Earlier versions of FGFS had assignments of joystick axis/buttons and key bindings hard coded. If you had a joystick that did not use -the default channel assignments, or wanted different key bindings +the default channel assignments, or wanted different key bindings, you had to edit the source code and recompile.
@@ -77,16 +77,16 @@ joystick buttons and keyboard events starts to blur. Storing alternate keyboard or joystick bindings can be done in a variety of ways. The order of precedence for options is thus:
-| -Source | Location | Format | Scope |
|---|---|---|---|
| command line | STDIN | see examples | session |
| .fgfsrc | Users home directory. | command line options | single user |
| system.fgfsrc | $FG_ROOT | command line options | system wide |
| joystick.xml | $FG_ROOT | XML property list | system wide |
| keyboard.xml | $FG_ROOT | XML property list | system wide |
- +
+Source Location Format Scope +------ -------- ------ ----- +command line STDIN see examples session +.fgfsrc ~/ command line options single user +system.fgfsrc $FG_ROOT command line options system wide +joystick.xml $FG_ROOT XML property list system wide +keyboard.xml $FG_ROOT XML property list system wide ++
+<PropertyList> + <!-- this is a comment, See I told you it was like HTML --> +</PropertyList> +
+Typical output of js_demo: + +Joystick test program. +~~~~~~~~~~~~~~~~~~~~~~ +Joystick 1 not detected <!-- remember we start at 0 --> +Joystick 2 not detected ++--------------JS.0--------------+ +| Btns Ax:0 Ax:1 Ax:2 | ++--------------------------------+ +| 0000 +0.0 +0.0 -1.0 | +
| Joystick test program. -~~~~~~~~~~~~~~~~~~~~~~ | ||||||
| Joystick 1 | -not detected | -<!-- remember we start at 0 --> | ||||
| Joystick 2 | -not detected | |||||
| - | ||||||
| -+---------------------JS.0-------------------+ | ||||||
| | | -Btns | -Ax:0 | -Ax:1 | -Ax:2 | -- | | |
| -+-------------------------------------------+ | ||||||
| | | -0000 | -+0.0 | -+0.0 | --1.0 | -. . . | -| | -
The buttons are handled internally as a binary number in which bit 0 (the least significant bit) represents button 0, bit 1 represents button 1, etc., but this number is displayed on the screen in hexadecimal notation, so: +
++ 0001 => button 0 pressed + 0002 => button 1 pressed + 0004 => button 2 pressed + 0008 => button 3 pressed + 0010 => button 4 pressed + 0020 => button 5 pressed + 0040 => button 6 pressed + ... etc. up to ... + 8000 => button 15 pressed + ... and ... + 0014 => buttons 2 and 4 pressed simultaneously + ... etc. +
| Axis 0 | = | Aileron |
| Axis 1 | = | Elevator |
| Axis 2 | = | Rudder |
| Axis 3 | = | Throttle |
| Button 0 | = | All brakes |
| Button 1 | = | Elevator trim (up)|
| Button 2 | = | Elevator trim (down)
+ Axis 0 = Aileron + Axis 1 = Elevator + Axis 2 = Rudder + Axis 3 = Throttle + Button 0 = All brakes + Button 1 = Elevator trim (up) + Button 2 = Elevator trim (down) ++
+Axis properties: -Axis properties:
+ dead-band + +-1 0 1 + ............... +-1 | | 1 + ^ + dead-band +
| dead-band | ||
|---|---|---|
| -1 | 0 | 1 |
| .............................. | ||
| -1 | | | | 1|
| ^ | ||
| dead-band - | ||
This is an area where signals are ignored. It is used to compensate @@ -255,25 +238,30 @@ number results in a tighter feel. In some cases such as throttle you may wish to not set a deadband. Use a value of 0.0 in this case.
-| offset | ||
|---|---|---|
| -1 0 | 1 | |
| ............................. | ||
| -1 ^ | 1 | |
| offset | ||
+ offset +-1 0 1 + ............. +-1 ^ 1 + offset ++
Used to maximize a controls use of it's axis, as in the case of a throttle where zero would be a minimum and not a center point like in the case of a rudder. Typical value -1.0.
-| tolerance |
|---|
tolerance+
Used to compensate for jittery potentiometer output, tolerance is in essence a gate. Amounts of movement below the threshold are ignored. Unlike dead-band, tolerance is relative to where ever the axis is at rest. - -
| factor |
|---|
factor+
Controls proportional movement of an axis. If the factor is too low it results in control not reaching its maximum possible limit. Negating the number will result in the control moving counter to the default. The default value is 1.0, think unity gain.
