bbg888.c

来自「linux嵌入式开发程序」· C语言 代码 · 共 92 行

/*===========================================================================
        2D Graphics Library
        ALL RIGHTS RESERVED, COPYRIGHT (C) FUJITSU LIMITED 1993-2002
        LICENSED MATERIAL - PROGRAM PROPERTY OF FUJITSU LIMITED
 ===========================================================================*/

#include "gl.h"
#include "defhook.h"

#define BitLen  24

int
_GL_bbgetRGB888(GL_WP *gp)
{
    long    soffs ;
    int     sbitp,dbitp,words,lines ;
    DWORD   dmask_head, dmask_tail ;
    char    *dadr ;

    soffs = gp->bitblt.soffs ;
    sbitp = gp->bitblt.sbitp ;
    dadr  = (char *)gp->bitblt.doffs ;
    dbitp = gp->bitblt.dbitp ;
    lines = gp->bitblt.ty ;

    while(lines--){

        AdjAccOffs32(soffs,sbitp) ;
        AdjAccAdr32(dadr, dbitp) ;

        dmask_head = (DWORD)-1L >> dbitp ;
        words      = gp->bitblt.tx * BitLen + dbitp ;
        dmask_tail = ~((DWORD)-1L >> (words&31)) ;
        words    >>= 5 ;

        if(words==0){
            dmask_head &= dmask_tail ;
            dmask_tail  = 0 ;
        } else
            words-- ;

        {
            register DWORD   *src ;
            register DWORD   *dst ;
            register DWORD   d, o ;
            register int     n ;

            src = _AddAdr(gp->hwork.VRAMadr[gp->hwork.page][0],soffs) ;
            dst = (DWORD  *)dadr ;

            n = sbitp-dbitp ;
            if(n){
                register int un ;
                d = *src++ ;
                if(n<0){
                    un = -n ;
                    n += 32 ;
                    *dst++ = *dst & ~dmask_head | (d>>un) & dmask_head ;
                } else {
                    un = 32 - n ;
                    o = *src++ ;
                    d = (d<<n)|(o>>un) ;
                    *dst++ = *dst & ~dmask_head | d & dmask_head ;
                    d = o ;
                }
                while(words--){
                    o = *src++ ;
                    *dst++ = (d<<n)|(o>>un) ;
                    d = o ;
                }
                if(dmask_tail)
                    *dst = *dst & ~dmask_tail| ((d<<n)|(*src>>un)) & dmask_tail ;
             } else {

                *dst++ = *dst & ~dmask_head | *src++ & dmask_head ;

                while(words--)
                    *dst++ = *src++ ;

                if(dmask_tail)
                    *dst = *dst & ~dmask_tail| *src & dmask_tail ;
            }
        }
        soffs += gp->bitblt.slbytes ;
        dadr   = _AddAdr(dadr, gp->bitblt.dlbytes) ;
    }

    return GL_Ok ;
}