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tippecanoe/mapbox/geometry/wagyu/intersect_util.hpp
Eric Fischer bdac4d4e80 Upgrade Wagyu to bfbf2893
2017-01-04 16:33:43 -08:00

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#pragma once
#include <mapbox/geometry/wagyu/active_bound_list.hpp>
#include <mapbox/geometry/wagyu/bound.hpp>
#include <mapbox/geometry/wagyu/config.hpp>
#include <mapbox/geometry/wagyu/intersect.hpp>
#include <mapbox/geometry/wagyu/ring_util.hpp>
#include <mapbox/geometry/wagyu/util.hpp>
namespace mapbox {
namespace geometry {
namespace wagyu {
template <typename T>
struct intersect_list_sorter {
inline bool operator()(intersect_node<T> const& node1, intersect_node<T> const& node2) {
if (!values_are_equal(node2.pt.y, node1.pt.y)) {
return node2.pt.y < node1.pt.y;
} else {
return ((*node2.bound1)->winding_count2 + (*node2.bound2)->winding_count2) >
((*node1.bound1)->winding_count2 + (*node1.bound2)->winding_count2);
}
}
};
template <typename T>
inline mapbox::geometry::point<T> round_point(mapbox::geometry::point<double> const& pt) {
return mapbox::geometry::point<T>(round_towards_max<T>(pt.x), round_towards_max<T>(pt.y));
}
template <typename T>
inline void swap_rings(bound<T>& b1, bound<T>& b2) {
ring_ptr<T> ring = b1.ring;
b1.ring = b2.ring;
b2.ring = ring;
}
template <typename T>
inline void swap_sides(bound<T>& b1, bound<T>& b2) {
edge_side side = b1.side;
b1.side = b2.side;
b2.side = side;
}
template <typename T1, typename T2>
bool get_edge_intersection(edge<T1> const& e1,
edge<T1> const& e2,
mapbox::geometry::point<T2>& pt) {
T2 p0_x = static_cast<T2>(e1.bot.x);
T2 p0_y = static_cast<T2>(e1.bot.y);
T2 p1_x = static_cast<T2>(e1.top.x);
T2 p1_y = static_cast<T2>(e1.top.y);
T2 p2_x = static_cast<T2>(e2.bot.x);
T2 p2_y = static_cast<T2>(e2.bot.y);
T2 p3_x = static_cast<T2>(e2.top.x);
T2 p3_y = static_cast<T2>(e2.top.y);
T2 s1_x, s1_y, s2_x, s2_y;
s1_x = p1_x - p0_x;
s1_y = p1_y - p0_y;
s2_x = p3_x - p2_x;
s2_y = p3_y - p2_y;
T2 s, 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);
if (s >= 0.0 && s <= 1.0 && t >= 0.0 && t <= 1.0) {
pt.x = p0_x + (t * s1_x);
pt.y = p0_y + (t * s1_y);
return true;
}
// LCOV_EXCL_START
return false;
// LCOV_EXCL_END
}
template <typename T>
void build_intersect_list(active_bound_list<T>& active_bounds, intersect_list<T>& intersects) {
// bubblesort ...
bool isModified = false;
do {
isModified = false;
auto bnd = active_bounds.begin();
auto bnd_next = std::next(bnd);
while (bnd_next != active_bounds.end()) {
if ((*bnd)->current_x > (*bnd_next)->current_x &&
!slopes_equal(*((*bnd)->current_edge), *((*bnd_next)->current_edge))) {
mapbox::geometry::point<double> pt;
if (!get_edge_intersection<T, double>(*((*bnd)->current_edge),
*((*bnd_next)->current_edge), pt)) {
// LCOV_EXCL_START
throw std::runtime_error(
"Trying to find intersection of lines that do not intersect");
// LCOV_EXCL_END
}
intersects.emplace_back(bnd, bnd_next, pt);
swap_positions_in_ABL(bnd, bnd_next, active_bounds);
bnd_next = std::next(bnd);
isModified = true;
} else {
bnd = bnd_next;
++bnd_next;
}
}
} while (isModified);
}
template <typename T>
void intersect_bounds(active_bound_list_itr<T>& b1,
active_bound_list_itr<T>& b2,
mapbox::geometry::point<T> const& pt,
clip_type cliptype,
fill_type subject_fill_type,
fill_type clip_fill_type,
ring_manager<T>& rings,
active_bound_list<T>& active_bounds) {
bool b1Contributing = ((*b1)->ring != nullptr);
bool b2Contributing = ((*b2)->ring != nullptr);
// update winding counts...
