int s_head = x1 & 7;    int d_head = x2 & 7;    if (s_head == d_head) {        if (d_head) {            if (d_head + w > 8) {                *dst = (*src & right_side_mask [d_head]) | (*dst & left_side_mask [d_head]);                src ++; dst ++;                w -= 8 - d_head;            }            else {                gal_uint8 mask = left_ban_mask [w] << d_head;                *dst = (*src & mask) | (*dst & ~mask);                return;            }        }        while (w > 7) {            *dst++ = *src++;            w -= 8;        }        if (w) {            *dst = (*src & left_side_mask [w]) | (*dst & (right_side_mask [w]));        }    }    else if (d_head > s_head) {        int shift = d_head - s_head;        gal_uint8 sl_half = *src << shift;        gal_uint8 sr_half;        gal_uint8 sb_new;        if (d_head + w > 8) {            *dst = (sl_half & right_side_mask [d_head]) | (*dst & left_side_mask [d_head]);            dst++;            w -= 8 - d_head;        }        else {            gal_uint8 mask = left_ban_mask [w] << d_head;            *dst = (sl_half & mask) | (*dst & ~mask);            return;        }        sr_half = *src & right_ban_mask [shift];        while (w > 7) {            src++;            sl_half = *src << shift;            sb_new = sl_half | (sr_half >> (8 - shift));            sr_half = *src & right_ban_mask [shift];            *dst = sb_new;            dst++;             w -= 8;        }        if (w) {            sr_half = *src & right_ban_mask [shift];            if (w > shift) {                src++;                sl_half = *src << shift;                sb_new = sl_half | (sr_half >> (8 - shift));            }            else                sb_new = (sr_half >> (8 - shift));            *dst = (sb_new & left_side_mask [w]) | (*dst & right_side_mask[w]);        }    }    else /* s_head > d_head */    {        int shift = s_head - d_head;        gal_uint8 sl_half = *src >> shift;        gal_uint8 sr_half;        gal_uint8 sb_new;        if (s_head + w > 8) {            sr_half = *(src + 1) & (left_ban_mask [shift]);            sb_new = sl_half | (sr_half << (8 - shift));        }        else            sb_new = sl_half;        if (d_head) {            if (d_head + w > 8) {                *dst = (sb_new & right_side_mask [d_head]) | (*dst & left_side_mask [d_head]);                dst++; src++;                w -= 8 - d_head;            }            else {                gal_uint8 mask = left_ban_mask [w] << d_head;                *dst = (sb_new & mask) | (*dst & ~mask);                return;            }        }        while (w > 7) {            sl_half = *src >> shift;            sr_half = *(++src) & (left_ban_mask [shift]);            sb_new = sl_half | (sr_half << (8 - shift));            *dst = sb_new;            dst++;             w -= 8;        }        if (w) {            sl_half = *src >> shift;            if (w > 8 - shift) {                sr_half = *(++src) & (left_ban_mask [shift]);                sb_new = sl_half | (sr_half << (8 - shift));            }            else                sb_new = sl_half;            *dst = (sb_new & left_side_mask [w]) | (*dst & right_side_mask[w]);        }    }}#if 0/* copy line from right to left, used when dst and src overlap */static void fblin1_copyline_rl (gal_uint8 *src, int x1, gal_uint8 *dst, int x2, int w){    int s_tail = (x1 + w - 1) & 7;    int d_tail = (x2 + w - 1) & 7;    if (s_tail == d_tail) {        if (d_tail) {            if (w > d_tail) {                *dst = (*src & left_side_mask [d_tail]) | (*dst & right_side_mask [d_tail]);                src --; dst --;                w -= d_tail;            }            else {                gal_uint8 mask = right_ban_mask [w] >> (8 - d_tail);                *dst = (*src & mask) | (*dst & ~mask);                return;            }        }        while (w > 7) {            *dst-- = *src--;            w -= 8;        }        if (w)            *dst = (*src & right_side_mask [w]) | (*dst & left_side_mask [w]);    }    else if (s_tail > d_tail) {        int shift = s_tail - d_tail;        gal_uint8 sr_half = *src >> shift;        gal_uint8 sl_half;        gal_uint8 sb_new;                if (w > d_tail) {            *dst = (sr_half & left_side_mask [d_tail]) | (*dst & right_side_mask [d_tail]);            dst--;            w -= d_tail;        }        else {            gal_uint8 mask = right_ban_mask [w] >> (8 - d_tail);            *dst = (sr_half & mask) | (*dst & ~mask);            return;        }        sl_half = *src & left_ban_mask [shift];        while (w > 7) {            src--;            sr_half = *src >> shift;            sb_new = sr_half | (sl_half << (8 - shift));            sl_half = *src & left_ban_mask [shift];            *dst = sb_new; dst--;            w -= 8;        }        if (w) {            src--;            sr_half = *src >> shift;            sb_new = sr_half | (sl_half << (8 - shift));            *dst = (sb_new & right_side_mask [w]) | (*dst & left_side_mask[w]);        }    }    else /* d_tail > s_tail */    {        int shift = d_tail - s_tail;        gal_uint8 sr_half = *src << shift;        gal_uint8 sl_half;        gal_uint8 sb_new;        if (w > s_tail) {            sl_half = *(src - 1) & (right_ban_mask [shift]);            sb_new = sr_half | (sl_half >> (8 - shift));        }        else            sb_new = sr_half;        if (w > d_tail) {            *dst = (sb_new & left_side_mask [d_tail]) | (*dst & right_side_mask [d_tail]);            dst--; src--;            w -= d_tail;        }        else {            gal_uint8 mask = right_ban_mask [w] >> (8 - d_tail);            *dst = (sb_new & mask) | (*dst & ~mask);            return;        }        while (w > 7) {            sr_half = *src << shift;            sl_half = *(--src) & (right_ban_mask [shift]);            sb_new = sr_half | (sl_half >> (8 - shift));            *dst = sb_new;            dst--;            w -= 8;        }        if (w) {            sr_half = *src << shift;            if (w > 8 - shift) {                sl_half = *(--src) & (right_ban_mask [shift]);                sb_new = sr_half | (sl_half >> (8 - shift));            }            else                sb_new = sr_half;            *dst = (sb_new & right_side_mask [w]) | (*dst & left_side_mask[w]);        }    }}#endifstatic void fblin1_copybox (PSD psd, int x1, int y1, int w, int h, int x2, int y2){    register gal_uint8 *src, *dst;    register int linelen = psd->linelen;    if (y1 == y2) {        if (x1 < x2 && x1 + w > x2) {#if 0            src= psd->addr + y1 * linelen + ((x1 + w - 1)>> 3);            dst= psd->addr + y2 * linelen + ((x2 + w - 1)>> 3);            while (h) {                fblin1_copyline_rl (src, x1, dst, x2, w);                src += linelen;                dst += linelen;                h--;            }#else            gal_uint8 *tmp = alloca (w >> 3);            src= psd->addr + y1 * linelen + (x1 >> 3);            dst= psd->addr + y2 * linelen + (x2 >> 3);            while (h) {                fblin1_copyline_lr (src, x1, tmp, 0, w);                fblin1_copyline_lr (tmp, 0, dst, x2, w);                src += linelen;                dst += linelen;                h--;            }#endif        }        else {            src= psd->addr + y1 * linelen + (x1 >> 3);            dst= psd->addr + y2 * linelen + (x2 >> 3);            while (h) {                fblin1_copyline_lr (src, x1, dst, x2, w);                src += linelen;                dst += linelen;                h--;            }        }    }    else if (y1 < y2 && y1 + h >= y2) {        y1 += (h-1);        y2 += (h-1);        src= psd->addr + y1 * linelen + (x1 >> 3);        dst= psd->addr + y2 * linelen + (x2 >> 3);        while (h) {            fblin1_copyline_lr (src, x1, dst, x2, w);            src -= linelen;            dst -= linelen;            h--;        }    }    else {        src= psd->addr + y1 * linelen + (x1 >> 3);        dst= psd->addr + y2 * linelen + (x2 >> 3);        while (h) {            fblin1_copyline_lr (src, x1, dst, x2, w);            src += linelen;            dst += linelen;            h--;        }    }}/* blit, no clipping */static void fblin1_blit (PSD dstpsd, int dstx, int dsty, int w, int h,    PSD srcpsd, int srcx, int srcy){    gal_uint8* dst;    gal_uint8* src;    dst = get_pixel_address (dstpsd, dstx, dsty);    src = get_pixel_address (srcpsd, srcx, srcy);    while (h) {        fblin1_copyline_lr (src, srcx, dst, dstx, w);        src += srcpsd->linelen;        dst += dstpsd->linelen;        h--;    }}SUBDRIVER fblinear1 = {    fblin1_init,    fblin1_drawpixel,    fblin1_readpixel,    fblin1_drawhline,    fblin1_drawvline,    fblin1_blit,    fblin1_putbox,    fblin1_getbox,    fblin1_putboxmask,    fblin1_copybox};#endif /* _FBLIN1R_SUPPORT */