Arc (ls_arc_t)

A circular segment defined by center, radius, thickness, and a start and end angle. Two of them make a gauge.

ls_error_code_t ls_arc_create(ls_screen_t * screen, ls_arc_t * arc);

Field	Type	Description
`center_x`, `center_y`	`int32_t`	Arc center
`radius`	`uint32_t`	Radius in pixels (default 30)
`thickness`	`uint32_t`	Line thickness in pixels (default 5)
`start_deg`, `end_deg`	`uint32_t`	Start/end angle in degrees (default 30 and 90)
`color`	`ls_color_t`	Arc color
`opa`	`uint8_t`	Opacity (0..255)

0° points right and angles grow clockwise.

Defaults after create: blue, opaque, center 30,30, radius 30, thickness 5, sweeping 30°→90°.

/*A gauge is two arcs: a full-sweep track, and a colored one on top of it whose
 `end_deg` you recompute when the value changes.*/
static ls_arc_t track;
static ls_arc_t fill;

if(ls_arc_create(&screen, &track) != LS_ERROR_CODE_OK) return 1;
track.center_x = 160;
track.center_y = 120;
track.radius = 50;
track.thickness = 10;
track.start_deg = 135;              /*opens downward*/
track.end_deg = 135 + 270;
track.color = LS_COLOR_HEX(0x2b333c);

if(ls_arc_create(&screen, &fill) != LS_ERROR_CODE_OK) return 1;
fill.center_x = 160;
fill.center_y = 120;
fill.radius = 50;
fill.thickness = 10;
fill.start_deg = 135;
fill.end_deg = 135 + (270 * (uint32_t) level) / 100;   /*update this as `level` moves*/
fill.color = LS_COLOR_HEX(0x3d8bfd);