bounce/examples/testbed/tests/cloth_test.h

347 lines
7.0 KiB
C++

/*
* Copyright (c) 2016-2016 Irlan Robson http://www.irlan.net
*
* 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 CLOTH_TESH_H
#define CLOTH_TESH_H
class ClothDragger
{
public:
ClothDragger(Ray3* ray, b3Cloth*& cloth) : m_ray(ray), m_cloth(cloth)
{
m_isSelected = false;
}
~ClothDragger()
{
}
bool IsSelected() const
{
return m_isSelected;
}
b3Vec3 GetPointA() const
{
B3_ASSERT(m_isSelected);
b3ClothMesh* m = m_cloth->GetMesh();
b3ClothMeshTriangle* t = m->triangles + m_selection;
b3Vec3 A = m->vertices[t->v1];
b3Vec3 B = m->vertices[t->v2];
b3Vec3 C = m->vertices[t->v3];
return m_u * A + m_v * B + (1.0f - m_u - m_v) * C;
}
b3Vec3 GetPointB() const
{
B3_ASSERT(m_isSelected);
return (1.0f - m_x) * m_ray->A() + m_x * m_ray->B();
}
bool StartDragging()
{
B3_ASSERT(m_isSelected == false);
if (Select(m_selection, m_x) == false)
{
return false;
}
m_isSelected = true;
b3ClothMesh* m = m_cloth->GetMesh();
b3ClothMeshTriangle* t = m->triangles + m_selection;
b3Particle* p1 = m_cloth->GetParticle(t->v1);
m_t1 = p1->type;
m_cloth->SetType(p1, e_staticParticle);
b3Particle* p2 = m_cloth->GetParticle(t->v2);
m_t2 = p2->type;
m_cloth->SetType(p2, e_staticParticle);
b3Particle* p3 = m_cloth->GetParticle(t->v3);
m_t3 = p3->type;
m_cloth->SetType(p3, e_staticParticle);
b3Vec3 v1 = p1->position;
b3Vec3 v2 = p2->position;
b3Vec3 v3 = p3->position;
b3Vec3 B = GetPointB();
float32 wABC[4];
b3BarycentricCoordinates(wABC, v1, v2, v3, B);
if (wABC[3] > B3_EPSILON)
{
m_u = wABC[0] / wABC[3];
m_v = wABC[1] / wABC[3];
}
else
{
m_u = m_v = 0.0f;
}
return true;
}
void Drag()
{
B3_ASSERT(m_isSelected);
b3ClothMesh* m = m_cloth->GetMesh();
b3ClothMeshTriangle* t = m->triangles + m_selection;
b3Vec3 A = GetPointA();
b3Vec3 B = GetPointB();
b3Vec3 dx = B - A;
b3Particle* p1 = m_cloth->GetParticle(t->v1);
m_cloth->ApplyTranslation(p1, dx);
b3Particle* p2 = m_cloth->GetParticle(t->v2);
m_cloth->ApplyTranslation(p2, dx);
b3Particle* p3 = m_cloth->GetParticle(t->v3);
m_cloth->ApplyTranslation(p3, dx);
}
void StopDragging()
{
B3_ASSERT(m_isSelected);
m_isSelected = false;
b3ClothMesh* m = m_cloth->GetMesh();
b3ClothMeshTriangle* t = m->triangles + m_selection;
b3Particle* p1 = m_cloth->GetParticle(t->v1);
m_cloth->SetType(p1, m_t1);
b3Particle* p2 = m_cloth->GetParticle(t->v2);
m_cloth->SetType(p2, m_t2);
b3Particle* p3 = m_cloth->GetParticle(t->v3);
m_cloth->SetType(p3, m_t3);
}
private:
bool RayCast(b3RayCastOutput* output, u32 triangleIndex) const
{
b3ClothMesh* mesh = m_cloth->GetMesh();
B3_ASSERT(triangleIndex < mesh->triangleCount);
b3ClothMeshTriangle* triangle = mesh->triangles + triangleIndex;
b3Vec3 v1 = mesh->vertices[triangle->v1];
b3Vec3 v2 = mesh->vertices[triangle->v2];
b3Vec3 v3 = mesh->vertices[triangle->v3];
b3Vec3 p1 = m_ray->A();
b3Vec3 p2 = m_ray->B();
b3Vec3 d = p2 - p1;
float32 maxFraction = b3Length(d);
b3Vec3 n = b3Cross(v2 - v1, v3 - v1);
n.Normalize();
float32 numerator = b3Dot(n, v1 - p1);
float32 denominator = b3Dot(n, d);
if (denominator == 0.0f)
{
return false;
}
float32 t = numerator / denominator;
// Is the intersection not on the segment?
