PostGIS  3.7.0dev-r@@SVN_REVISION@@

◆ encode_ptarray()

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

Definition at line 149 of file mvt.c.

150 {
151  uint32_t offset = 0;
152  uint32_t i, c = 0;
153  int32_t dx, dy, x, y;
154  const POINT2D *p;
155 
156  /* loop points and add to buffer */
157  for (i = 0; i < pa->npoints; i++)
158  {
159  /* move offset for command */
160  if (i == 0 || (i == 1 && type > MVT_POINT))
161  offset++;
162  /* skip closing point for rings */
163  if (type == MVT_RING && i == pa->npoints - 1)
164  break;
165  p = getPoint2d_cp(pa, i);
166  x = p->x;
167  y = p->y;
168  dx = x - *px;
169  dy = y - *py;
170  buffer[offset++] = p_int(dx);
171  buffer[offset++] = p_int(dy);
172  *px = x;
173  *py = y;
174  c++;
175  }
176 
177  /* determine initial move and eventual line command */
178  if (type == MVT_POINT)
179  {
180  /* point or multipoint, use actual number of point count */
181  buffer[0] = c_int(CMD_MOVE_TO, c);
182  }
183  else
184  {
185  /* line or polygon, assume count 1 */
186  buffer[0] = c_int(CMD_MOVE_TO, 1);
187  /* line command with move point subtracted from count */
188  buffer[3] = c_int(CMD_LINE_TO, c - 1);
189  }
190 
191  /* add close command if ring */
192  if (type == MVT_RING)
193  buffer[offset++] = c_int(CMD_CLOSE_PATH, 1);
194 
195  return offset;
196 }
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:97
@ CMD_MOVE_TO
Definition: mvt.c:50
@ CMD_CLOSE_PATH
Definition: mvt.c:52
@ CMD_LINE_TO
Definition: mvt.c:51
static uint32_t c_int(enum mvt_cmd_id id, uint32_t count)
Definition: mvt.c:139
@ MVT_POINT
Definition: mvt.c:57
@ MVT_RING
Definition: mvt.c:59
static uint32_t p_int(int32_t value)
Definition: mvt.c:144
type
Definition: ovdump.py:42
Datum buffer(PG_FUNCTION_ARGS)
double y
Definition: liblwgeom.h:390
double x
Definition: liblwgeom.h:390
uint32_t npoints
Definition: liblwgeom.h:427

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().

Here is the call graph for this function:
Here is the caller graph for this function: