out_scrn.c

unix vnc 协议源码. VNC是一款远程控制工具软件.

	else if (xloc == sp_intercepts.car[to] && xfrac < (sp_intercepts.inttype[to] & FRACTION))
        goto insert_element; /* ... drop out and insert here */
    from = to; /* move forward in list */
    }

insert_element: /* insert element "sp_globals.next_offset" between elements "from" */
                /* and "to" */

sp_intercepts.cdr[from] = sp_globals.next_offset;
sp_intercepts.cdr[sp_globals.next_offset] = to;

if (++sp_globals.next_offset >= MAX_INTERCEPTS) /* Intercept buffer full? */
    {
    sp_globals.intercept_oflo = TRUE;
/* There may be a few more calls to "add_intercept" from the current line */
/* To avoid problems, we set next_offset to a safe value. We don't care   */
/* if the intercept table gets trashed at this point                      */
    sp_globals.next_offset = sp_globals.first_offset;
    }
}

#endif

#if INCL_SCREEN
FUNCTION LOCAL  void sp_proc_intercepts_screen()
GDECL

/*  Called by sp_make_char to output accumulated intercept lists
 *  Clips output to sp_globals.xmin, sp_globals.xmax, sp_globals.ymin, sp_globals.ymax boundaries
 */
{
register fix15 i,j, jplus1, iminus1;
fix15 k,nextk, previ;
register fix15 from, to;          /* Start and end of run in pixel units   
                            relative to left extent of character  */
register fix15 y;
register fix15 scan_line;
         fix15 first_y, last_y;
         fix15 xsave;
         fix15 xmin, xmax;
         boolean clipleft, clipright;


fix15 diff;

#if DEBUG
printf("\nPROC_INTERCEPTS_SCREEN: Intercept lists before:\n");
#endif

#if INCL_CLIPPING
if ((sp_globals.specs.flags & CLIP_LEFT) != 0)
    clipleft = TRUE;
else
    clipleft = FALSE;
if ((sp_globals.specs.flags & CLIP_RIGHT) != 0)
    clipright = TRUE;
else
    clipright = FALSE;
if (clipleft || clipright)
        {
        xmax = sp_globals.clip_xmax + sp_globals.xmin;
        xmin = sp_globals.clip_xmin + sp_globals.xmin;
        }
if (!clipright)
        xmax = ((sp_globals.set_width.x+32768L) >> 16);
#endif

if ((first_y = sp_globals.y_band.band_max) >= sp_globals.ymax)    
    first_y = sp_globals.ymax - 1;               /* Clip to sp_globals.ymax boundary */

if ((last_y = sp_globals.y_band.band_min) < sp_globals.ymin)      
    last_y = sp_globals.ymin;                    /* Clip to sp_globals.ymin boundary */

last_y  -= sp_globals.y_band.band_min;

#if DEBUG
/* Print out all of the intercept info */
scan_line = sp_globals.ymax - first_y - 1;

for (y = first_y - sp_globals.y_band.band_min; y >= last_y; y--, scan_line++)
    {
    i = y;                            /* Index head of intercept list */
    while ((i = sp_intercepts.cdr[i]) != 0)         /* Link to next intercept if present */
        {
        if ((from = sp_intercepts.car[i] - sp_globals.xmin) < 0)
            from = 0;                 /* Clip to sp_globals.xmin boundary */
        i = sp_intercepts.cdr[i];                   /* Link to next intercept */
        if (i == 0)                   /* End of list? */
            {
            printf("****** proc_intercepts: odd number of intercepts\n");
            break;
            }
        if ((to = sp_intercepts.car[i]) > sp_globals.xmax)
            to = sp_globals.xmax - sp_globals.xmin;         /* Clip to sp_globals.xmax boundary */
        else
            to -= sp_globals.xmin;
        printf("    Y = %2d (scanline %2d): %d %d:\n", 
            y + sp_globals.y_band.band_min, scan_line, from, to);
        }
    }
#endif

/* CHECK INTERCEPT LIST FOR DROPOUT AND WINDING, FIX IF NECESSARY  */

for (y = first_y - sp_globals.y_band.band_min; y >= last_y; y--)
    {
	previ = y;
    i = sp_intercepts.cdr[y];                            /* Index head of intercept list */
    while (i  != 0)         /* Link to next intercept if present */
        {
		j = i;
        i = sp_intercepts.cdr[i];                   /* Link to next intercept */
		if (sp_intercepts.inttype[i] & LEFT_INT)
			{
			if (sp_intercepts.inttype[j] & LEFT_INT)
				{
				do { i = sp_intercepts.cdr[i]; } while (sp_intercepts.inttype[i] & LEFT_INT);
				do { i = sp_intercepts.cdr[i]; } while (sp_intercepts.cdr[i] && !(sp_intercepts.inttype[sp_intercepts.cdr[i]] & LEFT_INT));
				sp_intercepts.cdr[j] = i;
				}
			else
				{
				xsave = sp_intercepts.car[j];
				sp_intercepts.car[j] = sp_intercepts.car[i];
				sp_intercepts.car[i] = xsave;