if (t < 0.0f || maxFraction < t)
{
return false;
}
b3Vec3 q = p1 + t * d;
// Barycentric coordinates for q
b3Vec3 Q = q;
b3Vec3 A = v1;
b3Vec3 B = v2;
b3Vec3 C = v3;
b3Vec3 AB = B - A;
b3Vec3 AC = C - A;
b3Vec3 QA = A - Q;
b3Vec3 QB = B - Q;
b3Vec3 QC = C - Q;
b3Vec3 QB_x_QC = b3Cross(QB, QC);
b3Vec3 QC_x_QA = b3Cross(QC, QA);
b3Vec3 QA_x_QB = b3Cross(QA, QB);
b3Vec3 AB_x_AC = b3Cross(AB, AC);
float32 u = b3Dot(QB_x_QC, AB_x_AC);
float32 v = b3Dot(QC_x_QA, AB_x_AC);
float32 w = b3Dot(QA_x_QB, AB_x_AC);
// This tolerance helps intersections lying on
// shared edges to not be missed.
const float32 kTol = -B3_EPSILON;
// Is the intersection on the triangle?
if (u > kTol && v > kTol && w > kTol)
{
output->fraction = t;
// Does the ray start from below or above the triangle?
if (numerator > 0.0f)
{
output->normal = -n;
}
else
{
output->normal = n;
}
return true;
}
return false;
}
bool Select(u32& selection, float32& fraction) const
{
b3ClothMesh* m = m_cloth->GetMesh();
b3RayCastInput input;
input.p1 = m_ray->A();
input.p2 = m_ray->B();
input.maxFraction = m_ray->fraction;
float32 minFraction = B3_MAX_FLOAT;
b3Vec3 minNormal(0.0f, 0.0f, 0.0f);
u32 minIndex = ~0;
for (u32 i = 0; i < m->triangleCount; ++i)
{
b3RayCastOutput subOutput;
if (RayCast(&subOutput, i) == true)
{
if (subOutput.fraction < minFraction)
{
minFraction = subOutput.fraction;
minNormal = subOutput.normal;
minIndex = i;
}
}
}
if (minIndex != ~0)
{
selection = minIndex;
fraction = minFraction;
return true;
}
return false;
}
bool m_isSelected;
Ray3* m_ray;
float32 m_x;
b3Cloth*& m_cloth;
u32 m_selection;
float32 m_u, m_v;
b3ParticleType m_t1, m_t2, m_t3;
};
class ClothTest : public Test
{
public:
ClothTest() : m_clothDragger(&m_clothRay, m_cloth)
{
m_world.SetGravity(b3Vec3(0.0f, -10.0f, 0.0f));
m_clothRay.origin.SetZero();
m_clothRay.direction.Set(0.0f, 0.0f, -1.0f);
m_clothRay.fraction = g_camera->m_zFar;
m_cloth = nullptr;
}
void Step()
{
Test::Step();
m_cloth->Apply();
m_cloth->Draw();
extern u32 b3_clothSolverIterations;
g_draw->DrawString(b3Color_white, "Iterations = %u", b3_clothSolverIterations);
float32 E = m_cloth->GetEnergy();
g_draw->DrawString(b3Color_white, "E = %f", E);
if (m_clothDragger.IsSelected() == true)
{
g_draw->DrawSegment(m_clothDragger.GetPointA(), m_clothDragger.GetPointB(), b3Color_white);
}
}
void MouseMove(const Ray3& pw)
{
m_clothRay = pw;
if (m_clothDragger.IsSelected() == true)
{
m_clothDragger.Drag();
}
}
void MouseLeftDown(const Ray3& pw)
{
if (m_clothDragger.IsSelected() == false)
{
m_clothDragger.StartDragging();
}
}
void MouseLeftUp(const Ray3& pw)
{
if (m_clothDragger.IsSelected() == true)
{
m_clothDragger.StopDragging();
}
}
Ray3 m_clothRay;
b3Cloth* m_cloth;
ClothDragger m_clothDragger;
};
#endif