コード例 #1
0
static
void OGR2SQLITE_ST_Area(sqlite3_context* pContext,
                        int argc, sqlite3_value** argv)
{
    OGRGeometry* poGeom = OGR2SQLITE_GetGeom(pContext, argc, argv, NULL);
    if( poGeom != NULL )
    {
        CPLPushErrorHandler(CPLQuietErrorHandler);
        sqlite3_result_double( pContext, OGR_G_Area((OGRGeometryH)poGeom) );
        CPLPopErrorHandler();
    }
    else
        sqlite3_result_null(pContext);
    delete poGeom;
}
コード例 #2
0
ファイル: ogr_api.cpp プロジェクト: 0004c/node-gdal
/**
 * \brief Compute geometry area (deprecated)
 *
 * @deprecated
 * @see OGR_G_Area()
 */
double OGR_G_GetArea( OGRGeometryH hGeom )

{
    return OGR_G_Area( hGeom );
}
コード例 #3
0
ファイル: text.c プロジェクト: ashaw/simple-tiles
// Create and add a placement to the current lithograph if it doesn't overlap
// with current labels.
void
simplet_lithograph_add_placement(simplet_lithograph_t *litho,
  OGRFeatureH feature, simplet_list_t *styles, cairo_t *proj_ctx) {

  simplet_style_t *field = simplet_lookup_style(styles, "text-field");
  if(!field) return;

  OGRFeatureDefnH defn;
  if(!(defn = OGR_F_GetDefnRef(feature))) return;

  int idx = OGR_FD_GetFieldIndex(defn, (const char*) field->arg);
  if(idx < 0) return;

  // Find the largest sub geometry of a particular multi-geometry.
  OGRGeometryH super = OGR_F_GetGeometryRef(feature);
  OGRGeometryH geom = super;
  double area = 0.0;
  switch(wkbFlatten(OGR_G_GetGeometryType(super))) {
    case wkbMultiPolygon:
    case wkbGeometryCollection:
      for(int i = 0; i < OGR_G_GetGeometryCount(super); i++) {
        OGRGeometryH subgeom = OGR_G_GetGeometryRef(super, i);
        if(subgeom == NULL) continue;
        double ar = OGR_G_Area(subgeom);
        if(ar > area) {
          geom = subgeom;
          area = ar;
        }
      }
      break;
    default:
      ;
  }

  // Find the center of our geometry. This sometimes throws an invalid geometry
  // error, so there is a slight bug here somehow.
  OGRGeometryH center;
  if(!(center = OGR_G_CreateGeometry(wkbPoint))) return;
  if(OGR_G_Centroid(geom, center) == OGRERR_FAILURE) {
    OGR_G_DestroyGeometry(center);
    return;
  }

  // Turn font hinting off
  cairo_font_options_t *opts;
  if(!(opts = cairo_font_options_create())){
    OGR_G_DestroyGeometry(center);
    return;
  }

  cairo_font_options_set_hint_style(opts, CAIRO_HINT_STYLE_NONE);
  cairo_font_options_set_hint_metrics(opts, CAIRO_HINT_METRICS_OFF);
  pango_cairo_context_set_font_options(litho->pango_ctx, opts);
  cairo_font_options_destroy(opts);

  // Get the field containing the text for the label.
  char *txt = simplet_copy_string(OGR_F_GetFieldAsString(feature, idx));
  PangoLayout *layout = pango_layout_new(litho->pango_ctx);
  pango_layout_set_text(layout, txt, -1);
  free(txt);

  // Grab the font to use and apply tracking.
  simplet_style_t *font = simplet_lookup_style(styles, "font");
  simplet_apply_styles(layout, styles, "letter-spacing", NULL);

  const char *font_family;

  if(!font)
    font_family = "helvetica 12px";
  else
    font_family = font->arg;

  PangoFontDescription *desc = pango_font_description_from_string(font_family);
  pango_layout_set_font_description(layout, desc);
  pango_font_description_free(desc);

  double x = OGR_G_GetX(center, 0), y = OGR_G_GetY(center, 0);
  cairo_user_to_device(proj_ctx, &x, &y);

  // Finally try the placement and test for overlaps.
  try_and_insert_placement(litho, layout, x, y);
  OGR_G_DestroyGeometry(center);
}