Free fluid software for linux

The FlightGear flight simulator project is an open-source, multi-platform, cooperative flight simulator development project. Source code for the entire project is available and licensed under the GNU General Public License.

The goal of the FlightGear project is to create a sophisticated flight simulator framework for use in research or academic environments, for the development and pursuit of other interesting flight simulation ideas, and as an end-user application. We are developing a sophisticated, open simulation framework that can be expanded and improved upon by anyone interested in contributing.

There are many exciting possibilities for an open, free flight sim. We hope that this project will be interesting and useful to many people in many areas.

FlightGear is a free flight simulator project. It is being developed through the gracious contributions of source code and spare time by many talented people from around the globe. Among the many goals of this project are the quest to minimize short cuts and "do things right", the quest to learn and advance knowledge, and the quest to have better toys to play with.

The idea for Flight Gear was born out of a dissatisfaction with current commercial PC flight simulators. A big problem with these simulators is their proprietariness and lack of extensibility. There are so many people across the world with great ideas for enhancing the currently available simulators who have the ability to write code, and who have a desire to learn and contribute. Many people involved in education and research could use a spiffy flight simulator frame work on which to build their own projects; however, commercial simulators do not lend themselves to modification and enhancement. The Flight Gear project is striving to fill these gaps.

There are a wide range of people interested and participating in this project. This is truly a global effort with contributors from just about every continent. Interests range from building a realistic home simulator out old airplane parts, to university research and instructional use, to simply having a viable alternative to commercial PC simulators.

Flight Dynamics Models

With FlightGear it is possible to choose between three primary Flight Dynamics Models. It is possible to add new dynamics models or even interface to external "proprietary" flight dynamics models:

1. JSBSim: JSBSim is a generic, 6DoF flight dynamics model for simulating the motion of flight vehicles. It is written in C++. JSBSim can be run in a standalone mode for batch runs, or it can be the driver for a larger simulation program that includes a visuals subsystem (such as FlightGear.) In both cases, aircraft are modeled in an XML configuration file, where the mass properties, aerodynamic and flight control properties are all defined.

2. YASim: This FDM is an integrated part of FlightGear and uses a different approach than JSBSim by simulating the effect of the airflow on the different parts of an aircraft. The advantage of this approach is that it is possible to perform the simulation based on geometry and mass information combined with more commonly available performance numbers for an aircraft. This allows for quickly constructing a plausibly behaving aircraft that matches published performance numbers without requiring all the traditional aerodynamic test data.

3. UIUC: This FDM is based on LaRCsim originally written by the NASA. UIUC extends the code by allowing aircraft configuration files instead and by adding code for simulation of aircraft under icing conditions.

UIUC (like JSBSim) uses lookup tables to retrieve the component aerodynamic force and moment coefficients for an aircraft... and then uses these coefficients to calculate the sum of the forces and moments acting on the aircraft.

Extensive and Accurate World Scenery Data Base

Over 20,000 real world airports included in the full scenery set.
Correct runway markings and placement, correct runway and approach lighting.
Taxiways available for many larger airports (even including the green center line lights when appropriate.)
Sloping runways (runways change elevation like they usually do in real life.)
Directional airport lighting that smoothly changes intensity as your relative view direction changes.
World scenery fits on 3 DVDs. (Im not sure thats a feature or a problem!) But it means we have pretty detailed coverage of the entire world.
Accurate terrain worldwide, based on the most recently released SRTM terrain data.) 3 arc second resolution (about 90m post spacing) for North and South America, Europe, Asia, Africa, and Australia.
Scenery includes all vmap0 lakes, rivers, roads, railroads, cities, towns, land cover, etc.
Nice scenery night lighting with ground lighting concentrated in urban areas (based on real maps) and headlights visible on major highways. This allows for realistic night VFR flying with the ability to spot towns and cities and follow roads.
Scenery tiles are paged (loaded/unloaded) in a separate thread to minimize the frame rate hit when you need to load new areas.

