Trouble porting liquid simulation to Pascal - AARRGGHH!

[Ingemar]

I believe there is a setting in Lazarus (and I guess freepascal too) where you can use +=, -=, etc. operators, but I don't know about ++ and --

cheers,
Paul

Correct, and += and -= are pretty useful. ++ and --, however, I'd rather live without, especially when used for throwing in side effects while doing other things.

You even have << and >> in FPC. It is sensible, the few times where C syntax makes sense there is no reason not to incorporate it. But finding C-style "for" loops is something that was supposed to be working Pascal code, that was scary. One detail that makes me uncertain is the ability to spread variable declarations all over the place. Should variables be at one place or anywhere? Defining a variable locally within a for loop or inside a begin-end pair, well, not entirely unreasonable... or is it just a workaround for messy code, when C programmers write entirely too big functions?

Anyway, now that I know what files to look for I can compare what we do.

[User137]

I managed to partially do my idea on the pixelmap demo, just that i haven't done the solidifying part yet. With tiles that would be simple but i have to optimize the visuals for rendering to texture... So in the end all that would remain as particles is water surface and falling water, rest would become solid blue.

Cpu use was showing 0% at 3000, 12% at 5000 particles and going up from there. The solidifying would greatly reduce the amount of particles.

And it was quite fun to do too, was pulling my hair almost when equasion was wrong and water was disappearing slowly

Edit: Solidifying is working now in my dev version and it's awesome! Just 1 bug with some random particles leaving bubbling inside and doesn't fill their density up. After that's fixed i'll show again.

[Ingemar]

OK, now I have fixed a few glitches and my version of the water simulation runs quite well. No Mac dependencies, I am not even using the macpas mode. It should be pretty close to Paul's version. The problem was in the screen update, not the simulation. What is good about this conversion: Small, close to the original, uses OpenGL (so it is fast), isolates user interface stuff (GLUT) into a separate unit so you can change it easily. Mac binary included.

http://www.computer-graphics.se/water_sim_fpc.zip




The "continue" keyword seems to work just fine, and is equivalent to "cycle" in the macpas dialect.

I fixed the mouse support, so you can edit the map by clicking, which toggles between water and ground.

[paul_nicholls]

@Ingemar: Nice work
@User137: Wow! this is very cool!

cheers,
Paul

[User137]

So my pixel version should now be working correctly. Uploaded the files in its thread:
http://www.pascalgamedevelopment.com...4326#post64326

Here's additional eye candy when i was still debugging the behaviour.
Blue = solid water drawn in texture
red = moving water with density<254
yellow = moving water with density=254
gray = moving water with density=255

Another picture just added... First i piled up a massive amount of water. Then go middle of water, hold firing key down and do a full 360 turn and you get something like this:
http://imageshack.us/photo/my-images/825/waterbig.png/
I just love to see things huge, lol. 46000 living water particles waving the streams. Very soon after it stabilized to more normal number of 1300 moving, where cpu is happy at 0% use.