MATLAB/C++ Mixed Programming: call MATLAB directly in VC++
There are two ways in VC++ to call MATLAB:

distribute MATLAB code into MATLAB independent C++ shared library. Refer to the previous blog for details.

call MATLAB directly in VC++.
This blog will focus on the second approach (also the easier one).
Prework:
 Install MATLAB: unlike the first method, make sure you have the whole MATLAB application installed in order to call MATLAB directly in VC++ (only MATLAB Compiler Runtime is needed for the first method). We will take MATLABx64R2013a as an example (installed under
C:\Program Files\MATLAB\R2013a
).  Platform consistence: the platforms of MATLAB and VC++ compile platform must be the same, i.e. Win32/x86 VC++ compile platform can only use x86 MATLAB and x64 VC++ compile platform can only use x64 MATLAB.

Example: take the following example
myadd2.m
(assume underC:\
):function [y, z] = myadd2(a, b) % dummy function, just to demonstrate the idea y = a+b; z = a+2*b; disp('Output from MATLAB.'); end
VC setup:
 Add MATLAB include folder to project
Include
files: i.e.C:\Program Files\MATLAB\R2013a\extern\include
 Add MATLAB library folder to project
Library
files: i.e.C:\Program Files\MATLAB\R2013a\extern\lib\win64\microsoft
 Add relevant libraries to
Linker>Input>Additional Dependencies
:libmx.lib libeng.lib
 Add MATLAB Compiler Runtime binary folder to project
Debugging>Environment
: i.e.PATH=%PATH%;$(ProjectDir)\dlls_x64;C:\Program Files\MATLAB\R2013a\runtime\win64;C:\Program Files\MATLAB\R2013a\bin\win64
 Add header to main code:
#include "engine.h"

Call in VC++: refer to
VC_call_MATLAB_directly.cpp
for details.In this cpp file, there are also ways to handle data passing of different types between VC++ and MATLAB (see the
SHOW_EXTEND_INFO
part), which includes:double
(orint
/float
/…)string
 matrix
 grayscale image
 RGB image
Other Remarks:
 If
engOpen(NULL)
always returns0
orNULL
, you should register MATLAB first by^{1} Run DOS in admin mode.
 In DOS, go to MATLAB install folder that contains
matlab.exe
, e.g.D:\Program Files\MATLAB\R2014b\bin
.  Run command:
./matlab.exe /regserver
.
Note: it seems that given MATLAB can not both register both x86 & x64 (e.g. can only register MATLAB2015bx86 or MATLAB2015bx64, but not both). On the other hand, if we do want both x86 and x64 modes, we can install one MATLAB for one mode and one for another, e.g. MATLAB2015bx86 and MATLAB2014bx64.
 Try to close the previous MATLAB window first (extra command window) if stuck at
engOpen(NULL)
.

engOpen()
always returns 0: http://www.mathworks.com/matlabcentral/newsreader/view_thread/238828 ↩