add libvncserver
[presencevnc] / libvnc / libvncserver / rfbregion.c
diff --git a/libvnc/libvncserver/rfbregion.c b/libvnc/libvncserver/rfbregion.c
new file mode 100755 (executable)
index 0000000..0ab8a12
--- /dev/null
@@ -0,0 +1,886 @@
+/* -=- sraRegion.c
+ * Copyright (c) 2001 James "Wez" Weatherall, Johannes E. Schindelin
+ *
+ * A general purpose region clipping library
+ * Only deals with rectangular regions, though.
+ */
+
+#include <rfb/rfb.h>
+#include <rfb/rfbregion.h>
+
+/* -=- Internal Span structure */
+
+struct sraRegion;
+
+typedef struct sraSpan {
+  struct sraSpan *_next;
+  struct sraSpan *_prev;
+  int start;
+  int end;
+  struct sraRegion *subspan;
+} sraSpan;
+
+typedef struct sraRegion {
+  sraSpan front;
+  sraSpan back;
+} sraSpanList;
+
+/* -=- Span routines */
+
+sraSpanList *sraSpanListDup(const sraSpanList *src);
+void sraSpanListDestroy(sraSpanList *list);
+
+static sraSpan *
+sraSpanCreate(int start, int end, const sraSpanList *subspan) {
+  sraSpan *item = (sraSpan*)malloc(sizeof(sraSpan));
+  item->_next = item->_prev = NULL;
+  item->start = start;
+  item->end = end;
+  item->subspan = sraSpanListDup(subspan);
+  return item;
+}
+
+static sraSpan *
+sraSpanDup(const sraSpan *src) {
+  sraSpan *span;
+  if (!src) return NULL;
+  span = sraSpanCreate(src->start, src->end, src->subspan);
+  return span;
+}
+
+static void
+sraSpanInsertAfter(sraSpan *newspan, sraSpan *after) {
+  newspan->_next = after->_next;
+  newspan->_prev = after;
+  after->_next->_prev = newspan;
+  after->_next = newspan;
+}
+
+static void
+sraSpanInsertBefore(sraSpan *newspan, sraSpan *before) {
+  newspan->_next = before;
+  newspan->_prev = before->_prev;
+  before->_prev->_next = newspan;
+  before->_prev = newspan;
+}
+
+static void
+sraSpanRemove(sraSpan *span) {
+  span->_prev->_next = span->_next;
+  span->_next->_prev = span->_prev;
+}
+
+static void
+sraSpanDestroy(sraSpan *span) {
+  if (span->subspan) sraSpanListDestroy(span->subspan);
+  free(span);
+}
+
+#ifdef DEBUG
+static void
+sraSpanCheck(const sraSpan *span, const char *text) {
+  /* Check the span is valid! */
+  if (span->start == span->end) {
+    printf(text); 
+    printf(":%d-%d\n", span->start, span->end);
+  }
+}
+#endif
+
+/* -=- SpanList routines */
+
+static void sraSpanPrint(const sraSpan *s);
+
+static void
+sraSpanListPrint(const sraSpanList *l) {
+  sraSpan *curr;
+  if (!l) {
+         printf("NULL");
+         return;
+  }
+  curr = l->front._next;
+  printf("[");
+  while (curr != &(l->back)) {
+    sraSpanPrint(curr);
+    curr = curr->_next;
+  }
+  printf("]");
+}
+
+void
+sraSpanPrint(const sraSpan *s) {
+  printf("(%d-%d)", (s->start), (s->end));
+  if (s->subspan)
+    sraSpanListPrint(s->subspan);
+}
+
+static sraSpanList *
+sraSpanListCreate(void) {
+  sraSpanList *item = (sraSpanList*)malloc(sizeof(sraSpanList));
+  item->front._next = &(item->back);
+  item->front._prev = NULL;
+  item->back._prev = &(item->front);
+  item->back._next = NULL;
+  return item;
+}
+
+sraSpanList *
+sraSpanListDup(const sraSpanList *src) {
+  sraSpanList *newlist;
+  sraSpan *newspan, *curr;
+
+  if (!src) return NULL;
+  newlist = sraSpanListCreate();
+  curr = src->front._next;
+  while (curr != &(src->back)) {
+    newspan = sraSpanDup(curr);
