Add option for color quantization in the ColorBar options popup

data/gui.xml

@@ -745,6 +745,8 @@
       <item command="SavePalette" text="Save as Default Palette">
         <param name="preset" value="default" />
       </item>
+      <separator />
+      <item command="ColorQuantization" text="Create Palette from RGB Image" />
     </menu>
 
   </menus>

src/app/CMakeLists.txt

@@ -136,6 +136,7 @@ add_library(app-lib
   commands/cmd_clear.cpp
   commands/cmd_clear_cel.cpp
   commands/cmd_close_file.cpp
+  commands/cmd_color_quantization.cpp
   commands/cmd_configure_tools.cpp
   commands/cmd_copy.cpp
   commands/cmd_copy_cel.cpp

src/app/commands/cmd_color_quantization.cpp

@@ -0,0 +1,111 @@
+// Aseprite
+// Copyright (C) 2001-2015  David Capello
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License version 2 as
+// published by the Free Software Foundation.
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "app/cmd/set_palette.h"
+#include "app/commands/command.h"
+#include "app/console.h"
+#include "app/context.h"
+#include "app/context_access.h"
+#include "app/modules/palettes.h"
+#include "app/transaction.h"
+#include "app/ui/color_bar.h"
+#include "app/ui_context.h"
+#include "base/unique_ptr.h"
+#include "doc/palette.h"
+#include "doc/sprite.h"
+#include "render/quantization.h"
+#include "ui/manager.h"
+
+namespace app {
+
+class ColorQuantizationCommand : public Command {
+public:
+  ColorQuantizationCommand();
+  Command* clone() const override { return new ColorQuantizationCommand(*this); }
+
+protected:
+  bool onEnabled(Context* context) override;
+  void onExecute(Context* context) override;
+};
+
+ColorQuantizationCommand::ColorQuantizationCommand()
+  : Command("ColorQuantization",
+            "Color Quantization",
+            CmdRecordableFlag)
+{
+}
+
+bool ColorQuantizationCommand::onEnabled(Context* context)
+{
+  ContextWriter writer(context);
+  Sprite* sprite(writer.sprite());
+  return (sprite && sprite->pixelFormat() == IMAGE_RGB);
+}
+
+void ColorQuantizationCommand::onExecute(Context* context)
+{
+  try {
+    ContextWriter writer(UIContext::instance(), 500);
+    Sprite* sprite = writer.sprite();
+    frame_t frame = writer.frame();
+    if (sprite) {
+      PaletteView::SelectedEntries entries;
+      ColorBar::instance()->getPaletteView()->getSelectedEntries(entries);
+
+      // TODO convert SelectedEntries into a class, and put the
+      // following lines in that class it is used several times (here
+      // and in ColorBar)
+
+      int n = 0;
+      for (bool state : entries) {
+        if (state)
+          ++n;
+      }
+
+      if (n < 2) {
+        n = 0;
+        for (auto& state : entries) {
+          state = true;
+          ++n;
+        }
+      }
+
+      Palette palette(frame, n);
+      render::create_palette_from_rgb(sprite, frame, &palette);
+
+      Palette newPalette(*get_current_palette());
+
+      int i = 0, j = 0;
+      for (bool state : entries) {
+        if (state)
+          newPalette.setEntry(i, palette.getEntry(j++));
+        ++i;
+      }
+
+      Transaction transaction(writer.context(), "Color Quantization", ModifyDocument);
+      transaction.execute(new cmd::SetPalette(sprite, frame, &newPalette));
+      transaction.commit();
+
+      set_current_palette(&newPalette, false);
+      ui::Manager::getDefault()->invalidate();
+    }
+  }
+  catch (base::Exception& e) {
+    Console::showException(e);
+  }
+}
+
+Command* CommandFactory::createColorQuantizationCommand()
+{
+  return new ColorQuantizationCommand;
+}
+
+} // namespace app

src/app/commands/commands_list.h

@@ -20,6 +20,7 @@ FOR_EACH_COMMAND(ClearCel)
 FOR_EACH_COMMAND(CloseAllFiles)
 FOR_EACH_COMMAND(CloseFile)
 FOR_EACH_COMMAND(ColorCurve)
+FOR_EACH_COMMAND(ColorQuantization)
 FOR_EACH_COMMAND(ConfigureTools)
 FOR_EACH_COMMAND(ConvolutionMatrix)
 FOR_EACH_COMMAND(Copy)

src/render/quantization.cpp

@@ -47,7 +47,7 @@ Palette* create_palette_from_rgb(
   Palette* palette)
 {
   if (!palette)
-    palette = new Palette(frame_t(0), 256);
+    palette = new Palette(frame_t(0), Palette::MaxColors);
 
   bool has_background_layer = (sprite->backgroundLayer() != NULL);
 
@@ -481,7 +481,7 @@ void PaletteOptimizer::calculate(Palette* palette, bool has_background_layer)
   // Indexed).
   int first_usable_entry = (has_background_layer ? 0: 1);
   //int used_colors =
-  m_histogram.createOptimizedPalette(palette, first_usable_entry, 255);
+  m_histogram.createOptimizedPalette(palette, first_usable_entry, palette->size()-1);
   //palette->resize(first_usable_entry+used_colors);   // TODO
 }