356 lines
7.1 KiB
C++
356 lines
7.1 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 SPRING_CLOTH_TESH_H
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#define SPRING_CLOTH_TESH_H
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class ClothDragger
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{
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public:
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ClothDragger(Ray3* ray, b3SpringCloth* cloth)
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{
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m_ray = ray;
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m_cloth = cloth;
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m_isSelected = false;
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}
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~ClothDragger()
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{
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}
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bool IsSelected() const
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{
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return m_isSelected;
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}
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b3Vec3 GetPointA() const
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{
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B3_ASSERT(m_isSelected);
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b3ClothMesh* m = m_cloth->GetMesh();
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b3ClothMeshTriangle* t = m->triangles + m_selection;
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b3Vec3 A = m->vertices[t->v1];
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b3Vec3 B = m->vertices[t->v2];
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b3Vec3 C = m->vertices[t->v3];
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return m_u * A + m_v * B + (1.0f - m_u - m_v) * C;
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}
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b3Vec3 GetPointB() const
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{
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B3_ASSERT(m_isSelected);
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return (1.0f - m_x) * m_ray->A() + m_x * m_ray->B();
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}
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bool StartDragging()
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{
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B3_ASSERT(m_isSelected == false);
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if (Select(m_selection, m_x) == false)
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{
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return false;
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}
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m_isSelected = true;
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b3ClothMesh* m = m_cloth->GetMesh();
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b3ClothMeshTriangle* t = m->triangles + m_selection;
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m_t1 = m_cloth->GetType(t->v1);
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m_cloth->SetType(t->v1, b3MassType::e_staticMass);
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m_t2 = m_cloth->GetType(t->v2);
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m_cloth->SetType(t->v2, b3MassType::e_staticMass);
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m_t3 = m_cloth->GetType(t->v3);
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m_cloth->SetType(t->v3, b3MassType::e_staticMass);
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b3Vec3 v1 = m_cloth->GetPosition(t->v1);
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b3Vec3 v2 = m_cloth->GetPosition(t->v2);
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b3Vec3 v3 = m_cloth->GetPosition(t->v3);
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b3Vec3 B = GetPointB();
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float32 wABC[4];
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b3BarycentricCoordinates(wABC, v1, v2, v3, B);
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if (wABC[3] > B3_EPSILON)
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{
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m_u = wABC[0] / wABC[3];
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m_v = wABC[1] / wABC[3];
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}
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else
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{
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m_u = m_v = 0.0f;
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}
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return true;
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}
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void Drag()
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{
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B3_ASSERT(m_isSelected);
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b3ClothMesh* m = m_cloth->GetMesh();
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b3ClothMeshTriangle* t = m->triangles + m_selection;
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b3Vec3 A = GetPointA();
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b3Vec3 B = GetPointB();
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b3Vec3 dx = B - A;
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b3Vec3 v1 = m_cloth->GetPosition(t->v1);
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v1 += dx;
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m_cloth->SetPosition(t->v1, v1);
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b3Vec3 v2 = m_cloth->GetPosition(t->v2);
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v2 += dx;
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m_cloth->SetPosition(t->v2, v2);
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b3Vec3 v3 = m_cloth->GetPosition(t->v3);
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v3 += dx;
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m_cloth->SetPosition(t->v3, v3);
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}
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void StopDragging()
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{
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B3_ASSERT(m_isSelected);
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m_isSelected = false;
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b3ClothMesh* m = m_cloth->GetMesh();
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b3ClothMeshTriangle* t = m->triangles + m_selection;
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m_cloth->SetType(t->v1, m_t1);
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m_cloth->SetType(t->v2, m_t2);
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m_cloth->SetType(t->v3, m_t3);
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}
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private:
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bool RayCast(b3RayCastOutput* output, u32 triangleIndex) const
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{
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b3ClothMesh* mesh = m_cloth->GetMesh();
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B3_ASSERT(triangleIndex < mesh->triangleCount);
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b3ClothMeshTriangle* triangle = mesh->triangles + triangleIndex;
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b3Vec3 v1 = mesh->vertices[triangle->v1];
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b3Vec3 v2 = mesh->vertices[triangle->v2];
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b3Vec3 v3 = mesh->vertices[triangle->v3];
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b3Vec3 p1 = m_ray->A();
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b3Vec3 p2 = m_ray->B();
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b3Vec3 d = p2 - p1;
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float32 maxFraction = b3Length(d);
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b3Vec3 n = b3Cross(v2 - v1, v3 - v1);
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n.Normalize();
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float32 numerator = b3Dot(n, v1 - p1);
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float32 denominator = b3Dot(n, d);
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if (denominator == 0.0f)
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{
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return false;
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}
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float32 t = numerator / denominator;
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// Is the intersection not on the segment?