+    sraSpanInsertBefore(newspan, &(newlist->back));
+    curr = curr->_next;
+  }
+
+  return newlist;
+}
+
+void
+sraSpanListDestroy(sraSpanList *list) {
+  sraSpan *curr, *next;
+  while (list->front._next != &(list->back)) {
+    curr = list->front._next;
+    next = curr->_next;
+    sraSpanRemove(curr);
+    sraSpanDestroy(curr);
+    curr = next;
+  }
+  free(list);
+}
+
+static void
+sraSpanListMakeEmpty(sraSpanList *list) {
+  sraSpan *curr, *next;
+  while (list->front._next != &(list->back)) {
+    curr = list->front._next;
+    next = curr->_next;
+    sraSpanRemove(curr);
+    sraSpanDestroy(curr);
+    curr = next;
+  }
+  list->front._next = &(list->back);
+  list->front._prev = NULL;
+  list->back._prev = &(list->front);
+  list->back._next = NULL;
+}
+
+static rfbBool
+sraSpanListEqual(const sraSpanList *s1, const sraSpanList *s2) {
+  sraSpan *sp1, *sp2;
+
+  if (!s1) {
+    if (!s2) {
+      return 1;
+    } else {
+      rfbErr("sraSpanListEqual:incompatible spans (only one NULL!)\n");
+      return FALSE;
+    }
+  }
+
+  sp1 = s1->front._next;
+  sp2 = s2->front._next;
+  while ((sp1 != &(s1->back)) &&
+        (sp2 != &(s2->back))) {
+    if ((sp1->start != sp2->start) ||
+       (sp1->end != sp2->end) ||
+       (!sraSpanListEqual(sp1->subspan, sp2->subspan))) {
+      return 0;
+    }
+    sp1 = sp1->_next;
+    sp2 = sp2->_next;
+  }
+
+  if ((sp1 == &(s1->back)) && (sp2 == &(s2->back))) {
+    return 1;
+  } else {
+    return 0;
+  }    
+}
+
+static rfbBool
+sraSpanListEmpty(const sraSpanList *list) {
+  return (list->front._next == &(list->back));
+}
+
+static unsigned long
+sraSpanListCount(const sraSpanList *list) {
+  sraSpan *curr = list->front._next;
+  unsigned long count = 0;
+  while (curr != &(list->back)) {
+    if (curr->subspan) {
+      count += sraSpanListCount(curr->subspan);
+    } else {
+      count += 1;
+    }
+    curr = curr->_next;
+  }
+  return count;
+}
+
+static void
+sraSpanMergePrevious(sraSpan *dest) {
+  sraSpan *prev = dest->_prev;
+  while ((prev->_prev) &&
+        (prev->end == dest->start) &&
+        (sraSpanListEqual(prev->subspan, dest->subspan))) {
+    /*
+    printf("merge_prev:");
+    sraSpanPrint(prev);
+    printf(" & ");
+    sraSpanPrint(dest);
+    printf("\n");
+    */
+    dest->start = prev->start;
+    sraSpanRemove(prev);
+    sraSpanDestroy(prev);
+    prev = dest->_prev;
+  }
+}    
+
+static void
+sraSpanMergeNext(sraSpan *dest) {
+  sraSpan *next = dest->_next;
+  while ((next->_next) &&
+        (next->start == dest->end) &&
+        (sraSpanListEqual(next->subspan, dest->subspan))) {
+/*
+         printf("merge_next:");
+    sraSpanPrint(dest);
+    printf(" & ");
+    sraSpanPrint(next);
+    printf("\n");
+       */
+    dest->end = next->end;
+    sraSpanRemove(next);
+    sraSpanDestroy(next);
+    next = dest->_next;
+  }
+}
+
+static void
+sraSpanListOr(sraSpanList *dest, const sraSpanList *src) {
+  sraSpan *d_curr, *s_curr;
+  int s_start, s_end;
+
+  if (!dest) {
+    if (!src) {
+      return;
+    } else {
+      rfbErr("sraSpanListOr:incompatible spans (only one NULL!)\n");
+      return;
+    }
+  }
+
+  d_curr = dest->front._next;
+  s_curr = src->front._next;
+  s_start = s_curr->start;
+  s_end = s_curr->end;
