DirectX 3D将屏幕坐标映射到世界坐标系

#include <D3D9.h>
#include <DirectXMath.h>

struct Point
{
    Point(const int32_t x, const int32_t y)
        : _x(x)
        , _y(y)
    {
    }
    
    int32_t _x;
    int32_t _y;
};

struct PointF
{
    PointF(const double x, const double y)
        : _x(x)
        , _y(y)
    {
    }
    
    double _x;
    double _y;
};

PointF screen_pos_to_d3d_world_pos(HWND hWnd, IDirect3DDevice9* device, const Point& pt)
{
    using namespace DirectX;

    XMVECTOR screenPos = XMVectorSet(pt.x(), pt.y(), 0, 0);
    XMVECTOR worldPos;
    
    // 获取客户区宽高
    RECT clientRect;
    GetClientRect(hWnd, &clientRect);

    // 获取视口信息
    D3DVIEWPORT9 viewport;
    device->GetViewport(&viewport);

    // 获取投影矩阵
    D3DMATRIX projectionMatrix;
    device->GetTransform(D3DTS_PROJECTION, &projectionMatrix);

    // 获取世界矩阵
    D3DMATRIX worldMatrix;
    device->GetTransform(D3DTS_WORLD, &worldMatrix);

    // 获取视图矩阵
    D3DMATRIX viewMatrix;
    device->GetTransform(D3DTS_VIEW, &viewMatrix);

    XMMATRIX xmProjectionMatrix = XMLoadFloat4x4((XMFLOAT4X4*)&projectionMatrix);
    XMMATRIX xmWorldMatrix      = XMLoadFloat4x4((XMFLOAT4X4*)&worldMatrix);
    XMMATRIX xmViewMatrix       = XMLoadFloat4x4((XMFLOAT4X4*)&viewMatrix);

    worldPos = XMVector3Unproject(
        screenPos,
        viewport.X,
        viewport.Y,
        clientRect.right - clientRect.left,
        clientRect.bottom - clientRect.top,
        viewport.MinZ,
        viewport.MaxZ,
        xmProjectionMatrix,
        xmViewMatrix,
        xmWorldMatrix
    );

    return PointF(XMVectorGetX(worldPos), XMVectorGetY(worldPos));
}