godot/core/math/geometry_2d.cpp

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/*************************************************************************/
2020-06-25 22:33:44 +08:00
/* geometry_2d.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "geometry_2d.h"
#include "thirdparty/misc/clipper.hpp"
#include "thirdparty/misc/polypartition.h"
#define STB_RECT_PACK_IMPLEMENTATION
#include "thirdparty/misc/stb_rect_pack.h"
#define SCALE_FACTOR 100000.0 // Based on CMP_EPSILON.
Vector<Vector<Vector2>> Geometry2D::decompose_polygon_in_convex(Vector<Point2> polygon) {
Vector<Vector<Vector2>> decomp;
List<TPPLPoly> in_poly, out_poly;
TPPLPoly inp;
inp.Init(polygon.size());
for (int i = 0; i < polygon.size(); i++) {
inp.GetPoint(i) = polygon[i];
}
inp.SetOrientation(TPPL_ORIENTATION_CCW);
in_poly.push_back(inp);
TPPLPartition tpart;
if (tpart.ConvexPartition_HM(&in_poly, &out_poly) == 0) { // Failed.
ERR_PRINT("Convex decomposing failed!");
return decomp;
}
decomp.resize(out_poly.size());
int idx = 0;
for (List<TPPLPoly>::Element *I = out_poly.front(); I; I = I->next()) {
TPPLPoly &tp = I->get();
decomp.write[idx].resize(tp.GetNumPoints());
for (int64_t i = 0; i < tp.GetNumPoints(); i++) {
decomp.write[idx].write[i] = tp.GetPoint(i);
}
idx++;
}
return decomp;
}
struct _AtlasWorkRect {
Size2i s;
Point2i p;
int idx = 0;
_FORCE_INLINE_ bool operator<(const _AtlasWorkRect &p_r) const { return s.width > p_r.s.width; };
};
struct _AtlasWorkRectResult {
Vector<_AtlasWorkRect> result;
int max_w = 0;
int max_h = 0;
};
void Geometry2D::make_atlas(const Vector<Size2i> &p_rects, Vector<Point2i> &r_result, Size2i &r_size) {
// Super simple, almost brute force scanline stacking fitter.
// It's pretty basic for now, but it tries to make sure that the aspect ratio of the
// resulting atlas is somehow square. This is necessary because video cards have limits
// on texture size (usually 2048 or 4096), so the squarer a texture, the more the chances
// that it will work in every hardware.
// For example, it will prioritize a 1024x1024 atlas (works everywhere) instead of a
// 256x8192 atlas (won't work anywhere).
ERR_FAIL_COND(p_rects.size() == 0);
for (int i = 0; i < p_rects.size(); i++) {
ERR_FAIL_COND(p_rects[i].width <= 0);
ERR_FAIL_COND(p_rects[i].height <= 0);
}
Vector<_AtlasWorkRect> wrects;
wrects.resize(p_rects.size());
for (int i = 0; i < p_rects.size(); i++) {
wrects.write[i].s = p_rects[i];
wrects.write[i].idx = i;
}
wrects.sort();
int widest = wrects[0].s.width;
Vector<_AtlasWorkRectResult> results;
for (int i = 0; i <= 12; i++) {
int w = 1 << i;
int max_h = 0;
int max_w = 0;
if (w < widest) {
continue;
}
Vector<int> hmax;
hmax.resize(w);
for (int j = 0; j < w; j++) {
hmax.write[j] = 0;
}
// Place them.
int ofs = 0;
int limit_h = 0;
for (int j = 0; j < wrects.size(); j++) {
if (ofs + wrects[j].s.width > w) {
ofs = 0;
}
int from_y = 0;
for (int k = 0; k < wrects[j].s.width; k++) {
if (hmax[ofs + k] > from_y) {
from_y = hmax[ofs + k];
}
}
wrects.write[j].p.x = ofs;
wrects.write[j].p.y = from_y;
int end_h = from_y + wrects[j].s.height;
int end_w = ofs + wrects[j].s.width;
if (ofs == 0) {
limit_h = end_h;
}
for (int k = 0; k < wrects[j].s.width; k++) {
hmax.write[ofs + k] = end_h;
}
if (end_h > max_h) {
max_h = end_h;
}
if (end_w > max_w) {
max_w = end_w;
}
if (ofs == 0 || end_h > limit_h) { // While h limit not reached, keep stacking.
