planck-js/example/Tiles.js

2D JavaScript physics engine for cross-platform HTML5 game development

/*
 * MIT License
 * Copyright (c) 2019 Erin Catto
 *
 * 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.
 */

// This stress tests the dynamic tree broad-phase. This also shows that tile
// based collision is _not_ smooth due to Box2D not knowing about adjacency.
planck.testbed('Tiles', function(testbed) {
  var pl = planck, Vec2 = pl.Vec2;
  var world = pl.World(Vec2(0, -10));

  var COUNT = 20;

  var fixtureCount = 0;

  var a = 0.5;
  var ground = world.createBody(Vec2(0, -a));

  if (1) {
    var N = 200;
    var M = 10;
    var position = Vec2();
    position.y = 0.0;
    for (var j = 0; j < M; ++j) {
      position.x = -N * a;
      for (var i = 0; i < N; ++i) {
        ground.createFixture(pl.Box(a, a, position, 0.0), 0.0);
        ++fixtureCount;
        position.x += 2.0 * a;
      }
      position.y -= 2.0 * a;
    }

  } else {
    var N = 200;
    var M = 10;
    var position = Vec2();
    position.x = -N * a;
    for (var i = 0; i < N; ++i) {
      position.y = 0.0;
      for (var j = 0; j < M; ++j) {
        ground.createFixture(pl.Box(a, a, position, 0.0), 0.0);
        position.y -= 2.0 * a;
      }
      position.x += 2.0 * a;
    }
  }

  var a = 0.5;
  var shape = pl.Box(a, a);

  var x = Vec2(-7.0, 0.75);
  var y = Vec2();
  var deltaX = Vec2(0.5625, 1.25);
  var deltaY = Vec2(1.125, 0.0);

  for (var i = 0; i < COUNT; ++i) {
    y.set(x);

    for (var j = i; j < COUNT; ++j) {

      // bd.allowSleep = !(i == 0 && j == 0)

      var body = world.createDynamicBody(y);
      body.createFixture(shape, 5.0);
      ++fixtureCount;
      y.add(deltaY);
    }

    x.add(deltaX);
  }

  var createTime = Date.now();

  testbed.step = function() {
    var height = world.getTreeHeight();
    var leafCount = world.getProxyCount();
    var minimumNodeCount = 2 * leafCount - 1;
    var minimumHeight = Math.ceil(Math.log(minimumNodeCount) / Math.log(2.0));

    testbed.status("dynamic tree height", height);
    testbed.status("min", minimumHeight);
    testbed.status("create time", createTime + "ms");
    testbed.status("fixture count", fixtureCount);

    // var tree = world.m_broadPhase.m_tree;
    // if (stepCount++ == 400) {
    // tree.rebuildBottomUp();
    // }
  };

  return world;
});