axmol/tests/cpp-tests/Source/Box2DTestBed/tests/tiles.cpp

// 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.

#include "test.h"

/// 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.
class Tiles : public Test
{
public:
    enum
    {
        e_count = 20
    };

    Tiles()
    {
        m_fixtureCount = 0;
        b2Timer timer;

        {
            float a = 0.5f;
            b2BodyDef bd;
            bd.position.y  = -a;
            b2Body* ground = m_world->CreateBody(&bd);

#if 1
            int32 N = 200;
            int32 M = 10;
            b2Vec2 position;
            position.y = 0.0f;
            for (int32 j = 0; j < M; ++j)
            {
                position.x = -N * a;
                for (int32 i = 0; i < N; ++i)
                {
                    b2PolygonShape shape;
                    shape.SetAsBox(a, a, position, 0.0f);
                    ground->CreateFixture(&shape, 0.0f);
                    ++m_fixtureCount;
                    position.x += 2.0f * a;
                }
                position.y -= 2.0f * a;
            }
#else
            int32 N = 200;
            int32 M = 10;
            b2Vec2 position;
            position.x = -N * a;
            for (int32 i = 0; i < N; ++i)
            {
                position.y = 0.0f;
                for (int32 j = 0; j < M; ++j)
                {
                    b2PolygonShape shape;
                    shape.SetAsBox(a, a, position, 0.0f);
                    ground->CreateFixture(&shape, 0.0f);
                    position.y -= 2.0f * a;
                }
                position.x += 2.0f * a;
            }
#endif
        }

        {
            float a = 0.5f;
            b2PolygonShape shape;
            shape.SetAsBox(a, a);

            b2Vec2 x(-7.0f, 0.75f);
            b2Vec2 y;
            b2Vec2 deltaX(0.5625f, 1.25f);
            b2Vec2 deltaY(1.125f, 0.0f);

            for (int32 i = 0; i < e_count; ++i)
            {
                y = x;

                for (int32 j = i; j < e_count; ++j)
                {
                    b2BodyDef bd;
                    bd.type     = b2_dynamicBody;
                    bd.position = y;

                    // if (i == 0 && j == 0)
                    //{
                    //	bd.allowSleep = false;
                    // }
                    // else
                    //{
                    //	bd.allowSleep = true;
                    // }

                    b2Body* body = m_world->CreateBody(&bd);
                    body->CreateFixture(&shape, 5.0f);
                    ++m_fixtureCount;
                    y += deltaY;
                }

                x += deltaX;
            }
        }

        m_createTime = timer.GetMilliseconds();
    }

    void Step(Settings& settings) override
    {
        const b2ContactManager& cm = m_world->GetContactManager();
        int32 height               = cm.m_broadPhase.GetTreeHeight();
        int32 leafCount            = cm.m_broadPhase.GetProxyCount();
        int32 minimumNodeCount     = 2 * leafCount - 1;
        float minimumHeight        = ceilf(logf(float(minimumNodeCount)) / logf(2.0f));
        DrawString(5, m_textLine, "dynamic tree height = %d, min = %d", height, int32(minimumHeight));

        Test::Step(settings);

        DrawString(5, m_textLine, "create time = %6.2f ms, fixture count = %d", m_createTime, m_fixtureCount);

        // b2DynamicTree* tree = &m_world->m_contactManager.m_broadPhase.m_tree;

        // if (m_stepCount == 400)
        //{
        //	tree->RebuildBottomUp();
        // }
    }

    static Test* Create() { return new Tiles; }

    int32 m_fixtureCount;
    float m_createTime;
};

static int testIndex = RegisterTest("Benchmark", "Tiles", Tiles::Create);