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Diffstat (limited to 'misc/proto/vector_tile.proto')
-rw-r--r-- | misc/proto/vector_tile.proto | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/misc/proto/vector_tile.proto b/misc/proto/vector_tile.proto new file mode 100644 index 0000000000..1cde2c7aa9 --- /dev/null +++ b/misc/proto/vector_tile.proto @@ -0,0 +1,109 @@ +// Protocol Version 1 + +package mapboxgl.vector; + +option optimize_for = LITE_RUNTIME; + +enum geom_type { + Unknown = 0; + Point = 1; + LineString = 2; + Polygon = 3; +} + +// Variant type encoding +message value { + // Exactly one of these values may be present in a valid message + optional string string_value = 1; + optional float float_value = 2; + optional double double_value = 3; + optional int64 int_value = 4; + optional uint64 uint_value = 5; + optional sint64 sint_value = 6; + optional bool bool_value = 7; + + extensions 8 to max; +} + +message feature { + optional uint64 id = 1; + + // Tags of this feature. Even numbered values refer to the nth + // value in the keys list on the tile message, odd numbered + // values refer to the nth value in the values list on the tile + // message. + repeated uint32 tags = 2 [ packed = true ]; + + // The type of geometry stored in this feature. + optional geom_type type = 3 [ default = Unknown ]; + + // Contains a stream of commands and parameters (vertices). The + // repeat count is shifted to the left by 3 bits. This means + // that the command has 3 bits (0-15). The repeat count + // indicates how often this command is to be repeated. Defined + // commands are: + // - MoveTo: 1 (2 parameters follow) + // - LineTo: 2 (2 parameters follow) + // - ClosePath: 15 (no parameters follow) + // + // Ex.: MoveTo(3, 6), LineTo(8, 12), LineTo(20, 34), ClosePath + // Encoded as: [ 3 6 18 5 6 12 22 15 ] + // == command type 15 (ClosePath) + // ===== relative LineTo(+12, +22) == LineTo(20, 34) + // === relative LineTo(+5, +6) == LineTo(8, 12) + // == [00010 010] = command type 2 (LineTo), length 2 + // === relative MoveTo(+3, +6) + // = implicit command type 1 (MoveTo), length 1 + // Commands are encoded as uint32 varints, vertex parameters are + // encoded as sint32 varints (zigzag). Vertex parameters are + // also encoded as deltas to the previous position. The original + // position is (0,0) + repeated uint32 geometry = 4 [ packed = true ]; + + // A list of indices to the geometry array that specify a triangulation of + // this geometry. This must only exist if this feature is a polygon. + // These are the valid indices for the example above: + // 0 ==> (3/6) + // 1 ==> (8/12) + // 2 ==> (20/34) + // Indices beyond 2 are invalid, as the total number of vertices is 3. + repeated sint32 triangulation = 5 [ packed = true ]; + + // The total number of vertices encoded in the geometry field. This is can + // be deduced by manually iterating through the geometry field, but we can + // just as well store the number to avoid the overhead on parsing. + optional uint32 vertex_count = 6; +} + +message layer { + // Any compliant implementation must first read the version + // number encoded in this message and choose the correct + // implementation for this version number before proceeding to + // decode other parts of this message. + required uint32 version = 15 [ default = 1 ]; + + required string name = 1; + + // The actual features in this tile. + repeated feature features = 2; + + // Dictionary encoding for keys + repeated string keys = 3; + + // Dictionary encoding for values + repeated value values = 4; + + // The bounding box in this tile spans from 0..4095 units + optional uint32 extent = 5 [ default = 4096 ]; + + // Total vertex count in this layer. + optional uint32 vertex_count = 6; + + extensions 16 to max; +} + +message tile { + repeated layer layers = 3; + + extensions 16 to 8191; +} |