Files
bounce/src/bounce/dynamics/shapes/mesh_shape.cpp
Irlan Robson 8f29bc7e21 first commit
2016-12-18 18:39:47 -02:00

171 lines
4.0 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.
*/
#include <bounce\dynamics\shapes\mesh_shape.h>
#include <bounce\collision\shapes\mesh.h>
b3MeshShape::b3MeshShape()
{
m_type = e_meshShape;
m_radius = B3_HULL_RADIUS;
m_mesh = nullptr;
}
b3MeshShape::~b3MeshShape()
{
}
void b3MeshShape::Swap(const b3MeshShape& other)
{
m_radius = other.m_radius;
m_mesh = other.m_mesh;
}
void b3MeshShape::ComputeMass(b3MassData* massData, float32 density) const
{
B3_NOT_USED(density);
u32 n = m_mesh->vertexCount;
b3Vec3 c(0.0f, 0.0f, 0.0f);
for (u32 i = 0; i < n; ++i)
{
c += m_mesh->vertices[i];
}
if (n > 0)
{
c = 1.0f / float32(n) * c;
}
massData->center = c;
massData->mass = 0.0f;
massData->I.SetZero();
}
void b3MeshShape::ComputeAABB(b3AABB3* output, const b3Transform& xf) const
{
output->Compute(m_mesh->vertices, m_mesh->vertexCount, xf);
output->Extend(m_radius);
}
void b3MeshShape::ComputeAABB(b3AABB3* output, const b3Transform& xf, u32 index) const
{
*output = m_mesh->GetTriangleAABB(index);
}
bool b3MeshShape::TestPoint(const b3Vec3& point, const b3Transform& xf) const
{
B3_NOT_USED(point);
B3_NOT_USED(xf);
return false;
}
bool b3MeshShape::RayCast(b3RayCastOutput* output, const b3RayCastInput& input, const b3Transform& xf, u32 index) const
{
B3_ASSERT(index < m_mesh->triangleCount);
b3Triangle* triangle = m_mesh->triangles + index;
b3Vec3 p1 = input.p1;
b3Vec3 p2 = input.p2;
b3Vec3 d = p2 - p1;
b3Vec3 v1 = m_mesh->vertices[triangle->v1];
b3Vec3 v2 = m_mesh->vertices[triangle->v2];
b3Vec3 v3 = m_mesh->vertices[triangle->v3];
b3Vec3 n = b3Cross(v2 - v1, v3 - v1);
n.Normalize();
float32 offset = b3Dot(n, v1);
float32 numerator = b3Dot(n, v1 - p1);
float32 denominator = b3Dot(n, d);
if (denominator == 0.0f)
{
return false;
}
float32 t = numerator / denominator;
if (t < 0.0f || input.maxFraction < t)
{
return false;
}
b3Vec3 q = p1 + t * d;
float32 w[4];
b3Barycentric(w, v1, v2, v3, q);
if (w[0] > 0.0f && w[1] > 0.0f && w[2] > 0.0f)
{
output->fraction = t;
if (numerator > 0.0f)
{
output->normal = -n;
}
else
{
output->normal = n;
}
return true;
}
return false;
}
struct b3MeshRayCastCallback
{
float32 Report(const b3RayCastInput& input, u32 proxyId)
{
u32 index = mesh->m_mesh->tree.GetUserData(proxyId);
b3RayCastOutput indexOutput;
if (mesh->RayCast(&indexOutput, input, xf, index))
{
hit = true;
if (indexOutput.fraction < output.fraction)
{
output = indexOutput;
}
}
return 1.0f;
}
b3Transform xf;
const b3MeshShape* mesh;
bool hit;
b3RayCastOutput output;
};
bool b3MeshShape::RayCast(b3RayCastOutput* output, const b3RayCastInput& input, const b3Transform& xf) const
{
// Put the ray into the mesh's frame of reference.
b3RayCastInput subInput;
subInput.p1 = b3MulT(xf.rotation, input.p1 - xf.position);
subInput.p2 = b3MulT(xf.rotation, input.p2 - xf.position);
subInput.maxFraction = input.maxFraction;
b3MeshRayCastCallback callback;
callback.mesh = this;
callback.hit = false;
callback.output.fraction = B3_MAX_FLOAT;
m_mesh->tree.QueryRay(&callback, subInput);
output->fraction = callback.output.fraction;
output->normal = b3Mul(xf.rotation, callback.output.normal);
return callback.hit;
}