+++ /dev/null
-Users' Guide to FlightGear Hud configuration
-December 22 2000
-Neetha Girish <neetha@ada.ernet.in>
-
-This document describes the reconfigurable HUD of
-FlightGear implemented through XML config files.
-The present reconfigurable HUD code uses most of the code
-of version 0.6.1 vintage and I have adapted the same to provide
-a reconfigurable HUD for fgfs.
-Corrections and additions are welcome.
-
-Some History:
-
-Older versions of FGFS had a hard coded display of HUD.
-This was a less than ideal state of affairs when it came to
-using different aircraft Huds. I remember, somewhere in the 0.6.1 HUD code
-it was written that the HUD code is 'presently' hard coded but ideally should
-be moved into the aircraft configuration dataset, so that when you choose
-an aircraft, its HUD loads.
-This implementation make that possible, all you have to do is to
-create appropriate 'my_aircraft.xml' files in the HUD directory and
-without re-compiling the code you could have 'your_aircraft' HUD, by choosing that
-in the .fgfsrc file or as a command line option as described later. Of course,
-as of now, I have only implemented those HUD instruments in .xml readable form
-as was available in version 0.7.6 + few more used by ADA, Bangalore for our
-aircraft carrier take-off/landing simulation studies <www.flightgear.org/projects/ADA>.
-To use the ADA specific reticles/HUD objects, please contact me/ you can figure it out
-yourself by studying the code. All of them are relevant 'only' if you use the conformal
-climb/dive ladder, since they are all referenced to it.
-The rewrite of Hud display code was done using pre and post release v0.7.6 code
-allowing for configuration of the hud via XML.
-
-The present Configurable Hud implements the entire functionality of
-fgfs HUD (called default HUD) till this date.
-
-Using Default/Custom Hud:
-
-The default HUD location is $FG_ROOT/Huds/Default.
-$FG_ROOT is the place on your filesystem where you installed FG
-data files. Alternate huds can be specified on the command line
-or set as the default in the $HOME/.fgfsrc or $FG_ROOT/preferences.xml
-using a property specification. The command line format is as follows:
-
---prop:/sim/hud/path=Huds/Default/default.xml
-
-The path description shown is relative to $FG_ROOT. An absolute
-path may also be used for locations outside $FG_ROOT.
-For the custom Hud the path will be Huds/Custom/default.xml
-
-
-Hud - Implementation:
-
-All of the hud configuration files are XML-encoded property lists.
-The root element of each file is always named <PropertyList>. Tags are
-always found in pairs, with the closing tag having a slash prefixing
-the tag name, i.e </PropertyList>. The top level panel configuration
-file is composed of a <name> and zero or more <instruments>.
-Instruments are used by including a <"unique_name"> and a <path> to the
-instruments configuration file.
-Comments are bracketed with <!-- -->.
-
- Example Top Level Hud Config
-
-<PropertyList>
- <name>Default Aircraft Hud</name>
- <instruments>
-
- <hudladder> <!--unique name -->
- <path>Huds/Instruments/Default/hudladder.xml</path>
- </hudladder>
-
- <hudcard>
- <path>Huds/Instruments/Default/hudcard.xml</path>
- </hudcard>
-
- <instrlabel>
- <path>Huds/Instruments/Default/instrlabel.xml</path>
- </instrlabel>
-
- <fgTBI>
- <path>Huds/Instruments/Default/fgtbi.xml</path>
- </fgTBI>
-
- </instruments>
-</PropertyList>
-
-
-The default location for instrument files is $FG_ROOT/Huds/Instruments/Default.
-The location for custom instrument files is $FG_ROOT/Huds/Instruments/Custom.
-The location for minimal instrument files is $FG_ROOT/Huds/Instruments/Minimal.
-Alternate locations may be specified in the hud configuration, paths
-must be absolute to use files outside $FG_ROOT.
-
-About Instrument Placement:
-
-For the sake of simplicity the FGFS HUD overlay is always 640 x 480 res.
-so all x/y values for instrument placement should fall within these bounds.
-Being an OpenGL program, 0,0 represents the lower left hand corner of the
-screen.
-
-Instrument Implementation:
-
-Instruments are defined in separate configuration files.
-The Instruments are basically classified into 4 types( Each of them an xml file) :
-The Hud Ladder,
-The Hud Card,
-The Hud Label and
-The Turn Bank Indicator
-.... (Note that that the earlier HUD classes/objects have been retained)
-Newer objects may be instantiated using the above classes, Unless a totally
-new object is required).
