Discover how frames are encoded, use that knowledge to (finally) get the viewport locked in

internal/maps/maps.go

@@ -26,7 +26,7 @@ const (
 
 	CellSize = 16 // seems to be
 
-	cellDataOffset = 0x120 // tentatively
+	cellDataOffset = 0x110 // tentatively
 	cellCount      = MaxHeight * MaxLength * MaxWidth
 )
 
@@ -68,18 +68,28 @@ func (h Header) MapSetFilename() string {
 	return string(h.SetName[0:idx:idx]) + ".set"
 }
 
+type ObjRef struct {
+	AreaByte            byte
+	FrameAndUnknownByte byte
+}
+
+// The index into a set palette to retrieve the object
+func (o ObjRef) Index() int {
+	return int(o.AreaByte)
+}
+
+func (o ObjRef) Frame() int {
+	return int(o.FrameAndUnknownByte - 0x80)
+}
+
 type Cell struct {
 	DoorAndCanisterRelated    byte
 	DoorLockAndReactorRelated byte
 	Unknown2                  byte
-	Object0SurfaceArea        byte
-	Unknown4                  byte
-	Object1LeftArea           byte
-	Unknown6                  byte
-	Object2RightArea          byte
-	Unknown8                  byte
-	Object3CenterArea         byte
-	Unknown10                 byte
+	Surface                   ObjRef
+	Left                      ObjRef
+	Right                     ObjRef
+	Center                    ObjRef
 	Unknown11                 byte
 	Unknown12                 byte
 	Unknown13                 byte
@@ -96,21 +106,21 @@ func (c *Cell) At(n int) byte {
 	case 2:
 		return c.Unknown2
 	case 3:
-		return c.Object0SurfaceArea
+		return c.Surface.AreaByte
 	case 4:
-		return c.Unknown4
+		return c.Surface.FrameAndUnknownByte
 	case 5:
-		return c.Object1LeftArea
+		return c.Left.AreaByte
 	case 6:
-		return c.Unknown6
+		return c.Left.FrameAndUnknownByte
 	case 7:
-		return c.Object2RightArea
+		return c.Right.AreaByte
 	case 8:
-		return c.Unknown8
+		return c.Right.FrameAndUnknownByte
 	case 9:
-		return c.Object3CenterArea
+		return c.Center.AreaByte
 	case 10:
-		return c.Unknown10
+		return c.Center.FrameAndUnknownByte
 	case 11:
 		return c.Unknown11
 	case 12:

internal/sets/sets.go

@@ -19,13 +19,13 @@ type MapSet struct {
 	Palette []string
 }
 
-func LoadSets(dir string) (map[string]MapSet, error) {
+func LoadSets(dir string) (map[string]*MapSet, error) {
 	fis, err := ioutil.ReadDir(dir)
 	if err != nil {
 		return nil, err
 	}
 
-	out := make(map[string]MapSet, len(fis))
+	out := make(map[string]*MapSet, len(fis))
 
 	for _, fi := range fis {
 		filename := filepath.Join(dir, fi.Name())
@@ -48,35 +48,34 @@ func LoadSets(dir string) (map[string]MapSet, error) {
 	return out, nil
 }
 
-func LoadSet(filename string) (MapSet, error) {
-	var out MapSet
-	var err error
+func LoadSet(filename string) (*MapSet, error) {
+	out := &MapSet{}
 
 	s, err := asciiscan.New(filename)
 	if err != nil {
-		return out, err
+		return nil, err
 	}
 
 	defer s.Close()
 
 	out.Description, err = s.ConsumeString()
 	if err != nil {
-		return out, err
+		return nil, err
 	}
 
 	out.Defs, err = consumeDefs(s)
 	if err != nil {
-		return out, err
+		return nil, err
 	}
 
 	for {
 		str, err := s.ConsumeString()
 		if err != nil {
 			if err == io.EOF {
-				err = nil
+				return out, nil
 			}
 
-			return out, err
+			return nil, err
 		}
 
 		out.Palette = append(out.Palette, str)