Various:

- region_iter_get_row_for_y() commented out

- region_builder_add_row() untested

- todo.

1 files changed, 127 insertions, 6 deletions

diff --git a/region-iter.c b/region-iter.c
index cc49eb2..74e135d 100644
--- a/region-iter.c
+++ b/region-iter.c
@@ -10,6 +10,19 @@
  *     Useful for speeding up intersection, and
  *     would also be useful for "contains" functions.
  *
+ *     Ie., an overlapped iter that will can return one of the following:
+ *         - two blank rows
+ *         - one multi row, one blank row
+ *         - one multi row, one one-box row 
+ *         - one single row, one single row
+ *
+ *     We will need a subroutine row_iter_skip_to_y() that will skip
+ *     to the next row with a y2 > y.
+ *
+ *   - an iterator that will move backwards through a region and then
+ *     one that will move backwards through a row would be useful for
+ *     scrolling.
+ *
  */
 #include <stdlib.h>
 #include <stdio.h>
@@ -224,6 +237,59 @@ region_builder_add_box (region_builder_t *builder,
 }
 
 static pixman_bool_t
+region_builder_add_row (region_builder_t *builder, const row_t *row)
+{
+    pixman_box32_t *last_box;
+    const pixman_box32_t *first;
+    pixman_region32_data_t *data;
+    int n_boxes;
+
+    if (builder->data == BROKEN_DATA)
+	return FALSE;
+
+    n_boxes = row->last - row->first;
+    
+    if (!(data = region_data_append (builder->data, n_boxes)))
+    {
+	free (builder->data);
+	builder->data = BROKEN_DATA;
+	return FALSE;
+    }
+
+    builder->data = data;
+
+    if (data->numRects == 0)
+	last_box = NULL;
+    else
+	last_box = ((pixman_box32_t *)(data + 1)) + data->numRects - 1;
+
+    first = row->first;
+    if (last_box)
+    {
+	if (row->y1 != last_box->y1)
+	    region_builder_coalesce_rows (builder);
+	else if (row->first->x1 == last_box->x2)
+	{
+	    last_box->x2 = row->first->x2;
+	    first = row->first + 1;
+	    n_boxes--;
+	}
+    }
+
+    while (first != row->last)
+    {
+	pixman_box32_t *box = (pixman_box32_t *)(data + 1) + data->numRects++;
+
+	box->x1 = first->x1;
+	box->x2 = first->x2;
+	box->y1 = row->y1;
+	box->y2 = row->y2;
+
+	first++;
+    }
+}
+
+static pixman_bool_t
 region_builder_finish (region_builder_t *builder, pixman_region32_t *region)
 {
     region_builder_coalesce_rows (builder);
@@ -367,6 +433,41 @@ region_iter_get_row (region_iter_t *iter, row_t *row)
     return TRUE;
 }
 
+/* Skips forward to the first row whose y2 > @y */
+#if 0
+static pixman_bool_t
+region_iter_get_row_for_y (region_iter_t *iter, int y, row_t *row)
+{
+    pixman_box32_t *box;
+
+    while (iter->state != MIDDLE)
+    {
+	if (!region_iter_get_row (iter, row))
+	    return FALSE;
+
+	if (row->y2 > y)
+	    return TRUE;
+    }
+
+    box = find_box_for_y (iter->u.middle.first, iter->u.middle.last, y);
+
+    if (box != iter->u.middle.last)
+    {
+	if (box->y1 > y)
+	    iter->state = EMPTY;
+
+	iter->u.middle.first = box;
+    }
+    else
+    {
+	iter->state = FINAL;
+	iter->u.final.y1 = row->y2;
+    }
+
+    return region_iter_get_row (iter, row);
+}
+#endif
+
 /* Overlapped iter
  */
 typedef struct overlapped_iter_t overlapped_iter_t;
@@ -605,8 +706,8 @@ region_op (ops_t              op,
 	   pixman_region32_t *src2)
 {
     overlapped_iter_t iter;
-    row_t row1, row2;
     region_builder_t builder;
+    row_t row1, row2;
 
     region_builder_init (&builder);
 
@@ -616,13 +717,33 @@ region_op (ops_t              op,
 	segment_iter_t seg_iter;
 	segment_t segment;
 
-	segment_iter_init (&seg_iter, &row1, &row2);
-	while (segment_iter_get_segment (&seg_iter, &segment))
+	if (!row1.first && !row2.first)
 	{
-	    if (op & (1 << segment.type))
+	    /* Both are blank - nothing to do */
+	}
+	else if (!row1.first)
+	{
+	    /* row1 is blank, row2 is not */
+	    if (op & (1 << ROW2))
+		region_builder_add_row (&builder, &row2);
+	}
+	else if (!row2.first)
+	{
+	    /* row2 is blank, row1 is not */
+	    if (op & (1 << ROW1))
+		region_builder_add_row (&builder, &row1);
+	}
+	else
+	{
+	    /* Both are non blank */
+	    segment_iter_init (&seg_iter, &row1, &row2);
+	    while (segment_iter_get_segment (&seg_iter, &segment))
 	    {
-		region_builder_add_box (
-		    &builder, segment.x1, row1.y1, segment.x2, row1.y2);
+		if (op & (1 << segment.type))
+		{
+		    region_builder_add_box (
+			&builder, segment.x1, row1.y1, segment.x2, row1.y2);
+		}
 	    }
 	}
     }