+  while (s_curr != &(src->back)) {
+
+    /* - If we are at end of destination list OR
+       If the new span comes before the next destination one */
+    if ((d_curr == &(dest->back)) ||
+               (d_curr->start >= s_end)) {
+      /* - Add the span */
+      sraSpanInsertBefore(sraSpanCreate(s_start, s_end,
+                                       s_curr->subspan),
+                         d_curr);
+      if (d_curr != &(dest->back))
+       sraSpanMergePrevious(d_curr);
+      s_curr = s_curr->_next;
+      s_start = s_curr->start;
+      s_end = s_curr->end;
+    } else {
+
+      /* - If the new span overlaps the existing one */
+      if ((s_start < d_curr->end) &&
+         (s_end > d_curr->start)) {
+
+       /* - Insert new span before the existing destination one? */
+       if (s_start < d_curr->start) {
+         sraSpanInsertBefore(sraSpanCreate(s_start,
+                                           d_curr->start,
+                                           s_curr->subspan),
+                             d_curr);
+         sraSpanMergePrevious(d_curr);
+       }
+
+       /* Split the existing span if necessary */
+       if (s_end < d_curr->end) {
+         sraSpanInsertAfter(sraSpanCreate(s_end,
+                                          d_curr->end,
+                                          d_curr->subspan),
+                            d_curr);
+         d_curr->end = s_end;
+       }
+       if (s_start > d_curr->start) {
+         sraSpanInsertBefore(sraSpanCreate(d_curr->start,
+                                           s_start,
+                                           d_curr->subspan),
+                             d_curr);
+         d_curr->start = s_start;
+       }
+
+       /* Recursively OR subspans */
+       sraSpanListOr(d_curr->subspan, s_curr->subspan);
+
+       /* Merge this span with previous or next? */
+       if (d_curr->_prev != &(dest->front))
+         sraSpanMergePrevious(d_curr);
+       if (d_curr->_next != &(dest->back))
+         sraSpanMergeNext(d_curr);
+
+       /* Move onto the next pair to compare */
+       if (s_end > d_curr->end) {
+         s_start = d_curr->end;
+         d_curr = d_curr->_next;
+       } else {
+         s_curr = s_curr->_next;
+         s_start = s_curr->start;
+         s_end = s_curr->end;
+       }
+      } else {
+       /* - No overlap.  Move to the next destination span */
+       d_curr = d_curr->_next;
+      }
+    }
+  }
+}
+
+static rfbBool
+sraSpanListAnd(sraSpanList *dest, const sraSpanList *src) {
+  sraSpan *d_curr, *s_curr, *d_next;
+
+  if (!dest) {
+    if (!src) {
+      return 1;
+    } else {
+      rfbErr("sraSpanListAnd:incompatible spans (only one NULL!)\n");
+      return FALSE;
+    }
+  }
+
+  d_curr = dest->front._next;
+  s_curr = src->front._next;
+  while ((s_curr != &(src->back)) && (d_curr != &(dest->back))) {
+
+    /* - If we haven't reached a destination span yet then move on */
+    if (d_curr->start >= s_curr->end) {
+      s_curr = s_curr->_next;
+      continue;
+    }
+
+    /* - If we are beyond the current destination span then remove it */
+    if (d_curr->end <= s_curr->start) {
+      sraSpan *next = d_curr->_next;
+      sraSpanRemove(d_curr);
+      sraSpanDestroy(d_curr);
