Fix export sprite sheet to RGB is not exporting the palette (fix #3881)

src/app/doc_exporter.cpp

@@ -1180,10 +1180,13 @@ Doc* DocExporter::createEmptyTexture(const Samples& samples,
                                      base::task_token& token) const
 {
   ColorMode colorMode = ColorMode::INDEXED;
-  Palette* palette = nullptr;
+  Palette palette(0, 0);
   int maxColors = 256;
   gfx::ColorSpaceRef colorSpace;
   color_t transparentColor = 0;
+  const bool textureSupportsPalette =
+    (m_textureFilename.empty() || // This is the preview and we create the palette anyway
+    format_supports_palette(m_textureFilename));
 
   for (const auto& sample : samples) {
     if (token.canceled())
@@ -1210,15 +1213,22 @@ Doc* DocExporter::createEmptyTexture(const Samples& samples,
       else if (sample.sprite()->getPalettes().size() > 1) {
         colorMode = ColorMode::RGB;
       }
-      else if (palette &&
-               palette->countDiff(sample.sprite()->palette(frame_t(0)),
-                                  nullptr, nullptr) > 0) {
+      else if (palette.size() > 0 &&
+               palette.countDiff(sample.sprite()->palette(frame_t(0)),
+                                 nullptr, nullptr) > 0) {
         colorMode = ColorMode::RGB;
       }
-      else if (!palette) {
-        palette = sample.sprite()->palette(frame_t(0));
+      else if (palette.size() == 0) {
+        palette = *sample.sprite()->palette(frame_t(0));
         transparentColor = sample.sprite()->transparentColor();
       }
+      if (colorMode == ColorMode::RGB &&
+          textureSupportsPalette &&
+          sample.sprite() &&
+          sample.sprite()->getPalettes()[0]) {
+        Palette* samplePalette = sample.sprite()->getPalettes()[0];
+        palette.addNonRepeatedColors(samplePalette);
+      }
     }
   }
 
@@ -1236,8 +1246,8 @@ Doc* DocExporter::createEmptyTexture(const Samples& samples,
       maxColors,
       m_docBuf));
 
-  if (palette)
-    sprite->setPalette(palette, false);
+  if (palette.size() > 0)
+    sprite->setPalette(&palette, false);
 
   std::unique_ptr<Doc> document(new Doc(sprite.get()));
   sprite.release();

src/app/file/file.cpp

@@ -286,6 +286,16 @@ bool is_static_image_format(const std::string& filename)
   return (format && format->support(FILE_SUPPORT_SEQUENCES));
 }
 
+bool format_supports_palette(const std::string& filename)
+{
+  // Get the format through the extension of the filename
+  FileFormat* format =
+    FileFormatsManager::instance()
+    ->getFileFormat(dio::detect_format_by_file_extension(filename));
+
+  return (format && format->support(FILE_SUPPORT_PALETTES));
+}
+
 FileOpROI::FileOpROI()
   : m_document(nullptr)
   , m_slice(nullptr)

src/app/file/file.h

@@ -365,6 +365,9 @@ namespace app {
   // as sequence of files).
   bool is_static_image_format(const std::string& filename);
 
+  // Returns true if the given file format supports palette/s
+  bool format_supports_palette(const std::string& filename);
+
 } // namespace app
 
 #endif

src/doc/palette.cpp

@@ -175,6 +175,22 @@ int Palette::countDiff(const Palette* other, int* from, int* to) const
   return diff;
 }
 
+void Palette::addNonRepeatedColors(const Palette* palette,
+                                   const int max)
+{
+  ASSERT(palette);
+  if (!palette || size() >= max)
+    return;
+  for (int i=0; i < palette->size(); i++) {
+    color_t newColor = palette->getEntry(i);
+    if (!findExactMatch(newColor)) {
+      addEntry(newColor);
+      if (size() >= max)
+        return;
+    }
+  }
+}
+
 bool Palette::isBlack() const
 {
   for (std::size_t c=0; c<m_colors.size(); ++c)

src/doc/palette.h

@@ -86,6 +86,9 @@ namespace doc {
 
     int countDiff(const Palette* other, int* from, int* to) const;
 
+    void addNonRepeatedColors(const Palette* palette,
+                              const int max = 256);
+
     bool operator==(const Palette& other) const {
       return (countDiff(&other, nullptr, nullptr) == 0);
     }