, cuty, r.Max.X, r.Max.Y))
+	return top, bottom
+}
+
+func (r Rectangle) CutStart(width int) (start Rectangle, end Rectangle) {
+	cutx := r.Min.X + width
+	if cutx > r.Max.X {
+		cutx = r.Max.X
+	}
+	return r.cutX(cutx)
+}
+
+func (r Rectangle) CutEnd(width int) (start Rectangle, end Rectangle) {
+	cuty := r.Max.X - width
+	if cuty < r.Min.X {
+		cuty = r.Min.X
+	}
+	return r.cutX(cuty)
+}
+
+func (r Rectangle) cutX(cutx int) (start Rectangle, end Rectangle) {
+	start = Rectangle(image.Rect(r.Min.X, r.Min.Y, cutx, r.Max.Y))
+	end = Rectangle(image.Rect(cutx, r.Min.Y, r.Max.X, r.Max.Y))
+	return start, end
+}
+
+type Align struct {
+	Size image.Point
+}
+
+func (h *Align) Add(sz image.Point) image.Point {
+	if sz.Y > h.Size.Y {
+		h.Size.Y = sz.Y
+	}
+	if sz.X > h.Size.X {
+		h.Size.X = sz.X
+	}
+	return sz
+}
+
+func (h *Align) X(sz image.Point) int {
+	return (h.Size.X - sz.X) / 2
+}
+
+func (h *Align) Y(sz image.Point) int {
+	return (h.Size.Y - sz.Y) / 2
+}

gui/op/op.go

@@ -0,0 +1,372 @@
+package op
+
+import (
+	"image"
+	"image/color"
+
+	"golang.org/x/image/draw"
+	"golang.org/x/image/math/fixed"
+	"github.com/mineracks/seedhammer-v1-companion/font/bitmap"
+	"github.com/mineracks/seedhammer-v1-companion/image/alpha4"
+	"github.com/mineracks/seedhammer-v1-companion/image/ninepatch"
+	"github.com/mineracks/seedhammer-v1-companion/image/rgb565"
+)
+
+type Ops struct {
+	ops      []any
+	uniforms map[color.Color]*image.Uniform
+	ninep    map[ninepatch.Image]*ninepatch.Image
+	colors   map[color.NRGBA]*image.Uniform
+
+	prevOps  map[frameOp]bool
+	frameOps map[frameOp]bool
+	frame    []frameOp
+
+	scratch scratch
+}
+
+type Ctx struct {
+	beginIdx int
+	ops      *Ops
+}
+
+type frameOp struct {
+	state drawState
+	op    drawOp
+}
+
+func (o *Ctx) add(op any) {
+	if o.ops == nil {
+		return
+	}
+	o.ops.ops = append(o.ops.ops, op)
+}
+
+func (o *Ctx) Begin() Ctx {
+	if o.ops == nil {
+		return Ctx{}
+	}
+	o.add(beginOp{})
+	o.beginIdx = len(o.ops.ops)
+	return Ctx{ops: o.ops}
+}
+
+func (o *Ctx) End() CallOp {
+	if o.ops == nil {
+		return CallOp{}
+	}
+	if o.beginIdx == 0 {
+		panic("End without a Begin")
+	}
+	o.add(endOp{})
+	call := CallOp{startIdx: o.beginIdx}
+	o.beginIdx = 0
+	return call
+}
+
+func (o *Ops) Context() Ctx {
+	return Ctx{ops: o}
+}
+
+func (o *Ops) Reset() {
+	o.ops = o.ops[:0]
+	if o.frameOps == nil {
+		o.frameOps = make(map[frameOp]bool)
+	}
+	if o.prevOps == nil {
+		o.prevOps = make(map[frameOp]bool)
+	}
+	o.frameOps, o.prevOps = o.prevOps, o.frameOps
+	// Clear for GC.
