add embiggen, remove complicated constructor

invokeai/backend/generator/base.py

@@ -129,7 +129,8 @@ class InvokeAIGenerator(metaclass=ABCMeta):
             scheduler_name=generator_args.get('scheduler')
         )
         uc, c, extra_conditioning_info = get_uc_and_c_and_ec(prompt,model=model)
-        generator = self.load_generator(model, self._generator_name())
+        gen_class = self._generator_class()
+        generator = gen_class(model, self.params.precision)
         if self.params.variation_amount > 0:
             generator.set_variation(generator_args.get('seed'),
                                     generator_args.get('variation_amount'),
@@ -160,11 +161,8 @@ class InvokeAIGenerator(metaclass=ABCMeta):
         '''
         return list(self.scheduler_map.keys())
 
-    def load_generator(self, model: StableDiffusionGeneratorPipeline, class_name: str):
-        module_name = f'invokeai.backend.generator.{class_name.lower()}'
-        module = importlib.import_module(module_name)
-        constructor = getattr(module, class_name)
-        return constructor(model, self.params.precision)
+    def load_generator(self, model: StableDiffusionGeneratorPipeline, generator_class: Type[Generator]):
+        return generator_class(model, self.params.precision)
                
     def get_scheduler(self, scheduler_name:str, model: StableDiffusionGeneratorPipeline)->Scheduler:
         scheduler_class = self.scheduler_map.get(scheduler_name,'ddim')
@@ -175,17 +173,20 @@ class InvokeAIGenerator(metaclass=ABCMeta):
         return scheduler
 
     @classmethod
-    def _generator_name(cls):
+    def _generator_class(cls)->Type[Generator]:
         '''
         In derived classes return the name of the generator to apply.
         If you don't override will return the name of the derived
         class, which nicely parallels the generator class names.
         '''
-        return cls.__name__
+        return Generator
 
 # ------------------------------------
 class Txt2Img(InvokeAIGenerator):
-    pass
+    @classmethod
+    def _generator_class(cls):
+        from .txt2img import Txt2Img
+        return Txt2Img
 
 # ------------------------------------
 class Img2Img(InvokeAIGenerator):
@@ -198,6 +199,10 @@ class Img2Img(InvokeAIGenerator):
                                 strength=strength,
                                 **keyword_args
                                 )
+    @classmethod
+    def _generator_class(cls):
+        from .img2img import Img2Img
+        return Img2Img
 
 # ------------------------------------
 # Takes all the arguments of Img2Img and adds the mask image and the seam/infill stuff
@@ -231,6 +236,29 @@ class Inpaint(Img2Img):
             inpaint_fill=inpaint_fill,
             **keyword_args
         )
+    @classmethod
+    def _generator_class(cls):
+        from .inpaint import Inpaint
+        return Inpaint
+
+# ------------------------------------
+class Embiggen(Txt2Img):
+    def generate(
+            self,
+            embiggen: list=None,
+            embiggen_tiles: list = None,
+            strength: float=0.75,
+            **kwargs)->List[InvokeAIGeneratorOutput]:
+        return super().generate(embiggen=embiggen,
+                                embiggen_tiles=embiggen_tiles,
+                                strength=strength,
+                                **kwargs)
+    
+    @classmethod
+    def _generator_class(cls):
+        from .embiggen import Embiggen
+        return Embiggen
+    
 
 class Generator:
     downsampling_factor: int