Did some more porting this weekend... C++ version is now able to load & render a character model from my HTML5 Canvas demo (far right screenshot, in Chrome). A few glitches to debug, but it's basically done. Performance is better indeed... 3% CPU with one character, probably 10% during busy gameplay -- versus 60% in HTML5.
Next: animations, keyboard/gamepad controls, and collisions.
Hoping it won't be a total pain to do a Windows build so I can run this on my laptop at a local gamedev get-together on Tuesday.