困难的编组DirectX数组结构从C++到C#

Question

目标:Marshal C++(指向？)的结构数组到C#.

C++: CreateVertexDeclaration()

   HRESULT CreateVertexDeclaration(
     [in]           const D3DVERTEXELEMENT9 *pVertexElements,
     [out, retval]  IDirect3DVertexDeclaration9 **ppDecl
   );

C#:

我用它来定义D3DVERTEXELEMENT9结构.SharpDX是一个直接从DirectX SDK C++标头生成的托管DirectX库,因此它可以与COM互操作完全兼容.我实际上已经有10个其他钩子完美地工作了,但这是第一个带有指向结构数组的指针.

为了防止SharpDX的结构定义不起作用,我也尝试用我自己的定义替换它:

[StructLayout(LayoutKind.Sequential, Pack = 1)]
    public class D3DVERTEXELEMENT9
    {
        public short Stream;
        public short Offset;
        public DeclarationType Type;      // Enum
        public DeclarationMethod Method;  // Enum
        public DeclarationUsage Usage;    // Enum
        public byte UsageIndex;
    }

我尝试了以下C#方法签名:

注意:IntPtr devicePointer作为第一个参数应该不是问题.我有10个其他成功工作的钩子.

注意:这些是Direct3D API挂钩.所以我的程序正在传递我需要从非托管C++环境编组到托管C#环境的数据.

1:

CreateVertexDeclaration(IntPtr devicePointer, D3DVERTEXELEMENT9[] vertexElements, out IntPtr vertexDeclaration)

结果:数组有一个元素,但其值是默认值(没有意义).这意味着short Stream,short Offset,Type,Method,Usage,和UsageIndex均为0(枚举取他们的第一值).

2:

CreateVertexDeclaration(IntPtr devicePointer, ref D3DVERTEXELEMENT9[] vertexElements, out IntPtr vertexDeclaration)

结果:数组本身为null.

3:

CreateVertexDeclaration(IntPtr devicePointer, [In, Out] D3DVERTEXELEMENT9[] vertexElements, out IntPtr vertexDeclaration)

与1.相同.没有任何好处.

4:

CreateVertexDeclaration(IntPtr devicePointer, D3DVERTEXELEMENT9 vertexElements, out IntPtr vertexDeclaration)

与1相同,不会改变任何东西.我得到一个默认的结构.如果我打电话也一样new D3DVERTEXELEMENT9().

5:

CreateVertexDeclaration(IntPtr devicePointer, ref D3DVERTEXELEMENT9 vertexElements, out IntPtr vertexDeclaration)

我忘记了结果,但它没有用.我认为它实际上已经破坏了钩子.

6:

CreateVertexDeclaration(IntPtr devicePointer, IntPtr vertexElements, out IntPtr vertexDeclaration)

我认为这个#6或#1 /#2应该是正确的.我可能搞砸了这个方法的实现？

我试着用它来代码:

var vertex = (D3DVERTEXELEMENT9)Marshal.PtrToStructure(vertexElements, typeof(D3DVERTEXELEMENT9));

但它不起作用!它与#1相同.我编组的指针结构是一个默认的结构,就像我打电话一样new D3DVERTEXELEMENT9().

7:

CreateVertexDeclaration(IntPtr devicePointer, ref IntPtr vertexElements, out IntPtr vertexDeclaration)

空或零; 无效.

---

对于方法#6(使用IntPtr),我尝试在Visual Studio中查看内存区域.接下来的50个字节左右都是零.在250个零的字段中可能有一个字节.但是从提供给该方法的IntPtr开始,它几乎是49个字节的零.

这不是问题吗？这是不是意味着提供的指针已经不正确？所以我认为这意味着我有错误的方法签名.问题是我一直在尝试各种可能的组合,他们要么崩溃程序,要么给我一个默认数组,就像我打电话一样new D3DVERTEXELEMENT9().

问题:正确编组pVertexElements从C++到C#的结构数组的解决方案是什么,为什么我当前的签名不正确？

附加说明:在C++中,此特定数组的长度由后缀D3DDECL_END定义.我不知道如何在没有某种传递长度参数的情况下在C#中获取相应的数组长度.

---

其他工作钩:

C++:

BeginScene(LPDIRECT3DDEVICE9 pDevice)
BeginStateBlock(LPDIRECT3DDEVICE9 pDevice)
Clear(LPDIRECT3DDEVICE9 pDevice, DWORD Count,CONST D3DRECT* pRects,DWORD Flags,D3DCOLOR Color,float Z,DWORD Stencil)
ColorFill(LPDIRECT3DDEVICE9 pDevice, IDirect3DSurface9* pSurface,CONST RECT* pRect,D3DCOLOR color)
CreateAdditionalSwapChain(LPDIRECT3DDEVICE9 pDevice, D3DPRESENT_PARAMETERS* pPresentationParameters,IDirect3DSwapChain9** pSwapChain)
CreateCubeTexture(LPDIRECT3DDEVICE9 pDevice, UINT EdgeLength,UINT Levels,DWORD Usage,D3DFORMAT Format,D3DPOOL Pool,IDirect3DCubeTexture9** ppCubeTexture,HANDLE* pSharedHandle)

...

