Pulleys.h
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上传日期:2022-01-07
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- /*
- * Copyright (c) 2007-2009 Erin Catto http://www.gphysics.com
- *
- * 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 PULLEYS_H
- #define PULLEYS_H
- class Pulleys : public Test
- {
- public:
- Pulleys()
- {
- b2Body* ground = NULL;
- {
- b2BodyDef bd;
- ground = m_world->CreateBody(&bd);
- b2PolygonShape shape;
- shape.SetAsEdge(b2Vec2(-40.0f, 0.0f), b2Vec2(40.0f, 0.0f));
- ground->CreateFixture(&shape, 0.0f);
- }
- {
- float32 a = 2.0f;
- float32 b = 4.0f;
- float32 y = 16.0f;
- float32 L = 12.0f;
- b2PolygonShape shape;
- shape.SetAsBox(a, b);
- b2BodyDef bd;
- bd.type = b2_dynamicBody;
- bd.position.Set(-10.0f, y);
- b2Body* body1 = m_world->CreateBody(&bd);
- body1->CreateFixture(&shape, 5.0f);
- bd.position.Set(10.0f, y);
- b2Body* body2 = m_world->CreateBody(&bd);
- body2->CreateFixture(&shape, 5.0f);
- b2PulleyJointDef pulleyDef;
- b2Vec2 anchor1(-10.0f, y + b);
- b2Vec2 anchor2(10.0f, y + b);
- b2Vec2 groundAnchor1(-10.0f, y + b + L);
- b2Vec2 groundAnchor2(10.0f, y + b + L);
- pulleyDef.Initialize(body1, body2, groundAnchor1, groundAnchor2, anchor1, anchor2, 2.0f);
- m_joint1 = (b2PulleyJoint*)m_world->CreateJoint(&pulleyDef);
- }
- }
- void Keyboard(unsigned char key)
- {
- switch (key)
- {
- case 0:
- break;
- }
- }
- void Step(Settings* settings)
- {
- Test::Step(settings);
- float32 ratio = m_joint1->GetRatio();
- float32 L = m_joint1->GetLength1() + ratio * m_joint1->GetLength2();
- m_debugDraw.DrawString(5, m_textLine, "L1 + %4.2f * L2 = %4.2f", (float) ratio, (float) L);
- m_textLine += 15;
- }
- static Test* Create()
- {
- return new Pulleys;
- }
- b2PulleyJoint* m_joint1;
- };
- #endif