row iter

1 files changed, 108 insertions, 13 deletions

diff --git a/region-iter.c b/region-iter.c
index cf64ec2..41827ba 100644
--- a/region-iter.c
+++ b/region-iter.c
@@ -18,7 +18,7 @@ typedef enum
 {
     FIRST,
     MIDDLE,
-    EMPTY_ROW,
+    EMPTY,
     FINAL,
     DONE
 } state_t;
@@ -163,14 +163,14 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
     pixman_box32_t *first;
     pixman_box32_t *last;
     pixman_box32_t *box;
-    
+
     switch (iter->state)
     {
     case FIRST:
 	row->y1 = INT_MIN;
 	row->first = NULL;
 	row->last = NULL;
-	
+
 	if (!iter->u.first.region->data)
 	{
 	    iter->state = MIDDLE;
@@ -188,7 +188,7 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
 	    first = (pixman_box32_t *)(iter->u.first.region->data + 1);
 	    last = first + iter->u.first.region->data->numRects;
 	}
-	
+
 	if (iter->state == MIDDLE)
 	{
 	    row->y2 = first->y1;
@@ -196,25 +196,25 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
 	    iter->u.middle.last = last;
 	}
 	break;
-	
+
     case MIDDLE:
 	assert (iter->u.middle.last - iter->u.middle.first > 0);
-	
+
 	for (box = iter->u.middle.first; box != iter->u.middle.last; ++box)
 	{
 	    if (box->y1 != iter->u.middle.first->y1)
 		break;
 	}
-	
+
 	row->y1 = iter->u.middle.first->y1;
 	row->y2 = iter->u.middle.first->y2;
 	row->first = iter->u.middle.first;
 	row->last = box;
-	
+
 	if (box != iter->u.middle.last)
 	{
 	    if (box->y1 != row->y2)
-		iter->state = EMPTY_ROW;
+		iter->state = EMPTY;
 
 	    iter->u.middle.first = box;
 	}
@@ -225,7 +225,7 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
 	}
 	break;
 
-    case EMPTY_ROW:
+    case EMPTY:
 	row->y1 = (iter->u.middle.first - 1)->y2;
 	row->y2 = iter->u.middle.first->y1;
 	row->first = NULL;
@@ -233,7 +233,7 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
 
 	iter->state = MIDDLE;
 	break;
-	
+
     case FINAL:
 	row->first = NULL;
 	row->last = NULL;
@@ -241,7 +241,7 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
 	row->y2 = INT_MAX;
 	iter->state = DONE;
 	break;
-	
+
     case DONE:
 	return FALSE;
     }
@@ -302,6 +302,102 @@ overlapped_iter_get_rows (overlapped_iter_t *iter, row_t *row1, row_t *row2)
     return TRUE;
 }
 
+/* Row iter */
+typedef struct row_iter_t row_iter_t;
+
+struct row_iter_t
+{
+    state_t	state;
+
+    union
+    {
+	struct
+	{
+	    const row_t *row;
+	} first;
+
+	struct
+	{
+	    const pixman_box32_t *first;
+	    const pixman_box32_t *last;
+	} middle;
+
+	struct
+	{
+	    int x1;
+	} final;
+    } u;
+};
+
+static void
+row_iter_init (row_iter_t *iter, const row_t *row)
+{
+    iter->state = FIRST;
+
+    iter->u.first.row = row;
+}
+
+static pixman_bool_t
+row_iter_get_box (row_iter_t *iter, int *x1, int *x2, pixman_bool_t *on)
+{
+    switch (iter->state)
+    {
+    case FIRST:
+	*on = FALSE;
+	*x1 = INT_MIN;
+
+	if (iter->u.first.row->first)
+	{
+	    *x2 = iter->u.first.row->first->x1;
+
+	    iter->state = MIDDLE;
+	    iter->u.middle.first = iter->u.first.row->first;
+	    iter->u.middle.last = iter->u.first.row->last;
+	}
+	else
+	{
+	    *x2 = INT_MAX;
+	    iter->state = DONE;
+	}
+	break;
+
+    case MIDDLE:
+	*on = TRUE;
+	*x1 = iter->u.middle.first->x1;
+	*x2 = iter->u.middle.first->x2;
+
+	iter->u.middle.first++;
+	if (iter->u.middle.first == iter->u.middle.last)
+	{
+	    iter->state = FINAL;
+	    iter->u.final.x1 = *x2;
+	}
+	else
+	{
+	    iter->state = EMPTY;
+	}
+	break;
+
+    case EMPTY:
+	*on = FALSE;
+	*x1 = (iter->u.middle.first - 1)->x2;
+	*x2 = iter->u.middle.first->x1;
+	iter->state = MIDDLE;
+	break;
+
+    case FINAL:
+	*on = FALSE;
+	*x1 = iter->u.final.x1;
+	*x2 = INT_MAX;
+	break;
+
+    case DONE:
+	return FALSE;
+	break;
+    }
+    return TRUE;
+}
+
 /* Segment iter */
 typedef enum
 {
@@ -874,4 +970,3 @@ main ()
 }
 
 #endif
-