path.cc

/**
 * This file is part of the "clip" project
 *   Copyright (c) 2018 Paul Asmuth
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <iostream>
#include "path.h"

namespace clip {

double PathData::operator[](size_t idx) const {
  return coefficients[idx];
}

Path::Path() {}

Path::Path(const PathData* data, size_t size) {
  data_.reserve(size);

  for (size_t i = 0; i < size; ++i) {
    data_.emplace_back(data[i]);
  }
}

void Path::moveTo(double x, double y) {
  PathData d;
  d.command = PathCommand::MOVE_TO;
  d.coefficients[0] = x;
  d.coefficients[1] = y;
  data_.emplace_back(std::move(d));
}

void Path::moveTo(const Point& p) {
  PathData d;
  d.command = PathCommand::MOVE_TO;
  d.coefficients[0] = p.x;
  d.coefficients[1] = p.y;
  data_.emplace_back(std::move(d));
}

void Path::lineTo(double x, double y) {
  PathData d;
  d.command = PathCommand::LINE_TO;
  d.coefficients[0] = x;
  d.coefficients[1] = y;
  data_.emplace_back(std::move(d));
}

void Path::lineTo(const Point& p) {
  PathData d;
  d.command = PathCommand::LINE_TO;
  d.coefficients[0] = p.x;
  d.coefficients[1] = p.y;
  data_.emplace_back(std::move(d));
}

void Path::quadraticCurveTo(double cx, double cy, double x, double y) {
  PathData d;
  d.command = PathCommand::QUADRATIC_CURVE_TO;
  d.coefficients[0] = cx;
  d.coefficients[1] = cy;
  d.coefficients[2] = x;
  d.coefficients[3] = y;
  data_.emplace_back(std::move(d));
}

void Path::cubicCurveTo(double c1x, double c1y, double c2x, double c2y, double x, double y) {
  PathData d;
  d.command = PathCommand::CUBIC_CURVE_TO;
  d.coefficients[0] = c1x;
  d.coefficients[1] = c1y;
  d.coefficients[2] = c2x;
  d.coefficients[3] = c2y;
  d.coefficients[4] = x;
  d.coefficients[5] = y;
  data_.emplace_back(std::move(d));
}

void Path::closePath() {
  PathData d;
  d.command = PathCommand::CLOSE;
  data_.emplace_back(std::move(d));
}

const PathData& Path::operator[](size_t idx) const {
  return data_[idx];
}

PathData& Path::operator[](size_t idx) {
  return data_[idx];
}

const PathData* Path::data() const {
  return &*data_.data();
}

PathData* Path::data() {
  return &*data_.data();
}

const PathData* Path::begin() const {
  return &*data_.begin();
}

PathData* Path::begin() {
  return &*data_.begin();
}

const PathData* Path::end() const {
  return &*data_.end();
}

PathData* Path::end() {
  return &*data_.end();
}

size_t Path::size() const {
  return data_.size();
}

bool Path::empty() const {
  return data_.size() == 0;
}

Polygon2 path_to_polygon_simple(const Path& path) {
  Polygon2 poly;

  for (size_t i = 0; i < path.size(); ++i) {
    const auto& cmd = path[i];

    switch (cmd.command) {
      case PathCommand::MOVE_TO:
      case PathCommand::LINE_TO:
        poly.vertices.emplace_back(cmd[0], cmd[1]);
        break;
      case PathCommand::QUADRATIC_CURVE_TO:
        poly.vertices.emplace_back(cmd[2], cmd[3]);
        break;
      case PathCommand::CUBIC_CURVE_TO:
        poly.vertices.emplace_back(cmd[4], cmd[5]);
        break;
      case PathCommand::CLOSE:
        continue;
    }
  }

  return poly;
}

Path path_from_polygon(const Polygon2& poly) {
  Path p;

  if (poly.vertices.empty()) {
    return p;
  }

  p.moveTo(poly.vertices[0].x, poly.vertices[0].y);

  for (size_t i = 1; i < poly.vertices.size(); ++i) {
    p.lineTo(poly.vertices[i].x, poly.vertices[i].y);
  }

  p.closePath();
  return p;
}

Path path_from_poly2(const Poly2& poly) {
  Path p;
  path_add_poly_ring(&p, poly.boundary);

