Warning, GIGANTIC COMMIT!

Replaced Keyframe subclasses with Generic Types of Keyframe and replaced all instanceof calls
Replaced implementations of Linear and Spline interpolation to interpolate any Object that extends KeyframeValue and contains at least one public double Field. I'll need this for Keyframe interpolation in CustomImageObject Transformations
Made MarkerKeyframe *no* subclass of Keyframe to avoid conflicts with PositionKeyframe in instanceof checks for Keyframe#getValue
Created KeyframeList which extends ArrayList to provide some helping functions which DRY up the ReplayHandler
Split up ReplayHandler's keyframeList into timeKeyframeList and positionKeyframeList

src/main/java/eu/crushedpixel/replaymod/assets/AssetRepository.java

@@ -101,4 +101,8 @@ public class AssetRepository {
         return new ArrayList<ReplayAsset>(replayAssets.values());
     }
 
+    public ReplayAsset getAssetByUUID(UUID uuid) {
+        return replayAssets.get(uuid);
+    }
+
 }

src/main/java/eu/crushedpixel/replaymod/assets/CustomImageObject.java

@@ -0,0 +1,105 @@
+package eu.crushedpixel.replaymod.assets;
+
+import eu.crushedpixel.replaymod.holders.*;
+import eu.crushedpixel.replaymod.interpolation.GenericSplineInterpolation;
+import eu.crushedpixel.replaymod.interpolation.KeyframeList;
+import eu.crushedpixel.replaymod.registry.ResourceHelper;
+import eu.crushedpixel.replaymod.replay.ReplayHandler;
+import lombok.Getter;
+import lombok.Setter;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.texture.DynamicTexture;
+import net.minecraft.util.ResourceLocation;
+
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.util.UUID;
+
+public class CustomImageObject implements GuiEntryListEntry {
+
+    public CustomImageObject(Transformations transformations, String name, UUID assetUUID) throws IOException {
+        this.name = name;
+
+        setLinkedAsset(assetUUID);
+    }
+
+    @Getter @Setter private String name;
+    @Getter private UUID linkedAsset;
+
+    @Getter @Setter private float width, height;
+
+    public void setLinkedAsset(UUID assetUUID) throws IOException {
+        ReplayAsset asset = ReplayHandler.getAssetRepository().getAssetByUUID(assetUUID);
+
+        if(asset instanceof ReplayImageAsset) {
+            setImage(((ReplayImageAsset)asset).getObject());
+        } else {
+            throw new UnsupportedOperationException("A CustomImageObject requires a ReplayImageAsset");
+        }
+    }
+
+    public void setImage(final BufferedImage bufferedImage) throws IOException {
+
+        this.textureWidth = bufferedImage.getWidth();
+        this.textureHeight = bufferedImage.getHeight();
+
+        float w;
+        float h;
+
+        if(bufferedImage.getWidth() > bufferedImage.getHeight()) {
+            w = 1;
+            h = (bufferedImage.getHeight()/(float)bufferedImage.getWidth());
+        } else {
+            w = (bufferedImage.getWidth()/(float)bufferedImage.getHeight());
+            h = 1;
+        }
+
+        this.setWidth(w);
+        this.setHeight(h);
+
+        Minecraft.getMinecraft().addScheduledTask(new Runnable() {
+            @Override
+            public void run() {
+                resourceLocation = new ResourceLocation("customImages/"+linkedAsset.toString());
+                dynamicTexture = new DynamicTexture(bufferedImage);
+            }
+        });
+    }
+
+    private ResourceLocation resourceLocation;
+    private DynamicTexture dynamicTexture;
+
+    @Getter private float textureWidth, textureHeight;
+
+    public ResourceLocation getResourceLocation() {
+        if(!ResourceHelper.isRegistered(resourceLocation)) {
+            ResourceHelper.registerResource(resourceLocation);
+            Minecraft.getMinecraft().getTextureManager().loadTexture(resourceLocation, dynamicTexture);
+            dynamicTexture.updateDynamicTexture();
+        }
+
+        return resourceLocation;
+    }
+
+    @Override
+    public String getDisplayString() {
+        return name;
+    }
+
+    /**
+     * Keyframing Code
+     */
+
+    private KeyframeList<Keyframe<Position>> anchorPointKeyframes, positionKeyframes, orientationKeyframes;
+    private KeyframeList<Keyframe<Point>> scaleKeyframes;
+    private KeyframeList<Keyframe<TimestampValue>> opacityKeyframes;
+
+    private GenericSplineInterpolation<Position> anchorSpline, positionSpline, orientationSpline;
+    private GenericSplineInterpolation<Point> scaleSpline;
+    private GenericSplineInterpolation<TimestampValue> opacitySpline;
+
+    public Transformations getTransformationsForTimestamp(int timestamp) {
+        return null; //TODO
+    }
+
+}