[688] | 1 | #ifndef __ELT_H__ |
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| 2 | #define __ELT_H__ |
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| 3 | #include <list> |
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| 4 | #include "triple.hpp" |
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| 5 | |
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| 6 | #define NMAX 10 /**< maximum number of vertices for polygons */ |
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| 7 | |
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| 8 | #define NOT_FOUND -1 |
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| 9 | |
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| 10 | namespace sphereRemap { |
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| 11 | |
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| 12 | using namespace std; |
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| 13 | |
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| 14 | Coord barycentre(const Coord *x, int n); |
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| 15 | |
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| 16 | /** Two great or small circles (or mixed) have two or zero intersections. |
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| 17 | The coordinates of the intersections are stored in `pt` and `nb` holds the number of intersections (0 or 2). |
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| 18 | */ |
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| 19 | struct Ipt |
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| 20 | { |
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| 21 | int nb; |
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| 22 | Coord pt[2]; |
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| 23 | }; |
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| 24 | |
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| 25 | struct Sgm // edge |
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| 26 | { |
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| 27 | Coord n; // normal |
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| 28 | Coord xt[2]; // endpoints |
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| 29 | double d; // (see Elt) |
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| 30 | }; |
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| 31 | |
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| 32 | struct GloId |
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| 33 | { |
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| 34 | int rank; |
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| 35 | int ind; /* local id */ |
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| 36 | long globalId ; |
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| 37 | |
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| 38 | bool operator<(const GloId& other) const { |
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| 39 | return (rank == other.rank) ? (ind < other.ind) : (rank < other.rank); |
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| 40 | } |
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| 41 | }; |
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| 42 | |
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| 43 | struct Polyg |
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| 44 | { |
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| 45 | /* Note: for the target grid elements the id (rank and local id) depends on the order of the target grid elements as read from the nc-file whereas for source grid elements it depends on the SS-tree (i.e. super mesh distribution, not the order in the nc-file) */ |
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| 46 | struct GloId id; |
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| 47 | struct GloId src_id; |
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| 48 | int n; /* number of vertices */ |
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| 49 | double area; |
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[1614] | 50 | double given_area ; |
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[688] | 51 | Coord x; /* barycentre */ |
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| 52 | }; |
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| 53 | |
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| 54 | struct Elt : Polyg |
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| 55 | { |
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| 56 | Elt() {} |
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| 57 | Elt(const double *bounds_lon, const double *bounds_lat, int max_num_vert) |
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| 58 | { |
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| 59 | int k = 0; |
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| 60 | vertex[k++] = xyz(bounds_lon[0], bounds_lat[0]); |
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| 61 | for (int i = 1; i < max_num_vert; i++) |
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| 62 | { |
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| 63 | vertex[k] = xyz(bounds_lon[i], bounds_lat[i]); |
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| 64 | /* netCDF convention: if first vertex repeats element is finished (at least three vertices == triagle) */ |
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| 65 | if (k >= 3 && squaredist(vertex[k], vertex[0]) < EPS*EPS) |
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| 66 | break; |
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| 67 | /* eliminate zero edges: move to next vertex only if it is different */ |
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| 68 | if (squaredist(vertex[k], vertex[k-1]) > EPS*EPS) |
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| 69 | k++; |
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| 70 | else |
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[923] | 71 | /* cout << "Removed edge " << k << " due to zero length (coinciding endpoints)." << endl */ ; |
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[688] | 72 | } |
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| 73 | n = k; |
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| 74 | x = barycentre(vertex, n); |
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| 75 | } |
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| 76 | |
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| 77 | Elt& operator=(const Elt& rhs) |
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| 78 | { |
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| 79 | id = rhs.id; |
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| 80 | src_id = rhs.src_id; |
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| 81 | n = rhs.n; |
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| 82 | area = rhs.area; |
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[1614] | 83 | given_area = rhs.given_area; |
