Support --ignore-empty for --save-as (fix #551)

src/app/cli/default_cli_delegate.cpp

@@ -92,6 +92,9 @@ void DefaultCliDelegate::saveFile(Context* ctx, const CliOpenFile& cof)
     params.set("slice", cof.slice.c_str());
   }
 
+  if (cof.ignoreEmpty)
+    params.set("ignoreEmpty", "true");
+
   ctx->executeCommand(saveAsCommand, params);
 }
 

src/app/cli/preview_cli_delegate.cpp

@@ -98,6 +98,10 @@ void PreviewCliDelegate::saveFile(Context* ctx, const CliOpenFile& cof)
     std::cout << "  - Trim\n";
   }
 
+  if (cof.ignoreEmpty) {
+    std::cout << "  - Ignore empty frames\n";
+  }
+
   std::cout << "  - Size: "
             << cof.document->sprite()->width() << "x"
             << cof.document->sprite()->height() << "\n";
@@ -136,7 +140,8 @@ void PreviewCliDelegate::saveFile(Context* ctx, const CliOpenFile& cof)
       ctx,
       cof.roi(),
       cof.filename,
-      cof.filenameFormat));
+      cof.filenameFormat,
+      cof.ignoreEmpty));
 
   if (fop) {
     base::paths files;

src/app/commands/cmd_save_file.cpp

@@ -89,6 +89,7 @@ SaveFileBaseCommand::SaveFileBaseCommand(const char* id, CommandFlags flags)
   : Command(id, flags)
 {
   m_useUI = true;
+  m_ignoreEmpty = false;
 }
 
 void SaveFileBaseCommand::onLoadParams(const Params& params)
@@ -113,6 +114,9 @@ void SaveFileBaseCommand::onLoadParams(const Params& params)
 
   std::string useUI = params.get("useUI");
   m_useUI = (useUI.empty() || (useUI == "true"));
+
+  std::string ignoreEmpty = params.get("ignoreEmpty");
+  m_ignoreEmpty = (ignoreEmpty == "true");
 }
 
 // Returns true if there is a current sprite to save.
@@ -194,7 +198,8 @@ void SaveFileBaseCommand::saveDocumentInBackground(
       context,
       roi,
       filename,
-      m_filenameFormat));
+      m_filenameFormat,
+      m_ignoreEmpty));
   if (!fop)
     return;
 

src/app/commands/cmd_save_file.h

@@ -45,6 +45,7 @@ namespace app {
     doc::SelectedFrames m_selFrames;
     bool m_adjustFramesByFrameTag;
     bool m_useUI;
+    bool m_ignoreEmpty;
   };
 
 } // namespace app

src/app/file/file.cpp

@@ -104,7 +104,8 @@ int save_document(Context* context, Doc* document)
     FileOp::createSaveDocumentOperation(
       context,
       FileOpROI(document, "", "", SelectedFrames(), false),
-      document->filename(), ""));
+      document->filename(), "",
+      false));
   if (!fop)
     return -1;
 
@@ -317,14 +318,16 @@ done:;
 FileOp* FileOp::createSaveDocumentOperation(const Context* context,
                                             const FileOpROI& roi,
                                             const std::string& filename,
-                                            const std::string& filenameFormatArg)
+                                            const std::string& filenameFormatArg,
+                                            const bool ignoreEmptyFrames)
 {
   std::unique_ptr<FileOp> fop(
     new FileOp(FileOpSave, const_cast<Context*>(context)));
 
   // Document to save
   fop->m_document = const_cast<Doc*>(roi.document());
   fop->m_roi = roi;
+  fop->m_ignoreEmpty = ignoreEmptyFrames;
 
   // Get the extension of the filename (in lower case)
   LOG("FILE: Saving document \"%s\"\n", filename.c_str());
@@ -744,31 +747,42 @@ void FileOp::operate(IFileOpProgress* progress)
           render.renderSprite(m_seq.image.get(), sprite, frame);
         }
 
-        // Setup the palette.
-        sprite->palette(frame)->copyColorsTo(m_seq.palette);
+        bool save = true;
 
-        // Setup the filename to be used.
-        m_filename = m_seq.filename_list[outputFrame];
+        // Check if we have to ignore empty frames
+        if (m_ignoreEmpty &&
+            !sprite->isOpaque() &&
+            doc::is_empty_image(m_seq.image.get())) {
+          save = false;
+        }
 
-        // Make directories
-        {
-          std::string dir = base::get_file_path(m_filename);
-          try {
-            if (!base::is_directory(dir))
-              base::make_all_directories(dir);
+        if (save) {
+          // Setup the palette.
+          sprite->palette(frame)->copyColorsTo(m_seq.palette);
+
+          // Setup the filename to be used.
+          m_filename = m_seq.filename_list[outputFrame];
+
+          // Make directories
+          {
+            std::string dir = base::get_file_path(m_filename);
+            try {
+              if (!base::is_directory(dir))
+                base::make_all_directories(dir);
+            }
+            catch (const std::exception& ex) {
+              // Ignore errors and make the delegate fail
+              setError("Error creating directory \"%s\"\n%s",
+                       dir.c_str(), ex.what());
+            }
           }
-          catch (const std::exception& ex) {
-            // Ignore errors and make the delegate fail
-            setError("Error creating directory \"%s\"\n%s",
-                     dir.c_str(), ex.what());
-          }
-        }
 