@@ -292,45 +280,42 @@ are bound to commands. Commands *must* be specified for a binding to have an effect. The current list of commands is broken down here into two categories, mainly for my convenience. -+
Visual And File Related: - +command options used for +------- ------- -------- +null none clearing a previous binding +exit none Exiting FGFS +load file name* Load a saved flight +save file name* Save current flight +load-panel path ** Change/reload panel +load-preferences path ** Load preferences *** +screen-capture none Save a screenshot to ./fgfs-screen.ppm +view-cycle none Change the direction of the pilots view + -
| command | options | used for |
|---|---|---|
| ------- | ------- | -------- |
| null | none | useful for clearing a previous binding |
| exit | none | Exiting FGFS |
| load | file name* | Load a saved flight |
| save | file name* | Save current flight |
| load-panel | path ** | Change/reload panel |
| load-preferences | path ** | Load preferences *** |
| screen-capture | none | Save a screenshot to ./fgfs-screen.ppm |
| view-cycle | none | Change the direction of the pilots view |
-Flight Control: -
-| command | options | effect |
|---|---|---|
| ------- | ------- | ------ |
| property-toggle | property | toggle the property full on |
| property-assign | "" "", value | targets a property for action |
| property-adjust | "" "", step | Increment size for changes |
| property-swap | "" ""[0], "" ""[1] | Set values in a switch |
| property-scale | "" "", offset, factor | Processes the raw joystick value |
Here's a sample Joystick axis declaration in XML:
- -<axis n="0"> <!-- target an axis -->+<axis n="0"> <!-- target an axis --> + <desc>Aileron</desc> <!-- descriptive name (optional) --> + <binding> <!-- open a container for the binding --> + <command>property-scale</command> <!-- pick a command --> + <property>/controls/aileron</property> <!-- target a property --> + </binding> <!-- closing tag for binding --> +</axis> <!-- closing tag for axis --> ++
Remember how I said the property tree was a hierarchy? Thoughtful readers will notice how the nested tags keep things organized. @@ -369,10 +354,11 @@ This binding appears in the context /input/joysticks/js/, so the command-line option equivalent of this declaration (leaving out the 'desc', which isn't strictly necessary), is
- +--prop:/input/joysticks/js[0]/axis[0]/binding/command=property-scale --prop:/input/joysticks/js[0]/axis[0]/binding/property=/controls/aileron -+ +
Do you see how the command line versions uses a path to represent the hierarchy? Cool! You should read README.xmlpanel next, working with FGFS XML configuration @@ -385,30 +371,27 @@ Ok, back to business. The 'property-scale' command also recognizes 'offset' and specifying a double precision floating point number. A double has more discrete steps and gives a smoother action than a plain float.
- +-<axis n="2">-
- <desc>Throttle</desc>
- <!-- See important note about dead-band below -->
- <binding>
- <command>property-scale</command>
- <property>/controls/throttle</property>
- <offset type="double">-1.0</offset>
- <factor type="double">-0.5</factor>
- </binding>
+<axis n="2"> + <desc>Throttle</desc> + <!-- See important note about dead-band below --> + <binding> + <command>property-scale</command> + <property>/controls/throttle</property> + <offset type="double">-1.0</offset> + <factor type="double">-0.5</factor> + </binding> </axis>
*Important Note About dead-band*
--------------------------------
@@ -421,11 +404,11 @@ a dead-band, the tag *must* precede the binding tag. If you are using the comman
line format you must omit the 'binding' part like so:
--prop:/input/joysticks/js[0]/axis[2]/dead-band=0.005 -+ -
-<repeatable>+<repeatable> +<!-- Will be either true or false. If it is true, holding down a button (or key) will cause +repeated events, say, for moving the trim; if false (the default), pressing a key will cause only a single event. --> +<step> +<!-- The property-adjust command takes a 'step' argument specifying the amount of the adjustment +for each event. In the following example, the elevator trim moves 0.1% for each event (without automatic +repetition, you'd have a pretty sore finger). --> + +<value> +<!-- Use value on non-repeatables to supply the value for each consecutive press--> +<mod-up> +<!-- This stands for "modifier up", my favorite I think. This is used to set up a binding for +when you *release* a key. As you'll see, it comes in handy --> + +