-
-The Default as well as the Custom directory have the same (in terms of properties)
-set of configuration files (but with different values to suit the aircraft).
-
-We have a Base class - Hud Instrument Item.
-We derive two more base classes - Instrument Scale and Dual Instrument Item from this.
-(This implementation owes its existence to all those who wrote the HUD code for 0.6.1)
-
-The Hud Instrument Label is an instantiable class derived from Hud Instrument Item - for
-displaying alphanumeric labels (altitude, velocity, Mach no and/or anything else as long you
-have a call back function to pass the value using the property 'data_source').
-
-The Hud Card is an instantiable class derived from Instrument scale - for displaying
-tapes and guages (single variable display, for displaying aoa, g's, vsi, elevator_posn, etc.).
-
-The Hud Ladder is an instantiable class derived from Dual Instrument Item - for displaying
-pitch reference ladder or climb/dive ladder (two variable display, for dislaying two types of
-ladders, the pitch reference ladder or the climb/dive ladder as defined by MIL-1787b).
-
-The fgTBI Instrument is an instantiable class derived from Dual Instrument scale again
-- for display of Bank angle and Sideslip (two variable display, for display of TSI info, kept
-different from the two variable ladder object basically because of its totally different
-draw member function).
-
-Most Hud instruments may be instantiated using above. It is proposed to provide all
-Hud objects as defined in MIL-STD-1797A, soon.
-
-Here is how you position 'any' object:
-
-x ____________ x+width
- | |
- | |
-y ------------ y+height
-
-this defines the objects position centered about the centroid of above rectangle
-in HUD overlay plane (640x480) coordinates with 0,0 at bottom-left corner.
-
-One more, pixels per degree in the ladder class represents the compression factor of the
-pitch ladder. In case of conformal HUD (climd/dive ladder) it is <640/horizontal_fov>
-or <480/vertical_fov>. In case of pitch reference ladder it is
-<your_no_of vertical_pixels/your_no_of_ladder_degrees>.
-
-Example of Hud Ladder xml file.
-
-<PropertyList>
-
- <ladders>
-
- <l1>
- <name>Pitch Ladder</name> <!-- Name can be Pitch Ladder or Climb/Dive Ladder -->
- <x>260</x> <!-- x start -->
- <y>150</y> <!-- y start -->
- <width>120</width> <!-- x start + width = x end -->
- <height>180</height> <!-- y start + height = y end -->
- <compression_factor>2.68</compression_factor> <!-- Pixels per degree -->
- <loadfn>roll</loadfn> <!-- Name of the function to be called, here get_roll() is called provision made in Hud.cxx -->
- <loadfn1>pitch</loadfn1> <!-- Name of the function to be called, here get_pitch() is called -->
- <span_units>45.0</span_units> <!-- Range of the Ladder seen at any instant -->
- <division_units>10.0</division_units> <!-- Divisions -->
- <screen_hole>70</screen_hole> <!-- Hole b/w the Ladder Bars-->
- <lbl_pos>0</lbl_pos> <!-- Label Position to indicate pitch angle on bar -->
- <enable_frl>false</enable_frl> <!-- To Enable Pitch Reference Symbol (used by us) -->
- <enable_target_spot>true</enable_target_spot> <!-- To Enable Target Spot Symbol (fgfs uses this)-->
- <enable_velocity_vector>false</enable_velocity_vector> <!-- To Enable Velocity Vector Symbol (use only with climb/dive ladder)-->
- <enable_drift_marker>false</enable_drift_marker> <!-- To Enable Drift Marker Symbol (used by us)-->
- <enable_alpha_bracket>false</enable_alpha_bracket> <!-- To Enable Alpha Bracket Symbol (used by us, presently hard coded bracket values, alpha values will be moved to xml file)-->
- <enable_energy_marker>false</enable_energy_marker> <!-- To Enable Energy Marker Symbol (used by us)-->
- <enable_climb_dive_marker>false</enable_climb_dive_marker> <!-- To Enable Climb/Dive Marker (used by us)-->
- <enable_glide_slope_marker>false</enable_glide_slope_marker> <!--To Enable Glide/Slope Marker (tied to climb/dive ladder only)-->
- <glide_slope>0.0</glide_slope> <!-- Glide slope angle (specify the angle for drawing the reference bar)
- <enable_energy_worm>false</enable_energy_worm> <!-- To Enable Energy worm (used by us)>
- <enable_waypoint_marker>false</enable_waypoint_marker> <!-- To Enable Way point Marker (bearing marker)-->
- <working>true</working> <!use this to enable or disbale whole object>
- </l1>
-
- </ladders>
-
-</PropertyList>
-
-Before you read this, _____ this is tick_top | |
- | | |
- | |__________________|
- | this is cap_right,tick_left cap_bottom tick_right
- |
- _____| this is tick_bottom
-
-Example of Hud Card xml file.
