+++ /dev/null
-/* $XConsortium: hints.c,v 1.4 91/10/10 11:18:13 rws Exp $ */
-/* Copyright International Business Machines, Corp. 1991
- * All Rights Reserved
- * Copyright Lexmark International, Inc. 1991
- * All Rights Reserved
- *
- * License to use, copy, modify, and distribute this software and its
- * documentation for any purpose and without fee is hereby granted,
- * provided that the above copyright notice appear in all copies and that
- * both that copyright notice and this permission notice appear in
- * supporting documentation, and that the name of IBM or Lexmark not be
- * used in advertising or publicity pertaining to distribution of the
- * software without specific, written prior permission.
- *
- * IBM AND LEXMARK PROVIDE THIS SOFTWARE "AS IS", WITHOUT ANY WARRANTIES OF
- * ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO ANY
- * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
- * AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. THE ENTIRE RISK AS TO THE
- * QUALITY AND PERFORMANCE OF THE SOFTWARE, INCLUDING ANY DUTY TO SUPPORT
- * OR MAINTAIN, BELONGS TO THE LICENSEE. SHOULD ANY PORTION OF THE
- * SOFTWARE PROVE DEFECTIVE, THE LICENSEE (NOT IBM OR LEXMARK) ASSUMES THE
- * ENTIRE COST OF ALL SERVICING, REPAIR AND CORRECTION. IN NO EVENT SHALL
- * IBM OR LEXMARK BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
- * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
- * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
- * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
- * THIS SOFTWARE.
- */
- /* HINTS CWEB V0006 ******** */
-/*
-:h1.HINTS Module - Processing Rasterization Hints
-
-&author. Sten F. Andler; continuity by Jeffrey B. Lotspiech (lotspiech@almaden.ibm.com) and Duaine
-W. Pryor, Jr.
-
-
-:h3.Include Files
-
-The included files are:
-*/
-
-#include "objects.h"
-#include "spaces.h"
-#include "paths.h"
-#include "regions.h"
-#include "hints.h"
-
-/*
-:h3.Functions Provided to the TYPE1IMAGER User
-
-None.
-*/
-
-/*
-:h3.Functions Provided to Other Modules
-
-This module provides the following entry point to other modules:
-*/
-
-
-/*SHARED LINE(S) ORIGINATED HERE*/
-
-/*
-:h3.Macros Provided to Other Modules
-
-None.
-*/
-
-/*
-:h2.InitHints() - Initialize hint data structure
-*/
-
-#define MAXLABEL 20
-static struct {
- int inuse;
- int computed;
- struct fractpoint hint;
-} oldHint[MAXLABEL];
-
-#define ODD(x) (((int)(x)) & 01)
-#define FPFLOOR(fp) TOFRACTPEL((fp) >> FRACTBITS)
-#define FPROUND(fp) FPFLOOR((fp) + FPHALF)
-
-void InitHints()
-{
- int i;
-
- for (i = 0; i < MAXLABEL; i++)
- {
- oldHint[i].inuse = FALSE;
- oldHint[i].computed = FALSE;
- }
-}
-
-/*
-:h3.CloseHints(hintP) - Reverse hints that are still open
-*/
-
-void CloseHints(hintP)
- struct fractpoint *hintP;
-{
- int i;
-
- for (i = 0; i < MAXLABEL; i++)
- {
- if (oldHint[i].inuse)
- {
- hintP->x -= oldHint[i].hint.x;
- hintP->y -= oldHint[i].hint.y;
-
- oldHint[i].inuse = FALSE;
-
- IfTrace3((HintDebug > 1)," Hint %d was open, hint=(%p,%p)\n",
- i, hintP->x, hintP->y);
- }
- }
-}
-
-/*
-:h3.ComputeHint(hP, currX, currY, hintP) - Compute the value of a hint
-*/
-
-static void ComputeHint(hP, currX, currY, hintP)
- struct hintsegment *hP;
- fractpel currX, currY;
- struct fractpoint *hintP;
-{
- fractpel currRef, currWidth;
- int idealWidth;
- fractpel hintValue;
- char orientation;
-
-/*
-By construction, width is never zero. Therefore we can use the
-width value to determine if the hint has been rotated by a
-multiple of 90 degrees.
