Understanding composite and blending operation in kdrive

[Abhinav Duggal]

Hi all,
How does kdrive distinguish between blending and composite operation in
hw/kdrive/src/kaapict.c in the following code. What is the need of blending
operation separately if composite operation can perform blending?Correct me
if I am wrong.
And what are the checks in the if for composite specify.I am not very clear
about them.
Thanks.
        if (pScreenPriv->enabled && pKaaScr->info->PrepareBlend &&
            !pSrc->alphaMap && !pDst->alphaMap)
        {
            ret = kaaTryDriverBlend(op, pSrc, pDst, xSrc, ySrc, xDst, yDst,
                                    width, height);
            if (ret == 1)
                return;
        }
    }

    if (pSrc->pDrawable && (!pMask || pMask->pDrawable) &&
        pScreenPriv->enabled && pKaaScr->info->PrepareComposite &&
        !pSrc->alphaMap && (!pMask || !pMask->alphaMap) && !pDst->alphaMap)
    {
        ret = kaaTryDriverComposite(op, pSrc, pMask, pDst, xSrc, ySrc,
xMask,
                                    yMask, xDst, yDst, width, height);
        if (ret == 1)
            return;
    }
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