acceptable integration of new prompting system and inpainting

This was a difficult merge because both PR #1108 and #1243 made
changes to obscure parts of the diffusion code.

- prompt weighting, merging and cross-attention working
  - cross-attention does not work with runwayML inpainting
    model, but weighting and merging are tested and working
- CLI command parsing code rewritten in order to get embedded
  quotes right
- --hires now works with runwayML inpainting
- --embiggen does not work with runwayML and will give an error
- Added an --invert option to invert masks applied to inpainting
- Updated documentation

scripts/invoke.py

@@ -18,6 +18,7 @@ from ldm.invoke.image_util import make_grid
 from ldm.invoke.log import write_log
 from omegaconf import OmegaConf
 from pathlib import Path
+from pyparsing import ParseException
 
 # global used in multiple functions (fix)
 infile = None
@@ -328,12 +329,16 @@ def main_loop(gen, opt):
             if operation == 'generate':
                 catch_ctrl_c = infile is None # if running interactively, we catch keyboard interrupts
                 opt.last_operation='generate'
-                gen.prompt2image(
-                    image_callback=image_writer,
-                    step_callback=step_callback,
-                    catch_interrupts=catch_ctrl_c,
-                    **vars(opt)
-                )
+                try:
+                    gen.prompt2image(
+                        image_callback=image_writer,
+                        step_callback=step_callback,
+                        catch_interrupts=catch_ctrl_c,
+                        **vars(opt)
+                    )
+                except ParseException as e:
+                    print('** An error occurred while processing your prompt **')
+                    print(f'** {str(e)} **')
             elif operation == 'postprocess':
                 print(f'>> fixing {opt.prompt}')
                 opt.last_operation = do_postprocess(gen,opt,image_writer)
@@ -592,7 +597,9 @@ def write_config_file(conf_path, gen, model_name, new_config, clobber=False, mak
 
 def do_textmask(gen, opt, callback):
     image_path = opt.prompt
-    assert os.path.exists(image_path), '** "{image_path}" not found. Please enter the name of an existing image file to mask **'
+    if not os.path.exists(image_path):
+        image_path = os.path.join(opt.outdir,image_path)
+    assert os.path.exists(image_path), '** "{opt.prompt}" not found. Please enter the name of an existing image file to mask **'
     assert opt.text_mask is not None and len(opt.text_mask) >= 1, '** Please provide a text mask with -tm **'
     tm = opt.text_mask[0]
     threshold = float(opt.text_mask[1]) if len(opt.text_mask) > 1  else 0.5