+      d_curr = next;
+      continue;
+    }
+
+    /* - If we partially overlap a span then split it up or remove bits */
+    if (s_curr->start > d_curr->start) {
+      /* - The top bit of the span does not match */
+      d_curr->start = s_curr->start;
+    }
+    if (s_curr->end < d_curr->end) {
+      /* - The end of the span does not match */
+      sraSpanInsertAfter(sraSpanCreate(s_curr->end,
+                                      d_curr->end,
+                                      d_curr->subspan),
+                        d_curr);
+      d_curr->end = s_curr->end;
+    }
+
+    /* - Now recursively process the affected span */
+    if (!sraSpanListAnd(d_curr->subspan, s_curr->subspan)) {
+      /* - The destination subspan is now empty, so we should remove it */
+               sraSpan *next = d_curr->_next;
+      sraSpanRemove(d_curr);
+      sraSpanDestroy(d_curr);
+      d_curr = next;
+    } else {
+      /* Merge this span with previous or next? */
+      if (d_curr->_prev != &(dest->front))
+       sraSpanMergePrevious(d_curr);
+
+      /* - Move on to the next span */
+      d_next = d_curr;
+      if (s_curr->end >= d_curr->end) {
+       d_next = d_curr->_next;
+      }
+      if (s_curr->end <= d_curr->end) {
+       s_curr = s_curr->_next;
+      }
+      d_curr = d_next;
+    }
+  }
+
+  while (d_curr != &(dest->back)) {
+    sraSpan *next = d_curr->_next;
+    sraSpanRemove(d_curr);
+    sraSpanDestroy(d_curr);
+    d_curr=next;
+  }
+
+  return !sraSpanListEmpty(dest);
+}
+
+static rfbBool
+sraSpanListSubtract(sraSpanList *dest, const sraSpanList *src) {
+  sraSpan *d_curr, *s_curr;
+
+  if (!dest) {
+    if (!src) {
+      return 1;
+    } else {
+      rfbErr("sraSpanListSubtract:incompatible spans (only one NULL!)\n");
+      return FALSE;
+    }
+  }
+
+  d_curr = dest->front._next;
+  s_curr = src->front._next;
+  while ((s_curr != &(src->back)) && (d_curr != &(dest->back))) {
+
+    /* - If we haven't reached a destination span yet then move on */
+    if (d_curr->start >= s_curr->end) {
+      s_curr = s_curr->_next;
+      continue;
+    }
+
+    /* - If we are beyond the current destination span then skip it */
+    if (d_curr->end <= s_curr->start) {
+      d_curr = d_curr->_next;
+      continue;
+    }
+
+    /* - If we partially overlap the current span then split it up */
+    if (s_curr->start > d_curr->start) {
+      sraSpanInsertBefore(sraSpanCreate(d_curr->start,
+                                       s_curr->start,
+                                       d_curr->subspan),
+                         d_curr);
+      d_curr->start = s_curr->start;
+    }
+    if (s_curr->end < d_curr->end) {
+      sraSpanInsertAfter(sraSpanCreate(s_curr->end,
+                                      d_curr->end,
+                                      d_curr->subspan),
+                        d_curr);
+      d_curr->end = s_curr->end;
+    }
+
+    /* - Now recursively process the affected span */
+    if ((!d_curr->subspan) || !sraSpanListSubtract(d_curr->subspan, s_curr->subspan)) {
+      /* - The destination subspan is now empty, so we should remove it */
+      sraSpan *next = d_curr->_next;
+      sraSpanRemove(d_curr);
+      sraSpanDestroy(d_curr);
+      d_curr = next;
+    } else {
