Fossil

  int idx;                    /* Row index.  First is 1.  0 used for "none" */
  int idxTop;                 /* Direct descendent highest up on the graph */
  GraphRow *pChild;           /* Child immediately above this node */
  u8 isDup;                   /* True if this is duplicate of a prior entry */
  u8 bDescender;              /* True if riser from bottom of graph to here. */
  i8 iRail;                   /* Which rail this check-in appears on. 0-based.*/
  i8 mergeOut;                /* Merge out to this rail.  -1 if no merge-out */
  u8 mergeIn[GR_MAX_RAIL];    /* Merge in from non-zero rails */
  int aiRiser[GR_MAX_RAIL];   /* Risers from this node to a higher row. */

  int mergeUpto;              /* Draw the mergeOut rail up to this level */
  u32 mergeDown;              /* Draw merge lines up from bottom of graph */

  u32 railInUse;              /* Mask of occupied rails at this row */
};

/* Context while building a graph

  if( pParent->mergeOut<0 ){
    u = pParent->aiRiser[pParent->iRail];
    if( u>0 && u<pChild->idx ){
      /* The thick arrow up to the next primary child of pDesc goes
      ** further up than the thin merge arrow riser, so draw them both
      ** on the same rail. */
      pParent->mergeOut = pParent->iRail*4;
      if( pParent->iRail<pChild->iRail ) pParent->mergeOut += 2;
      pParent->mergeUpto = pChild->idx;
    }else{
      /* The thin merge arrow riser is taller than the thick primary
      ** child riser, so use separate rails. */
      int iTarget = pParent->iRail;
      pParent->mergeOut = findFreeRail(p, pChild->idx, pParent->idx-1,
                                       0, iTarget)*4 + 1;
      pParent->mergeUpto = pChild->idx;
      mask = 1<<(pParent->mergeOut/4);
      for(pLoop=pChild->pNext; pLoop && pLoop->rid!=pParent->rid;
           pLoop=pLoop->pNext){
        pLoop->railInUse |= mask;
      }
    }
  }
  pChild->mergeIn[pParent->mergeOut/4] = (pParent->mergeOut&3)+1;
}


/*
** Compute the complete graph
*/
void graph_finish(GraphContext *p, int omitDescenders){

    for(i=1; i<pRow->nParent; i++){
      int parentRid = pRow->aParent[i];
      pDesc = hashFind(p, parentRid);
      if( pDesc==0 ){
        /* Merge from a node that is off-screen */
        int iMrail = findFreeRail(p, pRow->idx, p->nRow, 0, 0);
        mask = 1<<iMrail;
        pRow->mergeIn[iMrail] = 2;
        pRow->mergeDown |= mask;
        for(pLoop=pRow->pNext; pLoop; pLoop=pLoop->pNext){
          pLoop->railInUse |= mask;
        }
      }else{
        /* Merge from an on-screen node */
        createMergeRiser(p, pDesc, pRow);

  /*
  ** Find the maximum rail number.
  */
  p->mxRail = 0;
  for(pRow=p->pFirst; pRow; pRow=pRow->pNext){
    if( pRow->iRail>p->mxRail ) p->mxRail = pRow->iRail;
    if( pRow->mergeOut/4>p->mxRail ) p->mxRail = pRow->mergeOut/4;
    while( p->mxRail<GR_MAX_RAIL && pRow->mergeDown>((1<<(p->mxRail+1))-1) ){
      p->mxRail++;
    }
  }
}

    **        to get an actual id, prepend "m" to the integer.  The top node
    **        is 1 and numbers increase moving down the timeline.
    **   bg:  The background color for this row
    **    r:  The "rail" that the node for this row sits on.  The left-most
    **        rail is 0 and the number increases to the right.
    **    d:  True if there is a "descender" - an arrow coming from the bottom
    **        of the page straight up to this node.
    **   mo:  "merge-out".  If non-zero, this is one more than the x-coordinate
    **        for the upward portion of a merge arrow.  The merge arrow goes up
    **        to the row identified by mu:.  If this value is zero then
    **        node has no merge children and no merge-out line is drawn.
    **   mu:  The id of the row which is the top of the merge-out arrow.





