diff --git a/src/AtlasLayerCombo.cpp b/src/AtlasLayerCombo.cpp
new file mode 100644
index 0000000..8f9537e
--- /dev/null
+++ b/src/AtlasLayerCombo.cpp
@@ -0,0 +1 @@
+// nothing yet
diff --git a/src/AtlasLayerCombo.h b/src/AtlasLayerCombo.h
new file mode 100644
index 0000000..8e37f7a
--- /dev/null
+++ b/src/AtlasLayerCombo.h
@@ -0,0 +1,72 @@
+#pragma once
+
+#include "ofMain.h"
+#include <ft2build.h>
+#include FT_FREETYPE_H
+#include "Layer.h"
+#include "Utils.h"
+#include <type_traits>
+#include <unordered_map>
+/*********
+ *
+ * plan:
+ * -> GPUFont has one font per layer
+ * -> use ofShader
+ * -> single glyph buffer in AtlasLayerCombo
+ * -> single curve buffer in AtlasLayerCombo
+ *
+ */
+
+namespace ofxVariableLab {
+
+struct ComboIdentifier {
+    std::string fontPath = "data/celines-fonts/Version-2-var.ttf";
+    Layer::Type type = Layer::MSDFGEN;
+
+    bool operator==(const ComboIdentifier & other) const {
+        return (this->fontPath == other.fontPath
+                && this->type == other.type);
+    }
+};
+
+class AtlasLayerCombo {
+    public:
+        virtual void setup(const ComboIdentifier & identifier) = 0;
+        virtual void update() = 0;
+        virtual void careForChild(shared_ptr <Layer> layer) = 0;
+        virtual const ComboIdentifier & getIdentifier() const = 0;
+
+        bool operator==(const AtlasLayerCombo & other) const {
+            return (this->getIdentifier() == other.getIdentifier());
+        }
+};
+}
+namespace std {
+template <>
+struct hash <ofxVariableLab::ComboIdentifier> {
+    std::size_t operator()(const ofxVariableLab::ComboIdentifier & k) const {
+        using std::size_t;
+        using std::hash;
+        using std::string;
+
+        size_t seed = 0;
+        ofxVariableLab::hash_combine(seed, k.fontPath);
+        ofxVariableLab::hash_combine(seed, k.type);
+
+        return seed;
+    }
+};
+template <>
+struct hash <ofxVariableLab::AtlasLayerCombo> {
+    std::size_t operator()(const ofxVariableLab::AtlasLayerCombo & k) const {
+        using std::size_t;
+        using std::hash;
+        using std::string;
+
+        size_t seed = 0;
+        ofxVariableLab::hash_combine(seed, k.getIdentifier());
+
+        return seed;
+    }
+};
+}
diff --git a/src/GPUFontAtlasLayerCombo.cpp b/src/GPUFontAtlasLayerCombo.cpp
new file mode 100644
index 0000000..01306d6
--- /dev/null
+++ b/src/GPUFontAtlasLayerCombo.cpp
@@ -0,0 +1,18 @@
+#include "GPUFontAtlasLayerCombo.h"
+
+namespace ofxVariableLab {
+
+void GPUFontAtlasLayerCombo::setup(const ComboIdentifier & identifier){
+}
+void GPUFontAtlasLayerCombo::update(){
+}
+void GPUFontAtlasLayerCombo::careForChild(shared_ptr <Layer> layer){
+}
+const ComboIdentifier & GPUFontAtlasLayerCombo::getIdentifier() const {
+    return identifier;
+}
+const vector <shared_ptr <GPUFontLayer> > & GPUFontAtlasLayerCombo::getLayers(){
+    return layers;
+}
+
+}
diff --git a/src/GPUFontAtlasLayerCombo.h b/src/GPUFontAtlasLayerCombo.h
new file mode 100644
index 0000000..3bd2dce
--- /dev/null
+++ b/src/GPUFontAtlasLayerCombo.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include "ofMain.h"
+#include "AtlasLayerCombo.h"
+#include "GPUFontLayer.h"
+
+namespace ofxVariableLab {
+class GPUFontAtlasLayerCombo : public AtlasLayerCombo {
+    public:
+        void setup(const ComboIdentifier & identifier) override;
+        void update() override;
+        void careForChild(shared_ptr <Layer> layer) override;
+        const ComboIdentifier & getIdentifier() const override;
+        const vector <shared_ptr <GPUFontLayer> > & getLayers();
+        shared_ptr <ofxGPUFont::Font> font;
+
+    private:
+        FT_Library library;
+        vector <shared_ptr <GPUFontLayer> > layers;
+        shared_ptr <ofShader> gpuFontShader;
+        ComboIdentifier identifier;
+        bool isDirty = false;
+};
+
+}
diff --git a/src/LayerComposition.cpp b/src/LayerComposition.cpp
index 8c6c821..6fc3f07 100644
--- a/src/LayerComposition.cpp
+++ b/src/LayerComposition.cpp
@@ -7,61 +7,6 @@
 