+      /* Merge this span with previous or next? */
+      if (d_curr->_prev != &(dest->front))
+       sraSpanMergePrevious(d_curr);
+      if (d_curr->_next != &(dest->back))
+       sraSpanMergeNext(d_curr);
+
+      /* - Move on to the next span */
+      if (s_curr->end > d_curr->end) {
+       d_curr = d_curr->_next;
+      } else {
+       s_curr = s_curr->_next;
+      }
+    }
+  }
+
+  return !sraSpanListEmpty(dest);
+}
+
+/* -=- Region routines */
+
+sraRegion *
+sraRgnCreate(void) {
+  return (sraRegion*)sraSpanListCreate();
+}
+
+sraRegion *
+sraRgnCreateRect(int x1, int y1, int x2, int y2) {
+  sraSpanList *vlist, *hlist;
+  sraSpan *vspan, *hspan;
+
+  /* - Build the horizontal portion of the span */
+  hlist = sraSpanListCreate();
+  hspan = sraSpanCreate(x1, x2, NULL);
+  sraSpanInsertAfter(hspan, &(hlist->front));
+
+  /* - Build the vertical portion of the span */
+  vlist = sraSpanListCreate();
+  vspan = sraSpanCreate(y1, y2, hlist);
+  sraSpanInsertAfter(vspan, &(vlist->front));
+
+  sraSpanListDestroy(hlist);
+
+  return (sraRegion*)vlist;
+}
+
+sraRegion *
+sraRgnCreateRgn(const sraRegion *src) {
+  return (sraRegion*)sraSpanListDup((sraSpanList*)src);
+}
+
+void
+sraRgnDestroy(sraRegion *rgn) {
+  sraSpanListDestroy((sraSpanList*)rgn);
+}
+
+void
+sraRgnMakeEmpty(sraRegion *rgn) {
+  sraSpanListMakeEmpty((sraSpanList*)rgn);
+}
+
+/* -=- Boolean Region ops */
+
+rfbBool
+sraRgnAnd(sraRegion *dst, const sraRegion *src) {
+  return sraSpanListAnd((sraSpanList*)dst, (sraSpanList*)src);
+}
+
+void
+sraRgnOr(sraRegion *dst, const sraRegion *src) {
+  sraSpanListOr((sraSpanList*)dst, (sraSpanList*)src);
+}
+
+rfbBool
+sraRgnSubtract(sraRegion *dst, const sraRegion *src) {
+  return sraSpanListSubtract((sraSpanList*)dst, (sraSpanList*)src);
+}
+
+void
+sraRgnOffset(sraRegion *dst, int dx, int dy) {
+  sraSpan *vcurr, *hcurr;
+
+  vcurr = ((sraSpanList*)dst)->front._next;
+  while (vcurr != &(((sraSpanList*)dst)->back)) {
+    vcurr->start += dy;
+    vcurr->end += dy;
+    
+    hcurr = vcurr->subspan->front._next;
+    while (hcurr != &(vcurr->subspan->back)) {
+      hcurr->start += dx;
+      hcurr->end += dx;
+      hcurr = hcurr->_next;
+    }
+
+    vcurr = vcurr->_next;
+  }
+}
+
+sraRegion *sraRgnBBox(const sraRegion *src) {
+  int xmin=((unsigned int)(int)-1)>>1,ymin=xmin,xmax=1-xmin,ymax=xmax;
+  sraSpan *vcurr, *hcurr;
+
+  if(!src)
+    return sraRgnCreate();
+
+  vcurr = ((sraSpanList*)src)->front._next;
+  while (vcurr != &(((sraSpanList*)src)->back)) {
+    if(vcurr->start<ymin)
+      ymin=vcurr->start;
+    if(vcurr->end>ymax)
+      ymax=vcurr->end;
+    
+    hcurr = vcurr->subspan->front._next;
+    while (hcurr != &(vcurr->subspan->back)) {
+      if(hcurr->start<xmin)
+       xmin=hcurr->start;
+      if(hcurr->end>xmax)
+       xmax=hcurr->end;
+      hcurr = hcurr->_next;
+    }
+
+    vcurr = vcurr->_next;
+  }
+
+  if(xmax<xmin || ymax<ymin)
+    return sraRgnCreate();
+
+  return sraRgnCreateRect(xmin,ymin,xmax,ymax);
+}
+
+rfbBool
+sraRgnPopRect(sraRegion *rgn, sraRect *rect, unsigned long flags) {
+  sraSpan *vcurr, *hcurr;
+  sraSpan *vend, *hend;
+  rfbBool right2left = (flags & 2) == 2;
+  rfbBool bottom2top = (flags & 1) == 1;
+
+  /* - Pick correct order */
+  if (bottom2top) {