    **    u:  Draw a thick child-line out of the top of this node and up to
    **        the node with an id equal to this value.  0 if there is no
    **        thick-line riser.
    **   au:  An array of integers that define thick-line risers for branches.
    **        The integers are in pairs.  For each pair, the first integer is
    **        is the rail on which the riser should run and the second integer
    **        is the id of the node upto which the riser should run.
    **   mi:  "merge-in".  An array of integer x-coordinates from which
    **        merge arrows should be drawn into this node.  If the value is
    **        negative, then the x-coordinate is the absolute value of mi[]
    **        and a thin merge-arrow descender is drawn to the bottom of
    **        the screen.
    */
    cgi_printf("var rowinfo = [\n");
    for(pRow=pGraph->pFirst; pRow; pRow=pRow->pNext){
      int mo = pRow->mergeOut;
      if( mo<0 ){
        mo = 0;
      }else{
        mo = (mo/4)*20 - 3 + 4*(mo&3);
      }
      cgi_printf("{id:%d,bg:\"%s\",r:%d,d:%d,mo:%d,mu:%d,u:%d,au:",
        pRow->idx,                      /* id */
        pRow->zBgClr,                   /* bg */
        pRow->iRail,                    /* r */
        pRow->bDescender,               /* d */
        mo,                             /* mo */
        pRow->mergeUpto,                /* mu */

        pRow->aiRiser[pRow->iRail]      /* u */
      );
      /* u */
      cSep = '[';
      for(i=0; i<GR_MAX_RAIL; i++){
        if( i==pRow->iRail ) continue;
        if( pRow->aiRiser[i]>0 ){
          cgi_printf("%c%d,%d", cSep, i, pRow->aiRiser[i]);
          cSep = ',';
        }
      }
      if( cSep=='[' ) cgi_printf("[");
      cgi_printf("],mi:");
      /* mi */
      cSep = '[';
      for(i=0; i<GR_MAX_RAIL; i++){
        if( pRow->mergeIn[i] ){
          int mi = i*20 - 8 + 4*pRow->mergeIn[i];
          if( pRow->mergeDown & (1<<i) ) mi = -mi;
          cgi_printf("%c%d", cSep, mi);
          cSep = ',';
        }
      }
      if( cSep=='[' ) cgi_printf("[");
      cgi_printf("]}%s", pRow->pNext ? ",\n" : "];\n");
    }
    cgi_printf("var nrail = %d\n", pGraph->mxRail+1);

    @     var u = rowinfo[p.u-1];
    @     drawUpArrow(p.x, u.y+6, p.y-5);
    @   }
    @   if( p.d ){
    @     drawUpArrow(p.x, p.y+6, btm);
    @   } 
    @   if( p.mo>0 ){
    @     var x1 = p.mo + left - 1;
    @     var y1 = p.y-3;
    @     var x0 = x1>p.x ? p.x+7 : p.x-6;
    @     var u = rowinfo[p.mu-1];
    @     var y0 = u.y+5;
    @     if( x1>=p.x-5 && x1<=p.x+5 ){
    @       y1 = p.y-5;
    @     }else{
    @       drawThinLine(x0,y1,x1,y1);
    @     }
    @     drawThinLine(x1,y0,x1,y1);
    @   }
    @   var n = p.au.length;

    @       drawBox("#600000",x1,u.y,u.x-6,u.y+1);
    @       drawBox("#600000",u.x-9,u.y-1,u.x-8,u.y+2);
    @       drawBox("#600000",u.x-11,u.y-2,u.x-10,u.y+3);
    @     }
    @   }
    @   for(var j in p.mi){
    @     var y0 = p.y+5;
    @     var mx = p.mi[j];
    @     if( mx<0 ){
    @       mx = left-mx;
    @       drawThinLine(mx,y0,mx,btm);
    @     }else{
    @       mx += left;
    @     }
    @     if( mx>p.x ){
    @       drawThinArrow(y0,mx,p.x+6);
    @     }else{
    @       drawThinArrow(y0,mx,p.x-5);
    @     }



    @   }
    @ }
    @ function renderGraph(){
    @   var canvasDiv = document.getElementById("canvas");
    @   while( canvasDiv.hasChildNodes() ){
    @     canvasDiv.removeChild(canvasDiv.firstChild);
    @   }