embedded_libs/box2d-2.4.1/testbed/tests/polygon_shapes.cpp
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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"
/// This tests stacking. It also shows how to use b2World::Query
/// and b2TestOverlap.
/// This callback is called by b2World::QueryAABB. We find all the fixtures
/// that overlap an AABB. Of those, we use b2TestOverlap to determine which fixtures
/// overlap a circle. Up to 4 overlapped fixtures will be highlighted with a yellow border.
class PolygonShapesCallback : public b2QueryCallback
{
public:
enum
{
e_maxCount = 4
};
PolygonShapesCallback()
{
m_count = 0;
}
/// Called for each fixture found in the query AABB.
/// @return false to terminate the query.
bool ReportFixture(b2Fixture* fixture) override
{
if (m_count == e_maxCount)
{
return false;
}
b2Body* body = fixture->GetBody();
b2Shape* shape = fixture->GetShape();
bool overlap = b2TestOverlap(shape, 0, &m_circle, 0, body->GetTransform(), m_transform);
if (overlap)
{
b2Color color(0.95f, 0.95f, 0.6f);
b2Vec2 center = body->GetWorldCenter();
g_debugDraw->DrawPoint(center, 5.0f, color);
++m_count;
}
return true;
}
b2CircleShape m_circle;
b2Transform m_transform;
b2Draw* g_debugDraw;
int32 m_count;
};
class PolygonShapes : public Test
{
public:
enum
{
e_maxBodies = 256
};
PolygonShapes()
{
// Ground body
{
b2BodyDef bd;
b2Body* ground = m_world->CreateBody(&bd);
b2EdgeShape shape;
shape.SetTwoSided(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));
ground->CreateFixture(&shape, 0.0f);
}
{
b2Vec2 vertices[3];
vertices[0].Set(-0.5f, 0.0f);
vertices[1].Set(0.5f, 0.0f);
vertices[2].Set(0.0f, 1.5f);
m_polygons[0].Set(vertices, 3);
}
{
b2Vec2 vertices[3];
vertices[0].Set(-0.1f, 0.0f);
vertices[1].Set(0.1f, 0.0f);
vertices[2].Set(0.0f, 1.5f);
m_polygons[1].Set(vertices, 3);
}
{
float w = 1.0f;
float b = w / (2.0f + b2Sqrt(2.0f));
float s = b2Sqrt(2.0f) * b;
b2Vec2 vertices[8];
vertices[0].Set(0.5f * s, 0.0f);
vertices[1].Set(0.5f * w, b);
vertices[2].Set(0.5f * w, b + s);
vertices[3].Set(0.5f * s, w);
vertices[4].Set(-0.5f * s, w);
vertices[5].Set(-0.5f * w, b + s);
vertices[6].Set(-0.5f * w, b);
vertices[7].Set(-0.5f * s, 0.0f);
m_polygons[2].Set(vertices, 8);
}
{
m_polygons[3].SetAsBox(0.5f, 0.5f);
}
{
m_circle.m_radius = 0.5f;
}
m_bodyIndex = 0;
memset(m_bodies, 0, sizeof(m_bodies));
}
void Create(int32 index)
{
if (m_bodies[m_bodyIndex] != NULL)
{
m_world->DestroyBody(m_bodies[m_bodyIndex]);
m_bodies[m_bodyIndex] = NULL;
}
b2BodyDef bd;
bd.type = b2_dynamicBody;
float x = RandomFloat(-2.0f, 2.0f);
bd.position.Set(x, 10.0f);
bd.angle = RandomFloat(-b2_pi, b2_pi);
if (index == 4)
{
bd.angularDamping = 0.02f;
}
m_bodies[m_bodyIndex] = m_world->CreateBody(&bd);
if (index < 4)
{
b2FixtureDef fd;
fd.shape = m_polygons + index;
fd.density = 1.0f;
fd.friction = 0.3f;
m_bodies[m_bodyIndex]->CreateFixture(&fd);
}
else
{
b2FixtureDef fd;
fd.shape = &m_circle;
fd.density = 1.0f;
fd.friction = 0.3f;
m_bodies[m_bodyIndex]->CreateFixture(&fd);
}
m_bodyIndex = (m_bodyIndex + 1) % e_maxBodies;
}
void DestroyBody()
{
for (int32 i = 0; i < e_maxBodies; ++i)
{
if (m_bodies[i] != NULL)
{
m_world->DestroyBody(m_bodies[i]);
m_bodies[i] = NULL;
return;
}
}
}
void Keyboard(int key) override
{
switch (key)
{
case GLFW_KEY_1:
case GLFW_KEY_2:
case GLFW_KEY_3:
case GLFW_KEY_4:
case GLFW_KEY_5:
Create(key - GLFW_KEY_1);
break;
case GLFW_KEY_A:
for (int32 i = 0; i < e_maxBodies; i += 2)
{
if (m_bodies[i])
{
bool enabled = m_bodies[i]->IsEnabled();
m_bodies[i]->SetEnabled(!enabled);
}
}
break;
case GLFW_KEY_D:
DestroyBody();
break;
}
}
void Step(Settings& settings) override
{
Test::Step(settings);
PolygonShapesCallback callback;
callback.m_circle.m_radius = 2.0f;
callback.m_circle.m_p.Set(0.0f, 1.1f);
callback.m_transform.SetIdentity();
callback.g_debugDraw = &g_debugDraw;
b2AABB aabb;
callback.m_circle.ComputeAABB(&aabb, callback.m_transform, 0);
m_world->QueryAABB(&callback, aabb);
b2Color color(0.4f, 0.7f, 0.8f);
g_debugDraw.DrawCircle(callback.m_circle.m_p, callback.m_circle.m_radius, color);
g_debugDraw.DrawString(5, m_textLine, "Press 1-5 to drop stuff, maximum of %d overlaps detected", PolygonShapesCallback::e_maxCount);
m_textLine += m_textIncrement;
g_debugDraw.DrawString(5, m_textLine, "Press 'a' to enable/disable some bodies");
m_textLine += m_textIncrement;
g_debugDraw.DrawString(5, m_textLine, "Press 'd' to destroy a body");
m_textLine += m_textIncrement;
}
static Test* Create()
{
return new PolygonShapes;
}
int32 m_bodyIndex;
b2Body* m_bodies[e_maxBodies];
b2PolygonShape m_polygons[4];
b2CircleShape m_circle;
};
static int testIndex = RegisterTest("Geometry", "Polygon Shapes", PolygonShapes::Create);