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// 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"
#include <algorithm>
// This test shows collision processing and tests
// deferred body destruction.
class CollisionProcessing : public Test
{
public:
CollisionProcessing()
{
// Ground body
{
b2EdgeShape shape;
shape.SetTwoSided(b2Vec2(-50.0f, 0.0f), b2Vec2(50.0f, 0.0f));
b2FixtureDef sd;
sd.shape = &shape;;
b2BodyDef bd;
b2Body* ground = m_world->CreateBody(&bd);
ground->CreateFixture(&sd);
}
float xLo = -5.0f, xHi = 5.0f;
float yLo = 2.0f, yHi = 35.0f;
// Small triangle
b2Vec2 vertices[3];
vertices[0].Set(-1.0f, 0.0f);
vertices[1].Set(1.0f, 0.0f);
vertices[2].Set(0.0f, 2.0f);
b2PolygonShape polygon;
polygon.Set(vertices, 3);
b2FixtureDef triangleShapeDef;
triangleShapeDef.shape = &polygon;
triangleShapeDef.density = 1.0f;
b2BodyDef triangleBodyDef;
triangleBodyDef.type = b2_dynamicBody;
triangleBodyDef.position.Set(RandomFloat(xLo, xHi), RandomFloat(yLo, yHi));
b2Body* body1 = m_world->CreateBody(&triangleBodyDef);
body1->CreateFixture(&triangleShapeDef);
// Large triangle (recycle definitions)
vertices[0] *= 2.0f;
vertices[1] *= 2.0f;
vertices[2] *= 2.0f;
polygon.Set(vertices, 3);
triangleBodyDef.position.Set(RandomFloat(xLo, xHi), RandomFloat(yLo, yHi));
b2Body* body2 = m_world->CreateBody(&triangleBodyDef);
body2->CreateFixture(&triangleShapeDef);
// Small box
polygon.SetAsBox(1.0f, 0.5f);
b2FixtureDef boxShapeDef;
boxShapeDef.shape = &polygon;
boxShapeDef.density = 1.0f;
b2BodyDef boxBodyDef;
boxBodyDef.type = b2_dynamicBody;
boxBodyDef.position.Set(RandomFloat(xLo, xHi), RandomFloat(yLo, yHi));
b2Body* body3 = m_world->CreateBody(&boxBodyDef);
body3->CreateFixture(&boxShapeDef);
// Large box (recycle definitions)
polygon.SetAsBox(2.0f, 1.0f);
boxBodyDef.position.Set(RandomFloat(xLo, xHi), RandomFloat(yLo, yHi));
b2Body* body4 = m_world->CreateBody(&boxBodyDef);
body4->CreateFixture(&boxShapeDef);
// Small circle
b2CircleShape circle;
circle.m_radius = 1.0f;
b2FixtureDef circleShapeDef;
circleShapeDef.shape = &circle;
circleShapeDef.density = 1.0f;
b2BodyDef circleBodyDef;
circleBodyDef.type = b2_dynamicBody;
circleBodyDef.position.Set(RandomFloat(xLo, xHi), RandomFloat(yLo, yHi));
b2Body* body5 = m_world->CreateBody(&circleBodyDef);
body5->CreateFixture(&circleShapeDef);
// Large circle
circle.m_radius *= 2.0f;
circleBodyDef.position.Set(RandomFloat(xLo, xHi), RandomFloat(yLo, yHi));
b2Body* body6 = m_world->CreateBody(&circleBodyDef);
body6->CreateFixture(&circleShapeDef);
}
void Step(Settings& settings) override
{
Test::Step(settings);
// We are going to destroy some bodies according to contact
// points. We must buffer the bodies that should be destroyed
// because they may belong to multiple contact points.
const int32 k_maxNuke = 6;
b2Body* nuke[k_maxNuke];
int32 nukeCount = 0;
// Traverse the contact results. Destroy bodies that
// are touching heavier bodies.
for (int32 i = 0; i < m_pointCount; ++i)
{
ContactPoint* point = m_points + i;
b2Body* body1 = point->fixtureA->GetBody();
b2Body* body2 = point->fixtureB->GetBody();
float mass1 = body1->GetMass();
float mass2 = body2->GetMass();
if (mass1 > 0.0f && mass2 > 0.0f)
{
if (mass2 > mass1)
{
nuke[nukeCount++] = body1;
}
else
{
nuke[nukeCount++] = body2;
}
if (nukeCount == k_maxNuke)
{
break;
}
}
}
// Sort the nuke array to group duplicates.
std::sort(nuke, nuke + nukeCount);
// Destroy the bodies, skipping duplicates.
int32 i = 0;
while (i < nukeCount)
{
b2Body* b = nuke[i++];
while (i < nukeCount && nuke[i] == b)
{
++i;
}
if (b != m_bomb)
{
m_world->DestroyBody(b);
}
}
}
static Test* Create()
{
return new CollisionProcessing;
}
};
static int testIndex = RegisterTest("Examples", "Collision Processing", CollisionProcessing::Create);
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