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[688] | 84 | x = rhs.x; |
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| 85 | val = rhs.val; |
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| 86 | grad = rhs.grad; |
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| 87 | is = rhs.is; |
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| 88 | |
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| 89 | for(int i = 0; i < NMAX; i++) |
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| 90 | { |
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| 91 | neighbour[i] = rhs.neighbour[i]; |
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| 92 | d[i] = rhs.d[i]; |
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| 93 | edge[i] = rhs.edge[i]; |
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| 94 | vertex[i] = rhs.vertex[i]; |
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| 95 | gradNeigh[i] = rhs.gradNeigh[i]; |
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| 96 | } |
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| 97 | return *this; |
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| 98 | } |
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| 99 | |
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| 100 | void delete_intersections() |
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| 101 | { |
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| 102 | for (list<Polyg*>::iterator it = this->is.begin(); it != this->is.end(); it++) |
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| 103 | { |
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| 104 | Polyg* poly = *it; |
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| 105 | delete poly; |
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| 106 | } |
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| 107 | } |
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| 108 | |
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[1158] | 109 | void insert_vertex(int i, const Coord& v) |
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| 110 | { |
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| 111 | for(int j=n; j > i ; j--) |
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| 112 | { |
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| 113 | vertex[j]=vertex[j-1] ; |
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| 114 | edge[j]=edge[j-1] ; |
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| 115 | d[j]=d[j-1] ; |
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| 116 | neighbour[j]=neighbour[j-1] ; |
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| 117 | } |
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| 118 | vertex[i+1]=v ; |
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| 119 | n++ ; |
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| 120 | } |
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| 121 | |
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[688] | 122 | int neighbour[NMAX]; |
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| 123 | double d[NMAX]; /**< distance of centre of small circle to origin, zero if great circle */ |
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| 124 | double val; /**< value (sample if src element, interpolated if dest element) */ |
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| 125 | Coord vertex[NMAX]; |
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| 126 | Coord edge[NMAX]; /**< edge normals: if great circle tangential to sphere, if small circle parallel to pole */ |
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| 127 | Coord grad; /**< gradient of the reconstructed linear function over this element */ |
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| 128 | Coord gradNeigh[NMAX]; /**< for weight computation: gradients for val=1 at individual neighbours */ |
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| 129 | struct GloId neighId[NMAX]; /**< weight computation needs to know global IDs for all sources with "link" */ |
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| 130 | std::list<Polyg*> is; /**< intersections */ |
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| 131 | }; |
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| 132 | |
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| 133 | static double normals(Elt &elt, const Coord &pole) |
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| 134 | { |
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| 135 | double nmin = 17.; |
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| 136 | for (int i = 0; i < elt.n; i++) // supposed oriented |
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| 137 | { |
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| 138 | int j = (i+1) % elt.n; |
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| 139 | elt.edge[i] = crossprod(elt.vertex[j], elt.vertex[i]); |
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| 140 | Coord t = elt.vertex[j] - elt.vertex[i]; |
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| 141 | /* polygonal grid || vertices not on same latitude */ |
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| 142 | if (pole == ORIGIN || fabs(scalarprod(t, pole)) > EPS) // great circle |
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| 143 | { |
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| 144 | double n = norm(elt.edge[i]); |
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| 145 | //assert(n > 0); |
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| 146 | if (n < nmin) nmin = n; |
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| 147 | elt.edge[i] = proj(elt.edge[i]); |
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| 148 | elt.d[i] = 0.0; |
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| 149 | } |
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| 150 | else /* lan lot grid && vertices on same latitude => small circle */ |
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| 151 | { |
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| 152 | int north = (scalarprod(elt.edge[i], pole) < 0) ? -1 : 1; |
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| 153 | elt.edge[i] = pole * north; |
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| 154 | elt.d[i] = scalarprod(elt.vertex[i], elt.edge[i]); |
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| 155 | } |
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| 156 | } |
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| 157 | return nmin; |
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| 158 | } |
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| 159 | |
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| 160 | } |
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| 161 | |
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| 162 | #endif |
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