Examples with RenderingContext2D org.geotoolkit.display2d.canvas.RenderingContext2D used on opensource projects

Example 6 with RenderingContext2D

use of org.geotoolkit.display2d.canvas.RenderingContext2D in project geotoolkit by Geomatys.

the class RenderingRoutines method prepareQuery.

/**
 * Creates an optimal query to send to the datastore, knowing which properties are knowned and
 * the appropriate bounding box to filter.
 */
public static Query prepareQuery(final RenderingContext2D renderingContext, FeatureSet fs, final MapLayer layer, final Set<String> styleRequieredAtts, final List<Rule> rules, double symbolsMargin) throws PortrayalException {
    final FeatureType schema;
    try {
        schema = fs.getType();
    } catch (DataStoreException ex) {
        throw new PortrayalException(ex.getMessage(), ex);
    }
    // Note: do not use layer boundary to define the target bbox, because it can be expensive.
    // Anyway, the target resource will be better to determine clipping between rendering boundaries and its own.
    final Envelope bbox = optimizeBBox(renderingContext, fs, symbolsMargin);
    final CoordinateReferenceSystem layerCRS = FeatureExt.getCRS(schema);
    final RenderingHints hints = renderingContext.getRenderingHints();
    /*
         * To restrict queried values to the rendering area, we must identify what geometries are used by the style.
         * For each applied symbol, there are 3 possible cases:
         * - if the rule uses default geometries, they will be added to the geometry property list after the loop
         * - The geometric expression is a value reference, we can safely register it in geometric properties. The
         *   reference xpath is unwrapped in a set to ensure we won't create any doublon filters.
         * - If the geometry property is a complex expression(Ex: a value computed from non geometric fields), we keep
         *   it as is to apply a filter directly upon it. Note that even if it's an expression derived from geometric
         *   fields, we cannot apply spatial filter on them, because the expression could drastically change topology.
         *   For example, if the expression is 'buffer', the result geometry would be larger than any of its operands.
         *   TODO: such cases are maybe manageable by replacing bbox filter by a distance filter based upon the buffer
         *   distance. But would it do more good than harm ?
         */
    boolean isDefaultGeometryNeeded = rules == null || rules.isEmpty();
    final Set<String> geomProperties = new HashSet<>();
    final Set<Expression> complexProperties = new HashSet<>();
    if (rules != null) {
        for (Rule r : rules) {
            for (Symbolizer s : r.symbolizers()) {
                final Expression expGeom = s.getGeometry();
                if (isNil(expGeom))
                    isDefaultGeometryNeeded = true;
                else if (expGeom instanceof ValueReference)
                    geomProperties.add(((ValueReference) expGeom).getXPath());
                else
                    complexProperties.add(expGeom);
            }
        }
    }
    if (isDefaultGeometryNeeded) {
        try {
            final PropertyType defaultGeometry = FeatureExt.getDefaultGeometry(schema);
            final String geomName = Features.getLinkTarget(defaultGeometry).orElseGet(() -> defaultGeometry.getName().toString());
            geomProperties.add(geomName);
        } catch (PropertyNotFoundException e) {
            throw new PortrayalException("Default geometry cannot be determined. " + "However, it is needed to properly define filtering rules.");
        } catch (IllegalStateException e) {
            // If there's multiple geometric properties, and no primary one, we will use them all
            schema.getProperties(true).stream().filter(p -> !Features.getLinkTarget(p).isPresent()).filter(AttributeConvention::isGeometryAttribute).map(p -> p.getName().toString()).forEach(geomProperties::add);
        }
    }
    if (!complexProperties.isEmpty()) {
        LOGGER.fine("A style rule uses complex geometric properties. It can severly affect performance");
    }
    final Optional<Filter> spatialFilter = Stream.concat(geomProperties.stream().map(FILTER_FACTORY::property), complexProperties.stream()).<Filter>map(expression -> FILTER_FACTORY.bbox(expression, bbox)).reduce(FILTER_FACTORY::or);
    Filter userFilter = null;
    // concatenate geographic filter with data filter if there is one
    if (layer != null) {
        Query query = layer.getQuery();
        if (query instanceof FeatureQuery) {
            userFilter = ((FeatureQuery) query).getSelection();
        }
    }
    Filter filter;
    if (spatialFilter.isPresent()) {
        if (userFilter == null)
            filter = spatialFilter.get();
        else
            // Note: we give priority to the spatial filter here, because it is our main use case: rendering is driven
            // by bounding box.
            filter = FILTER_FACTORY.and(spatialFilter.get(), userFilter);
    } else if (userFilter == null) {
        throw new PortrayalException("No spatial filter can be determined from style rules, and no user filter specified." + "We refuse dataset full-scan. To authorize it, manually specify Filter 'INCLUDE' on your map layer.");
    } else {
        LOGGER.warning("Spatial filter cannot be determined for rendering. However, user has provided a custom filter that we'll use as sole filtering policy");
        filter = userFilter;
    }
    final Set<String> copy = new HashSet<>();
    final FeatureType expected;
    final String[] atts;
    if (styleRequieredAtts == null) {
        // all properties are requiered
        expected = schema;
        atts = null;
    } else {
        final Set<String> attributs = styleRequieredAtts;
        copy.addAll(attributs);
        copy.addAll(geomProperties);
        try {
            // always include the identifier if it exist
