bd09b243c2
Since I started altering the testbed for better maintainability, I prefered to drop this (tested) large change with a single commit. Some changes below: Put some globals in their correct place, Now Testbed uses the MVC pattern (Model-View Controller). This way it becomes better to maintain than using no pattern in my opinion. Fixed some bugs in the debug draw interface. Of course, updated almost all tests because of the differences. Update script.
99 lines
2.4 KiB
C++
99 lines
2.4 KiB
C++
/*
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* Copyright (c) 2016-2016 Irlan Robson http://www.irlan.net
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*/
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#ifndef PENDULUM_H
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#define PENDULUM_H
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class SinglePendulum : public Test
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{
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public:
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SinglePendulum()
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{
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m_g = -10.0f;
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m_r = 10.0f;
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m_m = 1.0f;
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m_I = m_m * m_r * m_r;
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// Initial state
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m_theta = -0.5f * B3_PI;
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m_omega = 0.0f;
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}
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void Step()
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{
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float32 h = g_settings->inv_hertz;
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// Solution (acceleration)
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float32 omega_dot = -m_g / m_r * sin(m_theta);
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// Integrate acceleration
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m_omega += h * omega_dot;
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// Integrate velocity
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m_theta += h * m_omega;
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// Convert from polar coordinates (r, theta) to Cartesian coordinates (x, y)
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b3Vec3 c;
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c.x = m_r * sin(m_theta);
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c.y = m_r * cos(m_theta);
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c.z = 0.0f;
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g_debugDraw->DrawSolidSphere(c, 1.0f, b3Color_white);
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b3Vec3 pole;
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pole.SetZero();
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g_debugDraw->DrawSegment(pole, c, b3Color_white);
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// Kinetic energy
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float32 T = 0.5f * m_I * m_omega * m_omega;
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// Potential energy
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float32 V = -m_m * m_g * m_r * cos(m_theta);
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// Lagrangian
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float32 L = T - V;
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//
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g_debugDraw->DrawString(b3Color_white, "T = %f \nV = %f \nL = %f", T, V, L);
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}
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static Test* Create()
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{
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return new SinglePendulum();
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}
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// Gravity
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float32 m_g;
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// Mass, inertia
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float32 m_m, m_I;
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// Radial coordinate
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float32 m_r;
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// The allowable generalized coordinate in polar coordinate frame.
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// Only motions satisfying the constraints can be described
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// in this frame. Therefore, all solutions satisfy the constraints.
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// This is the so called reduced coordinates approach.
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float32 m_theta;
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// Velocity
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float32 m_omega;
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};
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#endif |