+	for i := range o.frameOps {
+		delete(o.frameOps, i)
+	}
+	for i := range o.frame {
+		o.frame[i] = frameOp{}
+	}
+	o.frame = o.frame[:0]
+}
+
+func (o *Ops) nrgba(c color.NRGBA) *image.Uniform {
+	if o == nil {
+		return image.NewUniform(c)
+	}
+	if o.colors == nil {
+		o.colors = make(map[color.NRGBA]*image.Uniform)
+	}
+	if u, ok := o.colors[c]; ok {
+		return u
+	}
+	u := image.NewUniform(c)
+	o.colors[c] = u
+	return u
+}
+
+func (o *Ops) intern(img image.Image) image.Image {
+	if o == nil {
+		return img
+	}
+	switch img := img.(type) {
+	case *image.Uniform:
+		if o.uniforms == nil {
+			o.uniforms = make(map[color.Color]*image.Uniform)
+		}
+		if img, ok := o.uniforms[img.C]; ok {
+			return img
+		}
+		o.uniforms[img.C] = img
+	case *ninepatch.Image:
+		if o.ninep == nil {
+			o.ninep = make(map[ninepatch.Image]*ninepatch.Image)
+		}
+		if img, ok := o.ninep[*img]; ok {
+			return img
+		}
+		o.ninep[*img] = img
+	}
+	return img
+}
+
+type drawState struct {
+	pos   image.Point
+	clip  image.Rectangle
+	mask  image.Image
+	maskp image.Point
+}
+
+type scratch struct {
+	glyph alpha4.Image
+}
+
+func (o *Ops) ExtractText(dst image.Rectangle) []string {
+	o.serialize(drawState{clip: dst}, 0)
+	var text []string
+	for _, op := range o.frame {
+		if op, ok := op.op.(TextOp); ok {
+			text = append(text, op.Txt)
+		}
+	}
+	return text
+}
+
+func (o *Ops) Clip(dst image.Rectangle) image.Rectangle {
+	o.serialize(drawState{clip: dst}, 0)
+	var clip image.Rectangle
+	for _, op := range o.frame {
+		o.frameOps[op] = true
+		if !o.prevOps[op] {
+			clip = clip.Union(op.state.clip)
+		} else {
+			delete(o.prevOps, op)
+		}
+	}
+	for op := range o.prevOps {
+		clip = clip.Union(op.state.clip)
+	}
+	return clip
+}
+
+func (o *Ops) Draw(dst draw.Image) {
+	b := dst.Bounds()
+	for _, op := range o.frame {
+		clip := b.Intersect(op.state.clip)
+		if clip.Empty() {
+			continue
+		}
+		pos := clip.Min.Sub(op.state.pos)
+		maskp := clip.Min.Sub(op.state.maskp)
+		op.op.draw(&o.scratch, dst, clip, op.state.mask, maskp, pos)
+	}
+}
+
+func (o *Ops) serialize(state drawState, from int) {
+	macros := 0
+	origState := state
+	for _, op := range o.ops[from:] {
+		switch op.(type) {
+		case beginOp:
+			macros++
+			continue
+		case endOp:
+			if macros == 0 {
+				return
+			}
+			macros--
+			continue
+		}
+		if macros > 0 {
+			continue
+		}
+		switch op := op.(type) {
+		case offsetOp:
+			state.pos = state.pos.Add(image.Point(op))
+			continue
+		case ClipOp:
+			r := image.Rectangle(op).Add(state.pos)
+			state.clip = state.clip.Intersect(r)
+			continue
+		case maskOp:
+			r := op.src.Bounds().Add(state.pos)
+			state.clip = state.clip.Intersect(r)
+			state.mask = op.src
+			state.maskp = state.pos
+			continue
+		case CallOp:
+			o.serialize(state, op.startIdx)
+		case drawOp:
+			r := op.bounds(&o.scratch).Add(state.pos)
+			state.clip = state.clip.Intersect(r)
+			if !state.clip.Empty() {
+				o.frame = append(o.frame, frameOp{state, op})
+			}
+		}
+		state = origState
+	}
+}
+
+type offsetOp image.Point
+
+func (o offsetOp) Add(ops Ctx) {
+	ops.add(o)
+}
+
+func Offset(ops Ctx, off image.Point) {
+	offsetOp(off).Add(ops)
+}
+
+func Position(ops Ctx, c CallOp, off image.Point) {
+	Offset(ops, off)
+	c.Add(ops)
+}
+
+type ClipOp image.Rectangle
+
+func (c ClipOp) Add(ops Ctx) {
+	ops.add(c)
+}
+
+func ColorOp(ops Ctx, col color.NRGBA) {
+	ops.add(imageOp{ops.ops.nrgba(col)})
+}
+
+func MaskOp(ops Ctx, img image.Image) {
+	ops.add(maskOp{ops.ops.intern(img)})
+}
+
+type maskOp struct {
+	src image.Image
+}
+
+func ImageOp(ops Ctx, img image.Image) {
+	ops.add(imageOp{ops.ops.intern(img)})
+}
+
+type imageOp struct {
+	src image.Image
+}
+
+func (im imageOp) bounds(scr *scratch) image.Rectangle {
+	return im.src.Bounds()
+}
+
+func (im imageOp) draw(_ *scratch, dst draw.Image, dr image.Rectangle, mask image.Image, maskp, pos image.Point) {
+	drawMask(dst, dr, im.src, pos, mask, maskp)
+}
+
+func drawMask(dst draw.Image, dr image.Rectangle, src image.Image, pos image.Point, mask image.Image, maskOff image.Point) {
+	// Optimize special cases.
+	if rgb, ok := dst.(*rgb565.Image); ok {
+		if mask == nil {
+			rgb.Draw(dr, src, pos, draw.Over)
+			return
+		}
+	}
+
+	// General case.
+	draw.DrawMask(
+		dst, dr,
+		src, pos,
+		mask, maskOff,
+		draw.Over,
+	)
+}
+
+type CallOp struct {
+	startIdx int
+}
+
+func (c CallOp) Add(ops Ctx) {
+	if c.startIdx > 0 {
+		ops.add(c)
+	}
+}
+
+type beginOp struct{}
+
+type endOp struct{}
+
+type drawOp interface {
+	bounds(scratch *scratch) image.Rectangle
+	draw(scratch *scratch, dst draw.Image, dr image.Rectangle, mask image.Image, maskp, pos image.Point)
+}
+
+type TextOp struct {
+	Src           image.Image
+	Face          *bitmap.Face
+	Dot           image.Point
+	Txt           string
+	LetterSpacing int
+}
+
+func (t TextOp) bounds(scr *scratch) image.Rectangle {
+	b := t.drawBounds(scr, nil, image.Rectangle{}, nil, image.Point{}, image.Point{})
+	return b.Intersect(t.Src.Bounds())
+}
+
+func (t TextOp) draw(scr *scratch, dst draw.Image, dr image.Rectangle, mask image.Image, maskp, pos image.Point) {
+	t.drawBounds(scr, dst, dr, mask, maskp, pos)
+}
+
+func (t TextOp) drawBounds(scr *scratch, dst draw.Image, dr image.Rectangle, mask image.Image, maskp, pos image.Point) image.Rectangle {
+	var orig draw.Image
+	src := t.Src
+	tpos := pos
+	if dst != nil && mask != nil {
+		orig = dst
+		src = mask
+		dst = image.NewAlpha(dr)
+		tpos = maskp
+	}
+	prevC := rune(-1)
+	dot := fixed.I(t.Dot.X)
+	var bounds image.Rectangle
+	for _, c := range t.Txt {
+		if prevC >= 0 {
+			dot += t.Face.Kern(prevC, c)
+		}
+		mask, advance, ok := t.Face.Glyph(c)
+		if !ok {
+			continue
+		}
+		off := image.Pt(dot.Round(), t.Dot.Y)
+		gdr := mask.Bounds().Add(off)
+		advance += fixed.I(t.LetterSpacing)
+		bounds = bounds.Union(gdr)
+		if dst != nil {
+			scr.glyph = mask
+			drawMask(dst, dr, src, tpos, &scr.glyph, pos.Sub(off))
+		}
+		dot += advance
+		prevC = c
+	}
+	if orig != nil {
+		drawMask(orig, dr, t.Src, pos, dst, dr.Min)
+	}
+	return bounds
+}
+
+func (t TextOp) Add(ops Ctx) {
+	t2 := t
+	t2.Src = ops.ops.intern(t2.Src)
+	ops.add(t2)
+}

gui/saver/saver.go

@@ -0,0 +1,495 @@
+package saver
+
+import (
+	"image"
+	"image/color"
+	"image/draw"
+	"math/rand"
+	"time"
+
+	"golang.org/x/image/math/fixed"
+	"github.com/mineracks/seedhammer-v1-companion/gui/assets"
+	"github.com/mineracks/seedhammer-v1-companion/image/rgb565"
+)
+
+type State struct {
+	before time.Time
+	prev   struct {
+		snake image.Rectangle
+		logo  image.Rectangle
+	}
+	snake []joint
+	food  struct {
+		color int
+		image.Point
+	}
+	dx, dy int
+	shY    fixed.Int26_6
+	shV    fixed.Int26_6
+	sY     fixed.Int26_6
+	sV     fixed.Int26_6
+	shTop  int
+	mode   mode
+	delay  int
+	rand   *rand.Rand
+
+	clear struct {
+		x int
+		y int
+	}
+}
+
+type mode int
+
+const (
+	modeClear mode = iota
+	modeSnake
+	modeGameOver
+)
+
+type joint struct {
+	filled bool
+	image.Point
+}
+
+const gridSize = 8
+const snakeLen = 5
+
+type logo struct {
+	Bounds image.Rectangle
+	Boxes  []image.Point
+}
+
+var (
+	tail  = rgb(0xd9d9d9)
+	white = rgb(0xffffff)
+)
+
+var colors = []image.Image{
+	rgb(0xff0000), // Red
+	rgb(0xffa202), // Orange Peel
+	rgb(0xffff00), // Yellow
+	rgb(0x00ff00), // Green
