DMUS_PMSG

The DMUS_PMSG structure contains information common to all DirectMusic messages. Because C does not support inheritance, the members of this structure are included in all message types (including DMUS_PMSG itself) by the inclusion of the DMUS_PMSG_PART macro, which expands to the syntax shown here.

typedef struct DMUS_PMSG {
    DWORD              dwSize;
    REFERENCE_TIME     rtTime;
    MUSIC_TIME         mtTime;
    DWORD              dwFlags;
    DWORD              dwPChannel;
    DWORD              dwVirtualTrackID;
    IDirectMusicTool*  pTool;
    IDirectMusicGraph* pGraph;
    DWORD              dwType;
    DWORD              dwVoiceID;
    DWORD              dwGroupID;
    IUnknown*          punkUser;
} DMUS_PMSG;
 

Members

dwSize

Size of the structure, in bytes.

rtTime

Real time (in 100 nanosecond increments) at which the message is to be played, modified by dwFlags.

mtTime

Music time at which the message is to be played, modified by dwFlags.

dwFlags

Various bits (see DMUS_PMSGF_FLAGS and DMUS_TIME_RESOLVE_FLAGS).

dwPChannel

Performance channel (PChannel). The port, channel group, and MIDI channel can be derived from this value by using the IDirectMusicPerformance::PChannelInfo method.

dwVirtualTrackID

Identifier of the track.

pTool

Tool interface pointer.

pGraph

Tool graph interface pointer.

dwType

Message type (see DMUS_PMSGT_TYPES).

dwVoiceID

Reserved for future use. This value is always 0.

dwGroupID

Identifier of the track group or groups the message belongs to. (Tracks are assigned to groups in the IDirectMusicSegment::InsertTrack method.)

punkUser

User COM pointer. This pointer is always released when the message is freed. If the application wishes to retain the object, it should call AddRef before the message is freed.

Remarks

The DMUS_PMSG structure is used by itself for messages containing the following values in the dwType member:

DMUS_PMSGT_STOP

Sending a message of this type stops the performance at the indicated time.

DMUS_PMSGT_DIRTY

When a control segment starts or ends, all tools in the segment and performance graphs receive a message of this type, indicating that if they cache data from GetParam calls, they must call GetParam again to refresh their data. Tools that want to receive this message type must indicate their desire through a call to IDirectMusicTool::GetMediaTypes. Also, note that tools in the performance graph will receive one copy of the message for each segment in the performance. Such tools can safely ignore the extra messages with the same time stamp.

QuickInfo

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in dmusici.h.

See Also

IDirectMusicPerformance::SendPMsg