Matrix4 Matrix4::InverseFast() const
{
// assert: only rotation and translation
// First calculate the inverse of the rotation section by transposing
Matrix3 inverse3x3(*this);
inverse3x3.Transpose();
// Next caculate the translation inverse
Vector3 translation = -GetTranslation();
translation = translation.Transform(inverse3x3);
// Next generate the 4x4 inverse by combining the rotation with the translation
return Matrix4(inverse3x3, translation);
}
VBData* WireCircle::InitialiseBuffer(ID3D11Device* _pd3d, bool _is3D)
{
VBData* data = new VBData();
data->topology = D3D11_PRIMITIVE_TOPOLOGY_LINELIST;
int numVerts = 48;
if (_is3D)
{
numVerts *= 3;
}
data->numPrims = numVerts / 2;
data->indexBuffer = NULL;
data->vertexBuffer = NULL;
Color white = Color(1.0f, 1.0f, 1.0f, 1.0f);
//calculate number of vertices and primatives
myVertex* m_vertices = new myVertex[numVerts];
WORD* indices = new WORD[numVerts];
//as using the standard VB shader set the tex-coords somewhere safe
for (int i = 0; i < numVerts; i++)
{
indices[i] = static_cast<WORD>(i);
m_vertices[i].texCoord = Vector2::One;
}
int vert = 0;
if (_is3D)
{
}
else
{
Vector3 startVert = Vector3(0, 1, 0);
Vector3 vert1 = startVert;
Vector3 vert2 = vert1;
float change = 1 / ((float)data->numPrims / 4);
int xSign = 1;
int ySign = -1;
for (int i = 0; i < (int)data->numPrims; ++i)
{
vert2.x = vert2.x + (change * xSign);
if (abs(vert2.x + (change * xSign)) > 1 + (change / 2))
{
xSign *= -1;
}
vert2.y = vert2.y + (change * ySign);
if (abs(vert2.y + (change * ySign)) > 1 + (change / 2))
{
ySign *= -1;
}
float angle = atan2(-vert1.x, vert1.y);
Matrix rot = Matrix::CreateRotationZ(angle);
Vector3 finalvert = startVert;
finalvert = finalvert.Transform(finalvert, rot);
m_vertices[vert].Color = white;
m_vertices[vert].Norm = Vector3(0, 0, 1);
m_vertices[vert++].Pos = finalvert;
angle = atan2(-vert2.x, vert2.y);
rot = Matrix::CreateRotationZ(angle);
finalvert = startVert;
finalvert = finalvert.Transform(finalvert, rot);
m_vertices[vert].Color = white;
m_vertices[vert].Norm = Vector3(0, 0, 1);
m_vertices[vert++].Pos = finalvert;
vert1 = vert2;
}
}
data->indexBuffer = VBGO::BuildIB(_pd3d, data->numPrims, indices);
data->vertexBuffer = VBGO::BuildVB(_pd3d, numVerts, m_vertices);
delete[] m_vertices; //this is no longer needed as this is now in the Vertex Buffer
delete[] indices;
return data;
}
Vector3 operator*(const Matrix4 &lhs, const Vector3 &rhs)
{
return Vector3(rhs.Transform(lhs));
}
