libmng_pixels.c

Trolltech公司发布的基于C++图形开发环境

  mng_uint8  iCr8, iCg8, iCb8;

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_DISPLAY_BGRA8, MNG_LC_START)
#endif
                                       /* viewable row ? */
  if ((pData->iRow >= pData->iSourcet) && (pData->iRow < pData->iSourceb))
  {                                    /* address destination row */
    pScanline = (mng_uint8p)pData->fGetcanvasline (((mng_handle)pData),
                                                   pData->iRow + pData->iDestt -
                                                   pData->iSourcet);
                                       /* adjust destination row starting-point */
    pScanline = pScanline + (pData->iCol << 2) + (pData->iDestl << 2);
    pDataline = pData->pRGBArow;       /* address source row */

    if (pData->bIsRGBA16)              /* adjust source row starting-point */
      pDataline = pDataline + ((pData->iSourcel / pData->iColinc) << 3);
    else
      pDataline = pDataline + ((pData->iSourcel / pData->iColinc) << 2);

    if (pData->bIsOpaque)              /* forget about transparency ? */
    {
      if (pData->bIsRGBA16)            /* 16-bit input row ? */
      {
        for (iX = pData->iSourcel + pData->iCol; iX < pData->iSourcer; iX += pData->iColinc)
        {                              /* scale down by dropping the LSB */
          *pScanline     = *(pDataline+4);
          *(pScanline+1) = *(pDataline+2);
          *(pScanline+2) = *pDataline;
          *(pScanline+3) = *(pDataline+6);

          pScanline += (pData->iColinc << 2);
          pDataline += 8;
        }
      }
      else
      {
        for (iX = pData->iSourcel + pData->iCol; iX < pData->iSourcer; iX += pData->iColinc)
        {                              /* copy the values */
          *pScanline     = *(pDataline+2);
          *(pScanline+1) = *(pDataline+1);
          *(pScanline+2) = *pDataline;
          *(pScanline+3) = *(pDataline+3);

          pScanline += (pData->iColinc << 2);
          pDataline += 4;
        }
      }
    }
    else
    {
      if (pData->bIsRGBA16)            /* 16-bit input row ? */
      {
        for (iX = pData->iSourcel + pData->iCol; iX < pData->iSourcer; iX += pData->iColinc)
        {                              /* get alpha values */
          iFGa16 = mng_get_uint16 (pDataline+6);
          iBGa16 = (mng_uint16)(*(pScanline+3));
          iBGa16 = (mng_uint16)(iBGa16 << 8) | iBGa16;

