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: