Revision 62052cafab4c49d6096846e41082887e231d3ac1 authored by Eric Fischer on 20 June 2015, 00:29:56 UTC, committed by Eric Fischer on 20 June 2015, 00:29:56 UTC
1 parent 265b686
geometry.cc
#include <iostream>
#include <fstream>
#include <string>
#include <stack>
#include <vector>
#include <algorithm>
#include <stdio.h>
#include <unistd.h>
#include <math.h>
#include <sqlite3.h>
#include <limits.h>
#include "geometry.hh"
extern "C" {
#include "tile.h"
#include "clip.h"
#include "projection.h"
}
drawvec decode_geometry(char **meta, int z, unsigned tx, unsigned ty, int detail, long long *bbox) {
drawvec out;
bbox[0] = LONG_LONG_MAX;
bbox[1] = LONG_LONG_MAX;
bbox[2] = LONG_LONG_MIN;
bbox[3] = LONG_LONG_MIN;
long long wx = initial_x, wy = initial_y;
while (1) {
draw d;
deserialize_byte(meta, &d.op);
if (d.op == VT_END) {
break;
}
if (d.op == VT_MOVETO || d.op == VT_LINETO) {
long long dx, dy;
deserialize_long_long(meta, &dx);
deserialize_long_long(meta, &dy);
wx += dx << geometry_scale;
wy += dy << geometry_scale;
long long wwx = wx;
long long wwy = wy;
if (z != 0) {
wwx -= tx << (32 - z);
wwy -= ty << (32 - z);
}
if (wwx < bbox[0]) {
bbox[0] = wwx;
}
if (wwy < bbox[1]) {
bbox[1] = wwy;
}
if (wwx > bbox[2]) {
bbox[2] = wwx;
}
if (wwy > bbox[3]) {
bbox[3] = wwy;
}
d.x = wwx;
d.y = wwy;
}
out.push_back(d);
}
return out;
}
void to_tile_scale(drawvec &geom, int z, int detail) {
unsigned i;
for (i = 0; i < geom.size(); i++) {
geom[i].x >>= (32 - detail - z);
geom[i].y >>= (32 - detail - z);
}
}
drawvec remove_noop(drawvec geom, int type) {
// first pass: remove empty linetos
long long x = 0, y = 0;
drawvec out;
unsigned i;
for (i = 0; i < geom.size(); i++) {
if (geom[i].op == VT_LINETO && geom[i].x == x && geom[i].y == y) {
continue;
}
if (geom[i].op == VT_CLOSEPATH) {
out.push_back(geom[i]);
} else { /* moveto or lineto */
out.push_back(geom[i]);
x = geom[i].x;
y = geom[i].y;
}
}
// second pass: remove unused movetos
geom = out;
out.resize(0);
for (i = 0; i < geom.size(); i++) {
if (geom[i].op == VT_MOVETO) {
if (i + 1 >= geom.size()) {
continue;
}
if (geom[i + 1].op == VT_MOVETO) {
continue;
}
if (geom[i + 1].op == VT_CLOSEPATH) {
i++; // also remove unused closepath
continue;
}
}
out.push_back(geom[i]);
}
// second pass: remove empty movetos
if (type == VT_LINE) {
geom = out;
out.resize(0);
for (i = 0; i < geom.size(); i++) {
if (geom[i].op == VT_MOVETO) {
if (i > 0 && geom[i - 1].op == VT_LINETO && geom[i - 1].x == geom[i].x && geom[i - 1].y == geom[i].y) {
continue;
}
}
out.push_back(geom[i]);
}
}
return out;
}
/* XXX */
#if 0
drawvec shrink_lines(drawvec &geom, int z, int detail, int basezoom, long long *here, double droprate) {
long long res = 200LL << (32 - 8 - z);
long long portion = res / exp(log(sqrt(droprate)) * (basezoom - z));
unsigned i;
drawvec out;
for (i = 0; i < geom.size(); i++) {
if (i > 0 && (geom[i - 1].op == VT_MOVETO || geom[i - 1].op == VT_LINETO) && geom[i].op == VT_LINETO) {
double dx = (geom[i].x - geom[i - 1].x);
double dy = (geom[i].y - geom[i - 1].y);
long long d = sqrt(dx * dx + dy * dy);
long long n;
long long next = LONG_LONG_MAX;
for (n = *here; n < *here + d; n = next) {
int within;
if (n % res < portion) {
next = (n / res) * res + portion;
within = 1;
} else {
next = (n / res + 1) * res;
within = 0;
}
if (next > *here + d) {
next = *here + d;
}
//printf("drawing from %lld to %lld in %lld\n", n - *here, next - *here, d);
double f1 = (n - *here) / (double) d;
double f2 = (next - *here) / (double) d;
if (within) {
out.push_back(draw(VT_MOVETO, geom[i - 1].x + f1 * (geom[i].x - geom[i - 1].x), geom[i - 1].y + f1 * (geom[i].y - geom[i - 1].y)));