            schema.getProperty(AttributeConvention.IDENTIFIER);
            copy.add(AttributeConvention.IDENTIFIER);
        } catch (PropertyNotFoundException ex) {
        // no id, ignore it
        }
        atts = copy.toArray(new String[copy.size()]);
        // then we reduce it to the first parent property.
        for (int i = 0; i < atts.length; i++) {
            String attName = atts[i];
            int index = attName.indexOf('/');
            if (index == 0) {
                // remove all xpath elements
                // remove first slash
                attName = attName.substring(1);
                final Pattern pattern = Pattern.compile("(\\{[^\\{\\}]*\\})|(\\[[^\\[\\]]*\\])|/{1}");
                final Matcher matcher = pattern.matcher(attName);
                final StringBuilder sb = new StringBuilder();
                int position = 0;
                while (matcher.find()) {
                    final String match = matcher.group();
                    sb.append(attName.substring(position, matcher.start()));
                    position = matcher.end();
                    if (match.charAt(0) == '/') {
                        // we don't query precisely sub elements
                        position = attName.length();
                        break;
                    } else if (match.charAt(0) == '{') {
                        sb.append(match);
                    } else if (match.charAt(0) == '[') {
                    // strip indexes or xpath searches
                    }
                }
                sb.append(attName.substring(position));
                atts[i] = sb.toString();
            }
        }
        try {
            expected = new ViewMapper(schema, atts).getMappedType();
        } catch (MismatchedFeatureException ex) {
            throw new PortrayalException(ex);
        }
    }
    // combine the filter with rule filters----------------------------------
    if (rules != null) {
        List<Filter<Object>> rulefilters = new ArrayList<>();
        for (Rule rule : rules) {
            if (rule.isElseFilter()) {
                // we can't append styling filters, an else rule match all features
                rulefilters = null;
                break;
            }
            final Filter rf = rule.getFilter();
            if (rf == null || rf == Filter.include()) {
                // we can't append styling filters, this rule matchs all features.
                rulefilters = null;
                break;
            }
            rulefilters.add(rf);
        }
        if (rulefilters != null) {
            final Filter combined;
            if (rulefilters.size() == 1) {
                // we can optimze here, since we pass the filter on the query, we can remove
                // the filter on the rule.
                final MutableRule mr = StyleUtilities.copy(rules.get(0));
                mr.setFilter(null);
                rules.set(0, mr);
                combined = rulefilters.get(0);
            } else {
                combined = FILTER_FACTORY.or(rulefilters);
            }
            if (filter != Filter.include()) {
                filter = FILTER_FACTORY.and(filter, combined);
            } else {
                filter = combined;
            }
        }
    }
    // optimize the filter---------------------------------------------------
    filter = FilterUtilities.prepare(filter, Feature.class, expected);
    final Hints queryHints = new Hints();
    final org.geotoolkit.storage.feature.query.Query qb = new org.geotoolkit.storage.feature.query.Query();
    qb.setTypeName(schema.getName());
    qb.setSelection(filter);
    qb.setProperties(atts);
    // resampling and ignore flag only works when we know the layer crs
    if (layerCRS != null) {
        // add resampling -------------------------------------------------------
        Boolean resample = (hints == null) ? null : (Boolean) hints.get(GO2Hints.KEY_GENERALIZE);
        if (!Boolean.FALSE.equals(resample)) {
            // we only disable resampling if it is explictly specified
            double[] res = renderingContext.getResolution(layerCRS);
            // adjust with the generalization factor
            final Number n = (hints == null) ? null : (Number) hints.get(GO2Hints.KEY_GENERALIZE_FACTOR);
            final double factor;
            if (n != null) {
                factor = n.doubleValue();
            } else {
                factor = GO2Hints.GENERALIZE_FACTOR_DEFAULT.doubleValue();
            }
            res[0] *= factor;
            res[1] *= factor;
            qb.setResolution(res);
            try {
                res = renderingContext.getResolution(CRS.forCode("EPSG:3395"));
                res[0] *= factor;
                res[1] *= factor;
                qb.setLinearResolution(Quantities.create(res[0], Units.METRE));
            } catch (FactoryException ex) {
                throw new PortrayalException(ex.getMessage(), ex);
            }
        }
    // add ignore flag ------------------------------------------------------
    // TODO this is efficient but erases values, when plenty of then are to be rendered
    // we should find another way to handle this
    // if(!GO2Utilities.visibleMargin(rules, 1.01f, renderingContext)){
    // //style does not expend itself further than the feature geometry
    // //that mean geometries smaller than a pixel will not be renderer or barely visible
    // queryHints.put(Hints.KEY_IGNORE_SMALL_FEATURES, renderingContext.getResolution(layerCRS));
    // }
    }
    // add reprojection -----------------------------------------------------
    // we don't reproject, the reprojection may produce curves but JTS can not represent those.
    // so we generate those curves in java2d shapes by doing the transformation ourself.
    // TODO wait for a new geometry implementation
    // qb.setCRS(renderingContext.getObjectiveCRS2D());
    // set the acumulated hints
    qb.setHints(queryHints);
    return qb;
}