-<!-- Will be either true or false. If it is true, holding down a button (or key) will cause repeated events, say, for moving the trim; if false (the default), pressing a key will cause only a single event. -->
-
-<step>
-<!-- The property-adjust command takes a 'step' argument specifying the amount of the adjustment for each event. In the following example, the elevator trim moves 0.1% for each event (without automatic repetition, you'd have a pretty sore finger). -->
-
-<value>
-<!-- Use value on non-repeatables to supply the value for each consecutive press-->
-<mod-up>
-<!-- This stands for "modifier up", my favorite I think. This is used to set up a binding for when you *release* a key. As you'll see, it comes in handy -->
-
Here's a sample joystick button declaration in XML:
- -<button n="1"> <!-- target a button -->+<button n="1"> <!-- target a button --> + <desc>Elevator trim up</desc> <!-- optional description --> + <repeatable>true</repeatable> <!-- Ok, repeatable is outside the command manager too --> + <binding> <!-- Open the "binding" node of the tree--> + <command>property-adjust</command> <!-- pick a command type to bind --> + <property>/controls/elevator-trim</property> <!-- target a property --> + <step type="double">0.001</step> + </binding> +</button> ++
In command-line option syntax, this would appear as
- - --prop:/input/joysticks/js[0]/button[1]/repeatable=true <-- See? no 'binding' -->+ --prop:/input/joysticks/js[0]/button[1]/repeatable=true <-- See? no 'binding' --> + --prop:/input/joysticks/js[0]/button[1]/binding/command=property-adjust + --prop:/input/joysticks/js[0]/button[1]/binding/property=/controls/elevator-trim + --prop:/input/joysticks/js[0]/button[1]/binding//step=0.001 ++
Here's a slightly fancier declaration, that applies the left (differential) brakes when button 4 is pressed, and releases them automatically when the user releases the button:
- -<button n="4">+<button n="4"> + <desc>Left brake</desc> + <binding> + <command>property-assign</command> + <property>/controls/brakes[0]</property> + <value type="double">1.0</value> <!-- brakes are a toggle so 1.0 represents on --> + </binding> + <mod-up> <!-- it's not a parking brake so we need to release it --> + <binding> + <command>property-assign</command> + <property>/controls/brakes[0]</property> + <value type="double">0.0</value> <!-- 1.0 is on so 0.0 is off, right? --> + </binding> + </mod-up> +</button> ++
The first binding is straight-forward: when the button is pressed, the 'property-assign' command assigns the value 1.0 (i.e. full) to the left brake @@ -507,63 +498,65 @@ value will not be assigned over and over again.
Here's the command-line equivalent:
- +--prop:/input/joysticks/js[0]/button[4]/binding/command=property-assign --prop:/input/joysticks/js[0]/button[4]/binding/property=/controls/brakes[0] --prop:/input/joysticks/js[0]/button[4]/binding/value=1.0 --prop:/input/joysticks/js[0]/button[4]/mod-up/binding/command=property-assign --prop:/input/joysticks/js[0]/button[4]/mod-up/binding/property=/controls/brakes[0] --prop:/input/joysticks/js[0]/button[4]/mod-up/binding/value=0.0 -+ +
Remember that more than one binding can be included in each context. Here's a very hairy example from the default bindings that fires all three brakes when button 0 is pressed, and releases all three when button 0 is released:
- - <button n="0">+ <button n="0"> + <desc>Brakes</desc> + <binding> + <command>property-assign</command> + <property>/controls/brakes[0]</property> + <value type="double">1.0</value> + </binding> + <binding> + <command>property-assign</command> + <property>/controls/brakes[1]</property> + <value type="double">1.0</value> + </binding> + <binding> + <command>property-assign</command> + <property>/controls/brakes[2]</property> + <value type="double">1.0</value> + </binding> + <mod-up> + <binding> + <command>property-assign</command> + <property>/controls/brakes[0]</property> + <value type="double">0.0</value> + </binding> + <binding> + <command>property-assign</command> + <property>/controls/brakes[1]</property> + <value type="double">0.0</value> + </binding> + <binding> + <command>property-assign</command> + <property>/controls/brakes[2]</property> + <value type="double">0.0</value> + </binding> + </mod-up> +</button> ++
For people who take pleasure in avoiding XML, here's the command-line equivalent (note the subscripts to distinguish multiple bindings; the XML will handle this automatically):
