How to set orthgraphic matrix for a 2d camera with zooming?

Posted by MahanGM on Game Development See other posts from Game Development or by MahanGM
Published on 2013-07-02T00:04:16Z Indexed on 2013/07/02 11:16 UTC
Read the original article Hit count: 254

Filed under:

c++

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2d

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camera

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directx9

I'm using ID3DXSprite to draw my sprites and haven't set any kind of camera projection matrix. How to setup an orthographic projection matrix for camera in DirectX which it would be able to support zoom functionality?

    D3DXMATRIX orthographicMatrix;
    D3DXMATRIX identityMatrix;

    D3DXMatrixOrthoLH(&orthographicMatrix, nScreenWidth, nScreenHeight, 0.0f, 1.0f);
    D3DXMatrixIdentity(&identityMatrix);

    device->SetTransform(D3DTS_PROJECTION, &orthographicMatrix);
    device->SetTransform(D3DTS_WORLD, &identityMatrix);
    device->SetTransform(D3DTS_VIEW, &identityMatrix);

This code is for initial setup. Then, for zooming I multiply zoom factor in nScreenWidth and nScreenHeight.

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