New eyedropper mode to pick colors from reference layers

data/pref.xml

@@ -55,6 +55,7 @@
     <enum id="EyedropperSample">
       <value id="ALL_LAYERS" value="0" />
       <value id="CURRENT_LAYER" value="1" />
+      <value id="FIRST_REFERENCE_LAYER" value="2" />
     </enum>
     <enum id="SelectionMode">
       <value id="DEFAULT" value="0" />

src/app/color_picker.cpp

@@ -23,6 +23,37 @@
 
 namespace app {
 
+namespace {
+
+bool get_cel_pixel(const Cel* cel,
+                   const double x,
+                   const double y,
+                   const frame_t frame,
+                   color_t& output)
+{
+  gfx::RectF celBounds;
+  if (cel->layer()->isReference())
+    celBounds = cel->boundsF();
+  else
+    celBounds = cel->bounds();
+
+  const doc::Image* image = cel->image();
+  gfx::PointF pos(x, y);
+  if (!celBounds.contains(pos))
+    return false;
+
+  pos.x = (pos.x-celBounds.x)*image->width()/celBounds.w;
+  pos.y = (pos.y-celBounds.y)*image->height()/celBounds.h;
+  const gfx::Point ipos(pos);
+  if (!image->bounds().contains(ipos))
+    return false;
+
+  output = get_pixel(image, ipos.x, ipos.y);
+  return true;
+}
+
+}
+
 ColorPicker::ColorPicker()
   : m_alpha(0)
   , m_layer(NULL)
@@ -53,51 +84,64 @@ void ColorPicker::pickColor(const doc::Site& site,
   }
 
   // Get the color from the image
-  if (mode == FromComposition) { // Pick from the composed image
-    m_color = app::Color::fromImage(
-      sprite->pixelFormat(),
-      render::get_sprite_pixel(sprite, pos.x, pos.y,
-                               site.frame(), proj));
+  switch (mode) {
 
-    doc::CelList cels;
-    sprite->pickCels(pos.x, pos.y, site.frame(), 128, cels);
-    if (!cels.empty())
-      m_layer = cels.front()->layer();
-  }
-  else {                        // Pick from the current layer
-    const Cel* cel = site.cel();
-    if (cel) {
-      gfx::RectF celBounds;
-      if (cel->layer()->isReference())
-        celBounds = cel->boundsF();
-      else
-        celBounds = cel->bounds();
+    // Pick from the composed image
+    case FromComposition: {
+      m_color = app::Color::fromImage(
+        sprite->pixelFormat(),
+        render::get_sprite_pixel(sprite, pos.x, pos.y,
+                                 site.frame(), proj));
 
-      const doc::Image* image = cel->image();
+      doc::CelList cels;
+      sprite->pickCels(pos.x, pos.y, site.frame(), 128,
+                       sprite->allVisibleLayers(), cels);
+      if (!cels.empty())
+        m_layer = cels.front()->layer();
+      break;
+    }
 
-      if (!celBounds.contains(pos))
-        return;
+    // Pick from the current layer
+    case FromActiveLayer: {
+      const Cel* cel = site.cel();
+      if (cel) {
+        doc::color_t imageColor;
+        if (!get_cel_pixel(cel, pos.x, pos.y,
+                           site.frame(), imageColor))
+          return;
 
-      pos.x = (pos.x-celBounds.x)*image->width()/celBounds.w;
-      pos.y = (pos.y-celBounds.y)*image->height()/celBounds.h;
-      const gfx::Point ipos(pos);
-      if (!image->bounds().contains(ipos))
-        return;
+        const doc::Image* image = cel->image();
+        switch (image->pixelFormat()) {
+          case IMAGE_RGB:
+            m_alpha = doc::rgba_geta(imageColor);
+            break;
+          case IMAGE_GRAYSCALE:
+            m_alpha = doc::graya_geta(imageColor);
+            break;
+        }
 
-      const doc::color_t imageColor =
-        get_pixel(image, ipos.x, ipos.y);
-
-      switch (image->pixelFormat()) {
-        case IMAGE_RGB:
-          m_alpha = doc::rgba_geta(imageColor);
-          break;
-        case IMAGE_GRAYSCALE:
-          m_alpha = doc::graya_geta(imageColor);
-          break;
+        m_color = app::Color::fromImage(image->pixelFormat(), imageColor);
+        m_layer = const_cast<Layer*>(site.layer());
       }
+      break;
+    }
 
-      m_color = app::Color::fromImage(image->pixelFormat(), imageColor);
-      m_layer = const_cast<Layer*>(site.layer());
+    case FromFirstReferenceLayer: {
+      doc::CelList cels;
+      sprite->pickCels(pos.x, pos.y, site.frame(), 128,
+                       sprite->allVisibleReferenceLayers(), cels);
+
+      for (const Cel* cel : cels) {
+        doc::color_t imageColor;
+        if (get_cel_pixel(cel, pos.x, pos.y,
+                          site.frame(), imageColor)) {
+          m_color = app::Color::fromImage(
+            cel->image()->pixelFormat(), imageColor);
+          m_layer = cel->layer();
+          break;
+        }
+      }
+      break;
     }
   }
 }

src/app/color_picker.h

@@ -24,7 +24,11 @@ namespace app {
 
   class ColorPicker {
   public:
-    enum Mode { FromComposition, FromActiveLayer };
+    enum Mode {
+      FromComposition,
+      FromActiveLayer,
+      FromFirstReferenceLayer
+    };
 