-        // Call the "save" procedure... did it fail?
-        if (!m_format->save(this)) {
-          setError("Error saving frame %d in the file \"%s\"\n",
-                   outputFrame+1, m_filename.c_str());
-          break;
+          // Call the "save" procedure... did it fail?
+          if (!m_format->save(this)) {
+            setError("Error saving frame %d in the file \"%s\"\n",
+                     outputFrame+1, m_filename.c_str());
+            break;
+          }
         }
 
         m_seq.progress_offset += m_seq.progress_fraction;
@@ -1153,6 +1167,7 @@ FileOp::FileOp(FileOpType type, Context* context)
   , m_done(false)
   , m_stop(false)
   , m_oneframe(false)
+  , m_ignoreEmpty(false)
   , m_preserveColorProfile(
       Preferences::instance().color.manage())
   , m_embeddedColorProfile(false)

src/app/file/file.h

@@ -105,7 +105,8 @@ namespace app {
     static FileOp* createSaveDocumentOperation(const Context* context,
                                                const FileOpROI& roi,
                                                const std::string& filename,
-                                               const std::string& filenameFormat);
+                                               const std::string& filenameFormat,
+                                               const bool ignoreEmptyFrames);
 
     ~FileOp();
 
@@ -196,6 +197,7 @@ namespace app {
     bool m_oneframe;            // Load just one frame (in formats
                                 // that support animation like
                                 // GIF/FLI/ASE).
+    bool m_ignoreEmpty;
 
     // Return if we've to save/embed the color space of the document
     // in the file.

src/doc/primitives.cpp

@@ -1,4 +1,5 @@
 // Aseprite Document Library
+// Copyright (c) 2018 Igara Studio S.A.
 // Copyright (c) 2001-2016 David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -295,6 +296,19 @@ void fill_ellipse(Image* image, int x1, int y1, int x2, int y2, color_t color)
 
 namespace {
 
+template<typename ImageTraits>
+bool is_plain_image_templ(const Image* img, const color_t color)
+{
+  const LockImageBits<ImageTraits> bits(img);
+  typename LockImageBits<ImageTraits>::const_iterator it, end;
+  for (it=bits.begin(), end=bits.end(); it!=end; ++it) {
+    if (*it != color)
+      return false;
+  }
+  ASSERT(it == end);
+  return true;
+}
+
 template<typename ImageTraits>
 int count_diff_between_images_templ(const Image* i1, const Image* i2)
 {
@@ -316,6 +330,25 @@ int count_diff_between_images_templ(const Image* i1, const Image* i2)
 
 } // anonymous namespace
 
+bool is_plain_image(const Image* img, color_t c)
+{
+  switch (img->pixelFormat()) {
+    case IMAGE_RGB:       return is_plain_image_templ<RgbTraits>(img, c);
+    case IMAGE_GRAYSCALE: return is_plain_image_templ<GrayscaleTraits>(img, c);
+    case IMAGE_INDEXED:   return is_plain_image_templ<IndexedTraits>(img, c);
+    case IMAGE_BITMAP:    return is_plain_image_templ<BitmapTraits>(img, c);
+  }
+  return false;
+}
+
+bool is_empty_image(const Image* img)
+{
+  color_t c = 0;                // alpha = 0
+  if (img->colorMode() == ColorMode::INDEXED)
+    c = img->maskColor();
+  return is_plain_image(img, 0);
+}
+
 int count_diff_between_images(const Image* i1, const Image* i2)
 {
   if ((i1->pixelFormat() != i2->pixelFormat()) ||

src/doc/primitives.h

@@ -1,4 +1,5 @@
 // Aseprite Document Library
+// Copyright (c) 2018 Igara Studio S.A.
 // Copyright (c) 2001-2016 David Capello
 //
 // This file is released under the terms of the MIT license.
@@ -39,6 +40,9 @@ namespace doc {
   void draw_ellipse(Image* image, int x1, int y1, int x2, int y2, color_t c);
   void fill_ellipse(Image* image, int x1, int y1, int x2, int y2, color_t c);
 
+  bool is_plain_image(const Image* img, color_t c);
+  bool is_empty_image(const Image* img);
+
   int count_diff_between_images(const Image* i1, const Image* i2);
 
   void remap_image(Image* image, const Remap& remap);

src/doc/sprite.cpp

@@ -149,16 +149,21 @@ void Sprite::setColorSpace(const gfx::ColorSpacePtr& colorSpace)
     cel->image()->setColorSpace(colorSpace);
 }
 
+bool Sprite::isOpaque() const
+{
+  Layer* bg = backgroundLayer();
+  return (bg && bg->isVisible());
+}
+
 bool Sprite::needAlpha() const
 {
   switch (pixelFormat()) {
     case IMAGE_RGB:
-    case IMAGE_GRAYSCALE: {
-      Layer* bg = backgroundLayer();
-      return (!bg || !bg->isVisible());
-    }
+    case IMAGE_GRAYSCALE:
+      return !isOpaque();
+    default:
+      return false;
   }
-  return false;
 }
 
 bool Sprite::supportAlpha() const

src/doc/sprite.h

@@ -84,6 +84,9 @@ namespace doc {
     void setSize(int width, int height);
     void setColorSpace(const gfx::ColorSpacePtr& colorSpace);
 
+    // Returns true if the sprite has a background layer and it's visible
+    bool isOpaque() const;
+
     // Returns true if the rendered images will contain alpha values less
     // than 255. Only RGBA and Grayscale images without background needs
     // alpha channel in the render.