Add block shape data

data/block/shape/gen_shape.go

@@ -0,0 +1,110 @@
+// gen_shape.go generates block shape information.
+
+//+build ignore
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/iancoleman/strcase"
+)
+
+const (
+	infoURL = "https://raw.githubusercontent.com/PrismarineJS/minecraft-data/master/data/pc/1.16.1/blockCollisionShapes.json"
+)
+
+func downloadInfo() (map[string]interface{}, error) {
+	resp, err := http.Get(infoURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var data map[string]interface{}
+	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
+func main() {
+	info, err := downloadInfo()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Println(`// Package shape stores information about the shapes of blocks in Minecraft.
+package shape
+
+import (
+  "github.com/Tnze/go-mc/data/block"
+)
+
+// ID describes a numeric shape ID.
+type ID uint32
+
+// Shape describes how collisions should be tested for an object.
+type Shape struct {
+	ID    ID
+  Boxes []BoundingBox
+}
+
+type BoundingTriplet struct {
+  X, Y, Z float64
+}
+
+type BoundingBox struct {
+  Min,Max BoundingTriplet
+}
+
+`)
+
+	fmt.Println()
+	fmt.Println()
+	fmt.Println("// ByBlockID is an index of shapes for each minecraft block variant.")
+	fmt.Println("var ByBlockID = map[block.ID][]ID{")
+	blocks := info["blocks"].(map[string]interface{})
+	for name, shapes := range blocks {
+		switch s := shapes.(type) {
+		case []interface{}:
+			set := make([]string, len(s))
+			for i := range s {
+				set[i] = fmt.Sprint(s[i])
+			}
+			fmt.Printf("  block.%s.ID: []ID{%s},\n", strcase.ToCamel(name), strings.Join(set, ", "))
+		default:
+			fmt.Printf("  block.%s.ID: []ID{%s},\n", strcase.ToCamel(name), fmt.Sprint(s))
+		}
+	}
+	fmt.Println("}")
+
+	fmt.Println()
+	fmt.Println()
+	fmt.Println("// Dimensions describes the bounding boxes of a shape ID.")
+	fmt.Println("var Dimensions = map[ID]Shape{")
+	shapes := info["shapes"].(map[string]interface{})
+	for id, boxes := range shapes {
+		fmt.Printf("  %s: Shape{\n", id)
+		fmt.Printf("    ID: %s,\n", id)
+		fmt.Printf("    Boxes: []BoundingBox{\n")
+		for _, box := range boxes.([]interface{}) {
+			elements := box.([]interface{})
+			if len(elements) != 6 {
+				panic("expected 6 elements")
+			}
+			fmt.Printf("      {\n")
+			fmt.Printf("        Min: BoundingTriplet{X: %v, Y: %v, Z: %v},\n", elements[0], elements[1], elements[2])
+			fmt.Printf("        Max: BoundingTriplet{X: %v, Y: %v, Z: %v},\n", elements[3], elements[4], elements[5])
+			fmt.Printf("      },\n")
+		}
+		fmt.Printf("    },\n")
+		fmt.Println("  },")
+	}
+	fmt.Println("}")
+}