-*/
-
- if (hP->width.y == 0)
- {
- orientation = 'v'; /* vertical */
- IfTrace0((HintDebug > 0)," vertical hint\n");
- }
- else if (hP->width.x == 0)
- {
- orientation = 'h'; /* horizontal */
- IfTrace0((HintDebug > 0)," horizontal hint\n");
- }
- else
- {
- IfTrace0((HintDebug > 0)," hint not vertical or horizontal\n");
- hintP->x = hintP->y = 0;
- return;
- }
-
- /* Compute currRef and currWidth with a unit of 1 pel */
- if (orientation == 'v') /* vertical */
- {
- currRef = hP->ref.x + currX;
- currWidth = ABS(hP->width.x);
- }
- else if (orientation == 'h') /* horizontal */
- {
- currRef = hP->ref.y + currY;
- currWidth = ABS(hP->width.y);
- }
- else /* error */
- {
- abort("ComputeHint: invalid orientation");
- }
-
- IfTrace4((HintDebug > 1),
- " currX=%p, currY=%p, currRef=%p, currWidth=%p\n",
- currX, currY,
- currRef, currWidth);
-
- if ((hP->hinttype == 'b') /* Bar or stem */
- || (hP->hinttype == 's')) /* Serif */
- {
- idealWidth = NEARESTPEL(currWidth);
- if (idealWidth == 0) idealWidth = 1;
- if (ODD(idealWidth)) /* Is ideal width odd? */
- {
- /* center "ref" over pel */
- hintValue = FPFLOOR(currRef) + FPHALF - currRef;
- }
- else
- {
- /* align "ref" on pel boundary */
- hintValue = FPROUND(currRef) - currRef;
- }
- if (HintDebug > 2) {
- IfTrace1(TRUE," idealWidth=%d, ", idealWidth);
- }
- }
- else if (hP->hinttype == 'c') /* Curve extrema */
- {
- /* align "ref" on pel boundary */
- hintValue = FPROUND(currRef) - currRef;
- }
- else /* error */
- {
- abort("ComputeHint: invalid hinttype");
- }
-
- IfTrace1((HintDebug > 1)," hintValue=%p", hintValue);
-
- if (orientation == 'v') /* vertical */
- {
- hintP->x = hintValue;
- hintP->y = 0;
- }
- else if (orientation == 'h') /* horizontal */
- {
- hintP->x = 0;
- hintP->y = hintValue;
- }
- else /* error */
- {
- abort("ComputeHint: invalid orientation");
- }
-}
-
-/*
-:h3.ProcessHint(hP, currX, currY, hintP) - Process a rasterization hint
-*/
-
-void ProcessHint(hP, currX, currY, hintP)
- struct hintsegment *hP;
- fractpel currX, currY;
- struct fractpoint *hintP;
-{
- struct fractpoint thisHint;
-
- IfTrace4((HintDebug > 1)," ref=(%p,%p), width=(%p,%p)",
- hP->ref.x, hP->ref.y,
- hP->width.x, hP->width.y);
- IfTrace4((HintDebug > 1),", %c %c %c %c",
- hP->orientation, hP->hinttype,
- hP->adjusttype, hP->direction);
- IfTrace1((HintDebug > 1),", label=%d\n", hP->label);
-
- if ((hP->adjusttype == 'm') /* Move */
- || (hP->adjusttype == 'a')) /* Adjust */
- {
- /* Look up hint in oldHint table */
- if ((hP->label >= 0) && (hP->label < MAXLABEL))
- {
- if (oldHint[hP->label].computed)
- /* Use old hint value if already computed */
- {
- thisHint.x = oldHint[hP->label].hint.x;
- thisHint.y = oldHint[hP->label].hint.y;
- oldHint[hP->label].inuse = TRUE;
- }
- else
- /* Compute new value for hint and store it for future use */
- {
- ComputeHint(hP, currX, currY, &thisHint);
-
- oldHint[hP->label].hint.x = thisHint.x;
- oldHint[hP->label].hint.y = thisHint.y;
- oldHint[hP->label].inuse = TRUE;
