multi-prompt extension for Flux and SDXL in Forge webUI

intended as quick proof of concept only

yet somehow updated already

install: Extensions tab, Install from URL, use URL for this repo

usage:

1. Enable the extension
2. use the Prompt textbox as normal
3. prompt for first text encoder
4. enter word SPLIT, use surrounding whitespace/newline as you like
5. prompt for second text encoder
6. Generate

Flux (CLIP-L / T5) assumed best usage is tags for first prompt, natural language for second. SDXL (CLIP-L / CLIP-G) would typically be tags for both but depends on training: seems likely that same captions would be used for both CLIPs so use may be limited.

update 1:

• added sdXL, why not? In process, prepped code for possible future additions of SD3 / Hunyuan / others?.
• changed unpatch location. Previously unpatched ASAP therefore wouldn't have applied during hires fix (only relevant if hires fix had new prompt which included SPLIT). In practice, unlikely to be relevant at all.
• only patches if using appropriate models (Flux or sdXL). Previously always patched if extension enabled, which would have left the patch in place if using a model which didn't use the patched function which would have unpatched itself but couldn't.
• Force clearance of cached conds when extension enabled/disabled.
• for explanation of these egregious errors, see line 2 of this document.

update 2:

• added control for Shift parameter (affects calculation of sigmas used to guide denoising per step). This is for the Simple scheduler only.
• Dynamic Shift is a different method of calculating the way Shift affects sigmas. From brief testing, it seems to work very badly with higher Shift values, but may be better at low values. It's the way Forge calculates, so included for completeness / reproducibility. Dynamic Shift is the term diffusers uses.

update 3:

• changed to base/max shift implementation. Max Shift > 0.0 means using the dynamic method.
• added separate controlsfor HighRes fix. Leave at 0 to use same values as non-HR.
• added automatic backup/restore of original sigmas, as this overwrites (so previously disabling extension left the last used settings in place)

update 4:

• added control over model prediction type. Particularly (only?) relevant for sd1.5 v-prediction models. Renamed to 'Forge2 extras'.