DMUS_PMSG

This 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 shown syntax.

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. This member is initialized by IDirectMusicPerformance::AllocPMsg.
• rtTime
  Reference time at which the message is to be played, modified by dwFlags. Used only if DMUS_PMSGF_REFTIME is present in dwFlags.
• mtTime
  Music time at which the message is to be played, modified by dwFlags. Used only if DMUS_PMSGF_MUSICTIME is present in dwFlags.
• dwFlags
  Various bits. For more information, see DMUS_PMSGF_FLAGS and DMUS_TIME_RESOLVE_FLAGS. Must contain DMUS_PMSGF_REFTIME or DMUS_PMSGF_MUSICTIME.
• dwPChannel
  Performance channel (PChannel). The port, channel group, and MIDI channel can be derived from this value by using the IDirectMusicPerformance::PChannelInfo method. Set this value to 0 for messages that are not channel-specific, such as tempo messages.
• dwVirtualTrackID
  Identifier of the track. Set to 0 if the message is not being sent by a track.
• pTool
  Address of the tool interface. Can be set by using IDirectMusicGraph::StampPMsg, or can be NULL if the message is not to go to tools other than the output tool.
• pGraph
  Address of the tool graph interface. Can be set by using IDirectMusicGraph::StampPMsg, or can be NULL if the message is not to go to tools other than the output tool.
• dwType
  Message type. For more information, see DMUS_PMSGT_TYPES.
• dwVoiceID
  Reserved for future use. Should be set to 0.
• dwGroupID
  Identifier of the track group or groups that the message belongs to if the message is being generated by a track. Tracks are assigned to groups in the IDirectMusicSegment::InsertTrack method. For most purposes, this value can be 0xFFFFFFF.
• punkUser
  Address of an IUnknown interface supplied by the application. This pointer is always released when the message is freed. If the application wants to retain the object, it should call AddRef before the message is freed. If the message does not need a COM pointer, this value should be NULL.

Remarks

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

Value	Description
DMUS_PMSGT_STOP	Sending a message of this type stops the performance at the specified 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 this through a call to IDirectMusicTool::GetMediaTypes. Tools in the performance graph 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.

Requirements

OS Versions: Windows CE .NET 4.0 and Windows CE .NET 4.1.
Header: Dmusici.h.

See Also

DMUS_PMSGF_FLAGS | DMUS_TIME_RESOLVE_FLAGS | IDirectMusicGraph::StampPMsg | IDirectMusicPerformance::AllocPMsg | IDirectMusicPerformance::PChannelInfo | IDirectMusicPerformance::SendPMsg | IDirectMusicSegment::InsertTrack | IDirectMusicTool::GetMediaTypes

 Last updated on Monday, April 12, 2004

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