+	rgb(0x00fff2), // Cyan / Aqua
+	rgb(0x0097fe), // Azure Radiance
+	rgb(0xe000ff), // Electric Violet
+	rgb(0xff00aa), // Hollywood Cerise
+}
+
+func logoFor(width int) logo {
+	return buildLogo(width > 400)
+}
+
+func (s *State) reset(dims image.Point) {
+	s.delay = 20
+	s.shY = 0
+	s.shV = fixed.I(-20)
+	s.sY = 0
+	s.sV = 0
+	s.mode = modeSnake
+	s.rand = rand.New(rand.NewSource(time.Now().UnixNano()))
+	location := image.Point{
+		X: s.rand.Intn(dims.X / gridSize),
+		Y: s.rand.Intn(dims.Y / gridSize),
+	}
+	switch s.rand.Intn(4) {
+	case 0:
+		s.dx = 0
+		s.dy = -1
+		location.Y = dims.Y + snakeLen
+	case 1:
+		s.dx = 1
+		s.dy = 0
+		location.X = -snakeLen - 1
+	case 2:
+		s.dx = 0
+		s.dy = 1
+		location.Y = -snakeLen - 1
+	case 3:
+		s.dx = -1
+		s.dy = 0
+		location.X = dims.X + snakeLen
+	}
+
+	s.snake = []joint{}
+	for len(s.snake) < snakeLen {
+		location.X += s.dx
+		location.Y += s.dy
+		s.snake = append(s.snake, joint{Point: location})
+	}
+	placeFood(s, dims)
+}
+
+func placeFood(s *State, dims image.Point) {
+outer:
+	for {
+		s.food.X = s.rand.Intn(dims.X/gridSize-2*1) + 1
+		s.food.Y = s.rand.Intn(dims.Y/gridSize-2*1) + 1
+		for _, j := range s.snake {
+			if j.Point == s.food.Point {
+				continue outer
+			}
+		}
+		break
+	}
+}
+
+func (s *State) stepClear(dims image.Point) {
+	for i := 0; i < 3; i++ {
+		s.snake = append(s.snake, joint{Point: image.Point{
+			s.clear.x,
+			s.clear.y,
+		}})
+		if len(s.snake) > snakeLen {
+			tail := s.snake[0]
+			if tail.Y*gridSize == dims.Y {
+				s.mode = modeSnake
+				s.reset(dims)
+				return
+			}
+			s.snake = append(s.snake[:0], s.snake[1:]...)
+		}
+		if s.clear.y%2 == 0 {
+			s.clear.x += 1
+		} else {
+			s.clear.x -= 1
+		}
+		if s.clear.x*gridSize >= dims.X || s.clear.x*gridSize < 0 {
+			s.clear.y += 1
+		}
+	}
+}
+
+func (s *State) update(dims image.Point) {
+	if s.delay > 0 {
+		s.delay -= 1
+		return
+	}
+	if s.mode == modeClear {
+		s.stepClear(dims)
+		return
+	}
+
+	head := s.snake[len(s.snake)-1]
+	switch {
+	case s.food.X < head.X:
+		s.dx = -1
+	case s.food.X > head.X:
+		s.dx = 1
+	case s.food.X == head.X:
+		s.dx = 0
+	}
+	switch {
+	case s.food.Y < head.Y:
+		s.dy = -1
+	case s.food.Y > head.Y:
+		s.dy = 1
+	case s.food.Y == head.Y:
+		s.dy = 0
+	}
+	if s.dx != 0 {
+		s.dy = 0
+	}
+
+update:
+	for s.mode == modeSnake {
+		newHead := image.Point{X: head.X + s.dx, Y: head.Y + s.dy}
+		if newHead.X < 0 {
+			newHead.X = dims.X/gridSize - 1
+		} else if newHead.X > dims.X/gridSize-1 {
+			newHead.X = 0
+		}
+		if newHead.Y < 0 {
+			newHead.Y = dims.Y/gridSize - 1
+		} else if newHead.Y > dims.Y/gridSize-1 {
+			newHead.Y = 0
+		}
+		neck := s.snake[len(s.snake)-2]
+
+		if neck.Point == newHead {
+			s.dx *= -1
+			s.dy *= -1
+			continue
+		}
+		for _, j := range s.snake {
+			if j.Point == newHead {
+				s.mode = modeGameOver
+				continue update
+			}
+
+		}
+		j := joint{
+			Point: newHead,
+		}
+		if newHead == s.food.Point {
+			s.snake = append(s.snake, j)
+			placeFood(s, dims)
+			for {
+				color := s.rand.Intn(len(colors))
+				if color != s.food.color {
+					s.food.color = color
+					break
+				}
+			}
+		} else {
+			s.snake = append(s.snake[:0], s.snake[1:]...)