  for (const auto& r : poly.holes) {
    path_add_poly_ring(&p, r);
  }

  return p;
}

Path path_transform(const Path& path, const mat3& transform) {
  Path path_out;

  for (const auto& cmd : path) {
    switch (cmd.command) {
      case PathCommand::MOVE_TO: {
        auto p0 = mul(transform, {cmd[0], cmd[1], 1.0});
        path_out.moveTo(p0.x, p0.y);
        break;
      }
      case PathCommand::LINE_TO: {
        auto p0 = mul(transform, {cmd[0], cmd[1], 1.0});
        path_out.lineTo(p0.x, p0.y);
        break;
      }
      case PathCommand::QUADRATIC_CURVE_TO: {
        auto p0 = mul(transform, {cmd[0], cmd[1], 1.0});
        auto p1 = mul(transform, {cmd[2], cmd[3], 1.0});
        path_out.quadraticCurveTo(p0.x, p0.y, p1.x, p1.y);
        break;
      }
      case PathCommand::CUBIC_CURVE_TO: {
        auto p0 = mul(transform, {cmd[0], cmd[1], 1.0});
        auto p1 = mul(transform, {cmd[2], cmd[3], 1.0});
        auto p2 = mul(transform, {cmd[4], cmd[5], 1.0});
        path_out.cubicCurveTo(p0.x, p0.y, p1.x, p1.y, p2.x, p2.y);
        break;
      }
      case PathCommand::CLOSE: {
        path_out.closePath();
        break;
      }
    }
  }

  return path_out;
}

void path_add_line(Path* path, vec2 from, vec2 to) {
  path->moveTo(from.x, from.y);
  path->lineTo(to.x, to.y);
}

void path_add_rectangle(Path* path, vec2 origin, vec2 size) {
  path->moveTo(
      origin.x + size.x / 2,
      origin.y + size.y / 2);

  path->lineTo(
      origin.x + size.x / 2,
      origin.y - size.y / 2);

  path->lineTo(
      origin.x - size.x / 2,
      origin.y - size.y / 2);

  path->lineTo(
      origin.x - size.x / 2,
      origin.y + size.y / 2);

  path->closePath();
}

void path_add_rectangle(Path* path, const Rectangle& box) {
  path->moveTo(box.x, box.y);
  path->lineTo(box.x, box.y + box.h);
  path->lineTo(box.x + box.w, box.y + box.h);
  path->lineTo(box.x + box.w, box.y);
  path->closePath();
}

void path_add_circle(Path* path, vec2 origin, double radius) {
  const double control_point_distance = 0.552284749831;

  path->moveTo(
      origin.x,
      origin.y - radius);

  path->cubicCurveTo(
      origin.x - radius * control_point_distance,
      origin.y - radius,
      origin.x - radius,
      origin.y - radius * control_point_distance,
      origin.x - radius,
      origin.y);

  path->cubicCurveTo(
      origin.x - radius,
      origin.y + radius * control_point_distance,
      origin.x - radius * control_point_distance,
      origin.y + radius,
      origin.x,
      origin.y + radius);

  path->cubicCurveTo(
      origin.x + radius * control_point_distance,
      origin.y + radius,
      origin.x + radius,
      origin.y + radius * control_point_distance,
      origin.x + radius,
      origin.y);

  path->cubicCurveTo(
      origin.x + radius,
      origin.y - radius * control_point_distance,
      origin.x + radius * control_point_distance,
      origin.y - radius,
      origin.x,
      origin.y - radius);

  path->closePath();
}

void path_add_poly_line(Path* path, const PolyLine2& line) {
  if (line.vertices.empty()) {
    return;
  }

  path->moveTo(line.vertices[0].x, line.vertices[0].y);

  for (size_t i = 1; i < line.vertices.size(); ++i) {
    path->lineTo(line.vertices[i].x, line.vertices[i].y);
  }
}

void path_add_poly_ring(Path* path, const PolyLine2& ring) {
  if (ring.vertices.empty()) {
    return;
  }

  path->moveTo(ring.vertices[0].x, ring.vertices[0].y);

  for (size_t i = 1; i < ring.vertices.size(); ++i) {
    path->lineTo(ring.vertices[i].x, ring.vertices[i].y);
  }

  path->closePath();
}

} // namespace clip