up3

server/block/banner_pattern_layer.go

@@ -0,0 +1,36 @@
+package block
+
+import (
+	"fmt"
+
+	"github.com/df-mc/dragonfly/server/internal/nbtconv"
+	"github.com/df-mc/dragonfly/server/item"
+)
+
+// BannerPatternLayer is a wrapper over BannerPatternType with a colour property.
+type BannerPatternLayer struct {
+	// Type represents the type of banner pattern.
+	Type BannerPatternType
+	// Colour is the colour the pattern should be rendered in.
+	Colour item.Colour
+}
+
+// EncodeNBT encodes the given BannerPatternLayer into an NBT map.
+func (b BannerPatternLayer) EncodeNBT() map[string]any {
+	return map[string]any{
+		"Pattern": bannerPatternID(b.Type),
+		"Color":   int32(invertColour(b.Colour)),
+	}
+}
+
+// DecodeNBT decodes the given NBT map into a BannerPatternLayer and returns it.
+func (b BannerPatternLayer) DecodeNBT(data map[string]any) any {
+	id := nbtconv.String(data, "Pattern")
+	pattern, exists := BannerPatternByID(id)
+	if !exists {
+		panic(fmt.Errorf("unknown banner pattern id %q", id))
+	}
+	b.Type = pattern
+	b.Colour = invertColourID(int16(nbtconv.Int32(data, "Color")))
+	return b
+}