Function transform_

deps/opencv/modules/core/src/matmul.cpp:1289–1348

{

template<typename T, typename WT> static void
transform_( const T* src, T* dst, const WT* m, int len, int scn, int dcn )
{
    int x;

    if( scn == 2 && dcn == 2 )
    {
        for( x = 0; x < len*2; x += 2 )
        {
            WT v0 = src[x], v1 = src[x+1];
            T t0 = saturate_cast<T>(m[0]*v0 + m[1]*v1 + m[2]);
            T t1 = saturate_cast<T>(m[3]*v0 + m[4]*v1 + m[5]);
            dst[x] = t0; dst[x+1] = t1;
        }
    }
    else if( scn == 3 && dcn == 3 )
    {
        for( x = 0; x < len*3; x += 3 )
        {
            WT v0 = src[x], v1 = src[x+1], v2 = src[x+2];
            T t0 = saturate_cast<T>(m[0]*v0 + m[1]*v1 + m[2]*v2 + m[3]);
            T t1 = saturate_cast<T>(m[4]*v0 + m[5]*v1 + m[6]*v2 + m[7]);
            T t2 = saturate_cast<T>(m[8]*v0 + m[9]*v1 + m[10]*v2 + m[11]);
            dst[x] = t0; dst[x+1] = t1; dst[x+2] = t2;
        }
    }
    else if( scn == 3 && dcn == 1 )
    {
        for( x = 0; x < len; x++, src += 3 )
            dst[x] = saturate_cast<T>(m[0]*src[0] + m[1]*src[1] + m[2]*src[2] + m[3]);
    }
    else if( scn == 4 && dcn == 4 )
    {
        for( x = 0; x < len*4; x += 4 )
        {
            WT v0 = src[x], v1 = src[x+1], v2 = src[x+2], v3 = src[x+3];
            T t0 = saturate_cast<T>(m[0]*v0 + m[1]*v1 + m[2]*v2 + m[3]*v3 + m[4]);
            T t1 = saturate_cast<T>(m[5]*v0 + m[6]*v1 + m[7]*v2 + m[8]*v3 + m[9]);
            dst[x] = t0; dst[x+1] = t1;
            t0 = saturate_cast<T>(m[10]*v0 + m[11]*v1 + m[12]*v2 + m[13]*v3 + m[14]);
            t1 = saturate_cast<T>(m[15]*v0 + m[16]*v1 + m[17]*v2 + m[18]*v3 + m[19]);
            dst[x+2] = t0; dst[x+3] = t1;
        }
    }
    else
    {
        for( x = 0; x < len; x++, src += scn, dst += dcn )
        {
            const WT* _m = m;
            int j, k;
            for( j = 0; j < dcn; j++, _m += scn + 1 )
            {
                WT s = _m[scn];
                for( k = 0; k < scn; k++ )
                    s += _m[k]*src[k];
                dst[j] = saturate_cast<T>(s);
            }
        }