void debug_draw_shape(std::vector<debug_line>& lines, const rgba col, const b2PolygonShape& sh, vec2 pos) {
const auto n = sh.GetVertexCount();
for (int i = 0; i < n; ++i) {
lines.emplace_back(col, pos + sh.GetVertex(i), pos + sh.GetVertex((i + 1) % n));
}
}
bool CollidableTemplate::ConfigureBox(const TiXmlElement *element, b2PolygonShape &shape)
{
// half-width and half-height
float w = 0, h = 0;
element->QueryFloatAttribute("w", &w);
element->QueryFloatAttribute("h", &h);
// center and rotation
b2Vec2 center(0.0f, 0.0f);
float rotation = 0.0f;
// process child elements
for (const TiXmlElement *child = element->FirstChildElement(); child != NULL; child = child->NextSiblingElement())
{
switch (Hash(child->Value()))
{
case 0x934f4e0a /* "position" */:
element->QueryFloatAttribute("x", ¢er.x);
element->QueryFloatAttribute("y", ¢er.y);
if (element->QueryFloatAttribute("angle", &rotation) == TIXML_SUCCESS)
rotation *= float(M_PI)/180.0f;
break;
}
}
shape.SetAsBox(w, h, center, rotation);
return true;
}
bool wyBox2DCollisionDetector::isCollided(wyRect& r1, wyRect& r2, wyBox2DCDResult* result) {
// init transform 1
sRectTrans1.SetIdentity();
b2Vec2 v;
v.x = pixel2Meter(r1.x + r1.width / 2);
v.y = pixel2Meter(r1.y + r1.height / 2);
sRectTrans1.Set(v, 0);
// init transform 2
sRectTrans2.SetIdentity();
v.x = pixel2Meter(r2.x + r2.width / 2);
v.y = pixel2Meter(r2.y + r2.height / 2);
sRectTrans2.Set(v, 0);
// init shape 1
sRectPoly1.SetAsBox(pixel2Meter(r1.width) / 2, pixel2Meter(r1.height) / 2);
// init shape 2
sRectPoly2.SetAsBox(pixel2Meter(r2.width) / 2, pixel2Meter(r2.height) / 2);
// collision detection
b2Manifold manifold;
b2CollidePolygons(&manifold, &sRectPoly1, sRectTrans1, &sRectPoly2, sRectTrans2);
// to world coordinates
if(manifold.pointCount > 0) {
// write data back
if(result) {
// convert to world coordinate
b2WorldManifold worldManifold;
worldManifold.Initialize(&manifold, sRectTrans1, sRectPoly1.m_radius, sRectTrans2, sRectPoly2.m_radius);
result->pointCount = manifold.pointCount;
for(int i = 0; i < manifold.pointCount; i++) {
result->points[i] = wyp(meter2Pixel(worldManifold.points[i].x), meter2Pixel(worldManifold.points[i].y));
}
result->normal = wyp(worldManifold.normal.x, worldManifold.normal.y);
}
}
return manifold.pointCount > 0;
}
static void set_polygon_shape( const World& trans,
const float l, const float t, const float r, const float b,
b2PolygonShape& out) {
const b2Vec2 lt = trans.Ci2BoxTranslation(ci::Vec3f(l, t, 0.0f), nullptr); // using nullptr for the sprite will make the polygon be in world space
const b2Vec2 rb = trans.Ci2BoxTranslation(ci::Vec3f(r, b, 0.0f), nullptr);
b2Vec2 vtx[4];
vtx[0].Set(lt.x, lt.y);
vtx[1].Set(rb.x, lt.y);
vtx[2].Set(rb.x, rb.y);
vtx[3].Set(lt.x, rb.y);
out.Set(vtx, 4);
}
bool CollidableTemplate::ConfigurePoly(const TiXmlElement *element, b2PolygonShape &shape)
{
// process child elements
for (const TiXmlElement *child = element->FirstChildElement(); child != NULL; child = child->NextSiblingElement())
{
ConfigurePolyItem(child, shape);
}
// update other properties
shape.Set(shape.m_vertices, shape.m_vertexCount);
return true;
}
bool CollidableTemplate::ConfigureEdge(const TiXmlElement *element, b2PolygonShape &shape)
{
// process child elements
for (const TiXmlElement *child = element->FirstChildElement(); child != NULL; child = child->NextSiblingElement())
{
const char *name = child->Value();
switch (Hash(name))
{
case 0x154c1122 /* "vertex1" */:
child->QueryFloatAttribute("x", &shape.m_vertices[0].x);
child->QueryFloatAttribute("y", &shape.m_vertices[0].y);
break;
case 0x144c0f8f /* "vertex2" */:
child->QueryFloatAttribute("x", &shape.m_vertices[1].x);
child->QueryFloatAttribute("y", &shape.m_vertices[1].y);
break;
}
}
shape.SetAsEdge(shape.m_vertices[0], shape.m_vertices[1]);
return true;
}
void CreateWorld() {
// Define the gravity vector.
b2Vec2 gravity(0.0f, 5.0f);
// Construct a world object, which will hold and simulate the rigid bodies.