out.push_back(draw(VT_LINETO, geom[i - 1].x + f2 * (geom[i].x - geom[i - 1].x), geom[i - 1].y + f2 * (geom[i].y - geom[i - 1].y)));
} else {
out.push_back(draw(VT_MOVETO, geom[i - 1].x + f2 * (geom[i].x - geom[i - 1].x), geom[i - 1].y + f2 * (geom[i].y - geom[i - 1].y)));
}
}
*here += d;
} else {
out.push_back(geom[i]);
}
}
return out;
}
#endif
static bool inside(draw d, int edge, long long area, long long buffer) {
long long clip_buffer = buffer * area / 256;
switch (edge) {
case 0: // top
return d.y > -clip_buffer;
case 1: // right
return d.x < area + clip_buffer;
case 2: // bottom
return d.y < area + clip_buffer;
case 3: // left
return d.x > -clip_buffer;
}
fprintf(stderr, "internal error inside\n");
exit(EXIT_FAILURE);
}
// http://stackoverflow.com/questions/563198/how-do-you-detect-where-two-line-segments-intersect
static draw get_line_intersection(draw p0, draw p1, draw p2, draw p3) {
double s1_x = p1.x - p0.x;
double s1_y = p1.y - p0.y;
double s2_x = p3.x - p2.x;
double s2_y = p3.y - p2.y;
double t;
// s = (-s1_y * (p0.x - p2.x) + s1_x * (p0.y - p2.y)) / (-s2_x * s1_y + s1_x * s2_y);
t = (s2_x * (p0.y - p2.y) - s2_y * (p0.x - p2.x)) / (-s2_x * s1_y + s1_x * s2_y);
return draw(VT_LINETO, p0.x + (t * s1_x), p0.y + (t * s1_y));
}
static draw intersect(draw a, draw b, int edge, long long area, long long buffer) {
long long clip_buffer = buffer * area / 256;
switch (edge) {
case 0: // top
return get_line_intersection(a, b, draw(VT_MOVETO, -clip_buffer, -clip_buffer), draw(VT_MOVETO, area + clip_buffer, -clip_buffer));
break;
case 1: // right
return get_line_intersection(a, b, draw(VT_MOVETO, area + clip_buffer, -clip_buffer), draw(VT_MOVETO, area + clip_buffer, area + clip_buffer));
break;
case 2: // bottom
return get_line_intersection(a, b, draw(VT_MOVETO, area + clip_buffer, area + clip_buffer), draw(VT_MOVETO, -clip_buffer, area + clip_buffer));
break;
case 3: // left
return get_line_intersection(a, b, draw(VT_MOVETO, -clip_buffer, area + clip_buffer), draw(VT_MOVETO, -clip_buffer, -clip_buffer));
break;
}
fprintf(stderr, "internal error intersecting\n");
exit(EXIT_FAILURE);
}
// http://en.wikipedia.org/wiki/Sutherland%E2%80%93Hodgman_algorithm
static drawvec clip_poly1(drawvec &geom, int z, int detail, int buffer) {
drawvec out = geom;
long long area = 0xFFFFFFFF;
if (z != 0) {
area = 1LL << (32 - z);
}
for (int edge = 0; edge < 4; edge++) {
if (out.size() > 0) {
drawvec in = out;
out.resize(0);
draw S = in[in.size() - 1];
for (unsigned e = 0; e < in.size(); e++) {
draw E = in[e];
if (inside(E, edge, area, buffer)) {
if (!inside(S, edge, area, buffer)) {
out.push_back(intersect(S, E, edge, area, buffer));
}
out.push_back(E);
} else if (inside(S, edge, area, buffer)) {
out.push_back(intersect(S, E, edge, area, buffer));
}
S = E;
}
}
}
if (out.size() > 0) {
out[0].op = VT_MOVETO;
for (unsigned i = 1; i < out.size(); i++) {
out[i].op = VT_LINETO;
}
}
return out;
}
drawvec clip_poly(drawvec &geom, int z, int detail, int buffer) {
if (z == 0) {
return geom;
}
drawvec out;
for (unsigned i = 0; i < geom.size(); i++) {
if (geom[i].op == VT_MOVETO) {
unsigned j;
for (j = i + 1; j < geom.size(); j++) {
if (geom[j].op == VT_CLOSEPATH || geom[j].op == VT_MOVETO) {
break;
}
}
drawvec tmp;
for (unsigned k = i; k < j; k++) {
tmp.push_back(geom[k]);
}
tmp = clip_poly1(tmp, z, detail, buffer);
for (unsigned k = 0; k < tmp.size(); k++) {
out.push_back(tmp[k]);
}
if (j >= geom.size() || geom[j].op == VT_CLOSEPATH) {
if (out.size() > 0 && out[out.size() - 1].op != VT_CLOSEPATH) {
