RegionIO/internal/worldgen/features.go

512 lines
16 KiB
Go

package worldgen
import (
"archive/zip"
"bytes"
_ "embed"
"encoding/json"
"fmt"
"path"
"strings"
"sync"
)
//go:embed feature_data.zip
var featureData []byte
// FeatureSet is the validated vanilla datapack graph used by decoration.
type FeatureSet struct {
Configured map[string]ConfiguredFeature
Placed map[string]PlacedFeature
Biomes map[string]BiomeGeneration
BlockTags map[string][]string
}
type ConfiguredFeature struct {
Type string
Config json.RawMessage
}
type PlacedFeature struct {
Feature string
Placement []PlacementModifier
}
type PlacementModifier struct {
Type string
Raw json.RawMessage
}
type OreFeatureConfig struct {
Size int
DiscardAirExposure float64 `json:"discard_chance_on_air_exposure"`
Targets []OreTarget
}
type OreTarget struct {
State struct {
Name string `json:"Name"`
} `json:"state"`
Target struct {
PredicateType string `json:"predicate_type"`
Tag string `json:"tag"`
} `json:"target"`
}
type SpringFeatureConfig struct {
HoleCount int `json:"hole_count"`
RequiresBlockBelow bool `json:"requires_block_below"`
RockCount int `json:"rock_count"`
State BlockState `json:"state"`
ValidBlocks []string `json:"valid_blocks"`
}
type TreeFeatureConfig struct {
TrunkProvider struct {
Type string `json:"type"`
State BlockState `json:"state"`
} `json:"trunk_provider"`
FoliageProvider struct {
Type string `json:"type"`
State BlockState `json:"state"`
} `json:"foliage_provider"`
TrunkPlacer struct {
Type string `json:"type"`
BaseHeight int `json:"base_height"`
HeightRandA int `json:"height_rand_a"`
HeightRandB int `json:"height_rand_b"`
} `json:"trunk_placer"`
FoliagePlacer struct {
Type string `json:"type"`
Height int `json:"height"`
Offset int `json:"offset"`
Radius int `json:"radius"`
} `json:"foliage_placer"`
}
type FeatureRef struct {
Name string
Placement []PlacementModifier
}
type RandomSelectorConfig struct {
Default FeatureRef
Features []RandomSelectorEntry
}
type RandomSelectorEntry struct {
Chance float32
Feature FeatureRef
}
type BlockState struct {
Name string `json:"Name"`
Properties map[string]string `json:"Properties"`
}
type PlacementPlan struct {
Count CountProvider
RarityChance int
HeightDistribution string
MinY HeightProvider
MaxY HeightProvider
}
type CountProvider struct {
Min, Max int
Weighted []WeightedInt
}
type WeightedInt struct {
Value, Weight int
}
type HeightProvider struct {
Absolute *int
AboveBottom *int
BelowTop *int
}
func (p CountProvider) Sample(r RandomSource) int {
if len(p.Weighted) > 0 {
total := 0
for _, entry := range p.Weighted {
total += entry.Weight
}
if total <= 0 {
return 0
}
roll := int(r.NextIntN(int32(total)))
for _, entry := range p.Weighted {
if roll < entry.Weight {
return entry.Value
}
roll -= entry.Weight
}
}
if p.Max <= p.Min {
return p.Min
}
return p.Min + int(r.NextIntN(int32(p.Max-p.Min+1)))
}
func (p HeightProvider) Resolve(minY, height int) int {
if p.Absolute != nil {
return *p.Absolute
}
if p.AboveBottom != nil {
return minY + *p.AboveBottom
}
if p.BelowTop != nil {
return minY + height - 1 - *p.BelowTop
}
return minY
}
func (p PlacementPlan) SampleY(r RandomSource, minY, height int) int {
lo, hi := p.MinY.Resolve(minY, height), p.MaxY.Resolve(minY, height)
if hi < lo {
return lo
}
span := hi - lo + 1
if p.HeightDistribution == "minecraft:trapezoid" {
plateau := 0
triangle := span - plateau
return lo + int(r.NextIntN(int32((triangle+1)/2))) + int(r.NextIntN(int32(triangle/2+1)))
}
if p.HeightDistribution == "minecraft:very_biased_to_bottom" {
const inner = 8
outer := span - inner + 1
if outer <= 0 {
return lo
}
bound := int(r.NextIntN(int32(outer))) + inner
return lo + int(r.NextIntN(int32(bound)))
}
return lo + int(r.NextIntN(int32(span)))
}
func DecorationRandom(seed int64, chunkX, chunkZ int) (*Legacy, int64) {
random := NewLegacy(0)
decorationSeed := random.SetDecorationSeed(seed, chunkX<<4, chunkZ<<4)
return random, decorationSeed
}
type BiomeGeneration struct {
Carvers json.RawMessage `json:"carvers"`
Features [][]string `json:"features"`
}
var (
featureSetOnce sync.Once
featureSet *FeatureSet
featureSetErr error
)
// LoadFeatureSet parses and validates the committed vanilla 26.1.2 feature
// datapack archive. The result is immutable and shared by all worlds.
