Hi

I need to render a full screen quad, until now I have been using this:


FLOAT fWidth5 = ( FLOAT )dtdsdRT.Width - 0.5f;
FLOAT fHeight5 = ( FLOAT )dtdsdRT.Height - 0.5f;


// Draw the quad
QuadVertex svQuad[4];

svQuad[0].Position = D3DXVECTOR4( -0.5f, -0.5f, 0.5f, 1.0f );
svQuad[0].Texture = D3DXVECTOR2( fLeftU, fTopV );

svQuad[1].Position = D3DXVECTOR4( fWidth5, -0.5f, 0.5f, 1.0f );
svQuad[1].Texture = D3DXVECTOR2( fRightU, fTopV );

svQuad[2].Position = D3DXVECTOR4( -0.5f, fHeight5, 0.5f, 1.0f );
svQuad[2].Texture = D3DXVECTOR2( fLeftU, fBottomV );

svQuad[3].Position = D3DXVECTOR4( fWidth5, fHeight5, 0.5f, 1.0f );
svQuad[3].Texture = D3DXVECTOR2( fRightU, fBottomV );

DWORD oldZ;
gEngine->GraphicsDevice()->GetDeviceCOM()->GetRenderState( D3DRS_ZENABLE, &oldZ );

if (oldZ)
gEngine->GraphicsDevice()->GetDeviceCOM()->SetRenderState( D3DRS_ZENABLE, FALSE );

gEngine->GraphicsDevice()->GetDeviceCOM()->SetFVF( D3DFVF_XYZRHW | D3DFVF_TEX1 );
gEngine->GraphicsDevice()->GetDeviceCOM()->DrawPrimitiveUP( D3DPT_TRIANGLESTRIP, 2, svQuad, sizeof( QuadVertex ) );

if (oldZ)
gEngine->GraphicsDevice()->GetDeviceCOM()->SetRenderState( D3DRS_ZENABLE, TRUE );



Which works just fine but does not go through the shader because of the D3DFVF_XYZRHW value.

So I tried to use XYZ and XYZW but both gave me incorrect results. I also tried rendering the quad at size of [0,1] and sizes [-1,1] as I saw online some discussions, both failed, also [0,width/height] seems to have failed, but I may have not tried XYZ or XYZW in one or the other.

What is the solution for this ? How should I make my vertices so I can have a fullscreen quad which will also go through the vertex shader (the reason for it to go through the vertex shader is because I need a corner index of the quad to pass values to the pixel shader, so my texture UV is actually D3DXVECTOR3 with z being the index).

I already tired that (and yes, I know how to set vertex decelerations thanks) and it didn't work, I said that in the beginning of the thread, that is why I came here.