Here are some things that I have in mind...
(sorry if its too long and technical)

Element/Tool suggestions:

- Ruler tool: RULR
Measures. Shift-drag to place one.

Shift-drag this and after releasing, the ruler tool will stay at its place. This is drawn like text, and is not a particle. (Maybe remove by rightclick)

Yeah, tpt.setdebug(4) looks the same, but its better if you can 'stick' it to somewhere you want, and have multiple rulers as guides.

- Heat ray: HRAY (No its not a heater or something like that!)
Sets temperature of a line of particles in front of it with its temp.

Use like DRAY. When SPRKed, sets the temperature of particles in front of it with its own temp. tmp - number of particles to set the temperature, tmp2 - amount of spacing between HRAY and the particles to be heated/cooled, like DRAY. ctype - the element that HRAY should not care about.

- Sound block: NOTE
Plays a sound when activated. Temp for the tone.

Plays a note. A square wave could do, but additional 'instruments', much better. Temp - tone of the sound produced, tmp - duration of the sound. (If instruments are added, ctype - type of instrument.(Not DUST, but rather, 1 (like, instrument 1 (piano?))))

Gameplay/Additions:

- Improvements in the PROP tool

Make the PROP tool accept inputs that is math or lua-like, for example:

2+4+8+32

this makes the tool set 46 on the property

math.floor(1.312)*2

result: 2 (math.floor is round-down) (maybe the functions can be used without the 'math.' in the beginning)

And also let it accept particle info like x, y, tmp, vx, etc.:

vx+10 add 10 to the current particle's vx. For example, vx+10 is inputted on the PROP tool, and using the PROP tool on a particle with 40 x velocity would make the particle now have 50 vx (vx+10 = 40+10 = 50)

Though if adding particle info to the PROP input, the PROP tool should not continuously change the particle's property. The PROP tool should work by click and not while holding the mouse button to avoid additional change.

And maybe, I suggest an advanced PROP panel. It has checkboxes for every property and a textbox for each one so that the PROP tool can change different properties at once.

Also, PROP tool history can be added. This works like the console, up and down buttons recalls previously entered values.

- In-game help

By hovering over an element, either from the simulation or the menus, pressing F1 would show information about the element in a pop-up window. The information can be available offline, or it can just be fetched online to preserve game size, though it won't be available without internet connection.

- Hotbar

It's just like a favorites menu, and select an element in the hotbar by using the <, and >. keys. The hotbar can be a small floating pane at the left/right, or its like a menu.

- Paste order

Let pasting have some modes, like:
Replace mode: Replace any particle underneath with the pasted object.
Add mode: Only paste the parts of the object when there is nothing under them.
Back mode: Paste the object behind the particles without deleting anything (Think of layering).
Front mode: Paste the object in front of the particles without deleting anything (layering).
_{Layering is useful!}

Currently when pasting, TPT does 'Replace mode'.

- Fine Pressure

Support 1 pixel pressure. Currently, TPT simulates air in a 4x4 grid. Fine pressure makes every pixel have its independent pressure, and allows air to pass through 1 pixel wide holes... It is CPU intensive though. It may be added as an option in the preferences menu.

- FILT red/blue shift

Make FILT tmp 4 (red shift) and 5 (blue shift) have its 'number of shifts' through the ctype or color of the FILT.

end

I hope you have read through this long post hahahaha :D

What do you guys think? Any comments and ideas are welcome and greatly appreciated!

_{my first topic, sorry if I broke some rules...}

Yeah, most of them would likely be rejected, perhaps they're already suggested, or its overcomplicated, or it has a few uses... But I hope some would get accepted :)

For the fine pressure, probably it won't be remembered when saving, and it would be a setting on the preferences menu, so users can turn it on if they want.

Walls,... maybe treat them as 4x4 particles, not as a whole, while not affecting the way it sits on the grid.

@yocheese (View Post)

Yeah, there would be a warning for it, like "May cause poor performance and may change how saves work", but it may not fit anymore in the preferences menu, its likely a simple checkbox would do.

@jacob1 (View Post)

Oh right, since RULR is a tool, most likely a lua script would do.

Also, what I meant for HRAY is that it can set temp. of particles that doesn't get temperature from those beside it, e.g. INSL, PSTN, WIFI, DLAY, some other powered things, etc.

For the prop tool, it is for ease of use or speed. Though, that and the 'Advanced prop' tool can also be just a lua script. I'll try to make a script for those.

But how about the particle infos (vx,tmp,etc.)? 

The wiki is not updated very much, so [F1] may just show basic information about the element, then it would be easier for beginners. If not, the simple tooltips already in TPT would do.

Honestly, I like the things from the TPT mods be added to the official game, though its up to the devs what would they do.

Actually, FILT mode 4 or 5 shifts according to its temperature, and problems can arise if it is accidentally heated.