ofs += wrects[j].s.width;
}
}
_AtlasWorkRectResult result;
result.result = wrects;
result.max_h = max_h;
result.max_w = max_w;
results.push_back(result);
}
// Find the result with the best aspect ratio.
int best = -1;
real_t best_aspect = 1e20;
for (int i = 0; i < results.size(); i++) {
real_t h = next_power_of_2(results[i].max_h);
real_t w = next_power_of_2(results[i].max_w);
real_t aspect = h > w ? h / w : w / h;
if (aspect < best_aspect) {
best = i;
best_aspect = aspect;
}
}
r_result.resize(p_rects.size());
for (int i = 0; i < p_rects.size(); i++) {
r_result.write[results[best].result[i].idx] = results[best].result[i].p;
}
r_size = Size2(results[best].max_w, results[best].max_h);
}
Vector<Vector<Point2>> Geometry2D::_polypaths_do_operation(PolyBooleanOperation p_op, const Vector<Point2> &p_polypath_a, const Vector<Point2> &p_polypath_b, bool is_a_open) {
using namespace ClipperLib;
ClipType op = ctUnion;
switch (p_op) {
case OPERATION_UNION:
op = ctUnion;
break;
case OPERATION_DIFFERENCE:
op = ctDifference;
break;
case OPERATION_INTERSECTION:
op = ctIntersection;
break;
case OPERATION_XOR:
op = ctXor;
break;
}
Path path_a, path_b;
// Need to scale points (Clipper's requirement for robust computation).
for (int i = 0; i != p_polypath_a.size(); ++i) {
path_a << IntPoint(p_polypath_a[i].x * (real_t)SCALE_FACTOR, p_polypath_a[i].y * (real_t)SCALE_FACTOR);
}
for (int i = 0; i != p_polypath_b.size(); ++i) {
path_b << IntPoint(p_polypath_b[i].x * (real_t)SCALE_FACTOR, p_polypath_b[i].y * (real_t)SCALE_FACTOR);
}
Clipper clp;
clp.AddPath(path_a, ptSubject, !is_a_open); // Forward compatible with Clipper 10.0.0.
clp.AddPath(path_b, ptClip, true); // Polylines cannot be set as clip.
Paths paths;
if (is_a_open) {
PolyTree tree; // Needed to populate polylines.
clp.Execute(op, tree);
OpenPathsFromPolyTree(tree, paths);
} else {
clp.Execute(op, paths); // Works on closed polygons only.
}
// Have to scale points down now.
Vector<Vector<Point2>> polypaths;
for (Paths::size_type i = 0; i < paths.size(); ++i) {
Vector<Vector2> polypath;
const Path &scaled_path = paths[i];
for (Paths::size_type j = 0; j < scaled_path.size(); ++j) {
polypath.push_back(Point2(
static_cast<real_t>(scaled_path[j].X) / (real_t)SCALE_FACTOR,
static_cast<real_t>(scaled_path[j].Y) / (real_t)SCALE_FACTOR));
}
polypaths.push_back(polypath);
}
return polypaths;
}
Vector<Vector<Point2>> Geometry2D::_polypath_offset(const Vector<Point2> &p_polypath, real_t p_delta, PolyJoinType p_join_type, PolyEndType p_end_type) {
using namespace ClipperLib;
JoinType jt = jtSquare;
switch (p_join_type) {
case JOIN_SQUARE:
jt = jtSquare;
break;
case JOIN_ROUND:
jt = jtRound;
break;
case JOIN_MITER:
jt = jtMiter;
break;
}
EndType et = etClosedPolygon;
switch (p_end_type) {
case END_POLYGON:
et = etClosedPolygon;
break;
case END_JOINED:
et = etClosedLine;
break;
case END_BUTT:
et = etOpenButt;
break;
case END_SQUARE:
et = etOpenSquare;
break;
case END_ROUND:
et = etOpenRound;
break;
}
ClipperOffset co(2.0, 0.25f * (real_t)SCALE_FACTOR); // Defaults from ClipperOffset.
