cvrotcalipers.cpp

opencv库在TI DM6437上的移植,目前包括两个库cv.lib和cxcore.lib的工程

        
        switch (mode)
        {
        case CV_CALIPERS_MAXHEIGHT:
            {
                /* now main element lies on edge alligned to calipers side */

                /* find opposite element i.e. transform  */
                /* 0->2, 1->3, 2->0, 3->1                */
                int opposite_el = main_element ^ 2;

                float dx = points[seq[opposite_el]].x - points[seq[main_element]].x;
                float dy = points[seq[opposite_el]].y - points[seq[main_element]].y;
                float dist;

                if( main_element & 1 )
                    dist = (float)fabs(dx * base_a + dy * base_b);
                else
                    dist = (float)fabs(dx * (-base_b) + dy * base_a);

                if( dist > max_dist )
                    max_dist = dist;

                break;
            }
        case CV_CALIPERS_MINAREARECT:
            /* find area of rectangle */
            {
                float height;
                float area;

                /* find vector left-right */
                float dx = points[seq[1]].x - points[seq[3]].x;
                float dy = points[seq[1]].y - points[seq[3]].y;

                /* dotproduct */
                float width = dx * base_a + dy * base_b;

                /* find vector left-right */
                dx = points[seq[2]].x - points[seq[0]].x;
                dy = points[seq[2]].y - points[seq[0]].y;

                /* dotproduct */
                height = -dx * base_b + dy * base_a;

                area = width * height;
                if( area <= minarea )
                {
                    float *buf = (float *) buffer;

                    minarea = area;
                    /* leftist point */
                    ((int *) buf)[0] = seq[3];
                    buf[1] = base_a;
                    buf[2] = width;
                    buf[3] = base_b;
                    buf[4] = height;
                    /* bottom point */
                    ((int *) buf)[5] = seq[0];
                    buf[6] = area;
                }
                break;
            }
        }                       /*switch */
    }                           /* for */

    switch (mode)
    {
    case CV_CALIPERS_MINAREARECT:
        {
            float *buf = (float *) buffer;

            float A1 = buf[1];
            float B1 = buf[3];

            float A2 = -buf[3];
            float B2 = buf[1];

            float C1 = A1 * points[((int *) buf)[0]].x + points[((int *) buf)[0]].y * B1;
            float C2 = A2 * points[((int *) buf)[5]].x + points[((int *) buf)[5]].y * B2;

            float idet = 1.f / (A1 * B2 - A2 * B1);

            float px = (C1 * B2 - C2 * B1) * idet;
            float py = (A1 * C2 - A2 * C1) * idet;

            out[0] = px;
            out[1] = py;

            out[2] = A1 * buf[2];
            out[3] = B1 * buf[2];

            out[4] = A2 * buf[4];
            out[5] = B2 * buf[4];
        }
        break;
    case CV_CALIPERS_MAXHEIGHT:
        {
            out[0] = max_dist;
        }
        break;
    }

    cvFree( &vect );
    cvFree( &inv_vect_length );
}


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;
}