func LoadFeatureSet() (*FeatureSet, error) {
featureSetOnce.Do(func() { featureSet, featureSetErr = loadFeatureSet(featureData) })
return featureSet, featureSetErr
}
func (s *FeatureSet) Ore(name string) (OreFeatureConfig, error) {
configured, ok := s.Configured[name]
if !ok || configured.Type != "minecraft:ore" {
return OreFeatureConfig{}, fmt.Errorf("worldgen: %s is not an ore feature", name)
}
var config OreFeatureConfig
if err := json.Unmarshal(configured.Config, &config); err != nil {
return OreFeatureConfig{}, fmt.Errorf("worldgen: decode %s: %w", name, err)
}
if config.Size < 1 || len(config.Targets) == 0 {
return OreFeatureConfig{}, fmt.Errorf("worldgen: invalid ore config %s", name)
}
return config, nil
}
func (s *FeatureSet) Spring(name string) (SpringFeatureConfig, error) {
configured, ok := s.Configured[name]
if !ok || configured.Type != "minecraft:spring_feature" {
return SpringFeatureConfig{}, fmt.Errorf("worldgen: %s is not a spring feature", name)
}
var config SpringFeatureConfig
if err := json.Unmarshal(configured.Config, &config); err != nil {
return SpringFeatureConfig{}, fmt.Errorf("worldgen: decode %s: %w", name, err)
}
if config.State.Name == "" || len(config.ValidBlocks) == 0 || config.HoleCount < 0 || config.RockCount < 0 {
return SpringFeatureConfig{}, fmt.Errorf("worldgen: invalid spring config %s", name)
}
return config, nil
}
func (s *FeatureSet) Tree(name string) (TreeFeatureConfig, error) {
configured, ok := s.Configured[name]
if !ok || configured.Type != "minecraft:tree" {
return TreeFeatureConfig{}, fmt.Errorf("worldgen: %s is not a tree feature", name)
}
var config TreeFeatureConfig
if err := json.Unmarshal(configured.Config, &config); err != nil {
return TreeFeatureConfig{}, fmt.Errorf("worldgen: decode %s: %w", name, err)
}
if config.TrunkPlacer.Type == "" || config.FoliagePlacer.Type == "" || config.TrunkProvider.State.Name == "" || config.FoliageProvider.State.Name == "" {
return TreeFeatureConfig{}, fmt.Errorf("worldgen: invalid tree config %s", name)
}
return config, nil
}
func (s *FeatureSet) RandomSelector(name string) (RandomSelectorConfig, error) {
configured, ok := s.Configured[name]
if !ok || configured.Type != "minecraft:random_selector" {
return RandomSelectorConfig{}, fmt.Errorf("worldgen: %s is not a random selector", name)
}
var raw struct {
Default json.RawMessage `json:"default"`
Features []struct {
Chance float32 `json:"chance"`
Feature json.RawMessage `json:"feature"`
} `json:"features"`
}
if err := json.Unmarshal(configured.Config, &raw); err != nil {
return RandomSelectorConfig{}, err
}
selector := RandomSelectorConfig{Features: make([]RandomSelectorEntry, len(raw.Features))}
var err error
selector.Default, err = parseFeatureRef(raw.Default)
if err != nil {
return RandomSelectorConfig{}, err
}
for i, entry := range raw.Features {
selector.Features[i].Chance = entry.Chance
selector.Features[i].Feature, err = parseFeatureRef(entry.Feature)
if err != nil {
