gnomes.gno
6.70 Kb · 235 lines
1// Package gnomes — Pixel Gnomes, one hundred of them.
2//
3// Every gnome is drawn by this realm from its row in traitTable (traits.gno):
4// no image files, nothing hosted. The table was picked off-chain, once, with
5// a fixed seed (tools/gen-gnome-traits.py), so rarity is deliberate and no
6// two gnomes share all nine traits.
7//
8// ANYONE MAY CALL Mint, once. Every gnome goes to `owner`, fixed in the
9// source, so it does not matter who sends the transaction.
10//
11// OWNERSHIP IS LAZY: all hundred belong to `owner` from the mint without a
12// hundred writes. A gnome is written down individually only the first time
13// it moves.
14//
15// ROYALTY is 5% to `royaltyReceiver`, reported by RoyaltyInfo in the EIP-2981 shape.
16// It is advisory, as on every chain: a marketplace has to choose to pay it,
17// and a direct wallet-to-wallet transfer does not.
18package pixelgnomes
19
20import (
21 "chain"
22 "chain/runtime"
23 "encoding/base64"
24 "strconv"
25 "strings"
26
27 "gno.land/p/nt/avl/v0"
28 "gno.land/p/nt/ufmt/v0"
29)
30
31const (
32 collectionName = "Pixel Gnomes"
33 collectionSymbol = "GNOME"
34 supply = 100
35 royaltyBps = int64(500) // 5%
36
37 owner = address("g1fjr5eezf73tmqzh0ml9qkhj7t8dkn4cgmxgp5f") // receives all 100 at mint
38 royaltyReceiver = address("g1d57q42jcymc7qvcea9de6kvadz7pfrvdg7zrgz") // receives the 5% royalty
39)
40
41var (
42 mintHeight int64
43
44 owners avl.Tree // token id -> address, only tokens that have moved
45 balances avl.Tree // address -> int64
46 approvals avl.Tree // token id -> address
47 operators avl.Tree // owner + "/" + operator -> true
48)
49
50// Mint brings all hundred into existence, once.
51func Mint(cur realm) {
52 if mintHeight != 0 {
53 panic(ufmt.Sprintf("gnomes: already minted, in block %d", mintHeight))
54 }
55 if len(traitTable) != supply*traitCount {
56 panic("gnomes: trait table does not match the supply")
57 }
58 mintHeight = runtime.ChainHeight()
59 balances.Set(owner.String(), int64(supply))
60 for i := 1; i <= supply; i++ {
61 chain.Emit("Transfer", "from", "", "to", owner.String(), "tid", strconv.Itoa(i))
62 }
63 chain.Emit("Minted", "height", strconv.FormatInt(mintHeight, 10), "supply", strconv.Itoa(supply), "to", owner.String())
64}
65
66// -- GRC-721 surface --
67
68func Name() string { return collectionName }
69func Symbol() string { return collectionSymbol }
70func Owner() address { return owner }
71func RoyaltyReceiver() address { return royaltyReceiver }
72func MintHeight() int64 { return mintHeight }
73func TotalSupply() int64 {
74 if mintHeight == 0 {
75 return 0
76 }
77 return supply
78}
79
80func BalanceOf(addr address) int64 {
81 v := balances.Get(addr.String())
82 if v == nil {
83 return 0
84 }
85 return v.(int64)
86}
87
88func OwnerOf(tid string) address { return ownerOf(mustID(tid)) }
89
90func GetApproved(tid string) address {
91 mustID(tid)
92 v := approvals.Get(tid)
93 if v == nil {
94 return ""
95 }
96 return v.(address)
97}
98
99func IsApprovedForAll(holder, operator address) bool {
100 return operators.Get(holder.String()+"/"+operator.String()) != nil
101}
102
103func Approve(cur realm, to address, tid string) {
104 caller := cur.Previous().Address()
105 holder := ownerOf(mustID(tid))
106 if caller != holder && !IsApprovedForAll(holder, caller) {
107 panic("gnomes: only the holder or an operator may approve")
108 }
109 if to == holder {
110 panic("gnomes: the holder does not need approving")
111 }
112 if to == "" {
113 approvals.Remove(tid)
114 } else {
115 approvals.Set(tid, to)
116 }
117 chain.Emit("Approval", "owner", holder.String(), "approved", to.String(), "tid", tid)
118}
119
