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1 \name{dynport}
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2 \alias{dynport}
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3 \alias{loadDynportNamespace}
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4 \title{Dynamic R Bindings to standard and common C libraries}
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5 \description{Function to bind APIs of standard and common C libraries to R via dynamically created interface environment objects
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6 comprising R wrappers for C functions, object-like macros, enums and data types.
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7 }
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8 \usage{
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9 dynport(portname, portfile=NULL,
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10 repo=system.file("dynports",package="rdyncall") )
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11 }
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12 \arguments{
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13 \item{portname}{the name of a dynport, given as a literal or character string.}
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14 \item{portfile}{\code{NULL} or character string giving a script file to parse ; \code{portname} and \code{repo} are .}
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15 \item{repo}{character string giving the path to the root of the \emph{dynport} repository.}
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16 }
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17 \details{
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18 \code{dynport} offers a convenient method for binding entire C libraries to R.
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19 This mechanism runs cross-platform and uses dynamic linkage but it implies
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20 that the run-time library of a choosen binding need to be preinstalled in the system.
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21 Depending on the OS, the run-time libraries may be preinstalled or require manual installation.
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22 See \link{rdyncall-demos} for OS-specific installation notes for several C libraries.
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23
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24 The binding method is data-driven using platform-portable specifications named \emph{DynPort} files.
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25 DynPort files are stored in a repository that is installed as part of the package installation.
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26 When \code{dynport} processes a \emph{DynPort} file given by \code{portname},
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27 an environment object is created, populated with R wrapper and helper objects
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28 that make up the interface to the C library, and attached to the search path with the name \code{dynport:<PORTNAME>}.
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29 Unloading of previously loaded dynport environments is achieved via \code{detach(dynport:<PORTNAME>)}.
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30
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31 Up to \pkg{rdyncall} version 0.7.4, R name space objects were used as containers as described in the article \emph{Foreign Library Interface}, thus
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32 dynport \sQuote{packages} appeared as \code{"package:<PORTNAME>"} on the search path. The mechanism to create synthesized R packages at run-time
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33 required the use of \code{.Internal} calls.
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34 But since the use of internal R functions is not permitted for packages distributed on CRAN we downgraded the package to use ordinary environment
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35 objects starting with version 0.7.5 until a public interface for the creation of R namespace objects is available.
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36
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37 The following gives a list of currently available \emph{DynPorts}:
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38 \tabular{ll}{
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39 \strong{DynPort name/C Library} \tab \strong{Description} \cr
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40 \code{expat} \tab Expat XML Parser Library \cr
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41 \code{GL} \tab OpenGL 1.1 API \cr
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42 \code{GLU} \tab OpenGL Utility Library \cr
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43 \code{GLUT} \tab OpenGL Utility Toolkit Library \cr
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44 \code{SDL} \tab Simple DirectMedia Layer library \cr
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45 \code{SDL_image} \tab Loading of image files (png,jpeg..) \cr
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46 \code{SDL_mixer} \tab Loading/Playing of ogg/mp3/mod music files. \cr
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47 \code{SDL_ttf} \tab Loading/Rendering of True Type Fonts. \cr
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48 \code{SDL_net} \tab Networking library. \cr
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49 \code{glew} \tab OpenGL Extension Wrangler (includes OpenGL 3.0) \cr
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50 \code{glfw} \tab OpenGL Windowing/Setup Library \cr
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51 \code{gl3} \tab strict OpenGL 3 (untested) \cr
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52 \code{R} \tab R shared library \cr
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53 \code{ode} \tab Open Dynamics (Physics-) Engine (untested) \cr
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54 \code{cuda} \tab NVIDIA Cuda (untested) \cr
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55 \code{csound} \tab Sound programming language and library \cr
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56 \code{opencl} \tab OpenCL (untested) \cr
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57 \code{stdio} \tab C Standard Library I/O Functions \cr
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58 \code{glpk} \tab GNU Linear Programming Kit \cr
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59 \code{EGL} \tab Embedded Systems Graphics Library \cr
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60 }
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61
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62 As of the current implementation \emph{DynPort} files are R scripts
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63 that perform up to three tasks:
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64
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65 \itemize{
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66 \item Functions (and pointer-to-function variables) are mapped via \code{\link{dynbind}} and a description of the C library using a \emph{library signatures}.
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67 \item Symbolic names are assigned to its values for object-like macro defines and C enum types.
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68 \item Run-time type-information objects for aggregate C data types (struct and union) are registered via \code{\link{parseStructInfos}} and \code{\link{parseUnionInfos}}.
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69 }
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70
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71 The file path to the \emph{DynPort} file is derived from
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72 \code{portname} per default. This would refer to \code{"<repo>/<portname>.R"}
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73 where \code{repo} usually refers to the initial \emph{DynPort} repository
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74 located at the sub-folder \code{"dynports/"} of the package.
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75 If \code{portfile} is given, then this value is taken as file path (usually
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76 for testing purpose).
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77
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78 A tool suite, comprising AWK (was boost wave), GCC Preprocessor, GCC-XML and XSLT, was used to generate the available \emph{DynPort} files automatically
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79 by extracting type information from C library header files.
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80
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81 In a future release, the DynPort format will be changed to
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82 a language-neutral text file document. For the interested reader:
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83 A first prototyp is currently available in an FFI extension to the Lua
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84 programming language (see \code{luadyncall} subversion sub-tree).
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85 A third revision (including function types in call signatures, bitfields, arrays, etc..)
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86 is currently in development.
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87 }
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88 \references{
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89 Adler, D. (2012) \dQuote{Foreign Library Interface}, \emph{The R Journal}, \bold{4(1)}, 30--40, June 2012.
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90 \url{http://journal.r-project.org/archive/2012-1/RJournal_2012-1_Adler.pdf}
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91
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92 Adler, D., Philipp, T. (2008) \emph{DynCall Project}. \url{http://dyncall.org}
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93
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94 Clark, J. (1998). expat - XML Parser Toolkit. \url{http://expat.sourceforge.net}
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95
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96 Ikits, M. and Magallon, M. (2002). The OpenGL Extension Wrangler Library. \url{http://glew.sourceforge.net}
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97
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98 Latinga, S. (1998). The Simple DirectMedia Layer Library. \url{http://www.libsdl.org}
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99
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100 Segal, M. and Akeley, K. (1992). The OpenGL Graphics System. A Specification, Version 1.0. \url{http://www.opengl.org}
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101
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102 Smith, R. (2001). Open Dynamics Engine. \url{http://www.ode.org}
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103 }
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104 \examples{
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105 \donttest{
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106 # Using SDL and OpenGL in R
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107 dynport(SDL)
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108 dynport(GL)
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109 # Initialize Video Sub-system
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110 SDL_Init(SDL_INIT_VIDEO)
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111 # Initialize Screen with OpenGL Context and Double Buffering
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112 SDL_SetVideoMode(320,256,32,SDL_OPENGL+SDL_DOUBLEBUF)
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113 # Clear Color and Clear Screen
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114 glClearColor(0,0,1,0) # blue
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115 glClear(GL_COLOR_BUFFER_BIT)
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116 # Flip Double-Buffer
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117 SDL_GL_SwapBuffers()
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118 }
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119 }
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120 \keyword{programming}
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121 \keyword{interface}
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122
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