Accurate and Detailed Sky Model

FlightGear implements extremely accurate time of day modeling with correctly placed sun, moon, stars, and planets for the specified time and date. FlightGear can track the current computer clock time in order to correctly place the sun, moon, stars, etc. in their current and proper place relative to the earth. If its dawn in Sydney right now, its dawn in the sim right now when you locate yourself in virtual Sidney. The sun, moon, stars, and planets all follow their correct courses through the sky. This modeling also correctly takes into account seasonal effects so you have 24 hour days north of the arctic circle in the summer, etc. We also illuminate the correctly placed moon with the correctly placed sun to get the correct phase of the moon for the current time/date, just like in real life.

Flexible and Open Aircraft Modeling System

FlightGear has the ability to model a wide variety of aircraft. Currently you can fly the 1903 Wright Flyer, strange flapping wing "ornithopters", a 747 and A320, various military jets, and several light singles. FlightGear has the ability to model those aircraft and just about everything in between.

FlightGear has extremely smooth and fluid instrument animation that updates at the same rate as your out-the-window view updates (i.e. as fast as your computer can crank, and not artificially limited and chunky like in some sims.)

FlightGear has the infrastructure to allow aircraft designers to build fully animated, fully operational, fully interactive 3d cockpits (which even update and display correctly from external chase plane views.)

FlightGear realistically models real world instrument behavior. Instruments that lag in real life, lag correctly in FlightGear, gyro drift is modeled correctly, the magnetic compass is subject to aircraft body forces -- all those things that make real world flying a challenge.

FlightGear also accurately models many instrument and system failures. If the vacuum system fails, the HSI gyros spin down slowly with a corresponding degradation in response as well as a slowly increasing bias/error.

Moderate Hardware Requirements

The intention of FlightGear is to look nice, but not at the expense of other aspects of a realistic simulator. Our focus is not on competing in the "game" market and not on the ultra-flashy graphic tricks.

The result is a simulator with moderate hardware requirements to run at smooth frame rates. You can be reasonably happy on a $500-1000 (USD) machine (possibly even less if you are careful) and dont necessarily need $3000 (USD) worth of new hardware like you do with the many of the newest games.

That said, the more hardware you throw at FlightGear, the better it looks and runs, so dont feel like you have to chuck your expensive new hardware if you just purchased it. :-)

Internal Properties EXPOSED!

FlightGear allows users and aircraft designers access to a very large number of internal state variables via numerous internal and external access mechanisms. These state variables are organized into a convenient hierarchal "property" tree.

Using the properties tree it is possible to monitor just about any internal state variable in FlightGear. Its possible to remotely control FlightGear from an external script. You can create model animations, sound effects, instrument animations and network protocols for about any situation imaginable just by editing a small number of human readable configuration files. This is a powerful system that makes FlightGear immensely flexible, configurable, and adaptable.

Networking options

A number of networking options allow FlightGear to communicate with other instances of FlightGear, GPS receivers, external flight dynamics modules, external autopilot or control modules, as well as other software such as the Open Glass Cockpit project and the Atlas mapping utility.

A generic input/output option allows for a user defined output protocol to a file, serial port or network client.

A multi player protocol is available for using FlightGear on a local network in a multi aircraft environment, for example to practice formation flight or for tower simulation purposes.

The powerful network options make it possible to synchronize several instances of FlightGear allowing for a multi-display, or even a cave environment. If all instances are running at the same frame rate consistently, it is possible to get extremely good and tight synchronization between displays.

Flight Gear and its source code have intentionally been kept open, available, and free. In doing so, we are able to take advantage of the efforts of tremendously talented people from around the world. Contrast this with the traditional approach of commercial software vendors, who are limited by the collective ability of the people they can hire and pay. Our approach brings its own unique challenges and difficulties, but we are confident (and other similarly structured projects have demonstrated) that in the long run we can outclass the commercial "competition."

Contributing to Flight Gear can be educational and a lot of fun. A long time developer, Curtis Olson, had this to say about working on Flight Gear:

Personally, Flight Gear has been a great learning experience for me. I have been exposed to many new ideas and have learned a tremendous amount of "good stuff" in the process of discussing and implementing various Flight Gear subsystems. If for no other reason, this alone makes it all worth while.

