512 /* * relevelv(midisyn *ms, uint_fast16_t voice, int16_t level_cB); * A driver should provide this method if it is able to change the * level of a sounding voice without rearticulating or glitching it. * How the driver should adjust 'level_cB' to account for envelope * decay since the initial level is not (quite, yet) specified; the * driver may save the last level it got from midisyn, subtract from * this one, and use the difference to adjust the current level out of * the envelope generator. Or not.... [not yet implemented in midisyn] */