out.push_back(draw(VT_CLOSEPATH, 0, 0));
}
i = j;
} else {
i = j - 1;
}
} else {
out.push_back(geom[i]);
}
}
return out;
}
drawvec reduce_tiny_poly(drawvec &geom, int z, int detail, bool *reduced, double *accum_area) {
drawvec out;
long long pixel = (1 << (32 - detail - z)) * 3;
*reduced = true;
for (unsigned i = 0; i < geom.size(); i++) {
if (geom[i].op == VT_MOVETO) {
unsigned j;
for (j = i + 1; j < geom.size(); j++) {
if (geom[j].op == VT_CLOSEPATH) {
break;
}
}
if (j + 1 < geom.size() && geom[j + 1].op == VT_CLOSEPATH) {
fprintf(stderr, "double closepath\n");
}
double area = 0;
for (unsigned k = i; k < j; k++) {
area += geom[k].x * geom[i + ((k - i + 1) % (j - i))].y;
area -= geom[k].y * geom[i + ((k - i + 1) % (j - i))].x;
}
area = fabs(area / 2);
if (area <= pixel * pixel) {
// printf("area is only %f vs %lld so using square\n", area, pixel * pixel);
*accum_area += area;
if (*accum_area > pixel * pixel) {
// XXX use centroid;
out.push_back(draw(VT_MOVETO, geom[i].x, geom[i].y));
out.push_back(draw(VT_LINETO, geom[i].x + pixel, geom[i].y));
out.push_back(draw(VT_LINETO, geom[i].x + pixel, geom[i].y + pixel));
out.push_back(draw(VT_LINETO, geom[i].x, geom[i].y + pixel));
out.push_back(draw(VT_CLOSEPATH, geom[i].x, geom[i].y));
*accum_area -= pixel * pixel;
}
} else {
// printf("area is %f so keeping instead of %lld\n", area, pixel * pixel);
for (unsigned k = i; k <= j && k < geom.size(); k++) {
out.push_back(geom[k]);
}
*reduced = false;
}
i = j;
} else {
fprintf(stderr, "how did we get here with %d in %d?\n", geom[i].op, (int) geom.size());
for (unsigned n = 0; n < geom.size(); n++) {
fprintf(stderr, "%d/%lld/%lld ", geom[n].op, geom[n].x, geom[n].y);
}
fprintf(stderr, "\n");
out.push_back(geom[i]);
}
}
return out;
}
drawvec clip_point(drawvec &geom, int z, int detail, long long buffer) {
drawvec out;
unsigned i;
long long min = 0;
long long area = 0xFFFFFFFF;
if (z != 0) {
area = 1LL << (32 - z);
min -= buffer * area / 256;
area += buffer * area / 256;
}
for (i = 0; i < geom.size(); i++) {
if (geom[i].x >= min && geom[i].y >= min && geom[i].x <= area && geom[i].y <= area) {
out.push_back(geom[i]);
}
}
return out;
}
int quick_check(long long *bbox, int z, int detail, long long buffer) {
long long min = 0;
long long area = 0xFFFFFFFF;
if (z != 0) {
area = 1LL << (32 - z);
min -= buffer * area / 256;
area += buffer * area / 256;
}
// bbox entirely outside the tile
if (bbox[0] > area || bbox[1] > area) {
return 0;
}
if (bbox[2] < min || bbox[3] < min) {
return 0;
}
// bbox entirely within the tile
if (bbox[0] > min && bbox[1] > min && bbox[2] < area && bbox[3] < area) {
return 1;
}
// some overlap of edge
return 2;
}
drawvec clip_lines(drawvec &geom, int z, int detail, long long buffer) {
drawvec out;
unsigned i;
long long min = 0;
long long area = 0xFFFFFFFF;
if (z != 0) {
area = 1LL << (32 - z);
min -= buffer * area / 256;
area += buffer * area / 256;
}
for (i = 0; i < geom.size(); i++) {
if (i > 0 && (geom[i - 1].op == VT_MOVETO || geom[i - 1].op == VT_LINETO) && geom[i].op == VT_LINETO) {
double x1 = geom[i - 1].x;
double y1 = geom[i - 1].y;
double x2 = geom[i - 0].x;
double y2 = geom[i - 0].y;
int c = clip(&x1, &y1, &x2, &y2, min, min, area, area);
if (c > 1) { // clipped
out.push_back(draw(VT_MOVETO, x1, y1));
out.push_back(draw(VT_LINETO, x2, y2));
out.push_back(draw(VT_MOVETO, geom[i].x, geom[i].y));
} else if (c == 1) { // unchanged
out.push_back(geom[i]);
} else { // clipped away entirely
out.push_back(draw(VT_MOVETO, geom[i].x, geom[i].y));
}
} else {
out.push_back(geom[i]);
}
}
return out;
}