+    vcurr = ((sraSpanList*)rgn)->back._prev;
+    vend = &(((sraSpanList*)rgn)->front);
+  } else {
+    vcurr = ((sraSpanList*)rgn)->front._next;
+    vend = &(((sraSpanList*)rgn)->back);
+  }
+
+  if (vcurr != vend) {
+    rect->y1 = vcurr->start;
+    rect->y2 = vcurr->end;
+
+    /* - Pick correct order */
+    if (right2left) {
+      hcurr = vcurr->subspan->back._prev;
+      hend = &(vcurr->subspan->front);
+    } else {
+      hcurr = vcurr->subspan->front._next;
+      hend = &(vcurr->subspan->back);
+    }
+
+    if (hcurr != hend) {
+      rect->x1 = hcurr->start;
+      rect->x2 = hcurr->end;
+
+      sraSpanRemove(hcurr);
+      sraSpanDestroy(hcurr);
+      
+      if (sraSpanListEmpty(vcurr->subspan)) {
+       sraSpanRemove(vcurr);
+       sraSpanDestroy(vcurr);
+      }
+
+#if 0
+      printf("poprect:(%dx%d)-(%dx%d)\n",
+            rect->x1, rect->y1, rect->x2, rect->y2);
+#endif
+      return 1;
+    }
+  }
+
+  return 0;
+}
+
+unsigned long
+sraRgnCountRects(const sraRegion *rgn) {
+  unsigned long count = sraSpanListCount((sraSpanList*)rgn);
+  return count;
+}
+
+rfbBool
+sraRgnEmpty(const sraRegion *rgn) {
+  return sraSpanListEmpty((sraSpanList*)rgn);
+}
+
+/* iterator stuff */
+sraRectangleIterator *sraRgnGetIterator(sraRegion *s)
+{
+  /* these values have to be multiples of 4 */
+#define DEFSIZE 4
+#define DEFSTEP 8
+  sraRectangleIterator *i =
+    (sraRectangleIterator*)malloc(sizeof(sraRectangleIterator));
+  if(!i)
+    return NULL;
+
+  /* we have to recurse eventually. So, the first sPtr is the pointer to
+     the sraSpan in the first level. the second sPtr is the pointer to
+     the sraRegion.back. The third and fourth sPtr are for the second
+     recursion level and so on. */
+  i->sPtrs = (sraSpan**)malloc(sizeof(sraSpan*)*DEFSIZE);
+  if(!i->sPtrs) {
+    free(i);
+    return NULL;
+  }
+  i->ptrSize = DEFSIZE;
+  i->sPtrs[0] = &(s->front);
+  i->sPtrs[1] = &(s->back);
+  i->ptrPos = 0;
+  i->reverseX = 0;
+  i->reverseY = 0;
+  return i;
+}
+
+sraRectangleIterator *sraRgnGetReverseIterator(sraRegion *s,rfbBool reverseX,rfbBool reverseY)
+{
+  sraRectangleIterator *i = sraRgnGetIterator(s);
+  if(reverseY) {
+    i->sPtrs[1] = &(s->front);
+    i->sPtrs[0] = &(s->back);
+  }
+  i->reverseX = reverseX;
+  i->reverseY = reverseY;
+  return(i);
+}
+
+static rfbBool sraReverse(sraRectangleIterator *i)
+{
+  return( ((i->ptrPos&2) && i->reverseX) ||
+     (!(i->ptrPos&2) && i->reverseY));
+}
+
+static sraSpan* sraNextSpan(sraRectangleIterator *i)
+{
+  if(sraReverse(i))
+    return(i->sPtrs[i->ptrPos]->_prev);
+  else
+    return(i->sPtrs[i->ptrPos]->_next);
+}
+
+rfbBool sraRgnIteratorNext(sraRectangleIterator* i,sraRect* r)
+{
+  /* is the subspan finished? */
+  while(sraNextSpan(i) == i->sPtrs[i->ptrPos+1]) {
+    i->ptrPos -= 2;
+    if(i->ptrPos < 0) /* the end */
+      return(0);
+  }
+
+  i->sPtrs[i->ptrPos] = sraNextSpan(i);
+
+  /* is this a new subspan? */
+  while(i->sPtrs[i->ptrPos]->subspan) {
+    if(i->ptrPos+2 > i->ptrSize) { /* array is too small */
+      i->ptrSize += DEFSTEP;
+      i->sPtrs = (sraSpan**)realloc(i->sPtrs, sizeof(sraSpan*)*i->ptrSize);
+    }
+    i->ptrPos =+ 2;
+    if(sraReverse(i)) {
+      i->sPtrs[i->ptrPos]   =   i->sPtrs[i->ptrPos-2]->subspan->back._prev;
