%% Fixed Point Parameters in Legacy Functions
% This example shows you how to use the Legacy Code Tool to integrate legacy C 
% functions that pass their inputs and outputs using parameters of fixed point
% data type.
% 
% 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 1990-2011 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.  
% 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:
%
% myFixpt timesS16(const myFixpt in1, const myFixpt in2, const uint8_T fracLength)
%
% where myFixpt is logically a fixed point data type which is physically
% a typedef to a 16-bit integer:

myFixpt = Simulink.NumericType;
myFixpt.DataTypeMode = 'Fixed-point: binary point scaling';
myFixpt.Signed = true;
myFixpt.WordLength = 16;
myFixpt.FractionLength = 10;
myFixpt.IsAlias = true;
myFixpt.HeaderFile = 'timesFixpt.h';

%%
% The legacy source code is found in the files
% <matlab:sldemo_lct_util('edit','sldemo_lct_src/timesFixpt.h') timesFixpt.h>, and
% <matlab:sldemo_lct_util('edit','sldemo_lct_src/timesS16.c') timesS16.c>.

% sldemo_sfun_gain_fixpt
def = legacy_code('initialize');
def.SFunctionName = 'sldemo_sfun_gain_fixpt';
def.OutputFcnSpec = 'myFixpt y1 = timesS16(myFixpt u1, myFixpt p1, uint8 p2)';
def.HeaderFiles   = {'timesFixpt.h'};
def.SourceFiles   = {'timesS16.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
% <matlab:sldemo_lct_util('edit','sldemo_sfun_gain_fixpt.c') sldemo_sfun_gain_fixpt.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);

%% Demoing the Generated Integration with Legacy Code
% The model <matlab:sldemo_lct_fixpt_params sldemo_lct_fixpt_params> 
% shows integration with the legacy
% code.  The subsystem TestFixpt serves as a harness for the call to the
% legacy C function via the generated S-function.

open_system('sldemo_lct_fixpt_params')
open_system('sldemo_lct_fixpt_params/TestFixpt')
sim('sldemo_lct_fixpt_params')




displayEndOfDemoMessage(mfilename)