// assumes that b1 will be to the Right of b2 ABOVE the intersection
if ((*b1)->poly_type == (*b2)->poly_type) {
if (is_even_odd_fill_type(*(*b1), subject_fill_type, clip_fill_type)) {
std::int32_t oldE1winding_count = (*b1)->winding_count;
(*b1)->winding_count = (*b2)->winding_count;
(*b2)->winding_count = oldE1winding_count;
} else {
if ((*b1)->winding_count + (*b2)->winding_delta == 0) {
(*b1)->winding_count = -(*b1)->winding_count;
} else {
(*b1)->winding_count += (*b2)->winding_delta;
}
if ((*b2)->winding_count - (*b1)->winding_delta == 0) {
(*b2)->winding_count = -(*b2)->winding_count;
} else {
(*b2)->winding_count -= (*b1)->winding_delta;
}
}
} else {
if (!is_even_odd_fill_type(*(*b2), subject_fill_type, clip_fill_type)) {
(*b1)->winding_count2 += (*b2)->winding_delta;
} else {
(*b1)->winding_count2 = ((*b1)->winding_count2 == 0) ? 1 : 0;
}
if (!is_even_odd_fill_type(*(*b1), subject_fill_type, clip_fill_type)) {
(*b2)->winding_count2 -= (*b1)->winding_delta;
} else {
(*b2)->winding_count2 = ((*b2)->winding_count2 == 0) ? 1 : 0;
}
}
fill_type b1FillType, b2FillType, b1FillType2, b2FillType2;
if ((*b1)->poly_type == polygon_type_subject) {
b1FillType = subject_fill_type;
b1FillType2 = clip_fill_type;
} else {
b1FillType = clip_fill_type;
b1FillType2 = subject_fill_type;
}
if ((*b2)->poly_type == polygon_type_subject) {
b2FillType = subject_fill_type;
b2FillType2 = clip_fill_type;
} else {
b2FillType = clip_fill_type;
b2FillType2 = subject_fill_type;
}
std::int32_t b1Wc, b2Wc;
switch (b1FillType) {
case fill_type_positive:
b1Wc = (*b1)->winding_count;
break;
case fill_type_negative:
b1Wc = -(*b1)->winding_count;
break;
case fill_type_even_odd:
case fill_type_non_zero:
default:
b1Wc = std::abs(static_cast<int>((*b1)->winding_count));
}
switch (b2FillType) {
case fill_type_positive:
b2Wc = (*b2)->winding_count;
break;
case fill_type_negative:
b2Wc = -(*b2)->winding_count;
break;
case fill_type_even_odd:
case fill_type_non_zero:
default:
b2Wc = std::abs(static_cast<int>((*b2)->winding_count));
}
if (b1Contributing && b2Contributing) {
if ((b1Wc != 0 && b1Wc != 1) || (b2Wc != 0 && b2Wc != 1) ||
((*b1)->poly_type != (*b2)->poly_type && cliptype != clip_type_x_or)) {
add_local_maximum_point(b1, b2, pt, rings, active_bounds);
} else {
add_point(b1, active_bounds, pt, rings);
add_point(b2, active_bounds, pt, rings);
swap_sides(*(*b1), *(*b2));
swap_rings(*(*b1), *(*b2));
}
} else if (b1Contributing) {
if (b2Wc == 0 || b2Wc == 1) {
add_point(b1, active_bounds, pt, rings);
(*b2)->last_point = pt;
swap_sides(*(*b1), *(*b2));
swap_rings(*(*b1), *(*b2));
}
} else if (b2Contributing) {
if (b1Wc == 0 || b1Wc == 1) {
(*b1)->last_point = pt;
add_point(b2, active_bounds, pt, rings);
swap_sides(*(*b1), *(*b2));
swap_rings(*(*b1), *(*b2));
}
} else if ((b1Wc == 0 || b1Wc == 1) && (b2Wc == 0 || b2Wc == 1)) {
// neither bound is currently contributing ...
