Add jack_position_t::tick_double, and flags around it

transport.h

@@ -47,18 +47,21 @@ typedef uint64_t jack_unique_t;		/**< Unique ID (opaque) */
  * Optional struct jack_position_t fields.
  */
 typedef enum {
-
-	JackPositionBBT =	  0x10,	/**< Bar, Beat, Tick */
-	JackPositionTimecode =	  0x20,	/**< External timecode */
-	JackBBTFrameOffset =      0x40,	/**< Frame offset of BBT information */
-	JackAudioVideoRatio =     0x80, /**< audio frames per video frame */
-	JackVideoFrameOffset =   0x100  /**< frame offset of first video frame */
+	JackPositionBBT      = 0x10,  /**< Bar, Beat, Tick */
+	JackPositionTimecode = 0x20,  /**< External timecode */
+	JackBBTFrameOffset   = 0x40,  /**< Frame offset of BBT information */
+	JackAudioVideoRatio  = 0x80,  /**< audio frames per video frame */
+	JackVideoFrameOffset = 0x100, /**< frame offset of first video frame */
+	JackTickDouble       = 0x200, /**< double-resolution tick */
 } jack_position_bits_t;
 
 /** all valid position bits */
 #define JACK_POSITION_MASK (JackPositionBBT|JackPositionTimecode|JackBBTFrameOffset|JackAudioVideoRatio|JackVideoFrameOffset)
 #define EXTENDED_TIME_INFO
 
+/** transport tick_double member is available for use */
+#define JACK_TICK_DOUBLE
+
 /**
  * Struct for transport position information.
  */
@@ -178,12 +181,21 @@ typedef struct {
 					     no video frame within this cycle. */
     /*}@*/
 
+    /*@{*/
+    /* JACK extra transport fields */
+    double              tick_double; /**< current tick-within-beat in double resolution.
+					     Should be assumed zero if JackTickDouble is not set.
+					     Since older versions of JACK do not expose this variable,
+					     the macro JACK_TICK_DOUBLE is provided,
+					     which can be used as build-time detection. */
+    /*}@*/
+
     /*@{*/
     /** @name Other fields */
     /* For binary compatibility, new fields should be allocated from
      * this padding area with new valid bits controlling access, so
      * the existing structure size and offsets are preserved. */
-    int32_t		padding[7];
+    int32_t		padding[5];
     /*}@*/
 
     /* When (unique_1 == unique_2) the contents are consistent. */