Scaling to preserve aspect ratio and centering

int src_w = 1000;
int src_h = 1000;
int dst_w = 595;
int dst_h = 824;

int letter_h = ( dst_w * src_h ) / src_w;
int pillar_w = ( dst_h * src_w ) / src_h;

result.h = dst_h;
result.w = pillar_w;

if ( result.w > dst_w )
{
    result.w = dst_w;
    result.h = letter_h;
}

result.x = ( dst_w - result.w ) / 2;
result.y = ( dst_h - result.h ) / 2;