          if (iFGa16)                  /* any opacity at all ? */
          {                            /* fully opaque or background fully transparent ? */
            if ((iFGa16 == 0xFFFF) || (iBGa16 == 0))
            {                          /* plain copy it */
              *pScanline     = *(pDataline+4);
              *(pScanline+1) = *(pDataline+2);
              *(pScanline+2) = *pDataline;
              *(pScanline+3) = *(pDataline+6);
            }
            else
            {
              if (iBGa16 == 0xFFFF)    /* background fully opaque ? */
              {                        /* get the proper values */
                iFGr16 = mng_get_uint16 (pDataline  );
                iFGg16 = mng_get_uint16 (pDataline+2);
                iFGb16 = mng_get_uint16 (pDataline+4);
                                       /* scale background up */
                iBGr16 = (mng_uint16)(*(pScanline+2));
                iBGg16 = (mng_uint16)(*(pScanline+1));
                iBGb16 = (mng_uint16)(*pScanline    );
                iBGr16 = (mng_uint16)((mng_uint32)iBGr16 << 8) | iBGr16;
                iBGg16 = (mng_uint16)((mng_uint32)iBGg16 << 8) | iBGg16;
                iBGb16 = (mng_uint16)((mng_uint32)iBGb16 << 8) | iBGb16;
                                       /* now compose */
                MNG_COMPOSE16(iFGr16, iFGr16, iFGa16, iBGr16)
                MNG_COMPOSE16(iFGg16, iFGg16, iFGa16, iBGg16)
                MNG_COMPOSE16(iFGb16, iFGb16, iFGa16, iBGb16)
                                       /* and return the composed values */
                *pScanline     = (mng_uint8)(iFGb16 >> 8);
                *(pScanline+1) = (mng_uint8)(iFGg16 >> 8);
                *(pScanline+2) = (mng_uint8)(iFGr16 >> 8);
                                       /* alpha remains fully opaque !!! */
              }
              else
              {                        /* scale background up */
                iBGr16 = (mng_uint16)(*(pScanline+2));
                iBGg16 = (mng_uint16)(*(pScanline+1));
                iBGb16 = (mng_uint16)(*pScanline    );
                iBGr16 = (mng_uint16)((mng_uint32)iBGr16 << 8) | iBGr16;
                iBGg16 = (mng_uint16)((mng_uint32)iBGg16 << 8) | iBGg16;
                iBGb16 = (mng_uint16)((mng_uint32)iBGb16 << 8) | iBGb16;
                                       /* let's blend */
                MNG_BLEND16 (mng_get_uint16 (pDataline  ),
                             mng_get_uint16 (pDataline+2),
                             mng_get_uint16 (pDataline+4), iFGa16,
                             iBGr16, iBGg16, iBGb16, iBGa16,
                             iCr16,  iCg16,  iCb16,  iCa16)
                                       /* and return the composed values */
                *pScanline     = (mng_uint8)(iCb16 >> 8);
                *(pScanline+1) = (mng_uint8)(iCg16 >> 8);
                *(pScanline+2) = (mng_uint8)(iCr16 >> 8);
                *(pScanline+3) = (mng_uint8)(iCa16 >> 8);
              }
            }
          }

          pScanline += (pData->iColinc << 2);
          pDataline += 8;
        }
      }
      else
      {
        for (iX = pData->iSourcel + pData->iCol; iX < pData->iSourcer; iX += pData->iColinc)
        {
          iFGa8 = *(pDataline+3);      /* get alpha values */
          iBGa8 = *(pScanline+3);

          if (iFGa8)                   /* any opacity at all ? */
          {                            /* fully opaque or background fully transparent ? */
            if ((iFGa8 == 0xFF) || (iBGa8 == 0))
            {                          /* then simply copy the values */
              *pScanline     = *(pDataline+2);
              *(pScanline+1) = *(pDataline+1);
              *(pScanline+2) = *pDataline;
              *(pScanline+3) = *(pDataline+3);
            }
            else
            {
              if (iBGa8 == 0xFF)       /* background fully opaque ? */
              {                        /* do alpha composing */
                MNG_COMPOSE8 (*pScanline,     *(pDataline+2), iFGa8, *pScanline    )
                MNG_COMPOSE8 (*(pScanline+1), *(pDataline+1), iFGa8, *(pScanline+1))
                MNG_COMPOSE8 (*(pScanline+2), *pDataline,     iFGa8, *(pScanline+2))
                                       /* alpha remains fully opaque !!! */
              }
              else
              {                        /* now blend */
                MNG_BLEND8 (*pDataline,     *(pDataline+1), *(pDataline+2), iFGa8,
                            *(pScanline+2), *(pScanline+1), *pScanline,     iBGa8,
                            iCr8, iCg8, iCb8, iCa8)
                                       /* and return the composed values */
                *pScanline     = iCb8;
                *(pScanline+1) = iCg8;
                *(pScanline+2) = iCr8;
                *(pScanline+3) = iCa8;
              }
            }
          }

          pScanline += (pData->iColinc << 2);
          pDataline += 4;
        }
      }
    }
  }

  check_update_region (pData);

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_DISPLAY_BGRA8, MNG_LC_END)
#endif

  return MNG_NOERROR;
}

/* ************************************************************************** */

mng_retcode display_bgra8_pm (mng_datap pData)
{
  mng_uint8p pScanline;
  mng_uint8p pDataline;
  mng_int32  iX;
  mng_uint32 s, t;