+			s.snake = append(s.snake, j)
+		}
+		break
+	}
+	if s.mode == modeGameOver {
+		minY := 1000
+		for _, c := range s.snake {
+			if c.Y < minY {
+				minY = c.Y
+			}
+		}
+		const a = fixed.Int26_6(1.7*10*64) / 10
+		const b = fixed.Int26_6(-3.5*10*64) / 10
+		s.shV += a
+		s.shY += s.shV
+		s.sV += b
+		if s.sV < 0 {
+			s.sV = 0
+		}
+		s.sY += s.sV
+		sTop := fixed.I(minY*gridSize) + s.sY
+		if sTop < s.shY && sTop < fixed.I(dims.Y) {
+			s.shY = fixed.I(minY*gridSize) + s.sY
+			s.sV = s.shV
+			const k = fixed.Int26_6(0.8*10*64) / 10
+			s.shV = -s.shV.Mul(k)
+		}
+		l := logoFor(dims.X)
+		s.shTop = s.shY.Round() - l.Bounds.Dy()
+		if s.shTop > dims.Y {
+			s.reset(dims)
+		}
+	}
+}
+
+type Screen interface {
+	DisplaySize() image.Point
+	// Dirty begins a refresh of the content
+	// specified by r.
+	Dirty(r image.Rectangle) error
+	// NextChunk returns the next chunk of the refresh.
+	NextChunk() (draw.RGBA64Image, bool)
+	Now() time.Time
+}
+
+func drawScreen(screen Screen, dr image.Rectangle, f func(chunk draw.RGBA64Image)) {
+	screen.Dirty(dr)
+	for {
+		c, ok := screen.NextChunk()
+		if !ok {
+			break
+		}
+		imageDraw(c, c.Bounds(), image.NewUniform(color.Black), image.Point{}, draw.Src)
+		f(c)
+	}
+}
+
+func imageDraw(dst draw.RGBA64Image, dr image.Rectangle, src image.Image, sp image.Point, op draw.Op) {
+	switch dst := dst.(type) {
+	case *rgb565.Image:
+		dst.Draw(dr, src, sp, op)
+		return
+	}
+	draw.Draw(dst, dr, src, sp, op)
+}
+
+func (s *State) Draw(screen Screen) {
+	// Throttle frame time.
+	now := screen.Now()
+	d := now.Sub(s.before)
+	s.before = now
+	const minFrameTime = 40 * time.Millisecond
+	if sleep := minFrameTime - d; sleep > 0 {
+		time.Sleep(sleep)
+	}
+
+	dims := screen.DisplaySize()
+	s.update(dims)
+	lr := s.prev.logo
+	s.prev.logo = image.Rectangle{}
+	var logo logo
+	if s.mode == modeGameOver {
+		logo = logoFor(dims.X)
+		centerx := (dims.X - logo.Bounds.Dx()) / 2
+		s.prev.logo = logo.Bounds.Add(image.Pt(centerx, s.shTop))
+		lr = lr.Union(s.prev.logo)
+	}
+	drawScreen(screen, lr, func(screen draw.RGBA64Image) {
+		if s.mode == modeGameOver {
+			b := s.prev.logo
+			drawBoxes(screen, logo.Boxes, b.Min.X, b.Min.Y)
+		}
+	})
+	var snake image.Rectangle
+	for _, j := range s.snake {
+		m := image.Pt(j.X*gridSize, j.Y*gridSize+s.sY.Round())
+		snake = snake.Union(image.Rectangle{
+			Min: m,
+			Max: m.Add(image.Pt(boxSize, boxSize)),
+		})
+	}
+	food := assets.LogoSmall.Bounds().Add(image.Pt(s.food.X*gridSize-6, s.food.Y*gridSize-3))
+	if s.mode == modeSnake {
+		snake = snake.Union(food)
+	}
+	drawScreen(screen, snake.Union(s.prev.snake), func(screen draw.RGBA64Image) {