static double square_distance_from_line(long long point_x, long long point_y, long long segA_x, long long segA_y, long long segB_x, long long segB_y) {
double p2x = segB_x - segA_x;
double p2y = segB_y - segA_y;
double something = p2x * p2x + p2y * p2y;
double u = 0 == something ? 0 : ((point_x - segA_x) * p2x + (point_y - segA_y) * p2y) / something;
if (u > 1) {
u = 1;
} else if (u < 0) {
u = 0;
}
double x = segA_x + u * p2x;
double y = segA_y + u * p2y;
double dx = x - point_x;
double dy = y - point_y;
return dx * dx + dy * dy;
}
// https://github.com/Project-OSRM/osrm-backend/blob/733d1384a40f/Algorithms/DouglasePeucker.cpp
static void douglas_peucker(drawvec &geom, int start, int n, double e) {
e = e * e;
std::stack<int> recursion_stack;
{
int left_border = 0;
int right_border = 1;
// Sweep linerarily over array and identify those ranges that need to be checked
do {
if (geom[start + right_border].necessary) {
recursion_stack.push(left_border);
recursion_stack.push(right_border);
left_border = right_border;
}
++right_border;
} while (right_border < n);
}
while (!recursion_stack.empty()) {
// pop next element
int second = recursion_stack.top();
recursion_stack.pop();
int first = recursion_stack.top();
recursion_stack.pop();
double max_distance = -1;
int farthest_element_index = second;
// find index idx of element with max_distance
int i;
for (i = first + 1; i < second; i++) {
double temp_dist = square_distance_from_line(geom[start + i].x, geom[start + i].y, geom[start + first].x, geom[start + first].y, geom[start + second].x, geom[start + second].y);
double distance = fabs(temp_dist);
if (distance > e && distance > max_distance) {
farthest_element_index = i;
max_distance = distance;
}
}
if (max_distance > e) {
// mark idx as necessary
geom[start + farthest_element_index].necessary = 1;
if (1 < farthest_element_index - first) {
recursion_stack.push(first);
recursion_stack.push(farthest_element_index);
}
if (1 < second - farthest_element_index) {
recursion_stack.push(farthest_element_index);
recursion_stack.push(second);
}
}
}
}
drawvec simplify_lines(drawvec &geom, int z, int detail) {
int res = 1 << (32 - detail - z);
unsigned i;
for (i = 0; i < geom.size(); i++) {
if (geom[i].op == VT_MOVETO) {
geom[i].necessary = 1;
} else if (geom[i].op == VT_LINETO) {
geom[i].necessary = 0;
} else {
geom[i].necessary = 1;
}
}
for (i = 0; i < geom.size(); i++) {
if (geom[i].op == VT_MOVETO) {
unsigned j;
for (j = i + 1; j < geom.size(); j++) {
if (geom[j].op == VT_CLOSEPATH || geom[j].op == VT_MOVETO) {
break;
}
}
geom[i].necessary = 1;
geom[j - 1].necessary = 1;
douglas_peucker(geom, i, j - i, res);
i = j - 1;
}
}
drawvec out;
for (i = 0; i < geom.size(); i++) {
if (geom[i].necessary) {
out.push_back(geom[i]);
}
}
return out;
}
drawvec reorder_lines(drawvec &geom) {
// Only reorder simple linestrings with a single moveto
if (geom.size() == 0) {
return geom;
}
unsigned i;
for (i = 0; i < geom.size(); i++) {
if (geom[i].op == VT_MOVETO) {
if (i != 0) {
return geom;
}
} else if (geom[i].op == VT_LINETO) {
if (i == 0) {
return geom;
}
} else {
return geom;
}
}
// Reorder anything that goes up and to the left
// instead of down and to the right
// so that it will coalesce better
unsigned long long l1 = encode(geom[0].x, geom[0].y);
unsigned long long l2 = encode(geom[geom.size() - 1].x, geom[geom.size() - 1].y);
if (l1 > l2) {
drawvec out;
for (i = 0; i < geom.size(); i++) {
out.push_back(geom[geom.size() - 1 - i]);
}
out[0].op = VT_MOVETO;
out[out.size() - 1].op = VT_LINETO;
return out;
}
return geom;
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...