gno.land/r/g1sw5xklxjjuv0yvuxy5f5s3l3mnj0nqq626a9wr/million/v0⧉

1// Package million is a pay-per-pixel collaborative canvas: anyone can paint2// any pixel of a Width x Height grid in one of 15 colors by sending exactly3// Price() ugnot per pixel along with the call. Pixels can be repainted by4// anyone, for the same price. Payments are forwarded to the admin wallet5// as they arrive, and the admin paints for free.6//7// The grid logic lives in gno.land/p/g1sw5xklxjjuv0yvuxy5f5s3l3mnj0nqq626a9wr/canvas/v0; this realm adds the8// payment guard, the owner controls and the read API used by the web client.9package million1011import (12	"chain"13	"chain/banker"14	"chain/runtime/unsafe"15	"strconv"16	"strings"1718	"gno.land/p/g1sw5xklxjjuv0yvuxy5f5s3l3mnj0nqq626a9wr/canvas/v0"19	"gno.land/p/nt/ufmt/v0"20)2122const (23	// Width and Height are fixed for the life of this version: changing24	// them would change the storage layout, so it means a new /vN.25	// 1250 x 800 is one million pixels in a 16:10 laptop aspect ratio.26	Width  = 125027	Height = 8002829	// MaxBatch bounds a single PaintBatch call so one tx cannot blow the30	// block gas limit or overflow the price arithmetic.31	MaxBatch = 5003233	// DefaultPrice is the initial price per pixel, in ugnot (0.05 GNOT).34	DefaultPrice int64 = 50_0003536	// DefaultAdmin receives every payment, paints for free and holds the37	// owner controls. Change it before deploying; TransferOwnership moves38	// it afterwards.39	DefaultAdmin = "g1sw5xklxjjuv0yvuxy5f5s3l3mnj0nqq626a9wr"4041	Denom = "ugnot"42)4344var (45	board = canvas.New(Width, Height)46	price = DefaultPrice47	owner = address(DefaultAdmin)4849	// Stats.50	revenue int64 // total ugnot ever paid for pixels51	paints  int64 // number of successful Paint/PaintBatch calls5253	// Change tracking, so clients fetch only the rows that moved.54	// version bumps once per successful paint call; rowVersion holds the55	// version of the last paint that touched each row (0 = never painted).56	version    int6457	rowVersion = make([]int64, Height)58)5960// Paint colors one pixel. Send exactly Price() ugnot (nothing for the admin).61func Paint(cur realm, x, y, color int) {62	if color <= 0 || color > int(canvas.MaxColor) {63		panic(canvas.ErrInvalidColor)64	}65	paint([]canvas.Pixel{{X: x, Y: y, Color: byte(color)}}, cur)66}6768// PaintBatch colors up to MaxBatch pixels in one call. The argument is69// "x,y,color;x,y,color;...". Send exactly Price() * count ugnot (nothing70// for the admin).71func PaintBatch(cur realm, pixels string) {72	px, err := canvas.ParsePixels(pixels)73	if err != nil {74		panic(err)75	}76	paint(px, cur)77}7879// paint takes the realm as its LAST parameter on purpose: a realm first80// parameter would make it a crossing function and Previous() would then81// be this realm instead of the user.82func paint(px []canvas.Pixel, rlm realm) {83	if !rlm.IsCurrent() {84		panic("spoofed realm")85	}86	// Payment guard: unsafe.OriginSend() describes the coins attached to87	// the transaction, which only provably landed here when the caller is88	// a plain user call (no intermediate or ephemeral realm). Keep the two89	// checks together. unsafe is imported for OriginSend only; caller90	// identity always comes from the realm handle.91	if !rlm.Previous().IsUserCall() {92		panic("must be called directly by a user (maketx call)")93	}94	painter := rlm.Previous().Address()95	n := len(px)96	if n == 0 {97		panic("nothing to paint")98	}99	if n > MaxBatch {100		panic(ufmt.Sprintf("too many pixels: %d > %d", n, MaxBatch))101	}102	for _, p := range px {103		if err := board.Check(p); err != nil {104			panic(err)105		}106	}107108	cost := price * int64(n)109	if painter == owner {110		cost = 0 // the admin paints for free111	}112	if sent := sentUgnot(unsafe.OriginSend()); sent != cost {113		panic(ufmt.Sprintf("must send exactly %d%s for %d pixel(s), got %d%s", cost, Denom, n, sent, Denom))114	}115	if cost > 0 {116		// Forward the payment to the admin right away, so nothing117		// accumulates in the realm. BankerTypeOriginSend can only move118		// what this very message sent, which is exactly cost.119		bnk := banker.NewBanker(banker.BankerTypeOriginSend, rlm)120		bnk.SendCoins(rlm.Address(), owner, chain.NewCoins(chain.NewCoin(Denom, cost)))121	}122123	version++124	for _, p := range px {125		board.Set(p)126		rowVersion[p.Y] = version127	}128	revenue += cost129	paints++130131	// The pixel list itself is not emitted: event attribute values are132	// size-capped by the node and a full batch exceeds it. Clients re-read133	// Rows() after a paint.134	chain.Emit("Paint",135		"painter", painter.String(),136		"count", strconv.Itoa(n),137		"paid", strconv.Itoa(int(cost))+Denom,138	)139}140141// sentUgnot returns the ugnot amount in coins and rejects any other denom,142// so a caller cannot pay with something the realm does not