- oldHint[hP->label].computed = TRUE;
- }
- }
- else /* error */
- {
- abort("ProcessHint: invalid label");
- }
- }
- else if (hP->adjusttype == 'r') /* Reverse */
- {
- /* Use the inverse of the existing hint value to reverse hint */
- if ((hP->label >= 0) && (hP->label < MAXLABEL))
- {
- if (oldHint[hP->label].inuse)
- {
- thisHint.x = -oldHint[hP->label].hint.x;
- thisHint.y = -oldHint[hP->label].hint.y;
- oldHint[hP->label].inuse = FALSE;
- }
- else /* error */
- {
- abort("ProcessHint: label is not in use");
- }
- }
- else /* error */
- {
- abort("ProcessHint: invalid label");
- }
-
- }
- else /* error */
- {
- abort("ProcessHint: invalid adjusttype");
- }
- IfTrace3((HintDebug > 1)," label=%d, thisHint=(%p,%p)\n",
- hP->label, thisHint.x, thisHint.y);
-
- hintP->x += thisHint.x;
- hintP->y += thisHint.y;
-
- IfTrace2((HintDebug > 1)," hint=(%p,%p)\n",
- hintP->x, hintP->y);
-}
-
-/*
-:h2 id=subpath.Navigation Through Edge Lists
-
-For continuity checking purposes, we need to navigate through edge
-lists by the "subpath" chains and answer questions about edges. The
-subpath chain links together edges that were part of the same subpath
-(no intervening move segments) when the interior of the path was
-calculated. Here we use the term "edge" to mean every edge list
-that was created in between changes of direction.
-
-The subpath chains are singly-linked circular chains. For the convenience
-of building them, they direction of the list (from edge to edge) is the
-reverse of the order in which they were built. Within any single edge,
-the subpath chain goes from top-to-bottom. (There might be a violation
-of this because of the way the user started the first chain; see
-:hdref refid=fixsubp..).
-
-:h3.ISTOP() and ISBOTTOM() - Flag Bits for Edge Lists at the Top and
-Bottom of Their SubPaths
-*/
-
-#define ISTOP(flag) ((flag)&0x20)
-#define ISBOTTOM(flag) ((flag)&0x10)
-/*
-:h3.ISLEFT() - Flag Bit for Left Edges
-*/
-
-#define ISLEFT(flag) ((flag)&0x08)
-
-/*
-:h3.XofY() - Macro to Find X Value at Given Y
-
-This macro can only be used if it is known that the Y is within the
-given edgelist's ymin and ymax.
-*/
-
-#define XofY(edge, y) edge->xvalues[y - edge->ymin]
-
-/*
-:h3.findXofY() - Like XofY(), Except not Restricted
-
-If the Y is out of bounds of the given edgelist, this macro will
-call SearchXofY to search the edge's subpath chain for the correct
-Y range. If the Y value is off the edge, MINPEL is returned.
-*/
-#define findXofY(edge, y) ((y < edge->ymin || y >= edge->ymax) ? SearchXofY(edge, y) : XofY(edge, y))
-
-/*
-:h4.SearchXofY() - Routine Called by FindXofY() for Difficult Cases
-
-The concept of this routine is to follow the subpath chain to find the
-edge just below (i.e., next in chain) or just above (i.e., immediately
-before in chain. It is assumed that the Y value is no more than one
-off of the edge's range; XofY() could be replace by FindXofY() to
-call ourselves recursively if this were not true.
