More investigation into animation

internal/idx/idx.go

@@ -0,0 +1,73 @@
+// package idx parses the Idx/WarHammer.idx file.
+//
+// No, I don't know what it's for yet.
+package idx
+
+import (
+	"encoding/binary"
+	//"fmt"
+	"log"
+	"os"
+	//"strings"
+)
+
+type Type1Record struct {
+	Offset1  uint32 // Where the type2 for this type1 is to be found
+	Unknown1 uint32 // ???
+	Offset2  uint32 // Another offset? But what to?
+}
+
+type Type2Record struct {
+	Unknown1 [4]byte // ???
+	Offset   uint32  // Where the type3 for this type2 is to be found
+	Unknown2 [4]byte // ??
+}
+
+type Type3Record struct {
+	First20 [20]byte
+	Last78  [78]byte
+}
+
+type Idx struct {
+	Filename string
+
+	Type1Records [512]Type1Record // Experimentally, there seem to be 512 of these
+	Type2Records []Type2Record
+	Type3Records []Type3Record
+}
+
+func Load(filename string) (*Idx, error) {
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	defer f.Close()
+
+	out := &Idx{Filename: filename}
+
+	if err := binary.Read(f, binary.LittleEndian, &out.Type1Records); err != nil {
+		return nil, err
+	}
+
+	for i, rec := range out.Type1Records {
+		var off1diff uint32
+		var off2diff uint32
+
+		if i > 0 && rec.Offset1 > 0 {
+			lastRec := out.Type1Records[i-1]
+			off1diff = rec.Offset1 - lastRec.Offset1
+			off2diff = rec.Offset2 - lastRec.Offset2
+		}
+
+		log.Printf(
+			"%.3d: 0x%.6x diff=%.6d %.4d 0x%.6x diff=%.6d",
+			i, rec.Offset1, off1diff, rec.Unknown1, rec.Offset2, off2diff,
+			//			i,
+			//			rec.Unknown1[0], rec.Unknown1[1], rec.Unknown1[2], rec.Unknown1[3],
+			//			rec.Unknown1[4], rec.Unknown1[5], rec.Unknown1[6], rec.Unknown1[7],
+		)
+	}
+
+	return out, nil
+}