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/*
* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#ifndef COLLISION_PROCESSING_H
#define COLLISION_PROCESSING_H
#include <algorithm>
// This test shows collision processing and tests
// deferred body destruction.
class CollisionProcessing : public Test
{
public:
CollisionProcessing()
{
// Ground body
{
b2EdgeShape shape;
shape.Set(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);
}
float32 xLo = -5.0f, xHi = 5.0f;
float32 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)
{
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();
float32 mass1 = body1->GetMass();
float32 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;
}
};
#endif
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