return RandomSelectorConfig{}, err
}
}
return selector, nil
}
func parseFeatureRef(raw json.RawMessage) (FeatureRef, error) {
var name string
if err := json.Unmarshal(raw, &name); err == nil {
return FeatureRef{Name: name}, nil
}
var inline struct {
Feature string `json:"feature"`
Placement []json.RawMessage `json:"placement"`
}
if err := json.Unmarshal(raw, &inline); err != nil || inline.Feature == "" {
return FeatureRef{}, fmt.Errorf("worldgen: invalid feature reference %s", raw)
}
ref := FeatureRef{Name: inline.Feature, Placement: make([]PlacementModifier, len(inline.Placement))}
for i, modifier := range inline.Placement {
if err := json.Unmarshal(modifier, &ref.Placement[i]); err != nil {
return FeatureRef{}, err
}
ref.Placement[i].Raw = modifier
}
return ref, nil
}
func (s *FeatureSet) Placement(name string) (PlacementPlan, error) {
placed, ok := s.Placed[name]
if !ok {
return PlacementPlan{}, fmt.Errorf("worldgen: placed feature %s missing", name)
}
plan := PlacementPlan{Count: CountProvider{Min: 1, Max: 1}, MinY: HeightProvider{AboveBottom: intPtr(0)}, MaxY: HeightProvider{Absolute: intPtr(320)}}
for _, modifier := range placed.Placement {
switch modifier.Type {
case "minecraft:rarity_filter":
var value struct {
Chance int `json:"chance"`
}
if err := json.Unmarshal(modifier.Raw, &value); err != nil || value.Chance < 1 {
return PlacementPlan{}, fmt.Errorf("worldgen: %s invalid rarity filter", name)
}
plan.RarityChance = value.Chance
case "minecraft:count":
var value struct {
Count json.RawMessage `json:"count"`
}
if err := json.Unmarshal(modifier.Raw, &value); err != nil {
return PlacementPlan{}, err
}
count, err := parseIntProvider(value.Count)
if err != nil {
return PlacementPlan{}, fmt.Errorf("worldgen: %s count: %w", name, err)
}
plan.Count = count
case "minecraft:height_range":
var value struct {
Height struct {
Type string `json:"type"`
Min json.RawMessage `json:"min_inclusive"`
Max json.RawMessage `json:"max_inclusive"`
} `json:"height"`
}
if err := json.Unmarshal(modifier.Raw, &value); err != nil {
return PlacementPlan{}, err
}
min, err := parseFeatureHeight(value.Height.Min)
if err != nil {
return PlacementPlan{}, err
}
max, err := parseFeatureHeight(value.Height.Max)
if err != nil {
return PlacementPlan{}, err
}
if value.Height.Type != "minecraft:uniform" && value.Height.Type != "minecraft:trapezoid" &&
value.Height.Type != "minecraft:very_biased_to_bottom" {
return PlacementPlan{}, fmt.Errorf("worldgen: %s unsupported height distribution %q", name, value.Height.Type)
}
plan.HeightDistribution, plan.MinY, plan.MaxY = value.Height.Type, min, max
case "minecraft:in_square", "minecraft:biome", "minecraft:surface_water_depth_filter",
"minecraft:heightmap", "minecraft:block_predicate_filter", "minecraft:noise_threshold_count",
"minecraft:random_offset":
// Coordinate spreading and biome validation are applied by the world
// executor. Keeping them in the parsed plan preserves their order.
