path: root/src/map/tile_parser.cpp

#include <llmr/map/tile_parser.hpp>

#include <llmr/map/vector_tile_data.hpp>
#include <llmr/style/style.hpp>
#include <llmr/style/style_layer.hpp>
#include <llmr/style/style_layer_group.hpp>
#include <llmr/renderer/fill_bucket.hpp>
#include <llmr/renderer/line_bucket.hpp>
#include <llmr/renderer/icon_bucket.hpp>
#include <llmr/renderer/text_bucket.hpp>
#include <llmr/renderer/raster_bucket.hpp>
#include <llmr/util/raster.hpp>
#include <llmr/util/constants.hpp>
#include <llmr/util/token.hpp>
#include <llmr/geometry/glyph_atlas.hpp>
#include <llmr/text/glyph_store.hpp>
#include <llmr/text/glyph.hpp>

#include <llmr/util/std.hpp>
#include <llmr/util/utf.hpp>

#include <locale>

#ifdef __linux__
#include <boost/regex.hpp>
namespace regex_impl = boost;
#else
#include <regex>
namespace regex_impl = std;
#endif

using namespace llmr;

TileParser::TileParser(const std::string &data, VectorTileData &tile,
                       const std::shared_ptr<const Style> &style,
                       const std::shared_ptr<GlyphAtlas> &glyphAtlas,
                       const std::shared_ptr<GlyphStore> &glyphStore,
                       const std::shared_ptr<SpriteAtlas> &spriteAtlas)
    : vector_data(pbf((const uint8_t *)data.data(), data.size())),
      tile(tile),
      style(style),
      glyphAtlas(glyphAtlas),
      glyphStore(glyphStore),
      spriteAtlas(spriteAtlas),
      placement(tile.id.z) {
}

void TileParser::parse() {
    parseStyleLayers(style->layers);
}

bool TileParser::obsolete() const { return tile.state == TileData::State::obsolete; }

void TileParser::addGlyph(uint64_t tileid, const std::string stackname,
                          const std::u32string &string, const FontStack &fontStack,
                          GlyphAtlas &glyphAtlas, GlyphPositions &face) {
    const std::map<uint32_t, SDFGlyph> &sdfs = fontStack.getSDFs();
    // Loop through all characters and add glyph to atlas, positions.
    for (uint32_t chr : string) {
        auto sdf_it = sdfs.find(chr);
        if (sdf_it != sdfs.end()) {
            const SDFGlyph& sdf = sdf_it->second;
            const Rect<uint16_t> rect = glyphAtlas.addGlyph(tileid, stackname, sdf);
            face.emplace(chr, Glyph{rect, sdf.metrics});
        }
    }
}

void TileParser::parseStyleLayers(std::shared_ptr<StyleLayerGroup> group) {
    if (!group) {
        return;
    }

    for (const std::shared_ptr<StyleLayer> &layer_desc : group->layers) {
        // Cancel early when parsing.
        if (obsolete()) {
            return;
        }

        if (layer_desc->isBackground()) {
            // background is a special, fake bucket
            continue;
        } else if (layer_desc->layers) {
            // This is a layer group.
            parseStyleLayers(layer_desc->layers);
        } else if (layer_desc->bucket) {
            // This is a singular layer. Check if this bucket already exists. If not,
            // parse this bucket.
            auto bucket_it = tile.buckets.find(layer_desc->bucket->name);
            if (bucket_it == tile.buckets.end()) {
                // We need to create this bucket since it doesn't exist yet.
                std::unique_ptr<Bucket> bucket = createBucket(layer_desc->bucket);
                if (bucket) {
                    // Bucket creation might fail because the data tile may not
                    // contain any data that falls into this bucket.
                    tile.buckets[layer_desc->bucket->name] = std::move(bucket);
                }
            }
        } else {
            fprintf(stderr, "[WARNING] layer '%s' does not have child layers or buckets\n", layer_desc->id.c_str());
        }
    }
}

std::unique_ptr<Bucket> TileParser::createBucket(std::shared_ptr<StyleBucket> bucket_desc) {
    if (!bucket_desc) {
        fprintf(stderr, "missing bucket desc\n");
        return nullptr;
    }

    auto layer_it = vector_data.layers.find(bucket_desc->source_layer);
    if (layer_it != vector_data.layers.end()) {
        const VectorTileLayer &layer = layer_it->second;
        if (bucket_desc->render.is<StyleBucketFill>()) {
            return createFillBucket(layer, bucket_desc->filter, bucket_desc->render.get<StyleBucketFill>());
        } else if (bucket_desc->render.is<StyleBucketLine>()) {
            return createLineBucket(layer, bucket_desc->filter, bucket_desc->render.get<StyleBucketLine>());
        } else if (bucket_desc->render.is<StyleBucketIcon>()) {
            return createIconBucket(layer, bucket_desc->filter, bucket_desc->render.get<StyleBucketIcon>());
        } else if (bucket_desc->render.is<StyleBucketText>()) {
            return createTextBucket(layer, bucket_desc->filter, bucket_desc->render.get<StyleBucketText>());
        } else if (bucket_desc->render.is<StyleBucketRaster>()) {
            return nullptr;
        } else {
            fprintf(stderr, "[WARNING] unknown bucket render type for layer '%s' (source layer '%s')\n", bucket_desc->name.c_str(), bucket_desc->source_layer.c_str());
        }
    } else {
        // The layer specified in the bucket does not exist. Do nothing.
        if (debug::tileParseWarnings) {
            fprintf(stderr, "[WARNING] layer '%s' does not exist in tile %d/%d/%d\n",
                    bucket_desc->source_layer.c_str(), tile.id.z, tile.id.x, tile.id.y);
        }
    }