-*/
-
-static pel SearchXofY(edge, y)
- register struct edgelist *edge; /* represents edge */
- register pel y; /* 'y' value to find edge for */
-{
- register struct edgelist *e; /* loop variable */
-
- if (y < edge->ymin) {
- if (ISTOP(edge->flag))
- return(MINPEL);
- for (e = edge->subpath; e->subpath != edge; e = e->subpath) { ; }
- if (e->ymax == edge->ymin)
- return(XofY(e, y));
- }
- else if (y >= edge->ymax) {
- if (ISBOTTOM(edge->flag))
- return(MINPEL);
- e = edge->subpath;
- if (e->ymin == edge->ymax)
- return(XofY(e, y));
- }
- else
- return(XofY(edge, y));
-
- abort("bad subpath chain");
- /*NOTREACHED*/
-}
-/*
-:h3.ISBREAK() Macro - Tests if an Edge List is at a "Break"
-
-The subpath chains are organized top to bottom. When the bottom of
-a given edge is reached, the subpath chain points to the top of the
-next edge. We call this a "break" in the chain. The following macro
-is the simple test for the break condition:
-*/
-
-#define ISBREAK(top,bot) (top->ymax != bot->ymin)
-
-
-/*
-:h3.ImpliedHorizontalLine() - Tests for Horizontal Connectivity
-
-This function returns true if two edges are connected horizontally.
-They are connected horizontally if they are consecutive in the subpath,
-and either we are at the bottom and the first edge is going down or we
-are at the top and the first edge is going up.
-*/
-
-#define BLACKABOVE -1
-#define BLACKBELOW +1
-#define NONE 0
-
-static int ImpliedHorizontalLine(e1, e2, y)
- register struct edgelist *e1,*e2; /* two edges to check */
- register int y; /* y where they might be connected */
-{
- register struct edgelist *e3,*e4;
-
- if (ISDOWN(e1->flag) == ISDOWN(e2->flag))
- return(NONE); /* can't be consecutive unless different directions */
-/*
-Now we check for consecutiveness: Can we get from 'e1' to 'e2' with
-only one intervening break? Can we get from 'e2' to 'e1' with only one
-intervening break? 'e3' will be as far as we can get after 'e1'; 'e4'
-will be has far as we can get after 'e2':
-*/
- for (e3 = e1; !ISBREAK(e3, e3->subpath); e3 = e3->subpath) { ; }
- for (e3 = e3->subpath; e3 != e2; e3 = e3->subpath)
- if (ISBREAK(e3, e3->subpath))
- break;
-
- for (e4 = e2; !ISBREAK(e4, e4->subpath); e4 = e4->subpath) { ; }
- for (e4 = e4->subpath; e4 != e1; e4 = e4->subpath)
- if (ISBREAK(e4, e4->subpath))
- break;
-/*
-If the edges are mutually consecutive, we must have horizontal lines
-both top and bottom:
-*/
- if (e3 == e2 && e4 == e1)
- return(TRUE);
-/*
-If the edges are not consecutive either way, no horizontal lines are
-possible:
-*/
- if (e3 != e2 && e4 != e1)
- return(NONE);
-/*
-Now let's swap 'e1' and 'e2' if necessary to enforce the rule that 'e2'
-follows 'e1'. Remember that subpath chains go in the opposite direction
-from the way the subpaths were built; this led to the simplest way
-do build them.
-*/
- if (e4 != e1) {
- e2 = e1;
- e1 = e3; /* remember e3 == e2, this just swaps 'e1' and 'e2' */
- }
-/*
-Now we have everything to return the answer:
-*/
- if (ISTOP(e1->flag) && y == e1->ymin)
- return(ISDOWN(e2->flag));
- else if (ISBOTTOM(e1->flag) && y == e1->ymax)
- return(!ISDOWN(e2->flag));
- else
- abort("ImpliedHorizontalLine: why ask?");
- /*NOTREACHED*/
-}
-
-/*
-:h3 id=fixsubp.FixSubPaths() - Must be Called to Organize Subpath Chains
-
-The region-building code in Interior(), in particular splitedge(),
-maintains the rule that sub-paths are linked top-to-bottom except
-at breaks. However, it is possible that there may be a "false break"
-because the user started the subpath in the middle of an edge (and
-went in the "wrong" direction from there, up instead of down). This
-routine finds and fixes false breaks.
