Fct_Contour_Get

Get the contour points associated with a TAG on a specific frame.

Syntax

int Fct_Contour_Get_Points(

SliceO_Frame * frame,

short tag,

Point_2D ** pts )

) ;

Parameters

frame

Pointer to the frame for which we want the points.

tag

TAG value for which we want the points.

pts

pointer to an array that will contain the points.

Return value

This function return the number of points in the vector.

Remarks

The contour points are kept in a user structure of the frame with ID=ID_3D_CONTOUR

Requirements

Header:

sliceO_include.hpp

Library:

sliceO_Structures.lib

Example

Computing the "Snake From TAG" in the "Snake" module. The snakes will be derived from a 2x2 sub-sampling contour.

// ----------------------------------------------------------------------------

// Snake_From_TAG

// Param: (void)

// Return: (int) NULL if error

// ----------------------------------------------------------------------------

int Snake_From_TAG( void )

{

Snake_Mode = 2 ;

unsigned short TAG_Nb = (unsigned short) Fct_Variable_Value( "$TAG_NB" ) ;

int *pts_tot = new int [TAG_Nb] ;

memset( (void *) pts_tot, NULL, TAG_Nb * sizeof(int) ) ;

// --- for each selected image ---

if ( ! Iterator_Init( ITERATOR_2, "Snake_From_TAG" ) )

return( 0 ) ;

// ================================================================

// --- no updates until we are done

// ================================================================

Fct_Update( UPDATE_DELAY_ON ) ;

SET_CURS_WAIT ;

while( SliceO_Frame *frame = (SliceO_Frame *) Iterator_Class( ITERATOR_2, CLASS_ID_FRAME, NULL, ITER_FLAG_SELECT ) ) {

// --- clear the present Snake values ---

for ( int i=0; i < Snake_Nb; i++ )

if ( Snake_List[i]->frame == frame )

Snake_Remove( Snake_List[i] ) ;

// --- compute a new contour with 2x2 oversampling ---

Fct_Contour_Create( frame, SHELL_MODE_LOOP | SHELL_MODE_BORDER, 2, 2 ) ;

// --- information stool ---

for ( unsigned char tag=1; tag < TAG_Nb; tag++ ) {

// --- Get the contour points for this tag and this frame ---

Point_2D *pts ;

int pts_nb = Fct_Contour_Get_Points( frame, tag, &pts ) ;

if ( ! pts_nb )

continue ;

pts_tot[tag] += pts_nb ;

// --- now get the connectivity for these points ---

SliceO_Buffer *loop_pt ;

int loop_nb = Fct_Contour_Get_Loops( frame, tag, &loop_pt ) ;

for ( int j=0; j < loop_nb; j++ ) {

int loop_pts_nb = loop_pt[j].Size_Get() / sizeof(int) ;

int *loop_pts_id = (int *) loop_pt[j].Data_Get() ;

// --- we need a minimum of points on the contour ---

if ( loop_pts_nb <= MIN_NB_PTS )

continue ;

// --- create a new snake ---

Snakes *snake = new Snakes ;

snake->Create( frame, tag ) ;

// --- add the new points ---

snake->nb_points = loop_pts_nb ;

MALLOC( Snake_Points *, snake->point, loop_pts_nb, sizeof(Snake_Points) ) ;

for ( int i=0; i < loop_pts_nb; i++ ) {

int index = loop_pts_id[i] ;

// --- insert new point ---

snake->point[i].radius = DEFAULT_RADIUS ;

snake->point[i].fx = pts[index].x + 0.5f ;

snake->point[i].fy = pts[index].y + 0.5f ;

snake->point[i].flag = REPARAM | RESNAKE | REFILTER ;

}

snake->creation = 0 ;

snake->flag = REPARAM | RESNAKE | REFILTER ;

// --- compute the Bounding box ---

snake->Compute_Bounding_Box() ;

Snake_Add( snake ) ;

}

// --- reset the lists ---

Fct_Contour_Free( frame ) ;

}

Iterator_End( ITERATOR_2 ) ;

for ( unsigned char tag=1; tag < TAG_Nb; tag++ )

if ( pts_tot[tag] )

Error_Fct( hwnd, ERROR_CODE_REPORT, "\tTAG[\001%d\002]: \001%d \002points on contours", tag, pts_tot[tag] ) ;

delete [] pts_tot ;

// ================================================================

// --- now we can restart the updates ---

// ================================================================

Fct_Update( UPDATE_DELAY_OFF ) ;

RESET_CURS ;

// --- redraw the image ---

Fct_Redraw( REDRAW_DB_OPENGL ) ;

return( 1 ) ;

}