Organic Maps

The webcolors library provides tools for working with color names and color codes defined by HTML and CSS specifications. It supports conversions between six-digit hexadecimal, three-digit hexadecimal, integer rgb() triplets, and percentage rgb() triplets.

Supported Formats:

• Six-digit hexadecimal (e.g., #0099cc)
• Three-digit hexadecimal (e.g., #09c)
• Integer rgb() triplets (e.g., (0, 153, 204))
• Percentage rgb() triplets (e.g., (0%, 60%, 80%))
• Predefined color names (e.g., white, AliceBlue)

Limitations:

• Does not support hsl() triplets.
• Does not support opacity/alpha-channel information (rgba() or hsla()).
• For HSL conversions, use the Python standard library's colorsys module.

The data/ directory contains the essential files required for the application to function, including map files, styles, and metadata. Key files include:

• borders/: Polygons describing country borders.
• countries.json: Map files hierarchy and checksums.
• countries_meta.txt: Country/region languages and driving sides.
• hierarchy.txt: Countries/map regions hierarchy, languages, and Wikidata IDs.
• faq.html: FAQ text for the Help screen.
• copyright.html: Attributions for 3rd-party libraries, data, icons, and fonts.

The JSON is converted into a compact binary format during maps generation. This format is optimized for minimal memory usage and fast UTC $\leftrightarrow$ local conversions.

Logical Binary Structure:

Timezone Header (28 bits $\rightarrow$ 4 bytes):

• format_version: 3 bits
• generation_year_offset: 6 bits
• base_offset: 7 bits
• dst_delta: 8 bits
• transition_count: 4 bits

Transition Entry (20 bits $\rightarrow$ 3 bytes):

• day_delta: 9 bits (days since previous transition)
• minute_of_day: 11 bits (0–1439)

Comparison: While a full zoneinfo database can be 20–50 KB per timezone, this binary format typically uses only 3–25 bytes per timezone.

When writing Kotlin, follow these specific rules enforced by the project:

• Naming Conventions: Hungarian notation (using an m prefix) is forbidden for private properties.
  • Use _camelCase for backing fields.
  • Use camelCase for regular properties.
• Formatting: Formatting is handled by ktlint, not detekt. There is no overlap between the two tools.

Map feature logic and OSM (OpenStreetMap) mapping are handled via several files:

• mapcss-mapping.csv: Maps OSM tags to Organic Maps (OM) types.
• replaced_tags.txt: Defines how similar OSM tags are merged.
• mixed_tags.txt: Identifies high-popularity pedestrian streets.
• editor.config: Configuration for the built-in OSM data editor (defines editable POIs and attributes).
• config.xsd: XML schema for editor.config.

Note: classificator.txt and types.txt are automatically generated files representing the hierarchical list of OM types.

The core engine is written in C++ and is organized into several functional modules:

• ge0/: The external API of the application.
• map/: Application business logic and scene management.
• routing/: In-app routing engine.
• search/: Ranking and searching classes.
• indexer/: Processor for map files, classificator, and styles.
• drape/: The core graphics library.
• platform/: Platform abstraction (file paths, HTTP, location services).
• storage/: Map reading functions.
• geometry/: Geometry primitives.
• shaders/: Rendering shaders.
• routing_common/: Shared routing logic.
• transit/: Experimental GTFS-based public transport support.

Localization is handled through various string files and generated JSON files:

• strings/: Primary translation files.
• categories.txt, categories_cuisines.txt, categories_brands.txt, countries_names.txt: Categorized strings.
• countries_synonyms.csv: Alternative country names.
• synonyms.txt: Country/region abbreviations and short names.
• languages.txt: Native language names.

Automatically generated localization files:

• countries-strings/: JSON files for country and map region names.
• sound-strings/: JSON files for Text-To-Speech.