-
-Also, this routine sets the ISTOP and ISBOTTOM flags in the edge lists.
-*/
-
-static void FixSubPaths(R)
- register struct region *R; /* anchor of region */
-{
- register struct edgelist *e; /* fast loop variable */
- register struct edgelist *edge; /* current edge in region */
- register struct edgelist *next; /* next in subpath after 'edge' */
- register struct edgelist *break1; /* first break after 'next' */
- register struct edgelist *break2; /* last break before 'edge' */
- register struct edgelist *prev; /* previous edge for fixing links */
- int left = TRUE;
-
- for (edge = R->anchor; edge != NULL; edge = edge->link) {
-
- if (left)
- edge->flag |= ISLEFT(ON);
- left = !left;
-
- next = edge->subpath;
-
- if (!ISBREAK(edge, next))
- continue;
- if (edge->ymax < next->ymin)
- abort("disjoint subpath?");
-/*
-'edge' now contains an edgelist at the bottom of an edge, and 'next'
-contains the next subsequent edgelist in the subpath, which must be at
-the top. We refer to this a "break" in the subpath.
-*/
- next->flag |= ISTOP(ON);
- edge->flag |= ISBOTTOM(ON);
-
- if (ISDOWN(edge->flag) != ISDOWN(next->flag))
- continue;
-/*
-We are now in the unusual case; both edges are going in the same
-direction so this must be a "false break" due to the way that the user
-created the path. We'll have to fix it.
-*/
- for (break1 = next; !ISBREAK(break1, break1->subpath); break1 = break1->subpath) { ; }
-
- for (e = break1->subpath; e != edge; e = e->subpath)
- if (ISBREAK(e, e->subpath))
- break2 = e;
-/*
-Now we've set up 'break1' and 'break2'. I've found the following
-diagram invaluable. 'break1' is the first break after 'next'. 'break2'
-is the LAST break before 'edge'.
-&drawing.
- next
- +------+ +---->+------+
- +--->| >-----+ | | >-----+
- | | | | | | | |
- | +-------------+ | +-------------+
- | | |break1| | | | |
- | +->| >-------+ +->| >-----+
- | | | | | |
- | | | +-------------+
- | +------+ | | |
- | +----------------+ | | |
- | | +------+ | +->| >-----+
- | +->| >-----+ | | | |
- | | | | | +-------------+
- | +-------------+ | | | |
- | | |edge | | | |break2|
- | +->| >-----+ | +->| >-----+
- | | | | | | | |
- | | | | | | | |
- | | | | | | | |
- | +------+ | | +------+ |
- | | | |
- +---------------+ +---------------+
-
-&edrawing.
-We want to fix this situation by having 'edge' point to where 'break1'
-now points, and having 'break1' point to where 'break2' now points.
-Finally, 'break2' should point to 'next'. Also, we observe that
-'break1' can't be a bottom, and is also not a top unless it is the same
-as 'next':
-*/
- edge->subpath = break1->subpath;
-
- break1->subpath = break2->subpath;
- if (ISBREAK(break1, break1->subpath))
- abort("unable to fix subpath break?");
-
- break2->subpath = next;
-
- break1->flag &= ~ISBOTTOM(ON);
- if (break1 != next)
- break1->flag &= ~ISTOP(ON);
- }
-/*
-This region might contain "ambiguous" edges; edges exactly equal to
-edge->link. Due to the random dynamics of where they get sorted into
-the list, they can yield false crossings, where the edges appear
-to cross. This confuses our continuity logic no end. Since we can
-swap them without changing the region, we do.
