Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <memdraw.h>

int
cloadmemimage(Memimage *i, Rectangle r, uchar *data, int ndata)
{
        int y, bpl, c, cnt, offs;
        uchar mem[NMEM], *memp, *omemp, *emem, *linep, *elinep, *u, *eu;

        if(!rectinrect(r, i->r))
                return -1;
        bpl = bytesperline(r, i->depth);
        u = data;
        eu = data+ndata;
        memp = mem;
        emem = mem+NMEM;
        y = r.min.y;
        linep = byteaddr(i, Pt(r.min.x, y));
        elinep = linep+bpl;
        for(;;){
                if(linep == elinep){
                        if(++y == r.max.y)
                                break;
                        linep = byteaddr(i, Pt(r.min.x, y));
                        elinep = linep+bpl;
                }
                if(u == eu){    /* buffer too small */
                        return -1;
                }
                c = *u++;
                if(c >= 128){
                        for(cnt=c-128+1; cnt!=0 ;--cnt){
                                if(u == eu){            /* buffer too small */
                                        return -1;
                                }
                                if(linep == elinep){    /* phase error */
                                        return -1;
                                }
                                *linep++ = *u;
                                *memp++ = *u++;
                                if(memp == emem)
                                        memp = mem;
                        }
                }
                else{
                        if(u == eu)     /* short buffer */
                                return -1;
                        offs = *u++ + ((c&3)<<8)+1;
                        if(memp-mem < offs)
                                omemp = memp+(NMEM-offs);
                        else
                                omemp = memp-offs;
                        for(cnt=(c>>2)+NMATCH; cnt!=0; --cnt){
                                if(linep == elinep)     /* phase error */
                                        return -1;
                                *linep++ = *omemp;
                                *memp++ = *omemp++;
                                if(omemp == emem)
                                        omemp = mem;
                                if(memp == emem)
                                        memp = mem;
                        }
                }
        }
        return u-data;
}