 namespace ofxVariableLab {
 
-void MsdfAtlasLayerCombo::setup(const ComboIdentifier & layerIdentifier){
-    this->identifier = layerIdentifier;
-    ofxMsdfgen::AtlasSettings atlasSettings;
-    //settings.characters = "ABCDEFGHIJKL";
-    atlasSettings.scale = 64;
-    atlasSettings.minimumScale = 64;
-    atlasSettings.characters = "";
-    atlasSettings.maxInterpolationStepSize = 50.0;
-
-    atlas = make_shared <ofxMsdfgen::Atlas>();
-
-    msdfShader = make_shared <ofShader>();
-    #ifdef TARGET_EMSCRIPTEN
-        msdfShader->load("ofxMsdfgen/shaders/mix/ES3/shader");
-    #else
-        msdfShader->load("ofxMsdfgen/shaders/mix/GL3/shader");
-    #endif
-
-    atlas->setup(this->identifier.fontPath, atlasSettings);
-}
-
-void MsdfAtlasLayerCombo::update(){
-    if(isDirty){
-        atlas->generate();
-        isDirty = false;
-    }
-}
-
-void MsdfAtlasLayerCombo::careForChild(shared_ptr <Layer> layer){
-    shared_ptr <MsdfLayer> msdfLayer = dynamic_pointer_cast <MsdfLayer>(layer);
-    msdfLayer->setAtlas(this->atlas);
-    msdfLayer->setShader(msdfShader);
-    auto & as = atlas->settings;
-    for(const char c : layer->getProps().text){
-        if(as.characters.find(c) == std::string::npos){
-            // not found
-            as.characters += c;
-            isDirty = true;
-        }
-    }
-    layers.push_back(msdfLayer);
-}
-
-const ComboIdentifier & MsdfAtlasLayerCombo::getIdentifier() const {
-    return identifier;
-}
-
-const ofImage & MsdfAtlasLayerCombo::getAtlasImage(){
-    return atlas->getAtlasImage();
-}
-
-string MsdfAtlasLayerCombo::getAtlasImagePath(){
-    return atlas->getAtlasPath();
-}
-
 void LayerComposition::setup(){
 }
 
@@ -124,10 +69,6 @@ shared_ptr <Layer> LayerComposition::getLayer(const LayerID & layerID){
     return layers[layerID];
 }
 
-const ofImage & LayerComposition::getAtlasImage(const ComboIdentifier & identifier){
-    return atlasLayerCombos[identifier]->getAtlasImage();
-}
-
 void LayerComposition::draw() const {
     for(const auto & layer_it : layers){
         layer_it.second->draw();
diff --git a/src/LayerComposition.h b/src/LayerComposition.h
index e98f046..6c7a489 100644
--- a/src/LayerComposition.h
+++ b/src/LayerComposition.h
@@ -1,124 +1,19 @@
 #pragma once
 