+		s.drawSnake(screen)
+		if s.mode == modeSnake {
+			draw.DrawMask(
+				screen,
+				food,
+				colors[s.food.color],
+				image.Pt(0, 0),
+				assets.LogoSmall,
+				image.Pt(0, 0),
+				draw.Over,
+			)
+		}
+	})
+	s.prev.snake = snake
+}
+
+func (s *State) drawSnake(screen draw.RGBA64Image) {
+	for i, j := range s.snake {
+		color := tail
+		if i == len(s.snake)-1 {
+			color = white
+		}
+		dr := image.Rectangle{
+			Min: image.Pt(j.X*gridSize, j.Y*gridSize+s.sY.Round()),
+		}
+		dr.Max = dr.Min.Add(image.Pt(boxSize, boxSize))
+		if j.filled {
+			clearBox(screen, dr.Min.X, dr.Min.Y, color)
+		} else {
+			drawBox(screen, dr.Min.X, dr.Min.Y, color)
+		}
+	}
+}
+
+func buildLogo(wide bool) logo {
+	S := []image.Point{
+		{0, 0}, {1, 0}, {2, 0},
+		{0, 1},
+		{0, 2}, {1, 2}, {2, 2},
+		{2, 3},
+		{0, 4}, {1, 4}, {2, 4},
+	}
+	E := []image.Point{
+		{0, 0}, {1, 0}, {2, 0},
+		{0, 1},
+		{0, 2}, {1, 2}, {2, 2},
+		{0, 3},
+		{0, 4}, {1, 4}, {2, 4},
+	}
+
+	D := []image.Point{
+		{0, 0}, {1, 0}, {2, 0},
+		{0, 1}, {3, 1},
+		{0, 2}, {3, 2},
+		{0, 3}, {3, 3},
+		{0, 4}, {1, 4}, {2, 4},
+	}
+	A := []image.Point{
+		{1, 0}, {2, 0},
+		{0, 1}, {3, 1},
+		{0, 2}, {1, 2}, {2, 2}, {3, 2},
+		{0, 3}, {3, 3},
+		{0, 4}, {3, 4},
+	}
+	H := []image.Point{
+		{0, 0}, {3, 0},
+		{0, 1}, {3, 1},
+		{0, 2}, {1, 2}, {2, 2}, {3, 2},
+		{0, 3}, {3, 3},
+		{0, 4}, {3, 4},
+	}
+	M := []image.Point{
+		{0, 0}, {4, 0},
+		{0, 1}, {1, 1}, {3, 1}, {4, 1},
+		{0, 2}, {1, 2}, {2, 2}, {3, 2}, {4, 2},
+		{0, 3}, {2, 3}, {4, 3},
+		{0, 4}, {4, 4},
+	}
+
+	R := []image.Point{
+		{0, 0}, {1, 0}, {2, 0},
+		{0, 1}, {3, 1},
+		{0, 2}, {1, 2}, {2, 2},
+		{0, 3}, {3, 3},
+		{0, 4}, {3, 4},
+	}
+
+	seedOff := 7
+	hammerOff := image.Pt(0, 6)
+
+	if wide {
+		seedOff = 0
+		hammerOff = image.Pt(12+seedOff+5, 0)
+	}
+	logo := logo{
+		Bounds: image.Rectangle{Min: image.Pt(10000, 10000)},
+	}
+	buildBoxes := func(boxes []image.Point, x, y int) {
+		for _, b := range boxes {
+			b = b.Add(image.Pt(x, y))
+			logo.Bounds = logo.Bounds.Union(image.Rectangle{
+				Min: image.Pt(b.X, b.Y),
+				Max: image.Pt(b.X+1, b.Y+1),
+			})
+			logo.Boxes = append(logo.Boxes, b)
+		}
+	}
+	buildBoxes(S, 0+seedOff, 0)
+	buildBoxes(E, 4+seedOff, 0)
+	buildBoxes(E, 8+seedOff, 0)
+	buildBoxes(D, 12+seedOff, 0)
+
+	buildBoxes(H, 0+hammerOff.X, hammerOff.Y)
+	buildBoxes(A, 5+hammerOff.X, hammerOff.Y)
+	buildBoxes(M, 10+hammerOff.X, hammerOff.Y)
+	buildBoxes(M, 16+hammerOff.X, hammerOff.Y)
+	buildBoxes(E, 22+hammerOff.X, hammerOff.Y)
+	buildBoxes(R, 26+hammerOff.X, hammerOff.Y)
+	logo.Bounds = logo.Bounds.Canon()
+	logo.Bounds = image.Rectangle{
