GeometryCollection VectorTileFeature::getGeometries() const {
uint8_t cmd = 1;
uint32_t length = 0;
int32_t x = 0;
int32_t y = 0;
const float scale = float(util::EXTENT) / layer.extent;
GeometryCollection lines;
lines.emplace_back();
GeometryCoordinates* line = &lines.back();
auto g_itr = geometry_iter.begin();
while (g_itr != geometry_iter.end()) {
if (length == 0) {
uint32_t cmd_length = static_cast<uint32_t>(*g_itr++);
cmd = cmd_length & 0x7;
length = cmd_length >> 3;
}
--length;
if (cmd == 1 || cmd == 2) {
x += protozero::decode_zigzag32(static_cast<uint32_t>(*g_itr++));
y += protozero::decode_zigzag32(static_cast<uint32_t>(*g_itr++));
if (cmd == 1 && !line->empty()) { // moveTo
lines.emplace_back();
line = &lines.back();
}
line->emplace_back(::round(x * scale), ::round(y * scale));
} else if (cmd == 7) { // closePolygon
if (!line->empty()) {
line->push_back((*line)[0]);
}
} else {
throw std::runtime_error("unknown command");
}
}
GeometryCollection VectorTileFeature::getGeometries() const {
pbf data(geometry_pbf);
uint8_t cmd = 1;
uint32_t length = 0;
int32_t x = 0;
int32_t y = 0;
GeometryCollection lines;
lines.emplace_back();
GeometryCoordinates* line = &lines.back();
while (data.data < data.end) {
if (length == 0) {
uint32_t cmd_length = data.varint();
cmd = cmd_length & 0x7;
length = cmd_length >> 3;
}
--length;
if (cmd == 1 || cmd == 2) {
x += data.svarint();
y += data.svarint();
if (cmd == 1 && !line->empty()) { // moveTo
lines.emplace_back();
line = &lines.back();
}
line->emplace_back(x, y);
} else if (cmd == 7) { // closePolygon
if (!line->empty()) {
line->push_back((*line)[0]);
}
} else {
throw std::runtime_error("unknown command");
}
}
static GeometryCoordinates fromClipperPath(const ClipperLib::Path& path) {
GeometryCoordinates result;
result.reserve(path.size() + 1);
result.reserve(path.size());
for (const auto& p : path) {
using Coordinate = GeometryCoordinates::coordinate_type;
assert(p.x >= std::numeric_limits<Coordinate>::min());
assert(p.x <= std::numeric_limits<Coordinate>::max());
assert(p.y >= std::numeric_limits<Coordinate>::min());
assert(p.y <= std::numeric_limits<Coordinate>::max());
result.emplace_back(Coordinate(p.x), Coordinate(p.y));
}
// Clipper does not repeat initial point, but our geometry model requires it.
if (!result.empty()) {
result.push_back(result.front());
}
return result;
}
Anchors getAnchors(const GeometryCoordinates &line, float spacing,
const float maxAngle, const float textLeft, const float textRight,
const float iconLeft, const float iconRight,
const float glyphSize, const float boxScale, const float overscaling) {
if (line.empty()) return {};
// Resample a line to get anchor points for labels and check that each
// potential label passes text-max-angle check and has enough froom to fit
// on the line.
const float angleWindowSize = (textLeft - textRight) != 0.0f ?
3.0f / 5.0f * glyphSize * boxScale :
0;
const float labelLength = fmax(textRight - textLeft, iconRight - iconLeft);
// Is the line continued from outside the tile boundary?
const bool continuedLine = (line[0].x == 0 || line[0].x == util::EXTENT || line[0].y == 0 || line[0].y == util::EXTENT);
// Is the label long, relative to the spacing?
// If so, adjust the spacing so there is always a minimum space of `spacing / 4` between label edges.
if (spacing - labelLength * boxScale < spacing / 4) {
spacing = labelLength * boxScale + spacing / 4;
}
// Offset the first anchor by:
// Either half the label length plus a fixed extra offset if the line is not continued
// Or half the spacing if the line is continued.
// For non-continued lines, add a bit of fixed extra offset to avoid collisions at T intersections.
const float fixedExtraOffset = glyphSize * 2;
const float offset = !continuedLine ?
std::fmod((labelLength / 2 + fixedExtraOffset) * boxScale * overscaling, spacing) :
std::fmod(spacing / 2 * overscaling, spacing);
return resample(line, offset, spacing, angleWindowSize, maxAngle, labelLength * boxScale, continuedLine, false);
}
