void render_frame(void)
{
static float index = 0.0f; index += 0.05f;
d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);
d3ddev->BeginScene();
d3ddev->SetFVF(CUSTOMFVF);
D3DXMATRIX matTranslateY;
D3DXMATRIX matRotateY;
D3DXMatrixTranslation(&matTranslateY, NULL, index, NULL);
D3DXMatrixRotationY(&matRotateY, index);
d3ddev->SetTransform(D3DTS_WORLD, &matRotateY);
d3ddev->SetTransform(D3DTS_WORLD, &matTranslateY);
D3DXMATRIX matView;
D3DXMatrixLookAtLH(&matView,
&D3DXVECTOR3 (0.0f, 0.0f, 10.0f), // the camera position
&D3DXVECTOR3 (0.0f, index, 0.0f), // the look-at position
&D3DXVECTOR3 (0.0f, 1.0f, 0.0f)); // the up direction
d3ddev->SetTransform(D3DTS_VIEW, &matView);
D3DXMATRIX matProjection;
D3DXMatrixPerspectiveFovLH(&matProjection,
D3DXToRadian(45), // the horizontal field of view
(FLOAT)SCREEN_WIDTH / (FLOAT)SCREEN_HEIGHT, // aspect ratio
1.0f, // the near view-plane
100.0f); // the far view-plane
d3ddev->SetTransform(D3DTS_PROJECTION, &matProjection);
// select which vertex format we are using
d3ddev->SetFVF(CUSTOMFVF);
// select the vertex buffer to display
d3ddev->SetStreamSource(0, t_buffer, 0, sizeof(CUSTOMVERTEX));
// copy the vertex buffer to the back buffer
d3ddev->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 1);
d3ddev->EndScene();
d3ddev->Present(NULL, NULL, NULL, NULL);
return;
}
Problems with DirectX Matrices
I am running an exercise after a one of the tutorials on directxtutorial.com. It's asking me to rotate and translate a triangle while having the camera follow it. I have it set up so that the camera follows the motion of the triangle, however it won't combine the rotation and the translation.
You need to multiply matrices in order to concatenate the transformations they represent. With Direct3D the transformations will be applied in the left-to-right order that the matrices are multiplied. So rotation * translation will rotate the triangle first, then translate it (which is probably what you want).
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