-*/
- for (edge = R->anchor, prev = NULL; VALIDEDGE(edge); prev = edge, edge = prev->link) {
-
- if (! ISAMBIGUOUS(edge->flag))
- continue;
-
- next = edge->subpath;
-
- while (ISAMBIGUOUS(next->flag) && next != edge)
- next = next->subpath;
-/*
-We've finally found a non-ambiguous edge; we make sure it is left/right
-compatible with 'edge':
-*/
- if ( (ISLEFT(edge->flag) == ISLEFT(next->flag) && ISDOWN(edge->flag) == ISDOWN(next->flag) )
- || (ISLEFT(edge->flag) != ISLEFT(next->flag) && ISDOWN(edge->flag) != ISDOWN(next->flag) ) )
- continue;
-
-/*
-Incompatible, we will swap 'edge' and the following edge in the list.
-You may think that there must be a next edge in this swath. So did I.
-No! If there is a totally ambiguous inner loop, for example, we could
-get all the way to the outside without resolving ambiguity.
-*/
- next = edge->link; /* note new meaning of 'next' */
- if (next == NULL || edge->ymin != next->ymin)
- continue;
- if (prev == NULL)
- R->anchor = next;
- else
- prev->link = next;
- edge->link = next->link;
- next->link = edge;
- edge->flag ^= ISLEFT(ON);
- edge->flag &= ~ISAMBIGUOUS(ON);
- next->flag ^= ISLEFT(ON);
- next->flag &= ~ISAMBIGUOUS(ON);
- edge = next;
- }
-}
-/*
-:h3.DumpSubPaths()
-
-A debug tool.
-*/
-
-static struct edgelist *before(); /* subroutine of DumpSubPaths */
-
-static void DumpSubPaths(anchor)
- struct edgelist *anchor;
-{
-
- register struct edgelist *edge,*e,*e2;
- pel y;
-
- for (edge = anchor; VALIDEDGE(edge); edge = edge->link) {
- if (ISPERMANENT(edge->flag))
- continue;
- IfTrace0(TRUE, "BEGIN Subpath\n");
- for (e2 = edge; !ISPERMANENT(e2->flag);) {
- if (ISDOWN(e2->flag)) {
- IfTrace1(TRUE, ". Downgoing edge's top at %x\n", e2);
- for (e = e2;; e = e->subpath) {
- IfTrace4(TRUE, ". . [%5d] %5d @ %x[%x]\n",
- e->ymin, *e->xvalues, e, e->flag);
- for (y=e->ymin+1; y < e->ymax; y++)
- IfTrace2(TRUE, ". . [%5d] %5d \"\n", y, e->xvalues[y-e->ymin]);
- e->flag |= ISPERMANENT(ON);
- if (ISBREAK(e, e->subpath))
- break;
- }
- }
- else {
- IfTrace1(TRUE, ". Upgoing edge's top at %x\n", e2);
- for (e = e2; !ISBREAK(e, e->subpath); e = e->subpath) { ; }
- for (;; e=before(e)) {
- IfTrace4(TRUE, ". . [%5d] %5d @ %x[%x]\n",
- e->ymax-1, e->xvalues[e->ymax-1-e->ymin], e, e->flag);
- for (y=e->ymax-2; y >= e->ymin; y--)
- IfTrace2(TRUE, ". . [%5d] %5d \"\n", y, e->xvalues[y-e->ymin]);
- e->flag |= ISPERMANENT(ON);
- if (e == e2)
- break;
- }
- }
- do {
- e2 = before(e2);
- } while (!ISBREAK(before(e2), e2));
- }
- }
-}
-
-static struct edgelist *before(e)
- struct edgelist *e;
-{
- struct edgelist *r;
- for (r = e->subpath; r->subpath != e; r = r->subpath) { ; }
- return(r);
-}
-
-/*
-:h2.Fixing Region Continuity Problems
-
-Small regions may become disconnected when their connecting segments are
-less than a pel wide. This may be correct in some applications, but in
-many (especially small font characters), it is more pleasing to keep
-connectivity. ApplyContinuity() (invoked by +CONTINUITY on the
-Interior() fill rule) fixes connection breaks. The resulting region
-is geometrically less accurate, but may be more pleasing to the eye.