     ColorPicker();
 

src/app/commands/cmd_eyedropper.cpp

@@ -46,16 +46,21 @@ void EyedropperCommand::pickSample(const doc::Site& site,
 {
   // Check if we've to grab alpha channel or the merged color.
   Preferences& pref = Preferences::instance();
-  bool allLayers =
-    (pref.eyedropper.sample() == app::gen::EyedropperSample::ALL_LAYERS);
+  ColorPicker::Mode mode = ColorPicker::FromComposition;
+  switch (pref.eyedropper.sample()) {
+    case app::gen::EyedropperSample::ALL_LAYERS:
+      mode = ColorPicker::FromComposition;
+      break;
+    case app::gen::EyedropperSample::CURRENT_LAYER:
+      mode = ColorPicker::FromActiveLayer;
+      break;
+    case app::gen::EyedropperSample::FIRST_REFERENCE_LAYER:
+      mode = ColorPicker::FromFirstReferenceLayer;
+      break;
+  }
 
   ColorPicker picker;
-  picker.pickColor(site,
-                   pixelPos,
-                   proj,
-                   (allLayers ?
-                    ColorPicker::FromComposition:
-                    ColorPicker::FromActiveLayer));
+  picker.pickColor(site, pixelPos, proj, mode);
 
   app::gen::EyedropperChannel channel =
     pref.eyedropper.channel();

src/app/ui/context_bar.cpp

@@ -1260,6 +1260,7 @@ public:
 
     m_sample.addItem("All Layers");
     m_sample.addItem("Current Layer");
+    m_sample.addItem("First Reference Layer");
 
     addChild(new Label("Pick:"));
     addChild(&m_channel);

src/doc/layer.cpp

@@ -391,6 +391,22 @@ void LayerGroup::allVisibleLayers(LayerList& list) const
   }
 }
 
+void LayerGroup::allVisibleReferenceLayers(LayerList& list) const
+{
+  for (Layer* child : m_layers) {
+    if (!child->isVisible())
+      continue;
+
+    if (child->isGroup())
+      static_cast<LayerGroup*>(child)->allVisibleReferenceLayers(list);
+
+    if (!child->isReference())
+      continue;
+
+    list.push_back(child);
+  }
+}
+
 void LayerGroup::allBrowsableLayers(LayerList& list) const
 {
   for (Layer* child : m_layers) {

src/doc/layer.h

@@ -192,6 +192,7 @@ namespace doc {
     void allLayers(LayerList& list) const;
     layer_t allLayersCount() const;
     void allVisibleLayers(LayerList& list) const;
+    void allVisibleReferenceLayers(LayerList& list) const;
     void allBrowsableLayers(LayerList& list) const;
 
     void getCels(CelList& cels) const override;

src/doc/sprite.cpp

@@ -449,13 +449,17 @@ void Sprite::remapImages(frame_t frameFrom, frame_t frameTo, const Remap& remap)
 //////////////////////////////////////////////////////////////////////
 // Drawing
 
-void Sprite::pickCels(double x, double y, frame_t frame, int opacityThreshold, CelList& cels) const
+void Sprite::pickCels(const double x,
+                      const double y,
+                      const frame_t frame,
+                      const int opacityThreshold,
+                      const LayerList& layers,
+                      CelList& cels) const
 {
-  LayerList layers = allVisibleLayers();
   gfx::PointF pos(x, y);
 
   for (int i=(int)layers.size()-1; i>=0; --i) {
-    Layer* layer = layers[i];
+    const Layer* layer = layers[i];
     if (!layer->isImage())
       continue;
 
@@ -463,7 +467,7 @@ void Sprite::pickCels(double x, double y, frame_t frame, int opacityThreshold, C
     if (!cel)
       continue;
 
-    Image* image = cel->image();
+    const Image* image = cel->image();
     if (!image)
       continue;
 
@@ -522,6 +526,13 @@ LayerList Sprite::allVisibleLayers() const
   return list;
 }
 
+LayerList Sprite::allVisibleReferenceLayers() const
+{
+  LayerList list;
+  m_root->allVisibleReferenceLayers(list);
+  return list;
+}
+
 LayerList Sprite::allBrowsableLayers() const
 {
   LayerList list;

src/doc/sprite.h

@@ -140,13 +140,19 @@ namespace doc {
     void replaceImage(ObjectId curImageId, const ImageRef& newImage);
     void getImages(std::vector<Image*>& images) const;
     void remapImages(frame_t frameFrom, frame_t frameTo, const Remap& remap);
-    void pickCels(double x, double y, frame_t frame, int opacityThreshold, CelList& cels) const;
+    void pickCels(const double x,
+                  const double y,
+                  const frame_t frame,
+                  const int opacityThreshold,
+                  const LayerList& layers,
+                  CelList& cels) const;
 
     ////////////////////////////////////////
     // Iterators
 
     LayerList allLayers() const;
     LayerList allVisibleLayers() const;
+    LayerList allVisibleReferenceLayers() const;
     LayerList allBrowsableLayers() const;
 
     CelsRange cels() const;