Ray Picking::CalcPickingRay(int x, int y)
{
float px = 0.0f;
float py = 0.0f;
D3DVIEWPORT9 vp;
d3ddev->GetViewport(&vp);
D3DXMATRIX proj;
d3ddev->GetTransform(D3DTS_PROJECTION, &proj);
px = ((( 2.0f * x) / vp.Width) - 1.0f) / proj(0,0);
py = (((-2.0f * y) / vp.Height) + 1.0f) / proj(1,1);
Ray ray;
ray.origin = D3DXVECTOR3(0.0f, 0.0f, 0.0f);
ray.direction = D3DXVECTOR3(px, py, 1.0f);
//transform the ray to world space
D3DXMATRIX view;
d3ddev->GetTransform(D3DTS_VIEW, &view);
D3DXMATRIX viewInverse;
D3DXMatrixInverse(&viewInverse, 0,&view);
TransformRay(&ray, &viewInverse);
return ray;
}
//
// WndProc
//
LRESULT CALLBACK d3d::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch( msg )
{
case WM_DESTROY:
::PostQuitMessage(0);
break;
case WM_KEYDOWN:
if( wParam == VK_ESCAPE )
::DestroyWindow(hwnd);
break;
case WM_LBUTTONDOWN:
// compute the ray in view space given the clicked screen point
d3d::Ray ray = CalcPickingRay(LOWORD(lParam), HIWORD(lParam));
// transform the ray to world space
D3DXMATRIX view;
Device->GetTransform(D3DTS_VIEW, &view);
D3DXMATRIX viewInverse;
D3DXMatrixInverse(&viewInverse, 0, &view);
TransformRay(&ray, &viewInverse);
// test for a hit
if( RaySphereIntTest(&ray, &BSphere) )
::MessageBox(0, "Hit!", "HIT", 0);
break;
}
return ::DefWindowProc(hwnd, msg, wParam, lParam);
}
bool Picking::IsPicked(int x, int y, const BoundingSphere* sphere)
{
Ray ray;
CalculatePickingRay(x, y, &ray);
D3DXMATRIX view_matrix, inverse_matrix;
m_pDevice->GetTransform(D3DTS_VIEW, &view_matrix);
//求出View矩阵的逆矩阵
D3DXMatrixInverse(&inverse_matrix, NULL, &view_matrix);
TransformRay(&ray, &inverse_matrix);
return Ray_SphereIntersect(&ray, sphere);
}
bool Rectangle::Intersect(const Ray &ray,
const RayInterval &interval,
SurfaceInteraction *const interaction) const {
// Compute local ray
Ray local_ray = TransformRay(world_to_local, ray);
// Check intersection with plane
if (std::abs(local_ray.Direction().y()) > 10e-6f) {
// Compute intersection with plane
float t = -local_ray.Origin().y() * local_ray.InvDirection().y();
// Check boundaries
if (interval.Inside(t)) {
// Compute intersection point
Vector3f hit_p = local_ray(t);
// Check hit point inside rectangle
if (hit_p.x() > -x_size / 2.f && hit_p.x() < x_size / 2.f &&
hit_p.z() > -z_size / 2.f && hit_p.z() < z_size / 2.f) {
// Fill interaction
interaction->hit_point = hit_p;
interaction->geom_frame = Frame(Vector3f(1.f, 0.f, 0.f),
Vector3f(0.f, 1.f, 0.f),
Vector3f(0.f, 0.f, 1.f));
interaction->sh_frame = Frame(Vector3f(1.f, 0.f, 0.f),
Vector3f(0.f, 1.f, 0.f),
Vector3f(0.f, 0.f, 1.f));
interaction->t = t;
interaction->wo = Normalize(-local_ray.Direction());
interaction->uv = Vector2f((hit_p.x() + x_size / 2.f) / x_size,
(hit_p.z() + z_size / 2.f) / z_size);
interaction->surface = this;
// Transform to global space
*interaction = TransformInteraction(local_to_world, world_to_local, *interaction);
return true;
}
}
}
return false;
}
bool Rectangle::IntersectP(const Ray &ray,
const RayInterval &interval) const {
// Compute local ray
Ray local_ray = TransformRay(world_to_local, ray);
// Check intersection with plane
if (std::abs(local_ray.Direction().y()) > EPS) {
// Compute intersection with plane
float t = -local_ray.Origin().y() * local_ray.InvDirection().y();
// Check boundaries
if (interval.Inside(t)) {
// Compute intersection point
Vector3f hit_p = local_ray(t);
// Check hit point inside rectangle
if (hit_p.x() > -x_size / 2.f && hit_p.x() < x_size / 2.f &&
hit_p.z() > -z_size / 2.f && hit_p.z() < z_size / 2.f) {
return true;
}
}
}
return false;
}
LRESULT CALLBACK d3d9::WndProc(
HWND hWnd,
UINT msg,
WPARAM wParam,
LPARAM lParam)
{
switch (msg)
{
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_KEYDOWN:
if (wParam == VK_ESCAPE)
DestroyWindow(hWnd);
break;
case WM_LBUTTONDOWN:
{
Ray ray;
if (CalcPickingRay(LOWORD(lParam), HIWORD(lParam), g_pDevice, &ray))
{
D3DXMATRIX view;
g_pDevice->GetTransform(D3DTS_VIEW, &view);
D3DXMATRIX inverse;
float determinant = D3DXMatrixDeterminant(&view);
D3DXMatrixInverse(&inverse, &determinant, &view);
TransformRay(&ray, &inverse);
if (RayHitSephere(&ray, &g_BSephere))
{
MessageBox(0, "Hit!", "HIT", 0);
}
}
break;
}
}
return DefWindowProc(hWnd, msg, wParam, lParam);
}
