ExternalVendorCode/tippecanoe
1
0
Fork 0
mirror of https://github.com/mapbox/tippecanoe.git synced 2025-04-08 11:34:12 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

More informative return value from clipping

Browse Source
This commit is contained in:
Eric Fischer 2018-06-12 11:32:40 -07:00
parent 22732f0ceb
commit 74a2e0ab15
2 changed files with 18 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
clip.hpp
View File

@ -23,11 +23,17 @@ static int computeOutCode(double x, double y, double xmin, double ymin, double x
return code;
}
#define CLIP_OK 0
#define CLIP_ELIMINATED 1
#define CLIP_CHANGED_FIRST 2
#define CLIP_CHANGED_SECOND 4
#define CLIP_CHANGED (CLIP_CHANGED_FIRST | CLIP_CHANGED_SECOND)
static int clip(double *x0, double *y0, double *x1, double *y1, double xmin, double ymin, double xmax, double ymax) {
int outcode0 = computeOutCode(*x0, *y0, xmin, ymin, xmax, ymax);
int outcode1 = computeOutCode(*x1, *y1, xmin, ymin, xmax, ymax);
int changed = CLIP_OK;
int accept = 0;
int changed = 0;
while (1) {
if (!(outcode0 | outcode1)) { // Bitwise OR is 0. Trivially accept and get out of loop
@ -65,19 +71,19 @@ static int clip(double *x0, double *y0, double *x1, double *y1, double xmin, dou
*x0 = x;
*y0 = y;
outcode0 = computeOutCode(*x0, *y0, xmin, ymin, xmax, ymax);
changed = 1;
changed |= CLIP_CHANGED_FIRST;
} else {
*x1 = x;
*y1 = y;
outcode1 = computeOutCode(*x1, *y1, xmin, ymin, xmax, ymax);
changed = 1;
changed |= CLIP_CHANGED_SECOND;
}
}
}
if (accept == 0) {
return 0;
if (accept) {
return changed;
} else {
return changed + 1;
return CLIP_ELIMINATED;
}
}

12
geometry.cpp
View File

@ -663,14 +663,14 @@ drawvec clip_lines(drawvec &geom, int z, long long buffer) {
int c = clip(&x1, &y1, &x2, &y2, min, min, area, area);
if (c > 1) { // clipped
if (c == CLIP_ELIMINATED) {
out.push_back(draw(VT_MOVETO, geom[i].x, geom[i].y));
} else if (c == CLIP_OK) {
out.push_back(geom[i]);
} else {
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]);
@ -776,7 +776,7 @@ drawvec impose_tile_boundaries(drawvec &geom, long long extent) {
int c = clip(&x1, &y1, &x2, &y2, 0, 0, extent, extent);
if (c > 1) { // clipped
if (c & CLIP_CHANGED) {
if (x1 != geom[i - 1].x || y1 != geom[i - 1].y) {
out.push_back(draw(VT_LINETO, x1, y1));
out[out.size() - 1].necessary = 1;