How would I display the progress indicator embedded in the html for Texture?
Ah, a very good find! We did test a progress indicator style page turning, but dropped it at some point. It's still present in the code but automatically disabled.
If you want to try it out, you can edit the story HTML and find G=!1 at the very end of the file. (It's in two places, you can change both if you're unsure.) If you change it to G="full" or G="sequential" the indicator will be enabled. It was never finalized so if you do enable it, it's not guaranteed to work correctly. Offered purely as a curiosity.
Great feature that would be cool to see expanded in future versions. A common issue I have with IF is not knowing how far along in the story I am. With a print book, you always have the weight indicator, and I enjoy seeing people implement similar features in their IF. In my story, I've numbered sections to help ground the reader just a bit. (The progress bar, unfortunately, didn't work properly in a story as long as mine, which makes sense given the alpha state.)
Absolutely, we played with the progress indicator for exactly the reason you mention -- how far along am I? But when you have branches that are asymmetrical in length then it's not straightforward to compute. With your book metaphor, instead of a linear book think about a choose your own adventure book and how hard that was to gauge how much of the book you'd read.
Totally makes sense! Perhaps there would be a way for authors to number their own pages (or parts) in some sort of customized way. It definitely wouldn't work for every story, but I could see people structuring by short "checkpoints" or something (like a save point in a video game) out of a total. But yes--definitely a complicated issue.