#ifdef MNG_SUPPORT_TRACE
  MNG_TRACE (pData, MNG_FN_DISPLAY_BGRA8PM, MNG_LC_START)
#endif
                                       /* viewable row ? */
  if ((pData->iRow >= pData->iSourcet) && (pData->iRow < pData->iSourceb))
  {                                    /* address destination row */
    pScanline = (mng_uint8p)pData->fGetcanvasline (((mng_handle)pData),
                                                   pData->iRow + pData->iDestt -
                                                   pData->iSourcet);
                                       /* adjust destination row starting-point */
    pScanline = pScanline + (pData->iCol << 2) + (pData->iDestl << 2);
    pDataline = pData->pRGBArow;       /* address source row */

    if (pData->bIsRGBA16)              /* adjust source row starting-point */
      pDataline = pDataline + ((pData->iSourcel / pData->iColinc) << 3);
    else
      pDataline = pDataline + ((pData->iSourcel / pData->iColinc) << 2);

    if (pData->bIsOpaque)              /* forget about transparency ? */
    {
      if (pData->bIsRGBA16)            /* 16-bit input row ? */
      {
        for (iX = pData->iSourcel + pData->iCol; iX < pData->iSourcer; iX += pData->iColinc)
        {                              /* scale down by dropping the LSB */
		  if ((s = pDataline[6]) == 0)
			*(mng_uint32*) pScanline = 0; /* set all components = 0 */
		  else
		  {
			if (s == 255)
			{
		      pScanline[0] = pDataline[4];
              pScanline[1] = pDataline[2];
              pScanline[2] = pDataline[0];
              pScanline[3] = 255;
			}
			else
			{
              pScanline[0] = DIV255B8(s * pDataline[4]);
              pScanline[1] = DIV255B8(s * pDataline[2]);
              pScanline[2] = DIV255B8(s * pDataline[0]);
              pScanline[3] = (mng_uint8)s;
			}
		  }
          pScanline += (pData->iColinc << 2);
          pDataline += 8;
        }
      }
      else
      {
        for (iX = pData->iSourcel + pData->iCol; iX < pData->iSourcer; iX += pData->iColinc)
        {                              /* copy the values and premultiply */
		  if ((s = pDataline[3]) == 0)
			*(mng_uint32*) pScanline = 0; /* set all components = 0 */
		  else
		  {
			if (s == 255)
			{
		      pScanline[0] = pDataline[2];
              pScanline[1] = pDataline[1];
              pScanline[2] = pDataline[0];
              pScanline[3] = 255;
			}
			else
			{
		      pScanline[0] = DIV255B8(s * pDataline[2]);
              pScanline[1] = DIV255B8(s * pDataline[1]);
              pScanline[2] = DIV255B8(s * pDataline[0]);
              pScanline[3] = (mng_uint8)s;
			}
		  }

          pScanline += (pData->iColinc << 2);
          pDataline += 4;
        }
      }
    }
    else
    {
      if (pData->bIsRGBA16)            /* 16-bit input row ? */
      {
        for (iX = pData->iSourcel + pData->iCol; iX < pData->iSourcer; iX += pData->iColinc)
        {                              /* get alpha values */
          if ((s = pDataline[6]) != 0)       /* any opacity at all ? */
          {                            /* fully opaque or background fully transparent ? */
            if (s == 255)
            {                          /* plain copy it */
              pScanline[0] = pDataline[4];
              pScanline[1] = pDataline[2];
              pScanline[2] = pDataline[0];
              pScanline[3] = 255;
            }
            else
            {                          /* now blend (premultiplied) */
			  t = 255 - s;
			  pScanline[0] = DIV255B8(s * pDataline[4] + t * pScanline[0]);
              pScanline[1] = DIV255B8(s * pDataline[2] + t * pScanline[1]);
              pScanline[2] = DIV255B8(s * pDataline[0] + t * pScanline[2]);
              pScanline[3] = (mng_uint8)(255 - DIV255B8(t * (255 - pScanline[3])));
            }