Make injected rscanvas turn around and call another class which will actually reside in the client, have a fake stub here for it to compile. Fix inject to inject getters on static fields in classes that arent Implemented, fixed signature of injected getters, this seems to work.

src/main/java/net/runelite/deob/injection/Inject.java

@@ -95,6 +95,31 @@ public class Inject
 			sig.addArg(toObType(t));
 		return sig;
 	}
+
+	private Type toApiType(Type t)
+	{
+		// t = vanilla type
+		
+		if (t.isPrimitive())
+			return t;
+		
+		String type = t.getType();
+		type = type.substring(1, type.length() - 1);
+
+		ClassFile cf = vanilla.findClass(type);
+		if (cf == null)
+			return t;
+		
+		for (Class c : cf.getInterfaces().getInterfaces())
+		{
+			if (c.getName().startsWith(API_PACKAGE_BASE.replace('.', '/')))
+			{
+				return new Type("L" + c.getName() + ";", t.getArrayDims());
+			}
+		}
+
+		return t;
+	}
 	
 	public void run()
 	{
@@ -114,8 +139,8 @@ public class Inject
 			assert other != null;
 			
 			java.lang.Class implementingClass = injectInterface(cf, other);
-			if (implementingClass == null)
-				continue;
+			// it can not implement an interface but still have exported static fields, which are
+			// moved to client
 
 			InjectReplace ij = new InjectReplace(cf, other);
 			try
@@ -132,7 +157,7 @@ public class Inject
 			{
 				an = f.getAttributes().getAnnotations();
 				
-				if (an.find(EXPORT) == null)
+				if (an == null || an.find(EXPORT) == null)
 					continue; // not an exported field
 				
 				String exportedName = an.find(EXPORT).getElement().getString();
@@ -153,12 +178,16 @@ public class Inject
 				
 				ClassFile targetClass = f.isStatic() ? vanilla.findClass("client") : other; // target class for getter
 				java.lang.Class targetApiClass = f.isStatic() ? clientClass : implementingClass; // target api class for getter
+				assert targetApiClass != null;
 				
 				java.lang.reflect.Method apiMethod = findImportMethodOnApi(targetApiClass, exportedName);
 				assert apiMethod != null;
 				
 				injectGetter(targetClass, apiMethod, otherf, getter);
 			}
+
+			if (implementingClass == null)
+				continue; // can't export methods from non implementing class
 			
 			for (Method m : cf.getMethods().getMethods())
 			{
@@ -271,7 +300,7 @@ public class Inject
 		assert field.isStatic() || field.getFields().getClassFile() == clazz;
 		
 		Signature sig = new Signature();
-		sig.setTypeOfReturnValue(field.getType());
+		sig.setTypeOfReturnValue(toApiType(field.getType()));
 		Method getterMethod = new Method(clazz.getMethods(), method.getName(), sig);
 		getterMethod.setAccessFlags(Method.ACC_PUBLIC);
 		

src/main/java/net/runelite/inject/RSCanvas.java

@@ -2,26 +2,16 @@ package net.runelite.inject;
 
 import java.awt.Canvas;
 import java.awt.Graphics;
-import java.awt.image.BufferedImage;
+import net.runelite.inject.callbacks.RSCanvasCallback;
 
 public abstract class RSCanvas extends Canvas
 {
-	private final BufferedImage clientBuffer = new BufferedImage(756, 503, BufferedImage.TYPE_INT_RGB);
-	private final BufferedImage gameBuffer = new BufferedImage(756, 503, BufferedImage.TYPE_INT_RGB);
+	private RSCanvasCallback callback = new RSCanvasCallback();
 	
 	@Override
 	public Graphics getGraphics()
 	{
-		Graphics clientGraphics = clientBuffer.getGraphics();
-		clientGraphics.drawImage(gameBuffer, 0, 0, null);
-		//clientGraphics.dispose();
-		
-		//clientGraphics = clientBuffer.getGraphics();
-		clientGraphics.drawString("something, something", 42, 42);
-
 		Graphics superGraphics = super.getGraphics();
-		superGraphics.drawImage(clientBuffer, 0, 0, null);
-		
-		return gameBuffer.getGraphics();
+		return callback.getGraphics(this, superGraphics);
 	}
 }

src/main/java/net/runelite/inject/callbacks/RSCanvasCallback.java

@@ -0,0 +1,12 @@
+package net.runelite.inject.callbacks;
+
+import java.awt.Canvas;
+import java.awt.Graphics;
+
+public class RSCanvasCallback
+{
+	public Graphics getGraphics(Canvas canvas, Graphics graphics)
+	{
+		return graphics;
+	}
+}

src/test/java/net/runelite/deob/injection/InjectTest.java

@@ -10,7 +10,7 @@ import org.junit.Test;
 
 public class InjectTest
 {
-	private static final File DEOBFUSCATED = new File("d:/rs/07/gamepack_v21_mapped.jar");//C:\\Users\\Adam\\.m2\\repository\\net\\runelite\\rs\\rs-client\\1.0-SNAPSHOT\\rs-client-1.0-SNAPSHOT.jar");
+	private static final File DEOBFUSCATED = new File("C:\\Users\\Adam\\.m2\\repository\\net\\runelite\\rs\\rs-client\\1.0-SNAPSHOT\\rs-client-1.0-SNAPSHOT.jar");
 	private static final File VANILLA = new File(InjectTest.class.getResource("/gamepack_v21.jar").getFile());
 	private static final File OUT = new File("d:/rs/07/adamout.jar");