%% Integrate External C Functions That Pass Input and Output Arguments as Signals with Complex Data
% Integrate legacy C functions using complex signals with the Legacy Code Tool. 
%
% With the Legacy Code Tool, you can:
%
% * Provide the legacy function specification.
% * Generate a C-MEX S-function that calls the legacy code during
% simulation.
% * Compile and build the generated S-function for simulation.
% * Generate a TLC block file and optional rtwmakecfg.m file that specifies
% how the generated code for a model calls the legacy code.

%   Copyright 2006-2015 The MathWorks, Inc.

%% Provide the Legacy Function Specification
% Legacy Code Tool functions take a specific data structure or array of
% structures as the argument. You can initialize the data structure by
% calling the function legacy_code() using 'initialize' as the first input.
% After initializing the structure, assign its properties to values
% corresponding to the legacy code being integrated. For detailed help on
% the properties, call <matlab:legacy_code('help') legacy_code('help')>.
% The prototype of the legacy functions being called in this example is:
%
% void cplx_gain(creal_T *input, creal_T *gain, creal_T *output);
%
% creal_T is the complex representation of a double.  The legacy source code is in the
% files
% <matlab:rtwdemo_lct_util('edit','rtwdemo_lct_src/cplxgain.h') cplxgain.h>, and
% <matlab:rtwdemo_lct_util('edit','rtwdemo_lct_src/cplxgain.c') cplxgain.c>.

% rtwdemo_sfun_gain_scalar
def = legacy_code('initialize');
def.SFunctionName = 'rtwdemo_sfun_cplx_gain';
def.OutputFcnSpec = ...
    ['void cplx_gain(complex<double> u1[1], '...
    'complex<double> p1[1], complex<double> y1[1])'];
def.HeaderFiles   = {'cplxgain.h'};
def.SourceFiles   = {'cplxgain.c'};
def.IncPaths      = {'rtwdemo_lct_src'}; 
def.SrcPaths      = {'rtwdemo_lct_src'}; 

%%  Generate an S-Function for Simulation
% To generate a C-MEX S-function according to the description provided by
% the input argument 'def', call the function legacy_code() again with the
% first input set to 'sfcn_cmex_generate'. The S-function calls the legacy
% functions during simulation. The source code for the S-function is in the
% file
% <matlab:rtwdemo_lct_util('edit','rtwdemo_sfun_cplx_gain.c') rtwdemo_sfun_cplx_gain.c>.

legacy_code('sfcn_cmex_generate', def);

%% Compile the Generated S-Function for Simulation
% After you generate the C-MEX S-function source file, to compile the S-function 
% for simulation with Simulink(R), call the function 
% legacy_code() again with the first input set to 'compile'.

legacy_code('compile', def);

%% Generate a TLC Block File for Code Generation
% After you compile the S-function and use it in simulation, you can call
% the function legacy_code() again with the first input set to
% 'sfcn_tlc_generate' to generate a TLC block file. The block file
% specifies how the generated code for a model calls the legacy code. If
% you do not generate a TLC block file and you try to generate code for a
% model that includes the S-function, code generation fails. The TLC block
% file for the S-function is:
% <matlab:rtwdemo_lct_util('edit','rtwdemo_sfun_cplx_gain.tlc') rtwdemo_sfun_cplx_gain.tlc>.

legacy_code('sfcn_tlc_generate', def);

%% Generate an rtwmakecfg.m File for Code Generation
% After you create the TLC block file, you can call the function
% legacy_code() again with the first input set to 'rtwmakecfg_generate' to
% generate an rtwmakecfg.m file to support code generation. If the required
% source and header files for the S-function are not in the same folder as
% the S-function, and you want to add these dependencies in the makefile
% produced during code generation, generate the rtwmakecfg.m file.

legacy_code('rtwmakecfg_generate', def);

%% Generate a Masked S-Function Block for Calling the Generated S-Function
% After you compile the C-MEX S-function source, you can call the function
% legacy_code() again with the first input set to 'slblock_generate' to
% generate a masked S-function block that calls that S-function.  The
% software places the block in a new model. From there you can copy it to
% an existing model.

legacy_code('slblock_generate', def);

%% Show the Integration of the Model with Legacy Code
% The model <matlab:rtwdemo_lct_cplxgain rtwdemo_lct_cplxgain> 
% shows integration of the model with the legacy
% code.  The subsystem complex_gain serves as a harness for the call to the
% legacy C function via the generate S-function.

if isempty(find_system('SearchDepth',0,'Name','rtwdemo_lct_cplxgain'))
    open_system('rtwdemo_lct_cplxgain')
    open_system('rtwdemo_lct_cplxgain/complex_gain')
    sim('rtwdemo_lct_cplxgain')
end