-*/
-/*
-Here are some macros which we will need:
-*/
-
-#define IsValidPel(j) (j!=MINPEL)
-
-/*
-:h3.writeXofY() - Stuffs an X Value Into an "edgelist"
-
-writeXofY writes an x value into an edge at position 'y'. It must
-update the edge's xmin and xmax. If there is a possibility that this
-new x might exceed the region's bounds, updating those are the
-responsibility of the caller.
-*/
-
-static void writeXofY(e, y, x)
- struct edgelist *e; /* relevant edgelist */
- int y; /* y value */
- int x; /* new x value */
-{
- if (e->xmin > x) e->xmin = x;
- if (e->xmax < x) e->xmax = x;
- e->xvalues[y - e->ymin] = x;
-}
-
-/*-------------------------------------------------------------------------*/
-/* the following three macros tell us whether we are at a birth point, a */
-/* death point, or simply in the middle of the character */
-/*-------------------------------------------------------------------------*/
-#define WeAreAtTop(e,i) (ISTOP(e->flag) && e->ymin == i)
-#define WeAreAtBottom(e,i) (ISBOTTOM(e->flag) && e->ymax-1 == i)
-#define WeAreInMiddle(e,i) \
- ((!ISTOP(e->flag) && !ISBOTTOM(e->flag))||(i < e->ymax-1 && i > e->ymin))
-/*
-The following macro tests if two "edgelist" structures are in the same
-swath:
-*/
-#define SAMESWATH(e1,e2) (e1->ymin == e2->ymin)
-
-/*
-:h3.CollapseWhiteRun() - Subroutine of ApplyContinuity()
-
-When we have a white run with an implied horizontal line above or
-below it, we better have black on the other side of this line. This
-function both tests to see if black is there, and adjusts the end
-points (collapses) the white run as necessary if it is not. The
-goal is to collapse the white run as little as possible.
-*/
-
-static void CollapseWhiteRun(anchor, yblack, left, right, ywhite)
- struct edgelist *anchor; /* anchor of edge list */
- pel yblack; /* y of (hopefully) black run above or below */
- struct edgelist *left; /* edgelist at left of WHITE run */
- struct edgelist *right; /* edgelist at right of WHITE run */
- pel ywhite; /* y location of white run */
-{
- struct edgelist *edge;
- struct edgelist *swathstart = anchor;
- register pel x;
-
- if (XofY(left, ywhite) >= XofY(right, ywhite))
- return;
-/*
-Find the swath with 'yblack'. If we don't find it, completely collapse
-the white run and return:
-*/
- while (VALIDEDGE(swathstart)) {
- if (yblack < swathstart->ymin) {
- writeXofY(left, ywhite, XofY(right, ywhite));
- return;
- }
- if (yblack < swathstart->ymax) break;
- swathstart = swathstart->link->link;
- }
- if(!VALIDEDGE(swathstart)) {
- writeXofY(left, ywhite, XofY(right, ywhite));
- return;
- }
-/*
-Now we are in the swath that contains 'y', the reference line above
-or below that we are trying to maintain continuity with. If black
-in this line begins in the middle of our white run, we must collapse
-the white run from the left to that point. If black ends in the
-middle of our white run, we must collapse the white run from the right
-to that point.
-*/
- for (edge = swathstart; VALIDEDGE(edge); edge = edge->link) {
-
- if (!SAMESWATH(swathstart,edge))
- break;
- if( XofY(edge, yblack) > XofY(left, ywhite)) {
- if (ISLEFT(edge->flag)) {
- x = XofY(edge, yblack);
- if (XofY(right, ywhite) < x)
- x = XofY(right, ywhite);
- writeXofY(left, ywhite, x);
- }
- else {
- x = XofY(edge, yblack);
- while (edge->link != NULL && SAMESWATH(edge, edge->link)
- && x >= XofY(edge->link, yblack) ) {
- edge = edge->link->link;
- x = XofY(edge, yblack);
- }
- if (x < XofY(right, ywhite))
- writeXofY(right, ywhite, x);
- return;
- }
- }
- }
- writeXofY(left, ywhite, XofY(right, ywhite));
-}
-
-/*
-:h3.ApplyContinuity() - Fix False Breaks in a Region
-
-This is the externally visible routine called from the REGIONS module
-when the +CONTINUITY flag is on the Interior() fill rule.