price.143func sentUgnot(coins chain.Coins) int64 {144	var amount int64145	for _, c := range coins {146		if c.Denom != Denom {147			panic("only " + Denom + " is accepted")148		}149		amount += c.Amount150	}151	return amount152}153154// --- owner controls ---155156// assertOwner panics unless the verified caller behind rlm is the owner.157// The realm is deliberately not the first parameter (see paint); the158// leading blank int is the same idiom gno.land/p/nt/ownable uses.159func assertOwner(_ int, rlm realm) {160	if !rlm.IsCurrent() {161		panic("spoofed realm")162	}163	if rlm.Previous().Address() != owner {164		panic("owner only")165	}166}167168// SetPrice changes the price per pixel, in ugnot. Zero makes painting free169// for everyone.170func SetPrice(cur realm, ugnot int64) {171	assertOwner(0, cur)172	if ugnot < 0 {173		panic("price must not be negative")174	}175	price = ugnot176}177178// Withdraw sends amount ugnot held by the realm to the given address.179// Payments are forwarded on arrival, so this only matters for coins sent180// to the realm outside of a paint call.181func Withdraw(cur realm, to address, amount int64) {182	assertOwner(0, cur)183	if !to.IsValid() {184		panic("invalid address")185	}186	if amount <= 0 {187		panic("amount must be positive")188	}189	bnk := banker.NewBanker(banker.BankerTypeRealmSend, cur)190	bnk.SendCoins(cur.Address(), to, chain.NewCoins(chain.NewCoin(Denom, amount)))191}192193// TransferOwnership hands the admin role (payments, free painting and the194// owner controls) to newOwner.195func TransferOwnership(cur realm, newOwner address) {196	assertOwner(0, cur)197	if !newOwner.IsValid() {198		panic("invalid address")199	}200	owner = newOwner201}202203// --- read API (used by the web client through vm/qeval) ---204205func GetWidth() int    { return Width }206func GetHeight() int   { return Height }207func Price() int64     { return price }208func Owner() address   { return owner }209func Painted() int     { return board.Painted() }210func Revenue() int64   { return revenue }211func Paints() int64    { return paints }212func MaxBatchSize() int { return MaxBatch }213214// Pixel returns the color index at (x, y); 0 means never painted.215func Pixel(x, y int) int { return int(board.Get(x, y)) }216217// Rows returns rows [from, to) as one hex digit per pixel, Width digits per218// row, with no separators. Clients page through the grid with it.219func Rows(from, to int) string { return board.Rows(from, to) }220221// Version is the number of successful paint calls so far. Clients remember222// it and ask DirtyRows for what changed since.223func Version() int64 { return version }224225// DirtyRows lists the rows painted after version `since`, as "y,y,y" in226// ascending order. DirtyRows(0) is every row that was ever painted, which227// is all a fresh client needs to load: the others are blank.228func DirtyRows(since int64) string {229	if since < 0 {230		since = 0231	}232	var sb strings.Builder233	for y, v := range rowVersion {234		if v <= since {235			continue236		}237		if sb.Len() > 0 {238			sb.WriteByte(',')239		}240		sb.WriteString(strconv.Itoa(y))241	}242	return sb.String()243}244245// Palette returns the 16 palette colors as comma-separated CSS hex values,246// index 0 being the blank color.247func Palette() string {248	return strings.Join(canvas.Palette[:], ",")249}250251// Render shows the game stats on gnoweb. The path is ignored.252func Render(_ string) string {253	var sb strings.Builder254	sb.WriteString("# Million Gno\n\n")255	sb.WriteString("A pay-per-pixel canvas. Pick a color, pay the price, own the pixel until someone repaints it. Payments go to the admin wallet, which paints for free.\n\n")256	sb.WriteString("| | |\n|---|---|\n")257	sb.WriteString(ufmt.Sprintf("| Size | %d x %d |\n", Width, Height))258	sb.WriteString(ufmt.Sprintf("| Price per pixel | %d%s |\n", price, Denom))259	sb.WriteString(ufmt.Sprintf("| Pixels painted | %d / %d |\n", board.Painted(), Width*Height))260	sb.WriteString(ufmt.Sprintf("| Paint calls | %d |\n", paints))261	sb.WriteString(ufmt.Sprintf("| Version | %d |\n", version))262	sb.WriteString(ufmt.Sprintf("| Revenue | %d%s |\n", revenue, Denom))263	sb.WriteString(ufmt.Sprintf("| Admin | %s |\n", owner.String()))264	sb.WriteString("\n## Palette\n\n")265	for i := 1; i <= int(canvas.MaxColor); i++ {266		sb.WriteString(ufmt.Sprintf("- %d: `%s`\n", i, canvas.Palette[i]))267	}268	sb.WriteString("\n## Paint\n\n")269	sb.WriteString("- [Paint one pixel](" + Realm + "$help&func=Paint): `Paint(x, y, color)` with `-send <price>ugnot`\n")270	sb.WriteString("- [Paint a batch](" + Realm + "$help&func=PaintBatch): `PaintBatch(\"x,y,color;x,y,color\")` with `-send <price*count>ugnot`\n")271	return sb.String()272}273274// Realm is this realm's gnoweb path.275const Realm = "/r/g1sw5xklxjjuv0yvuxy5f5s3l3mnj0nqq626a9wr/million/v0"276