Experience the Masters' code style _ opencv source code structure analysis 1

Recently, when calling opencv, I always look at the original code of opencv. In those complicated macro definitions, I still feel very interesting.

Cvget2d (const cvarr * arr, int y, int X); // The first coordinate is Y, and the Second coordinate is X.

 

Cv_impl cvscalar
Cvget2d (const cvarr * arr, int y, int X) // cv_impl macro defines extern "C"
{
Cvscalar scalar = {0, 0, 0 }};

Cv_funcname ("cvget2d"); // The cv_funcname here is to pass a function name to the Global static variable cvfuncname of the system, and then this variable will be used in cverror to output the function error.

_ Begin __; // here is {

Int type = 0;
Uchar * PTR;

If (cv_is_mat (ARR) // common matrix Array
{
Cvmat * MAT = (cvmat *) Arr;

If (unsigned) y >=( unsigned) (mat-> rows) |
(Unsigned) x> = (unsigned) (mat-> Cols ))
Cv_error (cv_stsoutofrange, "index is out of range ");

Type = cv_mat_type (mat-> type );
PTR = mat-> data. PTR + (size_t) y * mat-> step + x * icvpixsize [type];
}
Else if (! Cv_is_sparse_mat (ARR) // Image
PTR = cvptr2d (ARR, Y, X, & type );
Else // sparse matrix Array
{
Int idx [] = {Y, x };
PTR = icvgetnodeptr (cvsparsemat *) Arr, idx, & type, 0, 0 );
}

Cvrawdatatoscalar (PTR, type, & scalar );

_ End __; // here is # DEFINE _ end _ goto exit; exit :;}. an empty statement is actually executed. I don't understand what this macro means in every function.

Return scalar;
}

///

There are many macro definitions in opencv. ippi_call generally makes a judgment on the function pointer when calling a function.

 

When looking at the original file cvtemplmatch. cpp, we found some initial functions defined by the function.

// Define the pointer type of a function first. the following statement calls Intel's internal functions. The original Code cannot be found in opencv. I did not find it, but I don't know if anyone can find it.

/**************************** IPP match template functions ****** ************************/

Icvcross1_valid_norm_8u32f_c1r_t icvcross1_valid_norm_8u32f_c1r_p = 0;
Icvcross1_valid_normlevel_8u32f_c1r_t icvcross1_valid_normlevel_8u32f_c1r_p = 0;
Icvsqrdistancevalid_norm_8u32f_c1r_t icvsqrdistancevalid_norm_8u32f_c1r_p = 0;
Icvcross1_valid_norm_32f_c1r_t icvcross1_valid_norm_32f_c1r_p = 0;
Icvcross1_valid_normlevel_32f_c1r_t icvcross1_valid_normlevel_32f_c1r_p = 0;
Icvsqrdistancevalid_norm_32f_c1r_t icvsqrdistancevalid_norm_32f_c1r_p = 0;

Typedef cvstatus (cv_stdcall * cvtemplmatchippfunc)
(Const void * IMG, int imgstep, cvsize imgsize,
Const void * Templ, int templstep, cvsize templsize,
Void * result, int rstep );

/*************************************** **************************************** **********/

 

Define some function pointers, but these functions cannot be found

 

In the cvmatchtemplate function, select different functions based on different template matching methods.

Cvtemplmatchippfunc ipp_func =
Depth = cv_8u?
(Method = cv_tm_sqdiff_normed? (Cvtemplmatchippfunc) icvsqrdistancevalid_norm_8u32f_c1r_p:
Method = cv_tm_c1__normed? (Cvtemplmatchippfunc) icvcross1_valid_norm_8u32f_c1r_p:
(Cvtemplmatchippfunc) icvcross1_valid_normlevel_8u32f_c1r_p ):
(Method = cv_tm_sqdiff_normed? (Cvtemplmatchippfunc) icvsqrdistancevalid_norm_32f_c1r_p:
Method = cv_tm_c1__normed? (Cvtemplmatchippfunc) icvcross1_valid_norm_32f_c1r_p:
(Cvtemplmatchippfunc) icvcross1_valid_normlevel_32f_c1r_p );

There is a function body in opencv, but the function name is dynamically changed. This policy can be applied to code encryption.

# Define icv_decl_cross1__direct (flavor, arrtype, corrtype, worktype )/

Static cvstatus cv_stdcall/
Icvcross‑direct _ ## flavor # _ CNR (const arrtype * img0, int imgstep ,/
Cvsize imgsize, const arrtype * templ0, int templstep, cvsize templsize ,/
Corrtype * corr, int sequence step, cvsize sequence size, int CN )/
{

// Function body

}

The following function declaration

Icv_decl_cross1__direct (8u32f, uchar, float, INT)
Icv_decl_cross1__direct (32f, float, float, double)
Icv_decl_cross1__direct (64f, Double, double, double)

Typedef cvstatus (cv_stdcall * cvcross‑directfunc )(
Const void * IMG, int imgstep, cvsize imgsize,
Const void * Templ, int templstep, cvsize templsize,
Void * corr, int skip step, cvsize skip size, int CN );

The following is the call method.

Cvcross‑directfunc ‑_func = 0;
If (depth = cv_8u & pai_type = cv_32f)
Required _func = (cvcross1_directfunc) icvcross1_direct_8u32f_cnr;
Else if (depth = cv_32f & corr_type = cv_32f)
Required _func = (cvcross1_directfunc) icvcross1_direct_32f_cnr;
Else if (depth = cv_64f & corr_type = cv_64f)
Required _func = (cvcross1_directfunc) icvcross1_direct_64f_cnr;
Else
Cv_error (cv_stsunsupportedformat,
"Unsupported combination of input and output formats ");

Ippi_call (effec_func (IMG-> data. PTR, IMG-> step, imgsize,
Templ-> data. PTR, Templ-> step, templsize,
Corr-> data. PTR, corr-> step, shard size, CN ));

It's really interesting.