Path path;
// Need to scale points (Clipper's requirement for robust computation).
for (int i = 0; i != p_polypath.size(); ++i) {
path << IntPoint(p_polypath[i].x * (real_t)SCALE_FACTOR, p_polypath[i].y * (real_t)SCALE_FACTOR);
}
co.AddPath(path, jt, et);
Paths paths;
co.Execute(paths, p_delta * (real_t)SCALE_FACTOR); // Inflate/deflate.
// Have to scale points down now.
Vector<Vector<Point2>> polypaths;
for (Paths::size_type i = 0; i < paths.size(); ++i) {
Vector<Vector2> polypath;
const Path &scaled_path = paths[i];
for (Paths::size_type j = 0; j < scaled_path.size(); ++j) {
polypath.push_back(Point2(
static_cast<real_t>(scaled_path[j].X) / (real_t)SCALE_FACTOR,
static_cast<real_t>(scaled_path[j].Y) / (real_t)SCALE_FACTOR));
}
polypaths.push_back(polypath);
}
return polypaths;
}
Vector<Point2i> Geometry2D::pack_rects(const Vector<Size2i> &p_sizes, const Size2i &p_atlas_size) {
Vector<stbrp_node> nodes;
nodes.resize(p_atlas_size.width);
stbrp_context context;
stbrp_init_target(&context, p_atlas_size.width, p_atlas_size.height, nodes.ptrw(), p_atlas_size.width);
Vector<stbrp_rect> rects;
rects.resize(p_sizes.size());
for (int i = 0; i < p_sizes.size(); i++) {
rects.write[i].id = 0;
rects.write[i].w = p_sizes[i].width;
rects.write[i].h = p_sizes[i].height;
rects.write[i].x = 0;
rects.write[i].y = 0;
rects.write[i].was_packed = 0;
}
int res = stbrp_pack_rects(&context, rects.ptrw(), rects.size());
if (res == 0) { //pack failed
return Vector<Point2i>();
}
Vector<Point2i> ret;
ret.resize(p_sizes.size());
for (int i = 0; i < p_sizes.size(); i++) {
Point2i r(rects[i].x, rects[i].y);
ret.write[i] = r;
}
return ret;
}
Vector<Vector3i> Geometry2D::partial_pack_rects(const Vector<Vector2i> &p_sizes, const Size2i &p_atlas_size) {
Vector<stbrp_node> nodes;
nodes.resize(p_atlas_size.width);
memset(nodes.ptrw(), 0, sizeof(stbrp_node) * nodes.size());
stbrp_context context;
stbrp_init_target(&context, p_atlas_size.width, p_atlas_size.height, nodes.ptrw(), p_atlas_size.width);
Vector<stbrp_rect> rects;
rects.resize(p_sizes.size());
for (int i = 0; i < p_sizes.size(); i++) {
rects.write[i].id = i;
rects.write[i].w = p_sizes[i].width;
rects.write[i].h = p_sizes[i].height;
rects.write[i].x = 0;
rects.write[i].y = 0;
rects.write[i].was_packed = 0;
}
stbrp_pack_rects(&context, rects.ptrw(), rects.size());
Vector<Vector3i> ret;
ret.resize(p_sizes.size());
for (int i = 0; i < p_sizes.size(); i++) {
ret.write[rects[i].id] = Vector3i(rects[i].x, rects[i].y, rects[i].was_packed != 0 ? 1 : 0);
}
return ret;
}