- +--prop:/input/joysticks/button[0]/binding[0]/command=property-assign --prop:/input/joysticks/button[0]/binding[0]/property=/controls/brakes[0] --prop:/input/joysticks/button[0]/binding[0]/value=1.0 @@ -582,8 +575,8 @@ XML will handle this automatically): --prop:/input/joysticks/button[0]/mod-up/binding[2]/command=property-assign --prop:/input/joysticks/button[0]/mod-up/binding[2]/property=brakes[2] --prop:/input/joysticks/button[0]/mod-up/binding[2]/value=0.0 -- + +
This is a good time to remind you that command line formatted options are used in your .fgfsrc file. You can put them in $FG_ROOT/system.fgfsrc to make them @@ -604,19 +597,20 @@ of the common button properties. For example, if you just want to control view direction, you can map two of the axes to /sim/view/axes/long and /sim/view/axes/lat:
- +--prop:/input/joysticks/js/axis[5]/binding/command=property-scale --prop:/input/joysticks/js/axis[5]/binding/property=/sim/view/axes/lat --prop:/input/joysticks/js/axis[6]/binding/command=property-scale --prop:/input/joysticks/js/axis[6]/binding/property=/sim/view/axes/long -+ +
If you want to use them as buttons (say, to scroll the panel vertically or horizontally), you can use the high/low bindings. Here's an example of how to use an axis to adjust the elevator trim:
- +--prop:/input/joysticks/js/axis[1]/low/repeatable=true --prop:/input/joysticks/js/axis[1]/low/binding/command=property-adjust --prop:/input/joysticks/js/axis[1]/low/binding/property=/controls/elevator-trim @@ -626,7 +620,8 @@ Here's an example of how to use an axis to adjust the elevator trim: --prop:/input/joysticks/js/axis[1]/high/binding/command=property-adjust --prop:/input/joysticks/js/axis[1]/high/binding/property=/controls/elevator-trim --prop:/input/joysticks/js/axis[1]/high/binding/step=-0.001 -+ +
You could also bind some axes to brakes, so that you can use positions between between 0.0 (no brakes) and 1.0 (full brakes). @@ -640,17 +635,17 @@ Keyboard bindings are almost exactly identical to joystick-button bindings, as in the following example (the context is /input/keyboard):
- - <key n="1">+ <key n="1"> + <name>Ctrl-A</name> + <desc>Toggle autopilot altitude lock.</desc> + <binding> + <command>property-toggle</command> + <property>/autopilot/locks/altitude</property> + </binding> + </key> ++
There are a few gotcha's though. First, the index of the key specifies the key code that you're binding; in the above example, '1' @@ -660,10 +655,11 @@ function and arrow keys (you can get the value from include/GL/glut.h, but adding 256 to the special key code). Here is the command-line equivalent of the above, leaving out the documentation properties:
- +--prop:/input/keyboard/key[1]/binding/command=property-toggle --prop:/input/keyboard/key[1]/binding/property=/autopilot/locks/altitude -+ +
(The 'property-toggle' command switches a boolean value between true and false, so it needs no arguments except for the property name.) DON'T @@ -675,20 +671,20 @@ buttons. In addition to mod-up (representing the key release), a key may use any combination of nested 'mod-alt', 'mod-ctrl', and 'mod-shift' modifiers, as in the following example:
- - <key n="49">+ <key n="49"> + <name>1</name> + <mod-shift> + <desc>Look back left</desc> + <binding> + <command>property-assign</command> + <property>/sim/view/goal-offset</property> + <value type="double">135</value> + </binding> + </mod-shift> + </key> ++
In this example, the '1' key combined with shift causes the view to switch to back left. Note that this will work only with the keypad 1, @@ -707,47 +703,48 @@ With the new input module, the key-up events can also be detected for the keyboard, so it's possible to have touch-sensitive brakes (etc.) just as with the joystick:
- - <key n="44">+ <key n="44"> + <name>,</name> + <desc>Left brake</desc> + <binding> + <command>property-assign</command> + <property>/controls/brakes[0]</property> + <value type="double">1.0</value> + </binding> + <mod-up> + <binding> + <command>property-assign</command> + <property>/controls/brakes[0]</property> + <value type="double">0.0</value> + </binding> + </mod-up> + </key> ++
Now here is a different way to bind a brake. In this example, there is no <mod-up> tag, so it *does* work like a parking brake.
- - <key n="66">+ <key n="66"> + <name>B</name> + <desc>Toggle parking brake on or off</desc> + <binding> + <command>property-toggle</command> + <property>/controls/brakes[0]</property> + </binding> + <binding> + <command>property-toggle</command> + <property>/controls/brakes[1]</property> + </binding> + <binding> + <command>property-toggle</command> + <property>/controls/brakes[2]</property> + </binding> + </key> +