how to convert XMMATRIX to D3DMATRIX in DirectX 9? - c++

Question

I learn DirectX (DirectX 9) from www.directxtutorial.com and using visual studio 2012 in windows 8.
d3dx9 (d3dx) replace by other header like DirectXMath, therefore I replaced all that is needed, but there is a problem - convert XMMATRIX to D3DMATRIX.
The problem code (The problem written - /problem!/):
void render_frame(void) {
// clear the window to a deep blue
d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
d3ddev->BeginScene(); // begins the 3D scene
// select which vertex format we are using
d3ddev->SetFVF(CUSTOMFVF);
// SET UP THE PIPELINE
DirectX::XMMATRIX matRotateY; // a matrix to store the rotation information
static float index = 0.0f; index+=0.05f; // an ever-increasing float value
// build a matrix to rotate the model based on the increasing float value
matRotateY = DirectX::XMMatrixRotationY(index);
D3DMATRIX D3DMatRotateY = matRotateY.r;
// tell Direct3D about our matrix
d3ddev->SetTransform(D3DTS_WORLD, &matRotateY); /*problem!*/
DirectX::XMMATRIX matView; // the view transform matrix
DirectX::XMVECTOR CameraPosition = {0.0f,0.0f,10.0f};
DirectX::XMVECTOR LookAtPosition = {0.0f,0.0f,0.0f};
DirectX::XMVECTOR TheUpDirection = {0.0f,1.0f,0.0f};
matView = DirectX::XMMatrixLookAtLH(CameraPosition, // the camera position
LookAtPosition, // the look-at position
TheUpDirection); // the up direction
d3ddev->SetTransform(D3DTS_VIEW, &matView); /*problem!*/ // set the view transform to matView
DirectX::XMMATRIX matProjection; // the projection transform matrix
DirectX::XMMatrixPerspectiveFovLH(&matProjection,
DirectX::XMConvertToRadians(45), // the horizontal field of view
1.0f, // the near view-plane
100.0f); // the far view-plane
d3ddev->SetTransform(D3DTS_PROJECTION, &matProjection); /*problem!*/ // set the projection
// select the vertex buffer to display
d3ddev->SetStreamSource(0, v_buffer, 0, sizeof(CUSTOMVERTEX));
// copy the vertex buffer to the back buffer
d3ddev->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 1);
d3ddev->EndScene(); // ends the 3D scene
d3ddev->Present(NULL, NULL, NULL, NULL); /* displays the created frame on the screen */ }

Answer 1

You can use XMStoreFloat4x4 to convert XMMATRIX to a XMFLOAT4X4.
You should be able to pass in XMFLOAT4X4 to setTransform by casting.
DirectX::XMMATRIX matProjection;  
DirectX::XMFLOAT4X4 projectionMatrix;
DirectX::XMMatrixPerspectiveFovLH(&matProjection,DirectX::XMConvertToRadians(45),1.0f,100.0f);
XMStoreFloat4x4(&projectionMatrix, matProjection);
d3ddev->SetTransform(D3DTS_PROJECTION, (D3DXMATRIX*)&projectionMatrix);  /*problem!*/   // set the projection