Make doc::RgbMap a regular object (don't need to be an doc::Object)

src/doc/object_type.h

@@ -1,5 +1,5 @@
 // Aseprite Document Library
-// Copyright (C) 2019  Igara Studio S.A.
+// Copyright (C) 2019-2020  Igara Studio S.A.
 // Copyright (C) 2001-2017  David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -12,20 +12,25 @@
 namespace doc {
 
   enum class ObjectType {
-    Unknown,
-    Image,
-    Palette,
-    RgbMap,
-    Path,
-    Mask,
-    Cel,
-    CelData,
-    LayerImage,
-    LayerGroup,
-    Sprite,
-    Document,
-    Tag,
-    Slice,
+    Unknown = 0,
+    Image = 1,
+    Palette = 2,
+
+    // Deprecated values, we cannot re-use these indexes because
+    // backup sessions use them (check readLayer() function in
+    // src/app/crash/read_document.cpp).
+    //RgbMap = 3,
+    //Path = 4,
+
+    Mask = 5,
+    Cel = 6,
+    CelData = 7,
+    LayerImage = 8,
+    LayerGroup = 9,
+    Sprite = 10,
+    Document = 11,
+    Tag = 12,
+    Slice = 13,
   };
 
 } // namespace doc

src/doc/rgbmap.cpp

@@ -1,4 +1,5 @@
 // Aseprite Document Library
+// Copyright (c) 2020 Igara Studio S.A.
 // Copyright (c) 2001-2015 David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -22,8 +23,7 @@ namespace doc {
 #define MAPSIZE (RSIZE*GSIZE*BSIZE*ASIZE)
 
 RgbMap::RgbMap()
-  : Object(ObjectType::RgbMap)
-  , m_map(MAPSIZE)
+  : m_map(MAPSIZE)
   , m_palette(NULL)
   , m_modifications(0)
   , m_maskIndex(0)

src/doc/rgbmap.h

@@ -1,4 +1,5 @@
 // Aseprite Document Library
+// Copyright (c) 2020 Igara Studio S.A.
 // Copyright (c) 2001-2016 David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -19,7 +20,7 @@ namespace doc {
   class Palette;
 
   // It acts like a cache for Palette:findBestfit() calls.
-  class RgbMap : public Object {
+  class RgbMap {
     // Bit activated on m_map entries that aren't yet calculated.
     const int INVALID = 256;