world = new b2World(gravity);
// Define the dynamic body. We set its position and call the body factory.
b2BodyDef bodyDef;
bodyDef.type = b2_dynamicBody;
bodyDef.position.Set(cubeStart.x * SCALE + 25 ,cubeStart.y * SCALE + 50);
b2Body* body = world->CreateBody(&bodyDef);
bodyDef.awake = false;
// Define another box shape for our dynamic body.
b2PolygonShape dynamicBox;
dynamicBox.SetAsBox(100.0f*0.5f, 10.0f*0.5f);
// Define the dynamic body fixture.
b2FixtureDef fixtureDef;
fixtureDef.shape = &dynamicBox;
fixtureDef.restitution = 0.01f;
// Set the box density to be non-zero, so it will be dynamic.
fixtureDef.density = 3.0f;
// Override the default friction.
fixtureDef.friction = 0.01f;
// Add the shape to the body.
body->CreateFixture(&fixtureDef);
b2BodyDef bodyDefcircle;
bodyDefcircle.type = b2_dynamicBody;
bodyDefcircle.position.Set(25,100);
b2Body* circleBody = world->CreateBody(&bodyDefcircle);
b2FixtureDef circlefixtureDef;
b2CircleShape dynamicCircle;
dynamicCircle.m_radius = 20;
dynamicCircle.m_p.Set(0,0);
circlefixtureDef.shape = &dynamicCircle;
circlefixtureDef.restitution = 0.1f;
// Set the box density to be non-zero, so it will be dynamic.
circlefixtureDef.density = 1.0f;
// Override the default friction.
circlefixtureDef.friction = 0.8f;
// Add the shape to the body.
circleBody->CreateFixture(&circlefixtureDef);
b2RevoluteJointDef joint;
joint.Initialize(body,circleBody, b2Vec2(25,100));
joint.enableMotor = true;
joint.motorSpeed = 200;
joint.maxMotorTorque = 100000;
world->CreateJoint(&joint);
b2BodyDef bodyDefcircle2;
bodyDefcircle2.type = b2_dynamicBody;
bodyDefcircle2.position.Set(125,100);
b2Body* circleBody2 = world->CreateBody(&bodyDefcircle2);
b2FixtureDef circlefixtureDef2;
b2CircleShape dynamicCircle2;
dynamicCircle2.m_radius = 20;
dynamicCircle2.m_p.Set(0,0);
circlefixtureDef2.shape = &dynamicCircle;
circlefixtureDef2.restitution = 0.1f;
// Set the box density to be non-zero, so it will be dynamic.
circlefixtureDef2.density = 1.0f;
// Override the default friction.
circlefixtureDef2.friction = 0.8f;
// Add the shape to the body.
circleBody2->CreateFixture(&circlefixtureDef2);
joint.Initialize(body,circleBody2, b2Vec2(125,100));
joint.enableMotor = true;
joint.motorSpeed = 200;
joint.maxMotorTorque = 100000;
world->CreateJoint(&joint);
}
bool wyBox2DCollisionDetector::isCollided(wyNode* node, wyRect& r, wyBox2DCDResult* result) {
// init transform 2
sRectTrans2.SetIdentity();
b2Vec2 v;
v.x = pixel2Meter(r.x + r.width / 2);
v.y = pixel2Meter(r.y + r.height / 2);
sRectTrans2.Set(v, 0);
// init shape 2
sRectPoly2.SetAsBox(pixel2Meter(r.width) / 2, pixel2Meter(r.height) / 2);
// get node hash, if not, add it
wyNodeHash* hash = (wyNodeHash*)wyHashSetFind(m_nodeShapes, (size_t)node, node);
if(hash == NULL)
hash = addNode(node);
// update node1 transform
wyPoint pos = node->nodeToWorldSpace(wyp(node->getWidth() / 2, node->getHeight() / 2));
v.x = pixel2Meter(pos.x);
v.y = pixel2Meter(pos.y);
float angle = -wyMath::d2r(node->getRotation());
hash->transform.Set(v, angle);
// collision detection
bool reverseNormal = false;
b2Manifold manifold;
switch(hash->type) {
case b2Shape::e_polygon:
b2CollidePolygons(&manifold, &hash->poly, hash->transform, &sRectPoly2, sRectTrans2);
break;
case b2Shape::e_circle:
b2CollidePolygonAndCircle(&manifold, &sRectPoly2, sRectTrans2, &hash->circle, hash->transform);
reverseNormal = true;
break;
}
// to world coordinates
if(manifold.pointCount > 0) {
// write data back
if(result) {
// convert to world coordinate
b2WorldManifold worldManifold;
if(reverseNormal) {
worldManifold.Initialize(&manifold,
sRectTrans2,
sRectPoly2.m_radius,
hash->transform,
hash->type == b2Shape::e_polygon ? hash->poly.m_radius : hash->circle.m_radius);
} else {
worldManifold.Initialize(&manifold,