FreeWheeling is an audio tool for live looping. It provides a highly configurable, fluid user interface for instrumentalists to capture loops in real-time. Based on the JACK, ALSA, and SDL libraries, it integrates with FluidSynth, a software synthesizer.

Freewheeling empowers the trance of immediate creativity by bringing us into a circular process. Time is utterly relative, and we are freed from the future-oriented mindset of product sequencing. If inspiration flows, later arranging and editing on a timeline can be done with other tools.

New user interface:

Mouse support
Click on loops triggers them. This can be configured.
See loop-clicked in .fweelin.rc.

Joystick support
Joystick buttons can now trigger events.
For example, I have used FW with a DDR dance mat to trigger loops.
See joybutton in .fweelin.rc.

New engage and shot options in trigger-loop.
Engage forces a loop to ON or OFF, overriding the default toggle behavior.
You can use it to create triggers that play short bursts, rather than long loops.

"Shot to be implemented.

Stability improvements

Better thread safety and design improvements to the real-time memory manager have improved stability.

Significant improvements to loop/scene management and browsing

You can now give loops and scenes your own names
New names are stored within the filename of library files
Expanded browser window shows several items at once
Browser now sorts so that newer loops and scenes are first

Better handling of looppoints

Resolved issue with clicking at the looppoint on reloaded loops.
Resolved sporadic clicks on syncronized loops.

Better handling of loading/saving loops

Adjustable video loop delay

You can now adjust the performance of FreeWheeling by changing the delay between video refreshes. Several people asked for this feature, because FW is processor-heavy on the video side.

The video thread does run at a low priority, and so it should not affect the performance of other realtime audio threads. However, the system may get sluggish, and if this happens, you may want to increase the delay in .fweelin.rc:

< var videodelay="20"/ >

Fixes

Fixed pure virtual method called segfault
Fixed segfault when browsing past end of FluidSynth patch list
Various fixes to reduce CPU hogging
Merged patches from Piems debian package:
MaxVol, compile fixes for GCC 4.0, and removal of non-free elements
FW can now run without physical JACK inputs or outputs. Thanks to Piem for this patch.

Synfig application is a powerful, industrial-strength vector-based 2D animation software package, designed from the ground-up for producing feature-film quality animation with fewer people and resources.

While there are many other programs currently on the market to aid with the efficient production of 2D animation, we are currently unaware of any other software that can do what our software can.

2D Animation has traditionally been very expensive because every frame must be drawn by hand. Even with todays digital inking and painting software, the process still relies on individuals hand-drawing each frame. This laborious task is called "tweening".

Our animation technology eliminates the task of manual tweening, producing smooth, fluid motion without the animator having to draw out each frame individually.
This allows you to produce 2D animation with fewer people while producing a product of a higher quality.

Please keep in mind that this release of Synfig Studio is considered a developer preview. IE: It is targeted at developers, not end users. That being said, feel free to play around with it -- just be sure to give it another chance later on down the road if you find yourself a bit frustrated.

HTML::Truncate is a Perl module (beta software) that can truncate HTML by percentage or character count while preserving well-formedness.

ABSTRACT

When working with text it is convenient and common to want to truncate strings to make them fit a desired context. E.g., you might have a menu that is only 100px wide and prefer text doesnt wrap so youd truncate it around 15-30 characters, depending on preference and typeface size. This is trivial with plain text using substr but with HTML it is somewhat difficult because whitespace has fluid significance and open tags that are not properly closed destroy well-formedness and can wreck an entire layout.

HTML::Truncate attempts to account for those two problems by padding truncation for spacing and entities and closing any tags that remain open at the point of truncation.

SYNOPSIS

use strict;
use HTML::Truncate;

my $html =

We have to test something.

