C++ MusicDevices::begin方法代码示例

//.........这里部分代码省略.........
    case MT_GM:
    case MT_GS:
    case MT_MT32:
        if (flags & MDT_MIDI)
            return hdl;
        break;

    case MT_NULL:
        return hdl;

    default:
        break;
    }

    // If the selected driver did not match the flags setting,
    // we try to determine a suitable and "optimal" music driver.
    const MusicPlugin::List p = MusicMan.getPlugins();
    // If only MDT_MIDI but not MDT_PREFER_MT32 or MDT_PREFER_GM is set we prefer the other devices (which will always be
    // detected since they are hard coded and cannot be disabled.
    for (int l = (flags & (MDT_PREFER_GM | MDT_PREFER_MT32)) ? 1 : 0; l < 2; ++l) {
        if ((flags & MDT_MIDI) && (l == 1)) {
            // If a preferred MT32 or GM device has been selected that device gets returned
            if (flags & MDT_PREFER_MT32)
                hdl = getDeviceHandle(ConfMan.get("mt32_device"));
            else if (flags & MDT_PREFER_GM)
                hdl = getDeviceHandle(ConfMan.get("gm_device"));
            else
                hdl = getDeviceHandle("auto");

            const MusicType type = getMusicType(hdl);

            // If have a "Don't use GM/MT-32" setting we skip this part and jump
            // to AdLib, PC Speaker etc. detection right away.
            if (type != MT_NULL) {
                if (type != MT_AUTO && type != MT_INVALID) {
                    if (flags & MDT_PREFER_MT32)
                        // If we have a preferred MT32 device we disable the gm/mt32 mapping (more about this in mididrv.h)
                        _forceTypeMT32 = true;

                    return hdl;
                }

                // If we have no specific device selected (neither in the scummvm nor in the game domain)
                // and no preferred MT32 or GM device selected we arrive here.
                // If MT32 is preferred we try for the first available device with music type 'MT_MT32' (usually the mt32 emulator)
                if (flags & MDT_PREFER_MT32) {
                    for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); ++m) {
                        MusicDevices i = (**m)->getDevices();
                        for (MusicDevices::iterator d = i.begin(); d != i.end(); ++d) {
                            if (d->getMusicType() == MT_MT32)
                                return d->getHandle();
                        }
                    }
                }

                // Now we default to the first available device with music type 'MT_GM'
                for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); ++m) {
                    MusicDevices i = (**m)->getDevices();
                    for (MusicDevices::iterator d = i.begin(); d != i.end(); ++d) {
                        if (d->getMusicType() == MT_GM || d->getMusicType() == MT_GS)
                            return d->getHandle();
                    }
                }
            }
        }

        MusicType tp = MT_AUTO;
        if (flags & MDT_TOWNS)
            tp = MT_TOWNS;
        else if (flags & MDT_PC98)
            tp = MT_PC98;
        else if (flags & MDT_ADLIB)
            tp = MT_ADLIB;
        else if (flags & MDT_PCJR)
            tp = MT_PCJR;
        else if (flags & MDT_PCSPK)
            tp = MT_PCSPK;
        else if (flags & MDT_C64)
            tp = MT_C64;
        else if (flags & MDT_AMIGA)
            tp = MT_AMIGA;
        else if (flags & MDT_APPLEIIGS)
            tp = MT_APPLEIIGS;
        else if (l == 0)
            // if we haven't tried to find a MIDI device yet we do this now.
            continue;
        else
            tp = MT_AUTO;

        for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); ++m) {
            MusicDevices i = (**m)->getDevices();
            for (MusicDevices::iterator d = i.begin(); d != i.end(); ++d) {
                if (d->getMusicType() == tp)
                    return d->getHandle();
            }
        }
    }

    return 0;
}

//.........这里部分代码省略.........
			// to AdLib, PC Speaker etc. detection right away.
			if (type != MT_NULL) {
				if (type == MT_INVALID) {
					// If the preferred (expressly requested) selected driver or device cannot be found (no longer compiled in, turned off, etc.)
					// we display a warning and continue. Don't warn about the missing device if we did already (this becomes relevant if the
					// missing device is selected as preferred device and also as GM or MT-32 device).
					if (failedDevStr != devStr) {
						Common::String warningMsg = Common::String::format(_("The preferred audio device '%s' was not found (e.g. might be turned off or disconnected)."), devStr.c_str()) + " " + _("Attempting to fall back to the next available device...");
						GUI::MessageDialog dialog(warningMsg);
						dialog.runModal();
					}
				} else if (type != MT_AUTO) {
					if (checkDevice(hdl)) {
						if (flags & MDT_PREFER_MT32)
							// If we have a preferred MT32 device we disable the gm/mt32 mapping (more about this in mididrv.h).
							_forceTypeMT32 = true;
						return hdl;
					} else {
						// If the preferred (expressly requested) device cannot be used we display a warning and continue.
						// Don't warn about the failing device if we did already (this becomes relevant if the failing
						// device is selected as preferred device and also as GM or MT-32 device).
						if (failedDevStr != getDeviceString(hdl, MidiDriver::kDeviceName)) {
							Common::String warningMsg = Common::String::format(_("The preferred audio device '%s' cannot be used. See log file for more information."), getDeviceString(hdl, MidiDriver::kDeviceName).c_str()) + " " + _("Attempting to fall back to the next available device...");
							GUI::MessageDialog dialog(warningMsg);
							dialog.runModal();
						}
					}
				}

				// If no specific device is selected (neither in the scummvm nor in the game domain)
				// and there is no preferred MT32 or GM device selected either or if the detected device is unavailable we arrive here.
				// If MT32 is preferred we try for the first available device with music type 'MT_MT32' (usually the mt32 emulator).
				if (flags & MDT_PREFER_MT32) {
					for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); ++m) {
						MusicDevices i = (**m)->getDevices();
						for (MusicDevices::iterator d = i.begin(); d != i.end(); ++d) {
							if (d->getMusicType() == MT_MT32) {
								hdl = d->getHandle();
								if (checkDevice(hdl))
									return hdl;
							}
						}
					}
				}

				// Now we default to the first available device with music type 'MT_GM' if not
				// MT-32 is preferred or if MT-32 is preferred but all other devices have failed.
				if (!(flags & MDT_PREFER_MT32) || flags == (MDT_PREFER_MT32 | MDT_MIDI)) {
					for (MusicPlugin::List::const_iterator m = p.begin(); m != p.end(); ++m) {
						MusicDevices i = (**m)->getDevices();
						for (MusicDevices::iterator d = i.begin(); d != i.end(); ++d) {
							if (d->getMusicType() == MT_GM || d->getMusicType() == MT_GS) {
								hdl = d->getHandle();
								if (checkDevice(hdl))
									return hdl;
							}
						}
					}
					// Detection flags get removed after final detection attempt to avoid further attempts.
					flags &= ~(MDT_MIDI | MDT_PREFER_GM | MDT_PREFER_MT32);
				}
			}
		}

		// The order in this list is important, since this is the order of preference
		// (e.g. MT_ADLIB is checked before MT_PCJR and MT_PCSPK for a good reason).