				xsave = sp_intercepts.inttype[j];
				sp_intercepts.inttype[j] = sp_intercepts.inttype[i] & FRACTION;
				sp_intercepts.inttype[i] = xsave | LEFT_INT;

				sp_intercepts.cdr[previ] = i;
				sp_intercepts.cdr[j] = sp_intercepts.cdr[i];
				sp_intercepts.cdr[i] = j;
				i = j;
				j = sp_intercepts.cdr[previ];
				}
			}

        if (sp_intercepts.car[j] < sp_globals.xmin)
            sp_intercepts.car[j] = sp_globals.xmin;                 /* Clip to sp_globals.xmin boundary */

        if (sp_intercepts.car[i] > sp_globals.xmax)
            sp_intercepts.car[i] = sp_globals.xmax;

        if (sp_intercepts.car[j] >= sp_intercepts.car[i])
			{
			if ((ufix16)(sp_intercepts.inttype[j] & FRACTION) + (ufix16)(sp_intercepts.inttype[i] & FRACTION) > sp_intercepts.fracpix)
				++sp_intercepts.car[i];
			else
				--sp_intercepts.car[j];
			}
		if (sp_globals.first_pass)
			{
			if (sp_intercepts.inttype[i-1] & END_INT)
				{
				for (iminus1 = i+1; !(sp_intercepts.inttype[iminus1] & END_INT); iminus1++)
					;
				}
			else
				iminus1 = i-1;
	
			if (sp_intercepts.inttype[j] & END_INT)
				{
				for (jplus1 = j-1; !(sp_intercepts.inttype[jplus1] & END_INT); jplus1--)
					;
				jplus1++;
				}
			else
				jplus1 = j+1;

			if ((sp_intercepts.inttype[iminus1] & LEFT_INT)) 
				{
				if ( sp_intercepts.car[jplus1] > sp_intercepts.car[i])
					{
					diff = sp_intercepts.car[jplus1] - sp_intercepts.car[i];
					sp_intercepts.car[i] += diff/2;
	                sp_intercepts.car[jplus1] -= diff/2;
					if (diff & 1)
						{
						if ((ufix16)(sp_intercepts.inttype[i] & FRACTION) + (ufix16)(sp_intercepts.inttype[jplus1] & FRACTION) > sp_intercepts.fracpix)
							sp_intercepts.car[i] ++;
						else
							sp_intercepts.car[jplus1]--;
						}
					}
				}
			else if (!(sp_intercepts.inttype[jplus1] & LEFT_INT))
				{
				if (sp_intercepts.car[iminus1] < sp_intercepts.car[j])
					{
					diff = sp_intercepts.car[j] - sp_intercepts.car[iminus1];
					sp_intercepts.car[j] -= diff/2;
	                sp_intercepts.car[iminus1] += diff/2;
					if (diff & 1)
						{
						if ((ufix16)(sp_intercepts.inttype[j] & FRACTION) + 
	                                       (ufix16)(sp_intercepts.inttype[iminus1] & FRACTION) > sp_intercepts.fracpix)
							sp_intercepts.car[iminus1]++;
						else
							sp_intercepts.car[j]--;
						}
					}
				}
			if (sp_globals.tcb.mirror == -1) 
				{
				if (sp_intercepts.inttype[j-1] & END_INT)
					{
					for (jplus1 = j+1; !(sp_intercepts.inttype[jplus1] & END_INT); jplus1++)
						;
					}
				else
					{
					jplus1 = j-1;
					}
				}