default:
return PlacementPlan{}, fmt.Errorf("worldgen: %s unsupported placement modifier %q", name, modifier.Type)
}
}
return plan, nil
}
func parseIntProvider(raw json.RawMessage) (CountProvider, error) {
var fixed int
if err := json.Unmarshal(raw, &fixed); err == nil {
return CountProvider{Min: fixed, Max: fixed}, nil
}
var uniform struct {
Type string `json:"type"`
Min int `json:"min_inclusive"`
Max int `json:"max_inclusive"`
}
if err := json.Unmarshal(raw, &uniform); err == nil && uniform.Type == "minecraft:uniform" {
return CountProvider{Min: uniform.Min, Max: uniform.Max}, nil
}
var weighted struct {
Type string `json:"type"`
Distribution []struct {
Data int `json:"data"`
Weight int `json:"weight"`
} `json:"distribution"`
}
if err := json.Unmarshal(raw, &weighted); err == nil && weighted.Type == "minecraft:weighted_list" {
provider := CountProvider{Weighted: make([]WeightedInt, 0, len(weighted.Distribution))}
for _, entry := range weighted.Distribution {
if entry.Weight > 0 {
provider.Weighted = append(provider.Weighted, WeightedInt{Value: entry.Data, Weight: entry.Weight})
}
}
return provider, nil
}
return CountProvider{}, fmt.Errorf("unsupported count provider %s", raw)
}
func parseFeatureHeight(raw json.RawMessage) (HeightProvider, error) {
var value struct {
Absolute *int `json:"absolute"`
AboveBottom *int `json:"above_bottom"`
BelowTop *int `json:"below_top"`
}
if err := json.Unmarshal(raw, &value); err != nil {
return HeightProvider{}, err
}
if value.Absolute == nil && value.AboveBottom == nil && value.BelowTop == nil {
return HeightProvider{}, fmt.Errorf("unsupported height provider %s", raw)
}
return HeightProvider{Absolute: value.Absolute, AboveBottom: value.AboveBottom, BelowTop: value.BelowTop}, nil
}
func intPtr(value int) *int { return &value }
func loadFeatureSet(data []byte) (*FeatureSet, error) {
zr, err := zip.NewReader(bytes.NewReader(data), int64(len(data)))
if err != nil {
return nil, fmt.Errorf("worldgen: feature archive: %w", err)
}
set := &FeatureSet{
Configured: make(map[string]ConfiguredFeature),
Placed: make(map[string]PlacedFeature),
Biomes: make(map[string]BiomeGeneration),
BlockTags: make(map[string][]string),
}
for _, file := range zr.File {
r, err := file.Open()
if err != nil {
return nil, err
}
var raw json.RawMessage
if err := json.NewDecoder(r).Decode(&raw); err != nil {
r.Close()
return nil, fmt.Errorf("worldgen: decode %s: %w", file.Name, err)
}
r.Close()
name := resourceName(file.Name)
switch {
case strings.Contains(file.Name, "/configured_feature/"):
var value ConfiguredFeature
if err := json.Unmarshal(raw, &value); err != nil {
return nil, fmt.Errorf("worldgen: configured feature %s: %w", name, err)
}
set.Configured[name] = value
case strings.Contains(file.Name, "/placed_feature/"):
var value struct {
Feature string `json:"feature"`
Placement []json.RawMessage `json:"placement"`
}
if err := json.Unmarshal(raw, &value); err != nil {
return nil, fmt.Errorf("worldgen: placed feature %s: %w", name, err)
}
placed := PlacedFeature{Feature: value.Feature, Placement: make([]PlacementModifier, len(value.Placement))}
for i, modifierRaw := range value.Placement {
if err := json.Unmarshal(modifierRaw, &placed.Placement[i]); err != nil {
return nil, fmt.Errorf("worldgen: placed feature %s modifier %d: %w", name, i, err)
}
placed.Placement[i].Raw = modifierRaw
}
set.Placed[name] = placed
case strings.Contains(file.Name, "/biome/"):
var biome BiomeGeneration
if err := json.Unmarshal(raw, &biome); err != nil {
return nil, fmt.Errorf("worldgen: biome %s: %w", name, err)
}
set.Biomes[name] = biome
case strings.Contains(file.Name, "/tags/block/"):
var tag struct {
Values []string `json:"values"`
}
if err := json.Unmarshal(raw, &tag); err != nil {
return nil, fmt.Errorf("worldgen: block tag %s: %w", name, err)
}
set.BlockTags[name] = tag.Values
}
}
if len(set.Configured) < 200 || len(set.Placed) < 250 || len(set.Biomes) < 60 {
return nil, fmt.Errorf("worldgen: incomplete feature archive: %d configured, %d placed, %d biomes",
len(set.Configured), len(set.Placed), len(set.Biomes))
}
for name, placed := range set.Placed {
if strings.HasPrefix(placed.Feature, "minecraft:") {
if _, ok := set.Configured[placed.Feature]; !ok {
return nil, fmt.Errorf("worldgen: placed feature %s references missing %s", name, placed.Feature)
}
}
}
for biomeName, biome := range set.Biomes {
for stage, names := range biome.Features {
for _, name := range names {
if _, ok := set.Placed[name]; !ok {
return nil, fmt.Errorf("worldgen: biome %s stage %d references missing %s", biomeName, stage, name)
}
}
}
}
return set, nil
}
func resourceName(file string) string {
base := strings.TrimSuffix(path.Base(file), ".json")
return "minecraft:" + base
}