void Picking::CalculatePickingRay(int x, int y, Ray* ray)
{
D3DVIEWPORT9 viewport;
m_pDevice->GetViewport(&viewport);
D3DXMATRIX proj_matrix;
m_pDevice->GetTransform(D3DTS_PROJECTION, &proj_matrix);
float px = ((( 2.0f * x) / viewport.Width) - 1.0f) / proj_matrix(0, 0);
float py = (((-2.0f * y) / viewport.Height) + 1.0f) / proj_matrix(1, 1);
ray->m_vOrigin = D3DXVECTOR3(0.0f, 0.0f, 0.0f);
ray->m_vDirection = D3DXVECTOR3(px, py, 1.0f);
}
void Camera3D::updateMatricies ()
{
Matrix4F basis;
Vector3DF temp;
// compute camera direction vectors --- MATCHES OpenGL's gluLookAt function (DO NOT MODIFY)
dir_vec = to_pos; // f vector in gluLookAt docs
dir_vec -= from_pos; // eye = from_pos in gluLookAt docs
dir_vec.Normalize ();
side_vec = dir_vec;
side_vec.Cross ( up_dir );
side_vec.Normalize ();
up_vec = side_vec;
up_vec.Cross ( dir_vec );
up_vec.Normalize();
dir_vec *= -1;
// construct view matrix
rotate_matrix.Basis (side_vec, up_vec, dir_vec );
view_matrix = rotate_matrix;
//Matrix4F trans;
//trans.Translate ( -from_pos.x, -from_pos.y, -from_pos.z ); // !efficiency
view_matrix.PreTranslate ( Vector3DF(-from_pos.x, -from_pos.y, -from_pos.z ) );
// construct projection matrix --- MATCHES OpenGL's gluPerspective function (DO NOT MODIFY)
float sx = tan ( mFov * 0.5 * DEGtoRAD ) * mNear;
float sy = sx / mAspect;
proj_matrix = 0.0;
proj_matrix(0,0) = 2.0*mNear / sx; // matches OpenGL definition
proj_matrix(1,1) = 2.0*mNear / sy;
proj_matrix(2,2) = -(mFar + mNear)/(mFar - mNear); // C
proj_matrix(2,3) = -(2.0*mFar * mNear)/(mFar - mNear); // D
proj_matrix(3,2) = -1.0;
// construct tile projection matrix --- MATCHES OpenGL's glFrustum function (DO NOT MODIFY)
float l, r, t, b;
l = -sx + 2.0*sx*mTile.x; // Tile is in range 0 <= x,y <= 1
r = -sx + 2.0*sx*mTile.z;
t = sy - 2.0*sy*mTile.y;
b = sy - 2.0*sy*mTile.w;
tileproj_matrix = 0.0;
tileproj_matrix(0,0) = 2.0*mNear / (r - l);
tileproj_matrix(1,1) = 2.0*mNear / (t - b);
tileproj_matrix(0,2) = (r + l) / (r - l); // A
tileproj_matrix(1,2) = (t + b) / (t - b); // B
tileproj_matrix(2,2) = proj_matrix(2,2); // C
tileproj_matrix(2,3) = proj_matrix(2,3); // D
tileproj_matrix(3,2) = -1.0;
// construct inverse rotate and inverse projection matrix
Vector3DF tvz(0, 0, 0);
//invrot_matrix.InverseView ( rotate_matrix.GetDataF(), Vector3DF(0,0,0) ); // Computed using rule: "Inverse of a basis rotation matrix is its transpose." (So long as translation is taken out)
invrot_matrix.InverseView ( rotate_matrix.GetDataF(), tvz ); // Computed using rule: "Inverse of a basis rotation matrix is its transpose." (So long as translation is taken out)
invproj_matrix.InverseProj ( tileproj_matrix.GetDataF() ); // Computed using rule:
updateFrustum ();
}
