SLAStartTracking_t Struct Reference

Description

Command the system to start a track, stop a track, designate a track as primary, nudge a track, etc.

typedef struct {
  u8 cameraIndex;
  u16 col;
  u16 row;
  u16 width;
  u16 height;
  u8 flags;
  u16 nearVal;
  u8 userTrackId;
} SLAStartTracking_t;

Column and Row coordinates correspond to the pixel coordinate within a frame of video in display(stabilized) coordinates. The origin is in the upper left corner of the image with values increasing down and to the right. Up to 5 tracks may be simultaneously engaged. See the Target Tracking Guide for more details about tracking multiple targets. See SLACurrentImageSize_t for more information about capture image size.

Modify Mode

Value	Description
0	Show Cursor only. If in this mode Display Coordinate and Source Coordinate bits are ignored.
1	Kill any existing targets and then designate a new primary target at the cursor.
2	Designate a primary target at the cursor.
3	If there is a track near the coordinates, move track to coordinates and make secondary.
4	If there is a track near the coordinates, move track to coordinates and make secondary. Otherwise, add a new secondary track at coordinate location.
5	Designate track near coordinates as primary target. Also supports starting primary tracks from detections.
6	Designate track near coordinates as primary target if there is one. If not, add new track at coordinates and make primary. Also supports starting primary tracks from detections.
7	If there is a track near coordinates, move track to location of coordinates and designate as primary. Otherwise, add a new track at coordinates and make primary.
8	If there is a track near coordinates, move track to location of coordinates and designate as primary. Otherwise, kill all existing tracks and add a new primary track at location of coordinates.
9	Kill track near coordinates.
10	Kill all tracks, but the primary track. (Coordinates are ignored).
11	Reserved
12	Designate track near coordinates as secondary target. Also supports starting secondary tracks from detections.
13	Designate track near coordinates as secondary target if there is one. If not, add new track at coordinates and make secondary. Also supports starting secondary tracks from detections.

Message ID 0x08

Byte Offset	Name	Description
4	cameraIndex	Camera Index If not a valid value, applies to SLACommandCamera_t.
5-6	col	Track column coordinate
7-8	row	Track row coordinate
9-10	width	Width of object in pixels to track. (for user designated tracking) Maximum track box width is 500 pixels for all modes except static NOTE: In static track mode, if width or height is 255, use full screen for track box pixel stats.
11-12	height	Height of object in pixels to track. (for user designated tracking) Maximum track box height is 500 pixels for all modes except static
13	flags	Coordinate space flag and modification mode. Coordinate space bits – OR these with any modify mode. NOTE: Do not set both Display and Source coordinates. Bits Description 0-5 Modify Mode 6 Source Coordinates – OR this flag (set bit 6 to 1) with any of the modify modes to indicate that the coordinates specified are in the source image. By default, don't set this flag (bit 6 = 0) for coordinates in the display image space. 7 Display Coordinates – Rotate Zoom Modifier. OR this flag (set bit 7 to 1) with any of the modify modes to indicate coordinates are rotated and zoomed with the display. By default, set this flag (bit 7 = 1) for coordinates in the display image space.
14-15	nearVal	'radius of engagement' used with some modes. This is the area around an existing target that interactions can take place. Large values allow greater tolerance in selecting tracks. (default = 0 = use value from SLASetTrackingParameters_t)
16	userTrackId	User managed ID for this track. (0 for no ID)