-
-<PropertyList>
-
- <cards>
-
- <c1>
- <name>Gyrocompass</name>
- <x>220</x>
- <y>430</y>
- <width>200</width>
- <height>28</height>
- <loadfn>heading</loadfn> <!-- Name of the function to be called, here get_Heading() is called -->
- <options>4</options> <!-- Read Tape Options Below or Hud.hxx file for details -->
- <maxValue>360.0</maxValue> <!-- Maximum scale value -->
- <minValue>0.0</minValue> <!-- Minimum Scale Value -->
- <disp_scaling>1.0</disp_scaling> <!-- Multiply by this to get numbers shown on scale -->
- <major_divs>5</major_divs> <!-- major division marker units -->
- <minor_divs>1</minor_divs> <!-- minor division marker units -->
- <modulator>360</modulator> <!-- Its a rose, Roll Over Point -->
- <value_span>25.0</value_span> <!-- Range Shown -->
- <type>tape</type> <!-- Card type can be "tape" or "guage" -->
- <tick_bottom>false</tick_bottom> <!-- Read Ticks and Caps below -->
- <tick_top>false</tick_top>
- <tick_right>true</tick_right>
- <tick_left>true</tick_left>
- <cap_bottom>true</cap_bottom>
- <cap_top>false</cap_top>
- <cap_right>false</cap_right>
- <cap_left>false</cap_left>
- <marker_offset>0.0</marker_offset> <!-- Read Marker offset below -->
- <enable_pointer>true</enable_pointer> <!-- To draw a pointer -->
- <pointer_type>fixed</pointer_type> <!-- Type of pointer, Fixed or Moving (yet to be implemented)-->
- <working>true</working>
- </c1>
-
- </cards>
-
-</PropertyList>
-
-Tape Options:
-
-HUDS_AUTOTICKS = 0x0001
-HUDS_VERT = 0x0002
-HUDS_HORZ = 0x0000
-HUDS_TOP = 0x0004
-HUDS_BOTTOM = 0x0008
-HUDS_LEFT = HUDS_TOP
-HUDS_RIGHT = HUDS_BOTTOM
-HUDS_BOTH = (HUDS_LEFT | HUDS_RIGHT)
-HUDS_NOTICKS = 0x0010
-HUDS_ARITHTIC = 0x0020
-HUDS_DECITICS = 0x0040
-HUDS_NOTEXT = 0x0080
-HUDS_LEFT | HUDS_VERT = 0x0006
-HUDS_RIGHT | HUDS_VERT = 0x0010
-HUDS_TOP | HUDS_NOTEXT = 0x0084
-HUDS_BOTTOM | HUDS_NOTEXT = 0x0088
-HUDS_VERT | HUDS_LEFT | HUDS_NOTEXT = 0x0086
-HUDS_RIGHT | HUDS_VERT | HUDS_NOTEXT = 0x0090
-
-
-For clarity, I repeat, Ticks and Caps :
-
-
-1. Left Tick ->|_____|<- Right Tick
- |
- v
- Bottom Cap
-
-2. Top Cap
- |
- v
- _____
- | |
-
-
-3. Top Tick
- |
- v
- ---
- |
- |<- Right Cap
- |
- ---
- |
- v
- Bottom Tick
-
-4. ---
- |
- Left Cap -> |
- |
- ---
-
-Marker Offset :
-
-To Draw pointer on the scale markings. In the case of a our hud with offset 10.0
-The pointer is away from the scale and points at the markings.
-
- -| -
- -| -
- <| -<
- -| -
- -| -
-Marker offset = 0.0 Marker offset = 10.0
-
-This should be useful when I implement the fixed tape/moving pointer.
-
-
-Example of a Label xml file.