+		Min: logo.Bounds.Min.Mul(gridSize),
+		Max: logo.Bounds.Max.Mul(gridSize),
+	}
+
+	return logo
+}
+
+func drawBoxes(screen draw.RGBA64Image, boxes []image.Point, x, y int) {
+	for _, c := range boxes {
+		drawBox(screen, c.X*gridSize+x, c.Y*gridSize+y, white)
+	}
+}
+
+const boxSize = gridSize
+
+func clearBox(screen draw.RGBA64Image, x, y int, img image.Image) {
+	dr := image.Rect(x, y, x+boxSize, y+boxSize)
+	imageDraw(screen, dr, img, image.Point{}, draw.Src)
+}
+
+func drawBox(screen draw.RGBA64Image, x, y int, img image.Image) {
+	const boxSize = gridSize - 1
+	dr := image.Rect(x+1, y+1, x+boxSize, y+boxSize)
+	imageDraw(screen, dr, img, image.Point{}, draw.Src)
+}
+
+func rgb(c uint32) image.Image {
+	r := uint8(c >> 16)
+	g := uint8(c >> 8)
+	b := uint8(c)
+	return image.NewUniform(color.RGBA{
+		A: 0xff, R: r, G: g, B: b,
+	})
+}

gui/text/text.go

@@ -0,0 +1,118 @@
+package text
+
+import (
+	"image"
+	"unicode"
+	"unicode/utf8"
+
+	"golang.org/x/image/math/fixed"
+	"github.com/mineracks/seedhammer-v1-companion/font/bitmap"
+)
+
+type Line struct {
+	Text  string
+	Width int
+	Dot   image.Point
+}
+
+type Style struct {
+	Face          *bitmap.Face
+	Alignment     Alignment
+	LineHeight    float32
+	LetterSpacing int
+}
+
+type Alignment int
+
+const (
+	AlignStart Alignment = iota
+	AlignEnd
+	AlignCenter
+)
+
+func (l Style) Layout(maxWidth int, txt string) ([]Line, image.Point) {
+	var lines []Line
+	prevC := rune(-1)
+	adv := fixed.I(0)
+	wordAdv := fixed.I(0)
+	wordIdx := 0
+	maxAdv := 0
+	prev := 0
+	idx := 0
+	m := l.Face.Metrics()
+	asc, desc := m.Ascent, m.Descent
+	lheight := m.Height.Ceil()
+	if l.LineHeight != 0 {
+		lheight = int(float32(lheight) * l.LineHeight)
+	}
+	doty := asc.Ceil()
+	endLine := func() {
+		prevC = -1
+		if a := adv.Ceil(); a > maxAdv {
+			maxAdv = a
+		}
+		lines = append(lines, Line{
+			Text:  txt[prev:idx],
+			Width: adv.Ceil(),
+			Dot:   image.Pt(0, doty),
+		})
+		wordIdx = 0
+		wordAdv = 0
+		doty += lheight
+	}
+	for idx < len(txt) {
+		c, n := utf8.DecodeRuneInString(txt[idx:])
+		a, ok := l.Face.GlyphAdvance(c)
+		if !ok {
+			prevC = -1
+			idx += n
+			continue
+		}
+		softnl := unicode.IsSpace(c)
+		if softnl {
+			wordIdx = idx
+			wordAdv = adv
+		}
+		if prevC >= 0 {
+			a += l.Face.Kern(prevC, c)
+		}
+		a += fixed.I(l.LetterSpacing)
+		if c == '\n' || (idx > prev && (adv+a).Ceil() > maxWidth) {
+			if wordIdx > 0 {
+				idx = wordIdx
+				adv = wordAdv
+				_, n = utf8.DecodeRuneInString(txt[idx:])
+				softnl = true
+			}
+			endLine()
+			prev = idx
+			idx += n
+			adv = a
+			if softnl {
+				// Skip space or newline.
