1. UINT OffsetInBytes,Stride;
2. VOID* pIndex,*pData;
3. D3DXVECTOR3 Vector2D;
4. pDevice->GetVertexShaderConstantF(0,ViewProjectionMatrix,4);
5. pDevice->GetVertexShaderConstantF(230,LocalToWorld,4);
6. pDevice->GetVertexShaderConstantF(9,WorldToLocal,3);
7. pDevice->GetIndices(&pIndexData);
8. pDevice->GetViewport(&Viewport);
9. pDevice->GetStreamSource(0, &pStreamData, &OffsetInBytes, &Stride);
10.  
11. D3DXMatrixIdentity(&WorldToLocal);
12. D3DXVECTOR3 VectorMiddle(0,0,0),ScreenMiddle(Viewport.Width/2,Viewport.Height/2,0);
13.  
14.  
15. D3DXVec3Unproject(&VectorMiddle,&ScreenMiddle,&Viewport,&ViewProjectionMatrix,&LocalToWorld,&WorldToLocal);
16.  
17.  
18. D3DXVec3Project(&Vector2D,&Vector3D, &Viewport, &ViewProjectionMatrix,&LocalToWorld,&WorldToLocal);
19.  
20.    {
21.        
22.        DrawRectangle(Vector2D.x,Vector2D.y,30,30);
23.  
24.    }

代码是来之远古的。理解为通过对象计算出坐标。但为何我获取的 Vector2D.x 和 Y 都是 -1 呢？

1. pDevice->GetVertexShaderConstantF(0,ViewProjectionMatrix,4);
2. pDevice->GetVertexShaderConstantF(230,LocalToWorld,4);
3. pDevice->GetVertexShaderConstantF(9,WorldToLocal,3);

这三句话也不是很立即。

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