-#include "Utils.h"
 #include "ofMain.h"
-#include "ofxMsdfgen.h"
-#include "Layer.h"
+#include "AtlasLayerCombo.h"
+#include "MsdfAtlasLayerCombo.h"
 #include "MsdfLayer.h"
+#include "GPUFontAtlasLayerCombo.h"
 #include "GPUFontLayer.h"
-#include "Utils.h"
-#include <type_traits>
-#include <unordered_map>
-/*********
- *
- * plan:
- * -> GPUFont has one font per layer
- * -> use ofShader
- * -> single glyph buffer in AtlasLayerCombo
- * -> single curve buffer in AtlasLayerCombo
- *
- */
 
 namespace ofxVariableLab {
 
-struct ComboIdentifier {
-    std::string fontPath = "data/celines-fonts/Version-2-var.ttf";
-    Layer::Type type = Layer::MSDFGEN;
-
-    bool operator==(const ComboIdentifier & other) const {
-        return (this->fontPath == other.fontPath
-                && this->type == other.type);
-    }
-};
-
-class AtlasLayerCombo {
-    public:
-        virtual void setup(const ComboIdentifier & identifier) = 0;
-        virtual void update() = 0;
-        virtual void careForChild(shared_ptr <Layer> layer) = 0;
-        virtual const ComboIdentifier & getIdentifier() const = 0;
-        virtual const ofImage & getAtlasImage() = 0;
-        virtual string getAtlasImagePath() = 0;
-
-        bool operator==(const AtlasLayerCombo & other) const {
-            return (this->getIdentifier() == other.getIdentifier());
-        }
-};
-}
-namespace std {
-template <>
-struct hash <ofxVariableLab::ComboIdentifier> {
-    std::size_t operator()(const ofxVariableLab::ComboIdentifier & k) const {
-        using std::size_t;
-        using std::hash;
-        using std::string;
-
-        size_t seed = 0;
-        ofxVariableLab::hash_combine(seed, k.fontPath);
-        ofxVariableLab::hash_combine(seed, k.type);
-
-        return seed;
-    }
-};
-template <>
-struct hash <ofxVariableLab::AtlasLayerCombo> {
-    std::size_t operator()(const ofxVariableLab::AtlasLayerCombo & k) const {
-        using std::size_t;
-        using std::hash;
-        using std::string;
-
-        size_t seed = 0;
-        ofxVariableLab::hash_combine(seed, k.getIdentifier());
-
-        return seed;
-    }
-};
-}
-namespace ofxVariableLab {
-
-class MsdfAtlasLayerCombo : public AtlasLayerCombo {
-    public:
-        void setup(const ComboIdentifier & identifier) override;
-        void update() override;
-        void careForChild(shared_ptr <Layer> layer) override;
-        const ComboIdentifier & getIdentifier() const override;
-        const ofImage & getAtlasImage() override;
-        string getAtlasImagePath() override;
-        shared_ptr <Layer> getLayer();
-        shared_ptr <ofxMsdfgen::Atlas> atlas;
-
-    private:
-        vector <shared_ptr <MsdfLayer> > layers;
-        vector <ofxMsdfgen::GlyphGeometry> glyphGeometries;
-        shared_ptr <ofShader> msdfShader;
-        ComboIdentifier identifier;
-        bool isDirty = false;
-};
-
-class GPUFontAtlasLayerCombo : public AtlasLayerCombo {
-    public:
-        void setup(const ComboIdentifier & identifier) override;
-        void update() override;
-        void careForChild(shared_ptr <Layer> layer) override;
-        const ComboIdentifier & getIdentifier() const override;
-        const ofImage & getAtlasImage() override;
-        string getAtlasImagePath() override;
-        shared_ptr <Layer> getLayer();
-        shared_ptr <ofxGPUFont::Atlas> atlas;
-
-    private:
-        vector <shared_ptr <GPUFontLayer> > layers;
