CV_IMPL int
cvSampleLine( const void* img, CvPoint pt1, CvPoint pt2,
void* _buffer, int connectivity )
{
int count = -1;
int i, coi = 0, pix_size;
CvMat stub, *mat = cvGetMat( img, &stub, &coi );
CvLineIterator iterator;
uchar* buffer = (uchar*)_buffer;
if( coi != 0 )
CV_Error( CV_BadCOI, "" );
if( !buffer )
CV_Error( CV_StsNullPtr, "" );
count = cvInitLineIterator( mat, pt1, pt2, &iterator, connectivity );
pix_size = CV_ELEM_SIZE(mat->type);
for( i = 0; i < count; i++ )
{
for( int j = 0; j < pix_size; j++ )
buffer[j] = iterator.ptr[j];
buffer += pix_size;
CV_NEXT_LINE_POINT( iterator );
}
return count;
}
// Return the image points that are at the line segment
CvPoint *image_utils_get_line_points(IplImage *img, CvPoint A, CvPoint B, int *n_points)
{
int i;
CvLineIterator iterator;
*n_points = cvInitLineIterator(img, A, B, &iterator, 8, 0);
CvPoint* line_points = (CvPoint*)malloc((*n_points) * sizeof(CvPoint));
for(i = 0; i < *n_points; i++)
{
void *p_0 = &img->imageData[0];//get the memory address of the image data
void *p_c = &iterator.ptr[0];//get the memory address of the current point at the line segment
// computes the memory offset (in bytes) between image data and current point at the line segment
int offset = (char *)p_c - (char *)p_0;
// since 'offset = y * widthStep + x * nChannels', compute the current point at the line segment
line_points[i].x = (offset % img->widthStep) / img->nChannels;
line_points[i].y = offset / img->widthStep;
CV_NEXT_LINE_POINT(iterator);
}
return line_points;
}
static CvStatus
icvPreWarpImage8uC3R( int numLines, /* number of scanlines */
uchar * src, /* source image */
int src_step, /* line step */
uchar * dst, /* dest buffers */
int *dst_nums, /* lens of buffer */
CvSize src_size, /* image size in pixels */
int *scanlines ) /* scanlines array */
{
int k;
CvPoint start;
CvPoint end;
int curr;
int curr_dst;
CvMat mat;
curr = 0;
curr_dst = 0;
cvInitMatHeader( &mat, src_size.height, src_size.width, CV_8UC3, src, src_step );
for( k = 0; k < numLines; k++ )
{
start.x = scanlines[curr++];
start.y = scanlines[curr++];
end.x = scanlines[curr++];
end.y = scanlines[curr++];
#ifdef _DEBUG
{
CvLineIterator iterator;
assert( cvInitLineIterator( &mat, start, end, &iterator, 8 ) == dst_nums[k] );
}
#endif
cvSampleLine( &mat, start, end, dst + curr_dst, 8 );
curr_dst += dst_nums[k] * 3;
}
return CV_NO_ERR;
}
CV_IMPL int
cvSampleLine( const void* img, CvPoint pt1, CvPoint pt2,
void* _buffer, int connectivity )
{
int count = -1;
CV_FUNCNAME( "cvSampleLine" );
__BEGIN__;
int i, coi = 0, pix_size;
CvMat stub, *mat = (CvMat*)img;
CvLineIterator iterator;
uchar* buffer = (uchar*)_buffer;
CV_CALL( mat = cvGetMat( mat, &stub, &coi ));
if( coi != 0 )
CV_ERROR( CV_BadCOI, "" );
if( !buffer )
CV_ERROR( CV_StsNullPtr, "" );
CV_CALL( count = cvInitLineIterator( mat, pt1, pt2, &iterator, connectivity ));
pix_size = CV_ELEM_SIZE(mat->type);
for( i = 0; i < count; i++ )
{
CV_MEMCPY_AUTO( buffer, iterator.ptr, pix_size );
buffer += pix_size;
CV_NEXT_LINE_POINT( iterator );
}
__END__;
return count;
}
static CvStatus
icvPostWarpImage8uC3R( int numLines, /* number of scanlines */
uchar * src, /* source buffers */
int *src_nums, /* lens of buffers */
uchar * dst, /* dest image */
int dst_step, /* dest image step */
CvSize dst_size, /* dest image size */
int *scanlines ) /* scanline */
{
int i, k;
CvPoint start;
CvPoint end;
int curr;
int src_num;
int curr_src;
CvMat mat;
CvLineIterator iterator;
curr = 0;
curr_src = 0;
cvInitMatHeader( &mat, dst_size.height, dst_size.width, CV_8UC3, dst, dst_step );
for( k = 0; k < numLines; k++ )
{
start.x = scanlines[curr++];
start.y = scanlines[curr++];
end.x = scanlines[curr++];
end.y = scanlines[curr++];
src_num = src_nums[k];
if( cvInitLineIterator( &mat, start, end, &iterator, 8 ) != src_num )
{
assert(0);
return CV_NOTDEFINED_ERR;
}
for( i = 0; i < src_num; i++ )
{
memcpy( iterator.ptr, src + curr_src, 3 );
CV_NEXT_LINE_POINT( iterator );
curr_src += 3;
}
#if 0
err = icvDrawLine8uC3R( src + curr_src, /* sourse buffer */
src_num, /* len of buffer */
dst, /* dest image */
dst_step, /* dest image step */
dst_size, /* dest image size */
start, /* start point */
end ); /* end point */
curr_src += src_num * 3;
#endif
}
return CV_NO_ERR;
}
