Fix #71315 Add ereader power consumption to read_activity_actor

[random-cdda-modder]

Summary

Features "Add ereader power consumption to read_activity_actor"

Purpose of change

Fixes #71315

Currently EBOOKREAD capable items can be used indefinitely in a naturally bright area to read ebooks stored in the devices.

Power consumption to provide lighting (eink backlight or smartphone flashlight) is separate at code starting from

Cataclysm-DDA/src/iuse.cpp

Line 8780 in 47cebfe

// Only turn on the eBook light, if it's too dark to read

.

Describe the solution

Consumption in PR is simulated for just keeping the screen active while reading. Based on expectation that a smart_phone should be able to keep the screen on for roughly 10 hours, following values were used as baseline:

Item	Max charges available	Battery lifetime without using the light-providing features of the item
integrated_ar	implant	potentially infinite
ar_glasses_advanced	max 300 charges from disposable light battery	25 hours of reading
eink_tablet_pc	max 300 charges from disposable light battery	25 hours of reading
laptop	max 1200 charges from disposable medium battery	100 hours of reading
smart_phone	120 UPS charges	10 hours of reading

Describe alternatives you've considered

Implement feature to allow activities to impose temporary power_draw or other property changes on related items, to allow more combinations than the smart_phone_on type variants that are now hard-coded as transformations. But this way the PR is a two-liner.

Testing

Looks OK.

Additional context

[ashGlaw]

Just to ask clarifying question, specifically, the ink reader, your cost increases for having the backlight turned on, not for a reading in a already lit area, correct? Those things can last a week on a charge if they don't use a backlight.

[random-cdda-modder]

the consumption in PR is the base cost to flip through pages and have the display on. The backlight energy consumption is separate (the item is auto transformed to "backlight on" state by the code linked in description.

Which JSON property would you use to represent eink_tablet_pc being that efficient in power consumption?

[random-cdda-modder]

note that the eink_tablet_pc represented in game is running off a single light battery (should be AA sized if I've understood correctly) and not an integrated energy cell (NiCd or Li etc).

If we'd give eink_tablet_pc a laptop-sized medium battery then it'd last close to the expected week. (or switch them to UPS to represent an internal unswappable cell)