Allow prompt selection dynamically in formulas instead of From-To keyframes, Composable Diffusion as option

[EddMTH13]

Current behavior:

Lets say you have multiple (at least 2) prompts defined in prompt section and you set Overlap weight: Custom with according default formulas for prompt_weight_N. In keyframe grid, if you alternate prompt_weight_N values between 0 and 1 in a somewhat 'binary way', such as only one prompt weight can be 1 at any given time, rendered keyframes contains all prompts separated with AND (using Composable Diffusion), even when the prompt weight is zero - for example, for 3 prompts A,B and C, resulting prompt can look like A:0.0000 AND B:1.0000 AND C:0.0000.

Problem:
Using Composable Diffusion in this way causes some quirks in resulting animation - even when weight=0, those prompts are still somehow considered in Deforum, which can usually lead to undesired results.

Suggested behavior:
Instead of Composable Diffusion taking the shot, when setting the prompt_weight_* to 0 you could completely ignore this prompt in the resulting rendered frames (both positive and negative parts) instead of trying to compose it with ANDs. So, for abovementioned example, instead of A:0.0000 AND B:1.0000 AND C:0.0000, resulting prompt that goes into Deforum could simply be B. From user's point of view, this makes more sense IMO: when prompt_weight is set to 0, do not use the prompt at all.

This could:

• allow jumping between prompts in more dynamic way with more flexibility, as at any given keyframe, i could select the active prompt just by setting it's weight to 1 and others to 0, with using some existing functions, step interpolation etc..
• disregard prompt's From-To values (making them obsolete rather)
• reduce additional complexity and eliminate workarounds when trying to achieve this behavior

If somebody would still for some reason expect Composable Diffusion taking place even with prompt_weight=0, this could be still be enabled by some explicit option in the Overlap weight dropdown. This newly proposed behavior could be available in such way as well.