+      i->sPtrs[i->ptrPos+1] = &(i->sPtrs[i->ptrPos-2]->subspan->front);
+    } else {
+      i->sPtrs[i->ptrPos]   =   i->sPtrs[i->ptrPos-2]->subspan->front._next;
+      i->sPtrs[i->ptrPos+1] = &(i->sPtrs[i->ptrPos-2]->subspan->back);
+    }
+  }
+
+  if((i->ptrPos%4)!=2) {
+    rfbErr("sraRgnIteratorNext: offset is wrong (%d%%4!=2)\n",i->ptrPos);
+    return FALSE;
+  }
+
+  r->y1 = i->sPtrs[i->ptrPos-2]->start;
+  r->y2 = i->sPtrs[i->ptrPos-2]->end;
+  r->x1 = i->sPtrs[i->ptrPos]->start;
+  r->x2 = i->sPtrs[i->ptrPos]->end;
+
+  return(-1);
+}
+
+void sraRgnReleaseIterator(sraRectangleIterator* i)
+{
+  free(i->sPtrs);
+  free(i);
+}
+
+void
+sraRgnPrint(const sraRegion *rgn) {
+       sraSpanListPrint((sraSpanList*)rgn);
+}
+
+rfbBool
+sraClipRect(int *x, int *y, int *w, int *h,
+           int cx, int cy, int cw, int ch) {
+  if (*x < cx) {
+    *w -= (cx-*x);
+    *x = cx;
+  }
+  if (*y < cy) {
+    *h -= (cy-*y);
+    *y = cy;
+  }
+  if (*x+*w > cx+cw) {
+    *w = (cx+cw)-*x;
+  }
+  if (*y+*h > cy+ch) {
+    *h = (cy+ch)-*y;
+  }
+  return (*w>0) && (*h>0);
+}
+
+rfbBool
+sraClipRect2(int *x, int *y, int *x2, int *y2,
+           int cx, int cy, int cx2, int cy2) {
+  if (*x < cx)
+    *x = cx;
+  if (*y < cy)
+    *y = cy;
+  if (*x >= cx2)
+    *x = cx2-1;
+  if (*y >= cy2)
+    *y = cy2-1;
+  if (*x2 <= cx)
+    *x2 = cx+1;
+  if (*y2 <= cy)
+    *y2 = cy+1;
+  if (*x2 > cx2)
+    *x2 = cx2;
+  if (*y2 > cy2)
+    *y2 = cy2;
+  return (*x2>*x) && (*y2>*y);
+}
+
+/* test */
+
+#ifdef SRA_TEST
+/* pipe the output to sort|uniq -u and you'll get the errors. */
+int main(int argc, char** argv)
+{
+  sraRegionPtr region, region1, region2;
+  sraRectangleIterator* i;
+  sraRect rect;
+  rfbBool b;
+
+  region = sraRgnCreateRect(10, 10, 600, 300);
+  region1 = sraRgnCreateRect(40, 50, 350, 200);
+  region2 = sraRgnCreateRect(0, 0, 20, 40);
+
+  sraRgnPrint(region);
+  printf("\n[(10-300)[(10-600)]]\n\n");
+
+  b = sraRgnSubtract(region, region1);
+  printf("%s ",b?"true":"false");
+  sraRgnPrint(region);
+  printf("\ntrue [(10-50)[(10-600)](50-200)[(10-40)(350-600)](200-300)[(10-600)]]\n\n");
+
+  sraRgnOr(region, region2);
+  printf("%ld\n6\n\n", sraRgnCountRects(region));
+
+  i = sraRgnGetIterator(region);
+  while(sraRgnIteratorNext(i, &rect))
+    printf("%dx%d+%d+%d ",
+          rect.x2-rect.x1,rect.y2-rect.y1,
+          rect.x1,rect.y1);
+  sraRgnReleaseIterator(i);
+  printf("\n20x10+0+0 600x30+0+10 590x10+10+40 30x150+10+50 250x150+350+50 590x100+10+200 \n\n");
+
+  i = sraRgnGetReverseIterator(region,1,0);
+  while(sraRgnIteratorNext(i, &rect))
+    printf("%dx%d+%d+%d ",
+          rect.x2-rect.x1,rect.y2-rect.y1,
+          rect.x1,rect.y1);
+  sraRgnReleaseIterator(i);
+  printf("\n20x10+0+0 600x30+0+10 590x10+10+40 250x150+350+50 30x150+10+50 590x100+10+200 \n\n");
+
+  i = sraRgnGetReverseIterator(region,1,1);
+  while(sraRgnIteratorNext(i, &rect))
+    printf("%dx%d+%d+%d ",
+          rect.x2-rect.x1,rect.y2-rect.y1,
+          rect.x1,rect.y1);
+  sraRgnReleaseIterator(i);
+  printf("\n590x100+10+200 250x150+350+50 30x150+10+50 590x10+10+40 600x30+0+10 20x10+0+0 \n\n");
+
+  sraRgnDestroy(region);
+  sraRgnDestroy(region1);
+  sraRgnDestroy(region2);
+
+  return(0);
+}
+#endif