PostGIS  3.2.2dev-r@@SVN_REVISION@@

◆ encode_ptarray()

static uint32_t encode_ptarray ( __attribute__((__unused__)) mvt_agg_context ctx,
enum mvt_type  type,
POINTARRAY pa,
uint32_t *  buffer,
int32_t *  px,
int32_t *  py 
)
static

Definition at line 91 of file mvt.c.

94 {
95  uint32_t offset = 0;
96  uint32_t i, c = 0;
97  int32_t dx, dy, x, y;
98  const POINT2D *p;
99 
100  /* loop points and add to buffer */
101  for (i = 0; i < pa->npoints; i++)
102  {
103  /* move offset for command */
104  if (i == 0 || (i == 1 && type > MVT_POINT))
105  offset++;
106  /* skip closing point for rings */
107  if (type == MVT_RING && i == pa->npoints - 1)
108  break;
109  p = getPoint2d_cp(pa, i);
110  x = p->x;
111  y = p->y;
112  dx = x - *px;
113  dy = y - *py;
114  buffer[offset++] = p_int(dx);
115  buffer[offset++] = p_int(dy);
116  *px = x;
117  *py = y;
118  c++;
119  }
120 
121  /* determine initial move and eventual line command */
122  if (type == MVT_POINT)
123  {
124  /* point or multipoint, use actual number of point count */
125  buffer[0] = c_int(CMD_MOVE_TO, c);
126  }
127  else
128  {
129  /* line or polygon, assume count 1 */
130  buffer[0] = c_int(CMD_MOVE_TO, 1);
131  /* line command with move point subtracted from count */
132  buffer[3] = c_int(CMD_LINE_TO, c - 1);
133  }
134 
135  /* add close command if ring */
136  if (type == MVT_RING)
137  buffer[offset++] = c_int(CMD_CLOSE_PATH, 1);
138 
139  return offset;
140 }
static const POINT2D * getPoint2d_cp(const POINTARRAY *pa, uint32_t n)
Returns a POINT2D pointer into the POINTARRAY serialized_ptlist, suitable for reading from.
Definition: lwinline.h:101
@ CMD_MOVE_TO
Definition: mvt.c:56
@ CMD_CLOSE_PATH
Definition: mvt.c:58
@ CMD_LINE_TO
Definition: mvt.c:57
static uint32_t c_int(enum mvt_cmd_id id, uint32_t count)
Definition: mvt.c:81
@ MVT_POINT
Definition: mvt.c:63
@ MVT_RING
Definition: mvt.c:65
static uint32_t p_int(int32_t value)
Definition: mvt.c:86
type
Definition: ovdump.py:42
Datum buffer(PG_FUNCTION_ARGS)
double y
Definition: liblwgeom.h:404
double x
Definition: liblwgeom.h:404
uint32_t npoints
Definition: liblwgeom.h:441

References buffer(), c_int(), CMD_CLOSE_PATH, CMD_LINE_TO, CMD_MOVE_TO, getPoint2d_cp(), MVT_POINT, MVT_RING, POINTARRAY::npoints, p_int(), ovdump::type, POINT2D::x, pixval::x, POINT2D::y, and pixval::y.

Referenced by encode_mline(), encode_mpoly(), encode_poly(), and encode_ptarray_initial().

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