-        shared_ptr <ofShader> gpuFontShader;
-        ComboIdentifier identifier;
-        bool isDirty = false;
-};
-
 class LayerComposition {
     public:
         void setup();
         void update();
         void draw() const;
-        const ofImage & getAtlasImage(const ComboIdentifier & identifier);
         LayerID addLayer(const ComboIdentifier & identifier,
                          const string & text,
                          const std::vector <FontVariation> & variations);
diff --git a/src/MsdfAtlasLayerCombo.cpp b/src/MsdfAtlasLayerCombo.cpp
new file mode 100644
index 0000000..7cc3a15
--- /dev/null
+++ b/src/MsdfAtlasLayerCombo.cpp
@@ -0,0 +1,59 @@
+#include "MsdfAtlasLayerCombo.h"
+
+namespace ofxVariableLab {
+
+void MsdfAtlasLayerCombo::setup(const ComboIdentifier & layerIdentifier){
+    this->identifier = layerIdentifier;
+    ofxMsdfgen::AtlasSettings atlasSettings;
+    //settings.characters = "ABCDEFGHIJKL";
+    atlasSettings.scale = 64;
+    atlasSettings.minimumScale = 64;
+    atlasSettings.characters = "";
+    atlasSettings.maxInterpolationStepSize = 50.0;
+
+    atlas = make_shared <ofxMsdfgen::Atlas>();
+
+    msdfShader = make_shared <ofShader>();
+    #ifdef TARGET_EMSCRIPTEN
+        msdfShader->load("ofxMsdfgen/shaders/mix/ES3/shader");
+    #else
+        msdfShader->load("ofxMsdfgen/shaders/mix/GL3/shader");
+    #endif
+
+    atlas->setup(this->identifier.fontPath, atlasSettings);
+}
+
+void MsdfAtlasLayerCombo::update(){
+    if(isDirty){
+        atlas->generate();
+        isDirty = false;
+    }
+}
+
+void MsdfAtlasLayerCombo::careForChild(shared_ptr <Layer> layer){
+    shared_ptr <MsdfLayer> msdfLayer = dynamic_pointer_cast <MsdfLayer>(layer);
+    msdfLayer->setAtlas(this->atlas);
+    msdfLayer->setShader(msdfShader);
+    auto & as = atlas->settings;
+    for(const char c : layer->getProps().text){
+        if(as.characters.find(c) == std::string::npos){
+            // not found
+            as.characters += c;
+            isDirty = true;
+        }
+    }
+    layers.push_back(msdfLayer);
+}
+
+const ComboIdentifier & MsdfAtlasLayerCombo::getIdentifier() const {
+    return identifier;
+}
+
+const ofImage & MsdfAtlasLayerCombo::getAtlasImage(){
+    return atlas->getAtlasImage();
+}
+
+string MsdfAtlasLayerCombo::getAtlasImagePath(){
+    return atlas->getAtlasPath();
+}
+}
diff --git a/src/MsdfAtlasLayerCombo.h b/src/MsdfAtlasLayerCombo.h
new file mode 100644
index 0000000..a07d1c8
--- /dev/null
+++ b/src/MsdfAtlasLayerCombo.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include "AtlasLayerCombo.h"
+#include "MsdfLayer.h"
+
+namespace ofxVariableLab {
+class MsdfAtlasLayerCombo : public AtlasLayerCombo {
+    public:
+        void setup(const ComboIdentifier & identifier) override;
+        void update() override;
+        void careForChild(shared_ptr <Layer> layer) override;
+        const ComboIdentifier & getIdentifier() const override;
+        const ofImage & getAtlasImage();
+        string getAtlasImagePath();
+        shared_ptr <Layer> getLayer(); // TODO: is this used
+        shared_ptr <ofxMsdfgen::Atlas> atlas;
+
+    private:
+        vector <shared_ptr <MsdfLayer> > layers;
+        vector <ofxMsdfgen::GlyphGeometry> glyphGeometries;
+        shared_ptr <ofShader> msdfShader;
+        ComboIdentifier identifier;
+        bool isDirty = false;
+};
+}