GeometryCollection clipLines(const GeometryCollection &lines,
const int16_t x1, const int16_t y1, const int16_t x2, const int16_t y2) {
GeometryCollection clippedLines;
for (auto& line : lines) {
if (line.empty())
continue;
auto end = line.end() - 1;
for (auto it = line.begin(); it != end; it++) {
GeometryCoordinate p0 = *(it);
GeometryCoordinate p1 = *(it + 1);
if (p0.x < x1 && p1.x < x1) {
continue;
} else if (p0.x < x1) {
p0 = { x1, static_cast<int16_t>(::round(p0.y + (p1.y - p0.y) * ((float)(x1 - p0.x) / (p1.x - p0.x)))) };
} else if (p1.x < x1) {
p1 = { x1, static_cast<int16_t>(::round(p0.y + (p1.y - p0.y) * ((float)(x1 - p0.x) / (p1.x - p0.x)))) };
}
if (p0.y < y1 && p1.y < y1) {
continue;
} else if (p0.y < y1) {
p0 = { static_cast<int16_t>(::round(p0.x + (p1.x - p0.x) * ((float)(y1 - p0.y) / (p1.y - p0.y)))), y1 };
} else if (p1.y < y1) {
p1 = { static_cast<int16_t>(::round(p0.x + (p1.x - p0.x) * ((float)(y1 - p0.y) / (p1.y - p0.y)))), y1 };
}
if (p0.x >= x2 && p1.x >= x2) {
continue;
} else if (p0.x >= x2) {
p0 = { x2, static_cast<int16_t>(::round(p0.y + (p1.y - p0.y) * ((float)(x2 - p0.x) / (p1.x - p0.x)))) };
} else if (p1.x >= x2) {
p1 = { x2, static_cast<int16_t>(::round(p0.y + (p1.y - p0.y) * ((float)(x2 - p0.x) / (p1.x - p0.x)))) };
}
if (p0.y >= y2 && p1.y >= y2) {
continue;
} else if (p0.y >= y2) {
p0 = { static_cast<int16_t>(::round(p0.x + (p1.x - p0.x) * ((float)(y2 - p0.y) / (p1.y - p0.y)))), y2 };
} else if (p1.y >= y2) {
p1 = { static_cast<int16_t>(::round(p0.x + (p1.x - p0.x) * ((float)(y2 - p0.y) / (p1.y - p0.y)))), y2 };
}
if (clippedLines.empty() || (!clippedLines.back().empty() && !(p0 == clippedLines.back().back()))) {
clippedLines.emplace_back();
clippedLines.back().push_back(p0);
}
clippedLines.back().push_back(p1);
}
}
return clippedLines;
}
optional<GeometryCollection> FeatureIndex::translateQueryGeometry(
const GeometryCollection& queryGeometry,
const std::array<float, 2>& translate,
const TranslateAnchorType anchorType,
const float bearing,
const float pixelsToTileUnits) {
if (translate[0] == 0 && translate[1] == 0) return {};
GeometryCoordinate translateVec(translate[0] * pixelsToTileUnits, translate[1] * pixelsToTileUnits);
if (anchorType == TranslateAnchorType::Viewport) {
translateVec = util::rotate(translateVec, -bearing);
}
GeometryCollection translated;
for (auto& ring : queryGeometry) {
translated.emplace_back();
auto& translatedRing = translated.back();
for (auto& p : ring) {
translatedRing.push_back(p - translateVec);
}
}
return translated;
}
optional<GeometryCollection> offsetLine(const GeometryCollection& rings, const double offset) {
if (offset == 0) return {};
GeometryCollection newRings;
Point<double> zero(0, 0);
for (const auto& ring : rings) {
newRings.emplace_back();
auto& newRing = newRings.back();
for (auto i = ring.begin(); i != ring.end(); i++) {
auto& p = *i;
Point<double> aToB = i == ring.begin() ?
zero :
util::perp(util::unit(convertPoint<double>(p - *(i - 1))));
Point<double> bToC = i + 1 == ring.end() ?
zero :
util::perp(util::unit(convertPoint<double>(*(i + 1) - p)));
Point<double> extrude = util::unit(aToB + bToC);
const double cosHalfAngle = extrude.x * bToC.x + extrude.y * bToC.y;
extrude *= (1.0 / cosHalfAngle);
newRing.push_back(convertPoint<int16_t>(extrude * offset) + p);
}
}
return newRings;
}
static void processPolynodeBranch(ClipperLib::PolyNode* polynode, GeometryCollection& rings) {
// Exterior ring.
rings.push_back(fromClipperPath(polynode->Contour));
assert(signedArea(rings.back()) > 0);
// Interior rings.
for (auto * ring : polynode->Childs) {
rings.push_back(fromClipperPath(ring->Contour));
assert(signedArea(rings.back()) < 0);
}
// PolyNodes may be nested in the case of a polygon inside a hole.
for (auto * ring : polynode->Childs) {
for (auto * subRing : ring->Childs) {
processPolynodeBranch(subRing, rings);
}
}
}
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");
}
}
