Simplify overlapped iter

1 files changed, 24 insertions, 36 deletions

diff --git a/region-iter.c b/region-iter.c
index 8efb395..1f7c3e9 100644
--- a/region-iter.c
+++ b/region-iter.c
@@ -18,6 +18,7 @@ typedef enum
 {
     FIRST,
     MIDDLE,
+    EMPTY_ROW,
     FINAL,
     DONE
 } state_t;
@@ -154,6 +155,9 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
 	
 	if (box != iter->u.middle.last)
 	{
+	    if (box->y1 != row->y2)
+		iter->state = EMPTY_ROW;
+
 	    iter->u.middle.first = box;
 	}
 	else
@@ -162,6 +166,15 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
 	    iter->u.final.y1 = row->y2;
 	}
 	break;
+
+    case EMPTY_ROW:
+	row->y1 = (iter->u.middle.first - 1)->y2;
+	row->y2 = iter->u.middle.first->y1;
+	row->first = NULL;
+	row->last = NULL;
+
+	iter->state = MIDDLE;
+	break;
 	
     case FINAL:
 	row->first = NULL;
@@ -199,49 +212,22 @@ overlapped_iter_init (overlapped_iter_t *iter,
     region_iter_get_row (&iter->iter2, &iter->row2);
 }
 
+#define MIN(a,b)  (((a) < (b)) ? (a) : (b))
+
 static pixman_bool_t
 overlapped_iter_get_rows (overlapped_iter_t *iter, row_t *row1, row_t *row2)
 {
-    int y1, y2;
+    int m;
 
-    row1->first = iter->row1.first;
-    row1->last = iter->row1.last;
-    row2->first = iter->row2.first;
-    row2->last = iter->row2.last;
+    *row1 = iter->row1;
+    *row2 = iter->row2;
 
-    if (iter->row1.y1 < iter->row2.y1)
-    {
-	y1 = iter->row1.y1;
-	y2 = iter->row2.y1;
+    m = MIN (iter->row1.y2, iter->row2.y2);
 
-	iter->row1.y1 = iter->row2.y1;
-    }
-    else if (iter->row2.y1 < iter->row1.y1)
-    {
-	y1 = iter->row2.y1;
-	y2 = iter->row1.y1;
+    row1->y1 = row2->y1 = iter->row1.y1;
+    row1->y2 = row2->y2 = m;
 
-	iter->row2.y1 = iter->row1.y1;
-    }
-    else if (iter->row1.y2 < iter->row2.y2)
-    {
-	y1 = iter->row1.y1;
-	y2 = iter->row1.y2;
-
-	iter->row1.y1 = iter->row1.y2;
-	iter->row2.y1 = iter->row1.y2;
-    }
-    else
-    {
-	y1 = iter->row2.y1;
-	y2 = iter->row2.y2;
-
-	iter->row2.y1 = iter->row2.y2;
-	iter->row1.y1 = iter->row2.y2;
-    }
-
-    row1->y1 = row2->y1 = y1;
-    row1->y2 = row2->y2 = y2;
+    iter->row2.y1 = iter->row1.y1 = m;
 
     if (iter->row1.y1 == iter->row1.y2)
     {
@@ -681,6 +667,8 @@ main ()
     pixman_region32_init_rect (&region1, 100, 100, 200, 200);
     pixman_region32_union_rect (&region1, &region1, 100, 400, 200, 50);
 
+    dump_region ("input: ", &region1);
+
     pixman_region32_init_rect (&region2, 150, 50, 10, 520);
 
     region_op (NULL, &region1, &region2, INTERSECT);