DirectX: Cannot translate a rectangle - c++

Question

I have been following this tutorial of DirectX http://www.directxtutorial.com/Lesson.aspx?lessonid=9-4-5. I have just started DirectX with C++. I have drawn two rectangles on the screen but cannot translate them.Th rectangles have different position on screen and are stored in Array OurVertices. I have been reading from the tutorial and it says that you first have to apply world transformation to translate it in 3d but I dont want to get into 3d because I have two simple 2d rectangles. How you move simple 2d rectangles in DirectX C++. If I apply World Transformation using the tutorial I dont know why my camera position is tilted. My code is given below:
CUSTOMVERTEX OurVertices[] =
{
// 1
{ 0, 0, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 0), }, //meaning x,y,z,Dword
{ 100, 0, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 0), },
{ 0, 100, 0.0f, 1.0f, D3DCOLOR_XRGB(255, 255, 0), },
{ 100, 100, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 0), },
{ 200, 200, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 255), },
{ 400, 200, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 255), },
{ 200, 400, 0.0f, 1.0f, D3DCOLOR_XRGB(255, 255, 255), },
{ 400, 400, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 255), },
};
d3ddev->CreateVertexBuffer(8 * sizeof(CUSTOMVERTEX),
0,
CUSTOMFVF,
D3DPOOL_MANAGED,
&v_buffer,
NULL);
VOID* pVoid; // the void* we were talking about
v_buffer->Lock(0, 0, (void**)&pVoid, 0); // locks v_buffer, the buffer we made earlier
memcpy(pVoid, OurVertices, sizeof(OurVertices));
v_buffer->Unlock(); // unlock v_buffer
d3ddev->SetFVF(CUSTOMFVF);
void render_frame()
{
d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
d3ddev->BeginScene();
// select which vertex format we are using
// select the vertex buffer to display
d3ddev->SetFVF(CUSTOMFVF);
// SET UP THE PIPELINE
D3DXMATRIX matTranslate;
static float index = 0.0f;
index += 0.01f; // an ever-increasing float value
// build a matrix to rotate the model based on the increasing float value
D3DXMatrixTranslation(&matTranslate, 0, index , 0.0f);
// tell Direct3D about our matrix
d3ddev->SetTransform(D3DTS_WORLD, &matTranslate);
D3DXMATRIX matView; // the view transform matrix
D3DXMatrixLookAtLH(&matView,
&D3DXVECTOR3(0.0f, 0.0f, 10.0f), // the camera position
&D3DXVECTOR3(0.0f, 0.0f, 0.0f), // the look-at position
&D3DXVECTOR3(0.0f, 1.0f, 0.0f)); // the up direction
d3ddev->SetTransform(D3DTS_VIEW, &matView); // set the view transform to matView
D3DXMATRIX matProjection; // the projection transform matrix
D3DXMatrixPerspectiveFovLH(&matProjection,
D3DXToRadian(100), // the horizontal field of view
(FLOAT)800 / (FLOAT)600, // aspect ratio
1.0f, // the near view-plane
100.0f); // the far view-plane
d3ddev->SetTransform(D3DTS_PROJECTION, &matProjection); // 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_TRIANGLESTRIP, 0, 2);
d3ddev->DrawPrimitive(D3DPT_TRIANGLESTRIP, 4, 2);
d3ddev->EndScene();
d3ddev->Present(NULL, NULL, NULL, NULL);
}
Is there any way to translate two rectangles?

Answer 1

You are already working in 3D, when you specify the position of your vertices you have an extra z component wich is set to 0 at the moment. You can change it and see the effect on your scene.
{ 0, 0, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 0), }, //meaning x,y,z,Dword
{ 100, 0, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 0), },
{ 0, 100, 0.0f, 1.0f, D3DCOLOR_XRGB(255, 255, 0), },
{ 100, 100, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 0), },
{ 200, 200, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 255), },
{ 400, 200, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 255), },
{ 200, 400, 0.0f, 1.0f, D3DCOLOR_XRGB(255, 255, 255), },
{ 400, 400, 0.0f, 0.0f, D3DCOLOR_XRGB(255, 255, 255), },
So now each frame you are translating your vertices by an increasing amount on the y axis.
static float index = 0.0f;
index += 0.01f; // an ever-increasing float value
// build a matrix to rotate the model based on the increasing float value
D3DXMatrixTranslation(&matTranslate, 0, index , 0.0f);
If you print index each frame you will see him growing and you use this value to to build a translation matrix which will be apply before view/projection.
I don't know what is the effect you want.
But all the vertices of your scene will go from bottom to top, which you can look like your camera is going down.