use 1/16 the size (20KB) for the dim texture in the copybit/msm case

     * This burns a full-screen worth of graphic memory.

     */

    // copybit supports 4x scaling, so we only need to allocate 1/16 of the

    // buffer.

    // FIXME: we have to add 1px because the mdp fails

    w = w/4 + 1;

    h = h/4 + 1;

    const DisplayHardware& hw(flinger->graphicPlane(0).displayHardware());

    uint32_t flags = hw.getFlags();

        // initialize the texture with zeros

        GGLSurface t;

        buffer->lock(&t, GRALLOC_USAGE_SW_READ_NEVER | GRALLOC_USAGE_SW_WRITE_OFTEN);

        memset(t.data, 0, t.width * t.stride * 2);

        memset(t.data, 0, t.stride * t.height * 2);

        buffer->unlock();

        sUseTexture = true;

    }