The only way to use dolphin across 3 screens is with NVIDIA surround or AMD Eyefinity. AMD eyefinity supports a minimum of 3 displays, a max of 18. NVIDIA surround supports 3, but also supports nvidia surround + 3d displays. There is no way to hack either to work with only 2 displays mainly because if a hack was ever made, it would only work for one driver version (even though they are updated constantly).
edit: found the image of me playing surround, cropped it. http://i.imgur.com/uzYQc0t.png
Also, the way these technologies work is they make all the displays look like one giant virtual display to the OS at a really low level. To hack it you would need custom drivers and to know how they are structured.
edit: found the image of me playing surround, cropped it. http://i.imgur.com/uzYQc0t.png
Also, the way these technologies work is they make all the displays look like one giant virtual display to the OS at a really low level. To hack it you would need custom drivers and to know how they are structured.