CV_IMPL CvBox2D
cvMinAreaRect2( const CvArr* array, CvMemStorage* storage )
{
CvMemStorage* temp_storage = 0;
CvBox2D box;
CvPoint2D32f* points = 0;
CV_FUNCNAME( "cvMinAreaRect2" );
memset(&box, 0, sizeof(box));
__BEGIN__;
int i, n;
CvSeqReader reader;
CvContour contour_header;
CvSeqBlock block;
CvSeq* ptseq = (CvSeq*)array;
CvPoint2D32f out[3];
if( CV_IS_SEQ(ptseq) )
{
if( !CV_IS_SEQ_POINT_SET(ptseq) &&
(CV_SEQ_KIND(ptseq) != CV_SEQ_KIND_CURVE || !CV_IS_SEQ_CONVEX(ptseq) ||
CV_SEQ_ELTYPE(ptseq) != CV_SEQ_ELTYPE_PPOINT ))
CV_ERROR( CV_StsUnsupportedFormat,
"Input sequence must consist of 2d points or pointers to 2d points" );
if( !storage )
storage = ptseq->storage;
}
else
{
CV_CALL( ptseq = cvPointSeqFromMat(
CV_SEQ_KIND_GENERIC, array, &contour_header, &block ));
}
if( storage )
{
CV_CALL( temp_storage = cvCreateChildMemStorage( storage ));
}
else
{
CV_CALL( temp_storage = cvCreateMemStorage(1 << 10));
}
if( !CV_IS_SEQ_CONVEX( ptseq ))
{
CV_CALL( ptseq = cvConvexHull2( ptseq, temp_storage, CV_CLOCKWISE, 1 ));
}
else if( !CV_IS_SEQ_POINT_SET( ptseq ))
{
CvSeqWriter writer;
if( !CV_IS_SEQ(ptseq->v_prev) || !CV_IS_SEQ_POINT_SET(ptseq->v_prev))
CV_ERROR( CV_StsBadArg,
"Convex hull must have valid pointer to point sequence stored in v_prev" );
cvStartReadSeq( ptseq, &reader );
cvStartWriteSeq( CV_SEQ_KIND_CURVE|CV_SEQ_FLAG_CONVEX|CV_SEQ_ELTYPE(ptseq->v_prev),
sizeof(CvContour), CV_ELEM_SIZE(ptseq->v_prev->flags),
temp_storage, &writer );
for( i = 0; i < ptseq->total; i++ )
{
CvPoint pt = **(CvPoint**)(reader.ptr);
CV_WRITE_SEQ_ELEM( pt, writer );
}
ptseq = cvEndWriteSeq( &writer );
}
n = ptseq->total;
CV_CALL( points = (CvPoint2D32f*)cvAlloc( n*sizeof(points[0]) ));
cvStartReadSeq( ptseq, &reader );
if( CV_SEQ_ELTYPE( ptseq ) == CV_32SC2 )
{
for( i = 0; i < n; i++ )
{
CvPoint pt;
CV_READ_SEQ_ELEM( pt, reader );
points[i].x = (float)pt.x;
points[i].y = (float)pt.y;
}
}
else
{
for( i = 0; i < n; i++ )
{
CV_READ_SEQ_ELEM( points[i], reader );
}
}
if( n > 2 )
{
icvRotatingCalipers( points, n, CV_CALIPERS_MINAREARECT, (float*)out );
box.center.x = out[0].x + (out[1].x + out[2].x)*0.5f;
box.center.y = out[0].y + (out[1].y + out[2].y)*0.5f;
box.size.height = (float)sqrt((double)out[1].x*out[1].x + (double)out[1].y*out[1].y);
box.size.width = (float)sqrt((double)out[2].x*out[2].x + (double)out[2].y*out[2].y);
box.angle = (float)atan2( -(double)out[1].y, (double)out[1].x );
}
else if( n == 2 )
{
box.center.x = (points[0].x + points[1].x)*0.5f;
box.center.y = (points[0].y + points[1].y)*0.5f;
double dx = points[1].x - points[0].x;
double dy = points[1].y - points[0].y;
box.size.height = (float)sqrt(dx*dx + dy*dy);
box.size.width = 0;
box.angle = (float)atan2( -dy, dx );
}
else
{
if( n == 1 )
box.center = points[0];
}
box.angle = (float)(box.angle*180/CV_PI);
__END__;
cvReleaseMemStorage( &temp_storage );
cvFree( &points );
return box;
}
/*
* If curve is convex, return true. Otherwise return false.
*/
VALUE
rb_convex_q(VALUE self)
{
return CV_IS_SEQ_CONVEX(CVSEQ(self)) ? Qtrue : Qfalse;
}