%% Complex Signals in Legacy Function
% This example shows you how to use the Legacy Code Tool to integrate legacy C 
% functions using complex signals.
%
% The Legacy Code Tool allows you to:
%
% * Provide the legacy function specification,
% * Generate a C-MEX S-function that is used during simulation to call the legacy code, and
% * Compile and build the generated S-function for simulation.
%

%   Copyright 2006-2020 The MathWorks, Inc.

%% Providing the Legacy Function Specification
% Functions provided with the Legacy Code Tool take a specific data
% structure or array of structures as the argument. The data structure is
% initialized by calling the function legacy_code() using 'initialize' as
% the first input. After initializing the structure, you have to assign its
% properties to values corresponding to the legacy code being integrated.
% The prototype of the legacy functions being called in this example is:
%
% void cplx_gain(creal_T *input, creal_T *gain, creal_T *output);
%
% where creal_T is the complex representation of a double.  The legacy
% source code is found in the files |cplxgain.h| and |cplxgain.c|.

% sldemo_sfun_gain_scalar
def = legacy_code('initialize');
def.SFunctionName = 'sldemo_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      = {'sldemo_lct_src'}; 
def.SrcPaths      = {'sldemo_lct_src'}; 

%% Generating and Compiling an S-Function for Use During Simulation
% The function legacy_code() is called again with the first input set to
% 'generate_for_sim' in order to automatically generate and compile the
% C-MEX S-function according to the description provided by the input
% argument 'def'.  This S-function is used to call the legacy functions in
% simulation. The source code for the S-function is found in the file
% |sldemo_sfun_cplx_gain.c|.

legacy_code('generate_for_sim', def);

%% Generating an rtwmakecfg.m File for Code Generation
% After the TLC block file is created, the function
% legacy_code() can be called again with the first input set to 
% 'rtwmakecfg_generate' in order to generate an rtwmakecfg.m file to support
% code generation through Simulink(R) Coder(TM). Generate the rtwmakecfg.m 
% file if the required source and header files for the S-functions are not 
% in the same directory as the S-functions, and you want to add these 
% dependencies in the makefile produced during code generation.
%
% Note: Complete this step only if you are going to simulate the model in 
% accelerated mode.

legacy_code('rtwmakecfg_generate', def);

%% Generating a Masked S-Function Block for Calling the Generated S-Function
% After the C-MEX S-function source is compiled, the function 
% legacy_code() can be called again with the first input set to 'slblock_generate'
% in order to generate a masked S-function block that is configured to call that
% S-function.  The block is placed in a new model and can be copied to an
% existing model.

% legacy_code('slblock_generate', def);

%% Integration with Legacy Code
% The model |sldemo_lct_cplxgain| shows integration 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','sldemo_lct_cplxgain'))
    open_system('sldemo_lct_cplxgain')
    open_system('sldemo_lct_cplxgain/complex_gain')
    sim('sldemo_lct_cplxgain');
end