hash->transform,
hash->type == b2Shape::e_polygon ? hash->poly.m_radius : hash->circle.m_radius,
sRectTrans2,
sRectPoly2.m_radius);
}
// save contact points
result->pointCount = manifold.pointCount;
for(int i = 0; i < manifold.pointCount; i++) {
result->points[i] = wyp(meter2Pixel(worldManifold.points[i].x), meter2Pixel(worldManifold.points[i].y));
}
// save normal
if(reverseNormal)
result->normal = wyp(-worldManifold.normal.x, -worldManifold.normal.y);
else
result->normal = wyp(worldManifold.normal.x, worldManifold.normal.y);
}
}
return manifold.pointCount > 0;
}
void Init()
{
GameWin.create(sf::VideoMode(800, 600, 32), "Physics Test - [SFML & Box2D]");
if (!font.loadFromFile("arial.ttf"))
{
exit(0);
}
PauseText.setFont(font);
pauseText = to_string(Paused);
PauseText.setCharacterSize(10);
PauseText.setString("PAUSED:" + pauseText);
PauseText.setPosition(sf::Vector2f(700, 10));
PauseText.setFillColor(sf::Color::Yellow);
box.setPosition(sf::Vector2f(15, 5));
box.setSize(sf::Vector2f(10, 10));
box.setFillColor(sf::Color(255, 0, 0));
box2.setPosition(sf::Vector2f(50, 5));
box2.setSize(sf::Vector2f(15, 15));
box2.setFillColor(sf::Color(0, 255, 0));
ground.setPosition(sf::Vector2f(0, 540));
ground.setSize(sf::Vector2f(800, 560));
ground.setFillColor(sf::Color(0, 0,255));
wall.setPosition(sf::Vector2f(1, 1));
wall.setSize(sf::Vector2f(10, 580));
wall.setFillColor(sf::Color(0, 0, 255));
wall2.setPosition(sf::Vector2f(790, 1));
wall2.setSize(sf::Vector2f(10, 580));
wall2.setFillColor(sf::Color(0, 0, 255));
World = new b2World(gravity);
World->SetGravity(gravity);
groundBodyDef.type = b2_staticBody;
groundBodyDef.position.Set(0, 540);
groundBody = World->CreateBody(&groundBodyDef);
wallBodyDef.type = b2_staticBody;
wallBodyDef.position.Set(10, 580);
wallBody = World->CreateBody(&wallBodyDef);
wallBodyDef2.type = b2_staticBody;
wallBodyDef2.position.Set(790, 1);
wallBody2 = World->CreateBody(&wallBodyDef2);
ballBodyDef.type = b2_dynamicBody;
ballVector.Set(10, 10);
ballBodyDef.angularVelocity = 0.0f;
ballBodyDef.linearVelocity = ballVector;
ballBodyDef2.type = b2_dynamicBody;
ballVector2.Set(15, 15);
ballBodyDef2.angularVelocity = 0.0f;
ballBodyDef2.linearVelocity = ballVector2;
ballBodyDef.position.Set(15, 0);
ballBodyDef.awake = true;
Body = World->CreateBody(&ballBodyDef);
ballBodyDef2.position.Set(30, 0);
ballBodyDef2.awake = true;
Body2 = World->CreateBody(&ballBodyDef2);
boxShapeDef.shape = &groundBox;
boxShapeDef.density = 2.0f;
boxShapeDef.restitution = 0.5f;
groundBox.SetAsBox(800, 0);
groundBody->CreateFixture(&groundBox, 0);
wallBoxDef.shape = &wallBox;
wallBoxDef.density = 2.0f;
wallBoxDef.restitution = 0.5f;
wallBox.SetAsBox(1, 600);
wallBody->CreateFixture(&wallBox, 0);
wallBoxDef2.shape = &wallBox2;
wallBoxDef2.density = 2.0f;
wallBoxDef2.restitution = 0.5f;
wallBox2.SetAsBox(1, 600);
wallBody2->CreateFixture(&wallBox2, 0);
dynamicBox.SetAsBox(10.0f, 10.0f);
dynamicBox2.SetAsBox(10.0f, 10.0f);
fixtureDef.shape = &dynamicBox;
fixtureDef.density = 2.0f;
fixtureDef.friction = 1.5f;
fixtureDef.restitution = 0.9f;
Body->CreateFixture(&fixtureDef);
fixtureDef2.shape = &dynamicBox2;
fixtureDef2.density = 5.0f;
fixtureDef2.friction = 5.0f;
fixtureDef2.restitution = 1.0f;
Body2->CreateFixture(&fixtureDef2);
timeStep = 1.0f / 600.0f;
velIter = 1;
posIter = 1;
World->Step(timeStep, velIter, posIter);
b2Vec2 pos = Body->GetPosition();
float angle = Body->GetAngle();
box.setPosition(pos.x, pos.y);
box.setRotation(angle);
b2Vec2 pos2 = Body2->GetPosition();
float angle2 = Body2->GetAngle();
box2.setPosition(pos2.x, pos2.y);
box2.setRotation(angle2);
}
Polygon::Polygon(const b2PolygonShape& polygon) {
reserve(polygon.GetVertexCount());
for(int i = 0; i < polygon.GetVertexCount(); ++i) {
append((Point) polygon.GetVertex(i));
}
}