;

my $html_truncate = HTML::Truncate->new();
$html_truncate->chars(20);
$html_truncate->ellipsis($readmore);
print $html_truncate->truncate($html), $/;

# or

my $ht = HTML::Truncate->new(utf => 1,
chars => 1_000,
);
print $ht->truncate($html), $/;

Gerris project is an Open Source Free Software library for the solution of the partial differential equations describing fluid flow.
Gerris is supported by NIWA (National Institute of Water and Atmospheric research) and by the Marsden Fund of the Royal Society of New Zealand.
The code is written entirely in C and uses both the GLib Library and the GTS Library for geometrical functions and object-oriented programming.
Main features:
- The same code base is compiled with 2D and 3D support.
- Quadtree-based (Octree in 3D) spatial discretisation with automatic and dynamic local refinement.
- Multigrid Poisson solver.
- Second-order Godunov type advection scheme.
- Solves the time-dependent incompressible variable-density Euler, Stokes or Navier-Stokes equations or the 2D shallow-water and 3D hydrostatic oceanic equations.
- Support for complex solid boundaries (automatic locally-refined mesh generation).
- Semi-implicit multigrid diffusion solver with support for complex boundaries and associated boundary conditions in 2D and 3D.
- Semi-implicit multigrid barotropic solver for the oceanic equations.
- Adaptive mesh refinement: the resolution is adapted dynamically to the features of the flow.
- Flexible and powerful specifications of parameters.
- Flexible object-oriented custom specification of initial and boundary conditions, source terms, outputs etc...
- Portable parallel support using the MPI library.
- Volume of Fluid advection scheme for interfacial flows.
Enhancements:
- Bugfixes and significant speedups in the multilevel Poisson solver.
- Support for variable mesh resolution along solid boundaries.
- Improvements have been made to the robustness of very complex solid boundaries.
- Adaptive refinement of VOF-advected tracers has been added, as well as a preliminary implementation of CSF surface tension using Renardy El Ab.
- "proper discretisation".
- Solid boundaries can be refined according to the local curvature.
- Implicit Coriolis terms work with the Navier-Stokes solver.
- There is support for "thin" 3D domains.

Iter Vehemens ad Necem project is a graphical roguelike game.
Iter Vehemens ad Necem (IVAN) is a graphical roguelike game which currently runs in Windows, DOS, and Linux. It features advanced bodypart and material handling, multi-colored lighting and, above all, deep gameplay.
Fellow adventurer, turn back while you can! For here begins the roguelike Iter Vehemens ad Necem, a Violent Road to Death. If you choose to travel along it, you will dive into countless exciting adventures to gain items of great magic, attain powerful equipment made of mysterious materials, bathe in the blessings of mighty gods and recruit loyal allies of various shapes and sizes.
Unfortunately, along the way you will also often be dangerously injured, poisoned, catch numerous diseases, lose several limbs and transform into manifold different kinds of pitiful creatures in the darkest depths of hostile dungeons. And, at the end of the road, you are bound to perish in a most gruesome and painful way. Dont say we didnt warn you.
Enhancements:
- fluids can now cover items and characters and interact with them
- items made of iron alloys can now rust
- added directional light and day and night which use it
- added some cosmetical weather effects
- New Attnam has now many new NPCs, for instance a sumo wrestler who can be challenged
- polymorph control is now more interesting; you need to see a monster once before you can polymorph into it, and more powerful ones require more intelligence
- added wands of acid rain, mirroring and necromancy
- added scrolls of detect material, harden material and golem creation
- added several new monsters, eg. powerful named archangels for each god and necromancers who raise skeletons and zombies to do their bidding
- one can now give pets tactical commands, change their equipment and use them to carry extra stuff (these are accessed using Chat and Issue commands keys)
- the player can now panic if he gets hit too much, like the monsters have done in previous versions
- the player can now become exhausted if he fights for too long and/or uses the new run command too much
- spiders are now able to make webs
- you can now get stuck to slime
- badly hurt/trapped bodyparts now become unusable until they regain some HP/become untrapped
- it is now possible to browse detailed death reasons of individual monsters in the postgame massacre lists
- added many new informative graphical details, for instance recently altered attributes are shown with a different color for some time
- gloomy cave is now longer and has more special levels and rooms
- all the endgame battles are more complex
- added leprosy, a nasty disease which causes your limbs to drop off randomly