-
-<PropertyList>
-
- <labels>
-
- <i1>
- <name>machno</name>
- <x>25</x>
- <y>130</y>
- <width>40</width>
- <height>30</height>
- <data_source>mach</data_source> <!-- Name of the function to be called, here get_Heading() is called -->
- <label_format>%4.2f</label_format> <!-- The Label Format -->
- <pre_label_string>blank</pre_label_string> <!-- String to be written Pre Label -->
- <post_label_string>NULL</post_label_string> <!-- String to be written Post Label -->
- <scale_data>1.0</scale_data>
- <options>4</options> <!-- Read Tape options or Hud.hxx -->
- <justification>2</justification> <!-- Justify the label, 0=LEFT_JUSTIFY, 1=CENTER_JUSTIFY, 2=RIGHT_JUSTIFY -->
- <blinking>0</blinking> <!-- Yet to be implemented -->
- <working>true</working>
- <latitude>false</latitude> <!-- True if the label is to display Lattitude (special label, displays deg.min.sec)-->
- <longitude>false</longitude> <!-- True if the label is to display Longitude (special label, displays deg.min.sec)-->
- </i1>
-
- </labels>
-
-</PropertyList>
-
-
-Example of a Turn Bank Indicator xml file.
-
-<PropertyList>
-
- <tbis>
-
- <f1>
- <name>fgTBI_Instrument</name>
- <x>290</x>
- <y>45</y>
- <width>60</width>
- <height>10</height>
- <loadfn>roll</loadfn> <!-- Name of the function to be called, get_roll() is called here. -->
- <loadfn1>sideslip</loadfn1> <!-- Name of the function to be called, get_sideslip() is called here. -->
- <maxBankAngle>45.0</maxBankAngle> <!-- Maximum Angle of Bank -->
- <maxSlipAngle>5.0</maxSlipAngle> <!-- Maximum Angle of Slip -->
- <gap_width>5</gap_width> <!-- Screen Hole -->
- <working>true</working>
- </f1>
-
- </tbis>
-
-</PropertyList>
-
-I have still got to implement dials (as in MIL-STD-1787b).
-
-REMEMBER IF YOU NEED TO INDICATE ANY OTHER PARAMETER ON THE HUD OTHER THAN WHAT IS PROVIDED AS
-CALLBACK FUNCTIONS (PROPERTY NAMES LISTED BELOW) YOU HAVE TO FIDDLE WITH THE CODE, AS YET. LET ME
-KNOW AND I SHALL INCLUDE THAT.
-
-<loadfn>anzg</loadfn> <!-- Here get_anzg() is called -->
-<loadfn>heading</loadfn> <!-- Here get_heading() is called -->
-<loadfn>aoa</loadfn> <!-- Here get_aoa() is called -->
-<loadfn>climb</loadfn> <!-- Here get_climb() is called -->
-<loadfn>altitude</loadfn> <!-- Here get_altitude() is called -->
-<loadfn>agl</loadfn> <!-- Here get_agl() is called -->
-<loadfn>speed</loadfn> <!-- Here get_speed() is called -->
-<loadfn>view_direction</loadfn> <!-- Here get_view_direction() is called -->
-<loadfn>aileronval</loadfn> <!-- Here get_aileronval() is called -->
-<loadfn>elevatorval</loadfn> <!-- Here get_elevatorval() is called -->
-<loadfn>rudderval</loadfn> <!-- Here get_rudderval() is called -->
-<loadfn>throttleval</loadfn> <!-- Here get_throttleval() is called -->
-<loadfn>aux16</loadfn> <!-- Here get_aux16() is called -->
-<loadfn>aux17</loadfn> <!-- Here get_aux17() is called -->
-<loadfn>aux9</loadfn> <!-- Here get_aux9() is called -->
-<loadfn>aux11</loadfn> <!-- Here get_aux11() is called -->
-<loadfn>aux12</loadfn> <!-- Here get_aux12() is called -->
-<loadfn>aux10</loadfn> <!-- Here get_aux10() is called -->
-<loadfn>aux13</loadfn> <!-- Here get_aux13() is called -->
-<loadfn>aux14</loadfn> <!-- Here get_aux14() is called -->
-<loadfn>aux15</loadfn> <!-- Here get_aux15() is called -->
-<loadfn>aux8</loadfn> <!-- Here get_aux8() is called -->
-<loadfn>ax</loadfn> <!-- Here get_Ax() is called -->
-<loadfn>mach</loadfn> <!-- Here get_mach() is called -->
-<loadfn>framerate</loadfn> <!-- Here get_frame_rate() is called -->
-<loadfn>fov</loadfn> <!-- Here get_fov() is called -->
-<loadfn>vfc_tris_culled</loadfn> <!-- Here get_vfc_tris_culled() is called -->
-<loadfn>vfc_tris_drawn</loadfn> <!-- Here get_vfc_tris_drawn() is called -->
-<loadfn>latitude</loadfn> <!-- Here get_latitude() is called -->
-<loadfn>longitude</loadfn> <!-- Here get_longitude() is called -->
-
-
-
-
-
-
-
-
-
-
-
-
projects / flightgear.git / commitdiff