std::int32_t b1Wc2, b2Wc2;
switch (b1FillType2) {
case fill_type_positive:
b1Wc2 = (*b1)->winding_count2;
break;
case fill_type_negative:
b1Wc2 = -(*b1)->winding_count2;
break;
case fill_type_even_odd:
case fill_type_non_zero:
default:
b1Wc2 = std::abs(static_cast<int>((*b1)->winding_count2));
}
switch (b2FillType2) {
case fill_type_positive:
b2Wc2 = (*b2)->winding_count2;
break;
case fill_type_negative:
b2Wc2 = -(*b2)->winding_count2;
break;
case fill_type_even_odd:
case fill_type_non_zero:
default:
b2Wc2 = std::abs(static_cast<int>((*b2)->winding_count2));
}
if ((*b1)->poly_type != (*b2)->poly_type) {
add_local_minimum_point(b1, b2, active_bounds, pt, rings);
} else if (b1Wc == 1 && b2Wc == 1) {
switch (cliptype) {
case clip_type_intersection:
if (b1Wc2 > 0 && b2Wc2 > 0) {
add_local_minimum_point(b1, b2, active_bounds, pt, rings);
}
break;
default:
case clip_type_union:
if (b1Wc2 <= 0 && b2Wc2 <= 0) {
add_local_minimum_point(b1, b2, active_bounds, pt, rings);
}
break;
case clip_type_difference:
if ((((*b1)->poly_type == polygon_type_clip) && (b1Wc2 > 0) && (b2Wc2 > 0)) ||
(((*b1)->poly_type == polygon_type_subject) && (b1Wc2 <= 0) && (b2Wc2 <= 0))) {
add_local_minimum_point(b1, b2, active_bounds, pt, rings);
}
break;
case clip_type_x_or:
add_local_minimum_point(b1, b2, active_bounds, pt, rings);
}
} else {
swap_sides(*(*b1), *(*b2));
}
}
}
template <typename T>
bool bounds_adjacent(intersect_node<T> const& inode) {
return (std::next(inode.bound1) == inode.bound2) || (std::next(inode.bound2) == inode.bound1);
}
template <typename T>
void process_intersect_list(intersect_list<T>& intersects,
clip_type cliptype,
fill_type subject_fill_type,
fill_type clip_fill_type,
ring_manager<T>& rings,
active_bound_list<T>& active_bounds) {
for (auto node_itr = intersects.begin(); node_itr != intersects.end(); ++node_itr) {
if (!bounds_adjacent(*node_itr)) {
auto next_itr = std::next(node_itr);
while (next_itr != intersects.end() && !bounds_adjacent(*next_itr)) {
++next_itr;
}
if (next_itr == intersects.end()) {
throw std::runtime_error("Could not properly correct intersection order.");
}
std::iter_swap(node_itr, next_itr);
}
mapbox::geometry::point<T> pt = round_point<T>(node_itr->pt);
intersect_bounds(node_itr->bound1, node_itr->bound2, pt, cliptype, subject_fill_type,
clip_fill_type, rings, active_bounds);
swap_positions_in_ABL(node_itr->bound1, node_itr->bound2, active_bounds);
}
}
template <typename T>
void update_current_x(active_bound_list<T>& active_bounds, T top_y) {
std::size_t pos = 0;
for (auto& bnd : active_bounds) {
bnd->pos = pos++;
bnd->current_x = get_current_x(*bnd->current_edge, top_y);
}
}
template <typename T>
void process_intersections(T top_y,
active_bound_list<T>& active_bounds,
clip_type cliptype,
fill_type subject_fill_type,
fill_type clip_fill_type,
ring_manager<T>& rings) {
if (active_bounds.empty()) {
return;
}
update_current_x(active_bounds, top_y);
intersect_list<T> intersects;
build_intersect_list(active_bounds, intersects);
if (intersects.empty()) {
return;
}
// Restore order of active bounds list
active_bounds.sort(
[](bound_ptr<T> const& b1, bound_ptr<T> const& b2) { return b1->pos < b2->pos; });
// Sort the intersection list
std::stable_sort(intersects.begin(), intersects.end(), intersect_list_sorter<T>());
process_intersect_list(intersects, cliptype, subject_fill_type, clip_fill_type, rings,
active_bounds);
}
}
}
}
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