Todo list

Gravity

Busy loop = bad. I only have a dual core, and need the second core for all the other processes on my computer, so they are less likely to interrupt Powder Toy when it's busy massacring the first core with normal physics calculations....
Try to make calculation faster. Probably not much potential here - we're always going to end up with a ton of calculations to do
Force complete recalc after a certain number of difference only calculations?
Only memcpy gravx+gravy if changed
Pointer swap for putting th_gravmap in th_ogravmap. Also, we don't need to memset th_gravmap - will get completely overwritten by memcpy in main thread

Small tasks

Bounds checking when drawing stickman lines (crashes if at top of screen)
Fix H2 reaction with DESL under high pressure
Fix neutron cloning - ctype should be NEUT not PHOT. The other reason it doesn't work is that neutrons bounce off, so are never directly on top of clone.
Vertical flip?
Make electrolysis of watr/sltw easier?

Medium tasks

clipboard_pull_text
Shared stamp clipboard
Infinite stamps
Update legacy_mode reactions (and make loads of things unmeltable in legacy mode)
Fix off-by-one error in fillrect (need to check all boxes are still drawn with the right size/position after fixing)
Life behaviour (decrement, kill on change to zero) in ptypes.properties

Big tasks

Move drawing functions to element .c files
Rationalise number of properties used to describe state - currently have three
Translations. Will probably involve unicode support and lots of new characters
Configurable keyboard shortcuts (some work done on this already, not currently on github)
Element property brush

Hard tasks

Python without needing it installed on user's machine
Liquids in radial gravity (must remember to fix heat convection as well)
Prevent glass from hiding photons and neutrons passing through it
Fix edge direction detection (does not work at all angles, photons sometimes erroneously killed)

Stickman (some work done on this already, not currently on github though):

Radial gravity
Prevent going through walls
Better leg movement (should help make walking less jerky, and make controls feel more reponsive)
Improve climbing of diagonal surfaces/stairs
De-duplicate code - no need for two copies...
Store current element in ctype
Spawning
Temperature transfer between feet and head
More homeostasis? Currently just warms up head

Misc

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