120func SetApprovalForAll(cur realm, operator address, approved bool) {
121 caller := cur.Previous().Address()
122 if operator == caller {
123 panic("gnomes: you cannot make yourself your own operator")
124 }
125 key := caller.String() + "/" + operator.String()
126 if approved {
127 operators.Set(key, true)
128 } else {
129 operators.Remove(key)
130 }
131 chain.Emit("ApprovalForAll", "owner", caller.String(), "operator", operator.String(), "approved", strconv.FormatBool(approved))
132}
133
134func TransferFrom(cur realm, from, to address, tid string) {
135 caller := cur.Previous().Address()
136 id := mustID(tid)
137 holder := ownerOf(id)
138 if holder != from {
139 panic("gnomes: `from` does not hold this gnome")
140 }
141 if !to.IsValid() {
142 panic("gnomes: that is not a valid address")
143 }
144 if caller != holder && GetApproved(tid) != caller && !IsApprovedForAll(holder, caller) {
145 panic("gnomes: not the holder, not approved, not an operator")
146 }
147 approvals.Remove(tid)
148 owners.Set(tid, to)
149 addBalance(from, -1)
150 addBalance(to, 1)
151 chain.Emit("Transfer", "from", from.String(), "to", to.String(), "tid", tid)
152}
153
154// SafeTransferFrom is TransferFrom: there is no receiver hook on gno.land.
155func SafeTransferFrom(cur realm, from, to address, tid string) {
156 TransferFrom(cross(cur), from, to, tid)
157}
158
159// RoyaltyInfo answers the EIP-2981 question: for a sale at salePrice, who
160// should receive a royalty, and how much.
161func RoyaltyInfo(tid string, salePrice int64) (address, int64) {
162 mustID(tid)
163 if salePrice < 0 || salePrice > (int64(1)<<62)/royaltyBps {
164 panic("gnomes: sale price out of range")
165 }
166 return royaltyReceiver, salePrice * royaltyBps / 10000
167}
168
169func RoyaltyBps() int64 { return royaltyBps }
170
171// TokenURI is the artwork itself, as a data URI.
172func TokenURI(tid string) string {
173 return "data:image/svg+xml;base64," + base64.StdEncoding.EncodeToString([]byte(Art(tid)))
174}
175
176// Traits lists one gnome's traits as "trait:option" pairs.
177func Traits(tid string) string {
178 t := traitsOf(mustID(tid))
179 parts := make([]string, traitCount)
180 for i := 0; i < traitCount; i++ {
181 parts[i] = traitNames[i] + ":" + optionName(i, t[i])
182 }
183 return strings.Join(parts, ",")
184}
185
186// -- helpers --
187
188func mustID(tid string) int {
189 n, err := strconv.Atoi(tid)
190 if err != nil || n < 1 || n > supply || strconv.Itoa(n) != tid {
191 panic("gnomes: gnome ids are 1 to 100")
192 }
193 return n
194}
195
196func ownerOf(id int) address {
197 if mintHeight == 0 {
198 panic("gnomes: not minted yet")
199 }
200 if v := owners.Get(strconv.Itoa(id)); v != nil {
201 return v.(address)
202 }
203 return owner
204}
205
206func addBalance(a address, d int64) {
207 b := BalanceOf(a) + d
208 if b == 0 {
209 balances.Remove(a.String())
210 return
211 }
212 balances.Set(a.String(), b)
213}
214
215// Render: "" is the collection, "N" is gnome N.
216func Render(path string) string {
217 if path == "" {
218 var b strings.Builder
219 b.WriteString("# " + collectionName + "\n\n")
220 if mintHeight == 0 {
221 b.WriteString("100 pixel gnomes. Not minted yet.\n")
222 return b.String()
223 }
224 b.WriteString(ufmt.Sprintf("100 pixel gnomes, minted in block %d. Royalty 5%%.\n\n", mintHeight))
225 for i := 1; i <= supply; i++ {
226 b.WriteString(ufmt.Sprintf("[#%d](:%d) ", i, i))
227 }
228 b.WriteString("\n")
229 return b.String()
230 }
231 id := mustID(path)
232 tid := strconv.Itoa(id)
233 return ufmt.Sprintf("# %s #%d\n\n\n\n%s\n\nHolder: %s\n",
234 collectionName, id, id, TokenURI(tid), strings.ReplaceAll(Traits(tid), ",", " · "), ownerOf(id).String())
235}
