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libacfutils

This is a general purpose library of utility functions designed to make it easier to develop addons for the X-Plane flight simulator. It comes with everything needed to build it on Linux or macOS. No build support for Windows currently, sorry. The Linux version produces the Windows version of the library through a MinGW cross-compile.

LICENSE

This library is licensed under the CDDL 1.0 license. This lets you incorporate it into your projects (even closed-source/payware ones) without disclosing source code. The license only requires that you disclose modifications that you have done to the source code comprising this library. Any files that are not part of this library are not covered by this requirement.

How the library is organized

The top level of this source tree includes the dependencies organized into their individual sub-directories + build scripts. The source code of the library itself is located under src. The documentation is part of the .c files. The headers listing all the functions are under src/acfutils. To make the includes work properly, direct your compiler to include from the src sub-directory. Then include library headers using the following path:

#include <acfutils/filename.h>

What's included

• acfutils/acf_file.h: a parser for X-Plane's `.acf' files and support extracting individual properties.

• acfutils/airportdb.h: a global airport database, dynamically constructed from X-Plane's scenery, including highly accurate runway locations + automatic calculation of approach sectors. This is useful for determining your exact location with respect to a runway (e.g. when implementing a runway-awareness system). You can also use it to enumerate all nearby airports in a thread-friendly manner, without having to go through X-Plane's XPLMNavigation.h interface.

• acfutils/assert.h: a highly flexible assertion checking facility with support for logging backtraces to the X-Plane Log.txt file.

• acfutils/avl.h: generic binary search trees for storage of arbitrary data.

• acfutils/compress.h: a convenience frontend to the zlib (deflate) and 7-zip compression algorithms.

• acfutils/conf.h: a general purpose configuration file facility with support for key=value pairs and a convenient access interface.

• acfutils/crc64.h: an implementation of the CRC64 checksum algorithm, as well as a high-performance portable random number generator based on the CRC64 algorithm.

• acfutils/dr.h: a simple and highly flexible interface to X-Plane's dataref system. No need to write custom callbacks anymore or hope you got your data types right. Simply call one function to read or write datarefs in any format and dr.h automatically handles all data type conversions for you.

• acfutils/dsf.h: a simple set of functions to read & parse X-Plane's DSF files.

• acfutils/geom.h: a large collection of geometry-related convenience functions, including:

  • Manipulation of 2D- and 3D-vectors. Includes vector geometry constructions such as intersections, parallel tests, arithmetic, rotations, products, etc.

  • Geographic & geodesic coordinate manipulation. Allows translating between geographic coordinates (lat + lon + elev) into 3D vector coordinate space. Supports both spherical as well as geodesic coordinates (including the WGS84 ellipsoid).

  • Arbitrary flat-plane projections from spherical and geodesic coordinates, including some common canned projections such as orthographic, stereographic, gnomonic and lambert-conformal projections.

  • Function interpolation for functions defined using a set of quadratic bezier curve segments.

• acfutils/icao2cc.h: functions to translate an ICAO airport code into the country code of the containing country as well as the major language used in the region of the airport.

• acfutils/intl.h: a set of simple and portable internationalization functions. Simply supply a set of files in the strings.po format and you can use the _() macro to translate them on-the-fly.

• acfutils/list.h: generic doubly-linked lists for storage of arbitrary data.

• acfutils/log.h: convenience front-end to X-Plane Log.txt logging facility, with support for printf-style format strings and automatic appending of source code file names & line numbers for easy debugging.

• acfutils/math.h: a set of useful mathematical functions, such as:

  • a generic quadratic equation solver

  • linear function extrapolation (both single- and multi-segment linear functions)

  • weighted averages

  • value clamping

• acfutils/mt_cairo_render.h: a double-buffered multi-threaded Cairo canvas with automatic OpenGL compositing support. Simply supply a callback to draw the surface and tell it where to draw in your OpenGL output. You can configure rendering at a fixed FPS, or on-demand. Since the render takes place on a background thread, it doesn't interlock with X-Plane's OpenGL renderer. Also includes a convenience FreeType font loader function to simplify font handling.

• acfutils/osrand.h: a simple frontend to an OS-specific high quality random number generator. Use this to generate secure cryptographic keys. Uses /dev/random on Linux and macOS and CryptGenRandom on Windows.

• acfutils/paste.h: a platform-independent interface for cut-and-paste functionality on macOS, Windows and Linux.

• acfutils/perf.h: a large collection aerodynamics & performance-calculation functions. Includes many common physical unit conversion macros, as well as functions to convert air data such as impact pressures into airspeeds, mach-to-TAS, TAT-to-SAT, etc.

• acfutils/png.h: a simple frontend to libpng for reading and writing PNG files.

• acfutils/riff.h: a general-purpose RIFF file parser. Primarily used to read WAV files. For a more convenient interface to working with OpenAL as well as a variety of sound file formats, see wav.h.

• acfutils/shader.h: a set of shorthand functions to load OpenGL GLSL program shaders using a single call.

• acfutils/thread.h: platform-independent multi-threading primitives. Provides facilities for starting, stopping and synchronizing multiple execution threads. Uses the appropriate OS-specific backend underneath.

• acfutils/time.h: a platform-independent mechanism for getting microsecond-accurate timestamps anchored to UNIXTIME (microseconds since UTC 1970-01-01).

• acfutils/types.h: special typedefs used in the library. This should automatically be included by the appropriate library headers, so you shouldn't need to include this explicitly.

• acfutils/wav.h: a generic OpenAL and sound file interface. Provides facilities for loading files formatted in WAV, Opus and MP3 file formats. Also provides convenience functions for manipulation OpenAL's dedicated contexts and spacial sound parameters.

• acfutils/widget.h: helper functions to provide relative positioning of XPWidget objects. Also a generic popup-tooltip facility that can be attached to any X-Plane widget.

• acfutils/wmm.h: convenience functions for accessing world-magnetic-model files (WMM.COF). Simply load a WMM.COF file and translate between magnetic and true headings using just a couple of tiny functions.

• acfutils/worker.h: a general-purpose background worker thread abstraction object. Provides the ability to simply define a callback function, which will then be called a fixed interval in a separate thread, as well as the ability to synchronize with and terminate the background worker thread without having to deal with keeping track of individual locks and condition variables.