C#:

注意:我为所有这些代表使用SharpDX枚举和结构,它们工作正常.他们也都是从一开始IntPtr devicePointer.

BeginSceneDelegate(IntPtr devicePointer);
BeginStateBlocKDelegate(IntPtr devicePointer);
ClearDelegate(IntPtr devicePointer, int count, IntPtr rects, ClearFlags flags, ColorBGRA color, float z, int stencil);
ColorFillDelegate(IntPtr devicePointer, IntPtr surface, IntPtr rect, ColorBGRA color);
CreateAdditionalSwapChainDelegate(IntPtr devicePointer, [In, Out] PresentParameters presentParameters, out SwapChain swapChain);
CreateCubeTextureDelegate(IntPtr devicePointer, int edgeLength, int levels, Usage usage, Format format, Pool pool, out IntPtr cubeTexture, IntPtr sharedHandle);
...

其他挂钩的传递参数的日志:

DLL injection suceeded.
Setting up Direct3D 9 hooks...
Activating Direct3D 9 hooks...
CreateDepthStencilSurface(IntPtr devicePointer: 147414976, Int32 width: 1346, Int32 height: 827, Format format: D24S8, MultisampleType multiSampleType: None, Int32 multiSampleQuality: 0, Boolean discard: False, IntPtr& surface: (out), IntPtr sharedHandle: 0)
CreateDepthStencilSurface(IntPtr devicePointer: 147414976, Int32 width: 1346, Int32 height: 827, Format format: D24S8, MultisampleType multiSampleType: None, Int32 multiSampleQuality: 0, Boolean discard: False, IntPtr& surface: (out), IntPtr sharedHandle: 0)
Clear(IntPtr devicePointer: 147414976, Int32 count: 0, IntPtr rects: (Empty), ClearFlags flags: Target, ColorBGRA color: A:0 R:0 G:0 B:0, Single z: 1, Int32 stencil: 0)
Clear(IntPtr devicePointer: 147414976, Int32 count: 0, IntPtr rects: (Empty), ClearFlags flags: Target, ColorBGRA color: A:0 R:0 G:0 B:0, Single z: 1, Int32 stencil: 0)
BeginScene(IntPtr devicePointer: 147414976)
Clear(IntPtr devicePointer: 147414976, Int32 count: 0, IntPtr rects: (Empty), ClearFlags flags: Target, ColorBGRA color: A:0 R:0 G:0 B:0, Single z: 1, Int32 stencil: 0)
Clear(IntPtr devicePointer: 147414976, Int32 count: 0, IntPtr rects: (Empty), ClearFlags flags: Target, ColorBGRA color: A:0 R:0 G:0 B:0, Single z: 1, Int32 stencil: 0)
Clear(IntPtr devicePointer: 147414976, Int32 count: 0, IntPtr rects: (Empty), ClearFlags flags: ZBuffer, ColorBGRA color: A:0 R:0 G:0 B:0, Single z: 1, Int32 stencil: 0)
BeginScene(IntPtr devicePointer: 147414976)

与此类CreateVertexDeclaration()似的方法签名似乎是Clear().这是我的实现Clear():

private Result Clear(IntPtr devicePointer, int count, IntPtr rects, ClearFlags flags, ColorBGRA color, float z, int stencil)
        {
            try
            {
                var structSize = Marshal.SizeOf(typeof (Rectangle));
                var structs = new Rectangle[count];
                for (int i = 0; i < count; i++)
                {
                    structs[i] = (Rectangle) Marshal.PtrToStructure(rects, typeof (Rectangle));
                }
                // Seems to work fine, not sure why it doesn't work for CreateVertexDeclaration

                var rectangles = structs;
                Log.LogMethodSignatureTypesAndValues(devicePointer, count, rectangles.PrintTypesNamesValues(), flags,
                                                     color, z, stencil);
                GetOrCreateDevice(devicePointer);
                if (rectangles.Length == 0)
                    Device.Clear(flags, color, z, stencil);
                else
                    Device.Clear(flags, color, z, stencil, rectangles);
            }
            catch (Exception ex)
            {
                Log.Warn(ex.ToString());
            }

            return Result.Ok;
        }

Answer 1

首先，SharpDX 中的声明使用 Pack = 2（而不是 Pack = 1）：

    [StructLayout(LayoutKind.Sequential, Pack = 2 )]
    公共部分结构 VertexElement {  
     ...
    }

此外，如果您想确定编组，请尽可能使用 unsafe，而不是 Marshal.StructureToPtr 或任何其他编组方法（当结构直接映射到 C# 等效项时）。您将避免 Marshal 性能问题，并且您将确定内存布局（假设在 C# 中正确声明了该结构）

公共不安全静态无效CreateVertexDeclaration（IntPtr devicePointer，IntPtr vertexElementsPtr，out IntPtr vertexDeclaration）
{
    var vertexElements = (VertexElement*)vertexElementsPtr;

    // 访问所有VertexElement（最后一个元素由d3d9types.h中的Cmacro D3DDECL_END()指定）
    ...
}