New feature: soft bodies!

2019-05-13 19:03:23 -03:00
parent f1c4cf4679
commit 637199b5fd
21 changed files with 3588 additions and 298 deletions
--- a/examples/testbed/framework/softbody_dragger.cpp
+++ b/examples/testbed/framework/softbody_dragger.cpp
@@ -0,0 +1,128 @@
+/*
+* Copyright (c) 2016-2019 Irlan Robson https://irlanrobson.github.io
+*
+* 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.
+*/
+
+#include <testbed/framework/softbody_dragger.h>
+
+b3SoftBodyDragger::b3SoftBodyDragger(b3Ray3* ray, b3SoftBody* body)
+{
+	m_ray = ray;
+	m_body = body;
+	m_tetrahedron = nullptr;
+}
+
+b3SoftBodyDragger::~b3SoftBodyDragger()
+{
+
+}
+
+bool b3SoftBodyDragger::StartDragging()
+{
+	B3_ASSERT(IsDragging() == false);
+
+	b3SoftBodyRayCastSingleOutput rayOut;
+	if (m_body->RayCastSingle(&rayOut, m_ray->A(), m_ray->B()) == false)
+	{
+		return false;
+	}
+
+	m_mesh = m_body->GetMesh();
+	m_tetrahedron = m_mesh->tetrahedrons + rayOut.tetrahedron;
+	m_v1 = m_tetrahedron->v1;
+	m_v2 = m_tetrahedron->v2;
+	m_v3 = m_tetrahedron->v3;
+	m_v4 = m_tetrahedron->v4;
+	m_x = rayOut.fraction;
+
+	b3SoftBodyNode* n1 = m_body->GetVertexNode(m_v1);
+	b3SoftBodyNode* n2 = m_body->GetVertexNode(m_v2);
+	b3SoftBodyNode* n3 = m_body->GetVertexNode(m_v3);
+	b3SoftBodyNode* n4 = m_body->GetVertexNode(m_v4);
+
+	b3Vec3 v1 = n1->GetPosition();
+	b3Vec3 v2 = n2->GetPosition();
+	b3Vec3 v3 = n3->GetPosition();
+	b3Vec3 v4 = n4->GetPosition();
+
+	b3Vec3 B = GetPointB();
+
+	float32 wABCD[5];
+	b3BarycentricCoordinates(wABCD, v1, v2, v3, v4, B);
+
+	if (wABCD[4] > B3_EPSILON)
+	{
+		m_tu = wABCD[0] / wABCD[4];
+		m_tv = wABCD[1] / wABCD[4];
+		m_tw = wABCD[2] / wABCD[4];
+		m_tx = wABCD[3] / wABCD[4];
+	}
+	else
+	{
+		m_tu = m_tv = m_tw = m_tx = 0.0f;
+	}
+
+	return true;
+}
+
+void b3SoftBodyDragger::Drag()
+{
+	B3_ASSERT(IsDragging() == true);
+
+	b3Vec3 A = GetPointA();
+	b3Vec3 B = GetPointB();
+
+	b3Vec3 dx = B - A;
+
+	const float32 k = 100.0f;
+
+	b3Vec3 f = k * dx;
+
+	b3Vec3 f1 = m_tu * f;
+	b3Vec3 f2 = m_tv * f;
+	b3Vec3 f3 = m_tw * f;
+	b3Vec3 f4 = m_tx * f;
+
+	m_body->GetVertexNode(m_v1)->ApplyForce(f1);
+	m_body->GetVertexNode(m_v2)->ApplyForce(f2);
+	m_body->GetVertexNode(m_v3)->ApplyForce(f3);
+	m_body->GetVertexNode(m_v4)->ApplyForce(f4);
+}
+
+void b3SoftBodyDragger::StopDragging()
+{
+	B3_ASSERT(IsDragging() == true);
+	
+	m_tetrahedron = nullptr;
+}
+
+b3Vec3 b3SoftBodyDragger::GetPointA() const
+{
+	B3_ASSERT(IsDragging() == true);
+
+	b3Vec3 A = m_body->GetVertexNode(m_v1)->GetPosition();
+	b3Vec3 B = m_body->GetVertexNode(m_v2)->GetPosition();
+	b3Vec3 C = m_body->GetVertexNode(m_v3)->GetPosition();
+	b3Vec3 D = m_body->GetVertexNode(m_v4)->GetPosition();
+
+	return m_tu * A + m_tv * B + m_tw * C + m_tx * D;
+}
+
+b3Vec3 b3SoftBodyDragger::GetPointB() const
+{
+	B3_ASSERT(IsDragging() == true);
+	return (1.0f - m_x) * m_ray->A() + m_x * m_ray->B();
+}