-*/
-
-void ApplyContinuity(R)
-struct region *R;
-{
- struct edgelist *left;
- struct edgelist *right;
- struct edgelist *edge,*e2;
- pel rightXabove,rightXbelow,leftXabove,leftXbelow;
- pel leftX,rightX;
- int i;
- long newcenter,abovecenter,belowcenter;
-
- FixSubPaths(R);
- if (RegionDebug >= 3)
- DumpSubPaths(R->anchor);
- left = R->anchor;
-/* loop through and do all of the easy checking. ( no tops or bottoms) */
- while(VALIDEDGE(left))
- {
- right = left->link;
- for(i=left->ymin;i<left->ymax;++i)
- {
- leftX = findXofY(left,i);
- rightX = findXofY(right,i);
- leftXbelow = findXofY(left,i+1);
- rightXbelow = findXofY(right,i+1);
- if(rightX <= leftX)
- {
-/* then, we have a break in a near vertical line */
- leftXabove = findXofY(left,i-1);
- rightXabove = findXofY(right,i-1);
- if( IsValidPel(leftXabove) && IsValidPel(rightXabove) )
- {
- abovecenter = leftXabove + rightXabove;
- }
- else
- {
- abovecenter = leftX + rightX;
- }
- if( IsValidPel(leftXbelow) && IsValidPel(rightXbelow) )
- {
- belowcenter = leftXbelow + rightXbelow;
- }
- else
- {
- belowcenter = leftX + rightX;
- }
- newcenter = abovecenter + belowcenter;
- if( newcenter > 4*leftX )
- {
- rightX = rightX + 1;
- }
- else if( newcenter < 4*leftX)
- {
- leftX = leftX - 1;
- }
- else
- {
- rightX = rightX + 1;
- }
- writeXofY(right,i,rightX);
- writeXofY(left,i,leftX);
- if(rightX > R->xmax) {R->xmax = rightX;}
- if(leftX < R->xmin) {R->xmin = leftX;}
- }
- if( !WeAreAtBottom(left,i) && (leftXbelow>=rightX))
- {
-/* then we have a break in a near horizontal line in the middle */
- writeXofY(right,i,leftXbelow);
- }
- if( !WeAreAtBottom(right,i) && (leftX >=rightXbelow))
- {
-/* then we have a break in a near horizontal line in the middle */
- writeXofY(left,i,rightXbelow);
- }
- }
- left = right->link;
- }
-/*
-There may be "implied horizontal lines" between edges that have
-implications for continuity. This loop looks for white runs that
-have implied horizontal lines on the top or bottom, and calls
-CollapseWhiteRuns to check and fix any continuity problems from
-them.
-*/
- for (edge = R->anchor; VALIDEDGE(edge); edge = edge->link) {
- if ((!ISTOP(edge->flag) && !ISBOTTOM(edge->flag)) || ISLEFT(edge->flag))
- continue; /* at some future date we may want left edge logic here too */
- for (e2 = edge->link; VALIDEDGE(e2) && SAMESWATH(edge,e2); e2 = e2->link) {
- if (ISTOP(e2->flag) && ISTOP(edge->flag)
- && NONE != ImpliedHorizontalLine(edge,e2,edge->ymin)) {
- if (ISLEFT(e2->flag))
- CollapseWhiteRun(R->anchor, edge->ymin-1,
- edge, e2, edge->ymin);
- }
- if (ISBOTTOM(e2->flag) && ISBOTTOM(edge->flag)
- && NONE != ImpliedHorizontalLine(edge,e2, edge->ymax)) {
- if (ISLEFT(e2->flag))
- CollapseWhiteRun(R->anchor, edge->ymax,
- edge, e2, edge->ymax-1);
- }
- }
- }
-}
-
-
-
-
projects / rdpsrv / blobdiff