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Move code around so overzoom can link against parse_layers
This commit is contained in:
Erica Fischer
-148
@@ -381,154 +381,6 @@ drawvec reorder_lines(const drawvec &geom) {
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return geom;
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}
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drawvec fix_polygon(const drawvec &geom) {
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int outer = 1;
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drawvec out;
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for (size_t i = 0; i < geom.size(); i++) {
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if (geom[i].op == VT_CLOSEPATH) {
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outer = 1;
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} else if (geom[i].op == VT_MOVETO) {
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// Find the end of the ring
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size_t j;
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for (j = i + 1; j < geom.size(); j++) {
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if (geom[j].op != VT_LINETO) {
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break;
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}
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}
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// A polygon ring must contain at least three points
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// (and really should contain four). If this one does
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// not have any, avoid a division by zero trying to
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// calculate the centroid below.
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if (j - i < 1) {
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i = j - 1;
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outer = 0;
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continue;
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}
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// Make a temporary copy of the ring.
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// Close it if it isn't closed.
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drawvec ring;
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for (size_t a = i; a < j; a++) {
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ring.push_back(geom[a]);
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}
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if (j - i != 0 && (ring[0].x != ring[j - i - 1].x || ring[0].y != ring[j - i - 1].y)) {
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ring.push_back(ring[0]);
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}
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// A polygon ring at this point should contain at least four points.
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// Flesh it out with some vertex copies if it doesn't.
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while (ring.size() < 4) {
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ring.push_back(ring[0]);
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}
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// Reverse ring if winding order doesn't match
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// inner/outer expectation
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bool reverse_ring = false;
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if (prevent[P_USE_SOURCE_POLYGON_WINDING]) {
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// GeoJSON winding is reversed from vector winding
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reverse_ring = true;
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} else if (prevent[P_REVERSE_SOURCE_POLYGON_WINDING]) {
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// GeoJSON winding is reversed from vector winding
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reverse_ring = false;
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} else {
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double area = get_area(ring, 0, ring.size());
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if ((area > 0) != outer) {
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reverse_ring = true;
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}
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}
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if (reverse_ring) {
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drawvec tmp;
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for (int a = ring.size() - 1; a >= 0; a--) {
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tmp.push_back(ring[a]);
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}
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ring = tmp;
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}
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// Now we are rotating the ring to make the first/last point
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// one that would be unlikely to be simplified away.
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// calculate centroid
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// a + 1 < size() because point 0 is duplicated at the end
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long long xtotal = 0;
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long long ytotal = 0;
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long long count = 0;
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for (size_t a = 0; a + 1 < ring.size(); a++) {
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xtotal += ring[a].x;
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ytotal += ring[a].y;
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count++;
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}
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xtotal /= count;
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ytotal /= count;
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// figure out which point is furthest from the centroid
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long long dist2 = 0;
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long long furthest = 0;
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for (size_t a = 0; a + 1 < ring.size(); a++) {
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// division by 16 because these are z0 coordinates and we need to avoid overflow
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long long xd = (ring[a].x - xtotal) / 16;
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long long yd = (ring[a].y - ytotal) / 16;
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long long d2 = xd * xd + yd * yd;
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if (d2 > dist2 || (d2 == dist2 && ring[a] < ring[furthest])) {
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dist2 = d2;
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furthest = a;
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}
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}
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// then figure out which point is furthest from *that*,
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// which will hopefully be a good origin point since it should be
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// at a far edge of the shape.
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long long dist2b = 0;
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long long furthestb = 0;
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for (size_t a = 0; a + 1 < ring.size(); a++) {
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// division by 16 because these are z0 coordinates and we need to avoid overflow
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long long xd = (ring[a].x - ring[furthest].x) / 16;
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long long yd = (ring[a].y - ring[furthest].y) / 16;
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long long d2 = xd * xd + yd * yd;
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if (d2 > dist2b || (d2 == dist2b && ring[a] < ring[furthestb])) {
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dist2b = d2;
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furthestb = a;
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}
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}
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// rotate ring so the furthest point is the duplicated one.
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// the idea is that simplification will then be more efficient,
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// never wasting the start and end points, which are always retained,
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// on a point that has little impact on the shape.
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// Copy ring into output, fixing the moveto/lineto ops if necessary because of
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// reversal or closing
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for (size_t a = 0; a < ring.size(); a++) {
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size_t a2 = (a + furthestb) % (ring.size() - 1);
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if (a == 0) {
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out.push_back(draw(VT_MOVETO, ring[a2].x, ring[a2].y));
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} else {
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out.push_back(draw(VT_LINETO, ring[a2].x, ring[a2].y));
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}
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}
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// Next ring or polygon begins on the non-lineto that ended this one
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// and is not an outer ring unless there is a terminator first
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i = j - 1;
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outer = 0;
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} else {
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fprintf(stderr, "Internal error: polygon ring begins with %d, not moveto\n", geom[i].op);
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exit(EXIT_IMPOSSIBLE);
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}
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}
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return out;
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}
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#if 0
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std::vector<drawvec> chop_polygon(std::vector<drawvec> &geoms) {
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while (1) {
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