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if (t < 0.0f || maxFraction < t)
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{
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return false;
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}
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b3Vec3 q = p1 + t * d;
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// Barycentric coordinates for q
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b3Vec3 Q = q;
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b3Vec3 A = v1;
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b3Vec3 B = v2;
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b3Vec3 C = v3;
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b3Vec3 AB = B - A;
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b3Vec3 AC = C - A;
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b3Vec3 QA = A - Q;
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b3Vec3 QB = B - Q;
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b3Vec3 QC = C - Q;
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b3Vec3 QB_x_QC = b3Cross(QB, QC);
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b3Vec3 QC_x_QA = b3Cross(QC, QA);
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b3Vec3 QA_x_QB = b3Cross(QA, QB);
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b3Vec3 AB_x_AC = b3Cross(AB, AC);
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float32 u = b3Dot(QB_x_QC, AB_x_AC);
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float32 v = b3Dot(QC_x_QA, AB_x_AC);
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float32 w = b3Dot(QA_x_QB, AB_x_AC);
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// This tolerance helps intersections lying on
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// shared edges to not be missed.
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const float32 kTol = -0.005f;
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// Is the intersection on the triangle?
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if (u > kTol && v > kTol && w > kTol)
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{
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output->fraction = t;
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// Does the ray start from below or above the triangle?
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if (numerator > 0.0f)
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{
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output->normal = -n;
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}
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else
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{
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output->normal = n;
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}
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return true;
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}
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return false;
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}
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bool Select(u32& selection, float32& fraction) const
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{
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b3ClothMesh* m = m_cloth->GetMesh();
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b3RayCastInput input;
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input.p1 = m_ray->A();
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input.p2 = m_ray->B();
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input.maxFraction = m_ray->fraction;
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float32 minFraction = B3_MAX_FLOAT;
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b3Vec3 minNormal(0.0f, 0.0f, 0.0f);
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u32 minIndex = ~0;
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for (u32 i = 0; i < m->triangleCount; ++i)
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{
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b3RayCastOutput subOutput;
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if (RayCast(&subOutput, i) == true)
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{
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if (subOutput.fraction < minFraction)
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{
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minFraction = subOutput.fraction;
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minNormal = subOutput.normal;
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minIndex = i;
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}
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}
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}
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if (minIndex != ~0)
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{
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selection = minIndex;
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fraction = minFraction;
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return true;
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}
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return false;
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}
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bool m_isSelected;
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Ray3* m_ray;
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float32 m_x;
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b3SpringCloth * m_cloth;
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u32 m_selection;
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float32 m_u, m_v;
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b3MassType m_t1, m_t2, m_t3;
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};
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class SpringClothTest : public Test
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{
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public:
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SpringClothTest() : m_clothDragger(&m_clothRay, &m_cloth)
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{
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m_clothRay.origin.SetZero();
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m_clothRay.direction.Set(0.0f, 0.0f, -1.0f);
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m_clothRay.fraction = g_camera->m_zFar;
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}
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void Step()
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{
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float32 dt = g_testSettings->inv_hertz;
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m_cloth.Step(dt);
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m_cloth.Apply();
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b3Shape** shapes = m_cloth.GetShapes();
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for (u32 i = 0; i < m_cloth.GetShapeCount(); ++i)
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{
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b3Shape* s = shapes[i];
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b3Transform xf;
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xf.SetIdentity();
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g_draw->DrawSolidShape(s, b3Color_white, xf);
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}
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m_cloth.Draw();
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b3SpringClothStep step = m_cloth.GetStep();
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g_draw->DrawString(b3Color_white, "Iterations = %u", step.iterations);
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float32 E = m_cloth.GetEnergy();
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g_draw->DrawString(b3Color_white, "E = %f", E);
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if (m_clothDragger.IsSelected() == true)
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{
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g_draw->DrawSegment(m_clothDragger.GetPointA(), m_clothDragger.GetPointB(), b3Color_white);
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}
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}
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void MouseMove(const Ray3& pw)
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{
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m_clothRay = pw;
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if (m_clothDragger.IsSelected() == true)
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{
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m_clothDragger.Drag();
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}
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}
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void MouseLeftDown(const Ray3& pw)
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{
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if (m_clothDragger.IsSelected() == false)
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{
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m_clothDragger.StartDragging();
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}
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}
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void MouseLeftUp(const Ray3& pw)
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{
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if (m_clothDragger.IsSelected() == true)
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{
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m_clothDragger.StopDragging();
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}
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}
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Ray3 m_clothRay;
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b3StackAllocator m_clothAllocator;
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b3SpringCloth m_cloth;
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ClothDragger m_clothDragger;
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};
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#endif |