    return nullptr;
}

template <class Bucket>
void TileParser::addBucketFeatures(Bucket& bucket, const VectorTileLayer& layer, const FilterExpression &filter) {
    FilteredVectorTileLayer filtered_layer(layer, filter);
    for (pbf feature : filtered_layer) {
        if (obsolete())
            return;

        while (feature.next(4)) { // geometry
            pbf geometry_pbf = feature.message();
            if (geometry_pbf) {
                bucket->addGeometry(geometry_pbf);
            } else if (debug::tileParseWarnings) {
                fprintf(stderr, "[WARNING] geometry is empty\n");
            }
        }
    }
}

template <class Bucket, typename... Args>
void TileParser::addBucketFeatures(Bucket& bucket, const VectorTileLayer& layer, const FilterExpression &filter, Args&& ...args) {
    FilteredVectorTileLayer filtered_layer(layer, filter);
    for (const pbf &feature_pbf : filtered_layer) {
        if (obsolete()) {
            return;
        }
        bucket->addFeature({feature_pbf, layer}, std::forward<Args>(args)...);
    }
}


std::unique_ptr<Bucket> TileParser::createFillBucket(const VectorTileLayer& layer, const FilterExpression &filter, const StyleBucketFill &fill) {
    std::unique_ptr<FillBucket> bucket = std::make_unique<FillBucket>(tile.fillVertexBuffer, tile.triangleElementsBuffer, tile.lineElementsBuffer, fill);
    addBucketFeatures(bucket, layer, filter);
    return obsolete() ? nullptr : std::move(bucket);
}

std::unique_ptr<Bucket> TileParser::createLineBucket(const VectorTileLayer& layer, const FilterExpression &filter, const StyleBucketLine &line) {
    std::unique_ptr<LineBucket> bucket = std::make_unique<LineBucket>(tile.lineVertexBuffer, tile.triangleElementsBuffer, tile.pointElementsBuffer, line);
    addBucketFeatures(bucket, layer, filter);
    return obsolete() ? nullptr : std::move(bucket);
}

std::unique_ptr<Bucket> TileParser::createIconBucket(const VectorTileLayer& layer, const FilterExpression &filter, const StyleBucketIcon &icon) {
    std::unique_ptr<IconBucket> bucket = std::make_unique<IconBucket>(tile.iconVertexBuffer, icon);
    addBucketFeatures(bucket, layer, filter, *spriteAtlas);
    return obsolete() ? nullptr : std::move(bucket);
}

std::unique_ptr<Bucket> TileParser::createTextBucket(const VectorTileLayer& layer, const FilterExpression &filter, const StyleBucketText &text) {

    // Make sure that we always have a valid glyph store. If this is not set, the stylesheet
    // doesn't specify a glyph URL.
    if (!glyphStore) {
        return nullptr;
    }

    const StyleBucketText &properties = text;

    std::unique_ptr<TextBucket> bucket = std::make_unique<TextBucket>(
        tile.textVertexBuffer, tile.triangleElementsBuffer, properties, placement);

    util::utf8_to_utf32 ucs4conv;

    std::vector<std::pair<std::u32string, pbf>> labels;

    // Determine and load glyph ranges
    {
        std::set<GlyphRange> ranges;

        FilteredVectorTileLayer filtered_layer(layer, filter);
        for (const pbf &feature_pbf : filtered_layer) {
            if (obsolete())
                return nullptr;
            VectorTileFeature feature{feature_pbf, layer};

            std::string u8string = util::replaceTokens(properties.field, feature.properties);

            auto& convert = std::use_facet<std::ctype<char>>(std::locale());
            if (properties.transform == TextTransformType::Uppercase) {
                convert.toupper(&u8string[0], &u8string[0] + u8string.size());
            } else if (properties.transform == TextTransformType::Lowercase) {
                convert.tolower(&u8string[0], &u8string[0] + u8string.size());
            }

            std::u32string string = ucs4conv.convert(u8string);

            // Loop through all characters of this text and collect unique codepoints.
            for (char32_t chr : string) {
                ranges.insert(getGlyphRange(chr));
            }

            labels.emplace_back(string, feature.geometry);
        }

        glyphStore->waitForGlyphRanges(properties.font, ranges);
    }

    // Create a copy!
    const FontStack &fontStack = glyphStore->getFontStack(properties.font);
    GlyphPositions face;

    // Shape and place all labels.
    for (const std::pair<std::u32string, pbf> &label : labels) {

        // Shape labels.
        const Shaping shaping = fontStack.getShaping(label.first, properties.max_width,
                properties.line_height, properties.alignment,
                properties.vertical_alignment, properties.letter_spacing);

        // Place labels.
        addGlyph(tile.id.to_uint64(), properties.font, label.first, fontStack, *glyphAtlas,
                 face);

        bucket->addFeature(label.second, face, shaping);
    }

    return std::move(bucket);
}