+				prev += n
+				adv = 0
+			}
+			continue
+		}
+		idx += n
+		prevC = c
+		adv += a
+	}
+	idx = len(txt)
+	if prev < idx {
+		endLine()
+	}
+	for i, line := range lines {
+		switch l.Alignment {
+		case AlignCenter:
+			lines[i].Dot.X = (maxAdv - line.Width) / 2
+		case AlignEnd:
+			lines[i].Dot.X = maxAdv - line.Width
+		}
+	}
+	return lines, image.Point{
+		X: maxAdv,
+		Y: doty - lheight + desc.Ceil(),
+	}
+}

gui/theme.go

@@ -0,0 +1,120 @@
+package gui
+
+import (
+	"image/color"
+
+	"github.com/mineracks/seedhammer-v1-companion/font/comfortaa"
+	"github.com/mineracks/seedhammer-v1-companion/font/poppins"
+	"github.com/mineracks/seedhammer-v1-companion/gui/text"
+)
+
+var theme struct {
+	overlayMask  uint8
+	activeMask   uint8
+	inactiveMask uint8
+}
+
+type Styles struct {
+	title    text.Style
+	subtitle text.Style
+	body     text.Style
+	lead     text.Style
+	button   text.Style
+	word     text.Style
+	keyboard text.Style
+	warning  text.Style
+	nav      text.Style
+	debug    text.Style
+	progress text.Style
+}
+
+type Colors struct {
+	Background color.NRGBA
+	Text       color.NRGBA
+	Primary    color.NRGBA
+}
+
+var (
+	descriptorTheme Colors
+	singleTheme     Colors
+	engraveTheme    Colors
+	cameraTheme     Colors
+)
+
+const leadingSize = 44
+
+func init() {
+	prim := rgb(0x02427d)
+	descriptorTheme = Colors{
+		Background: rgb(0x267f26),
+		Text:       rgb(0xe9f2ea),
+		Primary:    prim,
+	}
+	singleTheme = Colors{
+		Background: rgb(0xdd9700),
+		Text:       rgb(0xfbf4e8),
+		Primary:    prim,
+	}
+	engraveTheme = Colors{
+		Background: rgb(0xd1e83cb),
+		Text:       rgb(0xdffffff),
+		Primary:    prim,
+	}
+	cameraTheme = Colors{
+		Text: rgb(0xfbf4e8),
+	}
+	theme.overlayMask = 0x55
+	theme.activeMask = 0x55
+	theme.inactiveMask = 0x55
+}
+
+func NewStyles() Styles {
+	return Styles{
+		title: text.Style{
+			Face:          poppins.Bold23,
+			Alignment:     text.AlignCenter,
+			LetterSpacing: -1,
+			LineHeight:    0.75,
+		},
+		body: text.Style{
+			Face:       poppins.Regular16,
+			LineHeight: 0.75,
+		},
+		debug: text.Style{
+			Face: poppins.Bold10,
+		},
+		warning: text.Style{
+			Face:       poppins.Bold23,
+			LineHeight: 0.75,
+			Alignment:  text.AlignCenter,
+		},
+		lead: text.Style{
+			Face:       poppins.Regular16,
+			LineHeight: 0.9,
+			Alignment:  text.AlignCenter,
+		},
+		subtitle: text.Style{
+			Face:       poppins.Bold16,
+			LineHeight: 0.9,
+		},
+		nav: text.Style{
+			Face: poppins.Bold23,
+		},
+		button: text.Style{
+			Face:       poppins.Bold20,
+			Alignment:  text.AlignCenter,
+			LineHeight: 0.70,
+		},
+		word: text.Style{
+			Face: comfortaa.Bold17,
+		},
+		keyboard: text.Style{
+			Face: poppins.Bold16,
+		},
+		progress: text.Style{
+			Face:          poppins.Boldprogress45,
+			Alignment:     text.AlignCenter,
+			LetterSpacing: -1,
+		},
+	}
+}

gui/widget/label.go

@@ -0,0 +1,28 @@
+package widget
+
+import (
+	"image"
+	"image/color"
+	"math"
+
+	"github.com/mineracks/seedhammer-v1-companion/gui/op"
+	"github.com/mineracks/seedhammer-v1-companion/gui/text"
+)
+
+func Label(ops op.Ctx, l text.Style, col color.NRGBA, txt string) image.Point {
+	return LabelW(ops, l, math.MaxInt, col, txt)
+}
+
+func LabelW(ops op.Ctx, l text.Style, width int, col color.NRGBA, txt string) image.Point {
+	lines, sz := l.Layout(width, txt)
+	for _, line := range lines {
+		(&op.TextOp{
+			Src:           image.NewUniform(col),
+			Face:          l.Face,
+			Dot:           image.Pt(line.Dot.X, line.Dot.Y),
+			Txt:           line.Text,
+			LetterSpacing: l.LetterSpacing,
+		}).Add(ops)
+	}
+	return sz
+}