			if (!(sp_intercepts.inttype[jplus1] & LEFT_INT) && 
                           sp_intercepts.car[j] > sp_intercepts.car[jplus1])
				{
				k = sp_intercepts.cdr[y - 1];
				while (k > 0)
					{
					nextk = sp_intercepts.cdr[k];
					if (!(sp_intercepts.inttype[k] & LEFT_INT) && 
	                        (sp_intercepts.inttype[nextk] & LEFT_INT) && 
						         sp_intercepts.car[nextk] > sp_intercepts.car[jplus1])
						{
						if ((diff=sp_intercepts.car[j] - sp_intercepts.car[k]) > 0)
							{
							if (diff <= (sp_intercepts.car[nextk] - sp_intercepts.car[jplus1]))
								{
								sp_intercepts.car[j] -= diff/2;
		    		            sp_intercepts.car[k] += diff/2;
								if (diff & 1)
									{
									if ((ufix16)(sp_intercepts.inttype[j] & FRACTION) + 
	                        	               (ufix16)(sp_intercepts.inttype[k] & FRACTION) > sp_intercepts.fracpix)
										sp_intercepts.car[j]--;
									else
										sp_intercepts.car[k]++;
									}
								}
							else
								{
						 		diff = sp_intercepts.car[nextk] - sp_intercepts.car[jplus1];
								sp_intercepts.car[nextk] -= diff/2;
		    		            sp_intercepts.car[jplus1] += diff/2;
								if (diff & 1)
									{
									if ((ufix16)(sp_intercepts.inttype[jplus1] & FRACTION) + 
	                        	               (ufix16)(sp_intercepts.inttype[nextk] & FRACTION) > sp_intercepts.fracpix)
										sp_intercepts.car[nextk]--;
									else
										sp_intercepts.car[jplus1]++;
									}
								}
							}
						break;
						}
					k = nextk;
					}
				}
			if (j > 0 && sp_intercepts.car[j-1] > sp_intercepts.car[i] && !(sp_intercepts.inttype[j-1] & END_INT))
				{
				diff = sp_intercepts.car[j-1] - sp_intercepts.car[i];
				sp_intercepts.car[i] += diff/2;
	            sp_intercepts.car[j-1] -= diff/2;
				if (diff & 1)
					{
					if ((ufix16)(sp_intercepts.inttype[i] & FRACTION) + (ufix16)(sp_intercepts.inttype[j-1] & FRACTION) > sp_intercepts.fracpix)
						sp_intercepts.car[i]++;
					else
						sp_intercepts.car[j-1]--;
					}
				}
			if (sp_intercepts.car[i+1] < sp_intercepts.car[j] && !(sp_intercepts.inttype[i] & END_INT))
				{
				diff = sp_intercepts.car[j] - sp_intercepts.car[i+1];
				sp_intercepts.car[j] -= diff/2;
	            sp_intercepts.car[i+1] += diff/2;
				if (diff & 1)
					{
					if ((ufix16)(sp_intercepts.inttype[j] & FRACTION) + (ufix16)(sp_intercepts.inttype[i+1] & FRACTION) > sp_intercepts.fracpix)
						sp_intercepts.car[i+1]++;
					else
						sp_intercepts.car[j]--;
					}
	
				}
			previ = i;
	        }
		i = sp_intercepts.cdr[i];
	    }
	}

#if DEBUG
printf("\nPROC_INTERCEPTS_SCREEN: Intercept lists after:\n");
/* Print out all of the intercept info */
scan_line = sp_globals.ymax - first_y - 1;

for (y = first_y - sp_globals.y_band.band_min; y >= last_y; y--, scan_line++)
    {
    i = y;                            /* Index head of intercept list */
    while ((i = sp_intercepts.cdr[i]) != 0)         /* Link to next intercept if present */
        {
        if ((from = sp_intercepts.car[i] - sp_globals.xmin) < 0)
            from = 0;                 /* Clip to sp_globals.xmin boundary */
        i = sp_intercepts.cdr[i];                   /* Link to next intercept */
        if (i == 0)                   /* End of list? */
            {
            printf("****** proc_intercepts: odd number of intercepts\n");
            break;
            }
        if ((to = sp_intercepts.car[i]) > sp_globals.xmax)
            to = sp_globals.xmax - sp_globals.xmin;         /* Clip to sp_globals.xmax boundary */
        else
            to -= sp_globals.xmin;
        printf("    Y = %2d (scanline %2d): %d %d:\n", 
            y + sp_globals.y_band.band_min, scan_line, from, to);
        }
    }
#endif                                                            

/*  INTERCEPTS ALL PATCHED, NOW DRAW THE IMAGE */
scan_line = sp_globals.ymax - first_y - 1;

for (y = first_y - sp_globals.y_band.band_min; y >= last_y; y--, scan_line++)
    {
    i = sp_intercepts.cdr[y];                            /* Index head of intercept list */
    while (i  != 0)         /* Link to next intercept if present */
        {
        from = sp_intercepts.car[i];
        i = sp_intercepts.cdr[i];                   /* Link to next intercept */
        to = sp_intercepts.car[i];
#if INCL_CLIPPING
        if (clipleft)
                        {
                        if (to <= xmin)
				{
		                i = sp_intercepts.cdr[i];
                                continue;
				}
                        if (from < xmin)
                                from = xmin;
                        }
        if (clipright)
                        {
                        if (from >= xmax)
				{
		                i = sp_intercepts.cdr[i];
                                continue;
				}
                        if (to > xmax)
                                to = xmax;
                        }
#endif
        set_bitmap_bits(scan_line, from-sp_globals.xmin, to-sp_globals.xmin);
	i = sp_intercepts.cdr[i];
        }
    }
}

#endif