poll_events: align rectangles to even boundaries

The current rectinsert code does this, but it does it in the absolute root
window coordinate space.

In preparation for dropping all the alignment stuff out of rectinsert, do
the alignment at the rectinsert caller and do it in the rrect-relative
coordinate space.

1 files changed, 41 insertions, 2 deletions

diff --git a/recordmydesktop/src/rmd_poll_events.c b/recordmydesktop/src/rmd_poll_events.c
index 349aeba..96730fd 100644
--- a/recordmydesktop/src/rmd_poll_events.c
+++ b/recordmydesktop/src/rmd_poll_events.c
@@ -97,6 +97,43 @@ static int clip_event_area(XDamageNotifyEvent *e, XRectangle *cliprect, XRectang
 }
 
 
+/* Try align xrect to even boundaries relative to cliprect,
+ * this is done for the UV routines which operate at 2x2 rgb pixel granularity.
+ */
+static void uv_align(XRectangle *cliprect, XRectangle *xrect) {
+	XRectangle	rel;
+
+	rel.x = xrect->x - cliprect->x;
+	rel.y = xrect->y - cliprect->y;
+
+	if (rel.x % 2) {
+		rel.x -= 1;
+		rel.width = xrect->width + 1;
+	} else {
+		rel.width = xrect->width;
+	}
+
+	if (rel.y % 2) {
+		rel.y -= 1;
+		rel.height = xrect->height + 1;
+	} else {
+		rel.height = xrect->height;
+	}
+
+	/* XXX: note when cliprect prevents an even width, we can't do anything
+	 * about it.  rmd could force even-sized recording windows to prevent
+	 * this, but that would be kind of annoying.  For now it's assumed
+	 * the UV routines will handle the exception - which might temporarily
+	 * mean they just lop the odd row/column off the edge.
+	 */
+	if (rel.width % 2  && rel.width + rel.x < cliprect->x + cliprect->width)
+		rel.width++;
+
+	if (rel.height % 2 && rel.height + rel.y < cliprect->y + cliprect->height)
+		rel.height++;
+}
+
+
 void rmdInitEventsPolling(ProgData *pdata) {
 	Window root_return,
 		   parent_return,
@@ -198,8 +235,10 @@ void rmdEventLoop(ProgData *pdata) {
 				XDamageNotifyEvent	*e = (XDamageNotifyEvent *)&event;
 				XRectangle		xrect;
 
-				if (clip_event_area(e, &pdata->brwin.rrect, &xrect))
-					inserts += rmdRectInsert(&pdata->rect_root,&xrect);
+				if (clip_event_area(e, &pdata->brwin.rrect, &xrect)) {
+					uv_align(&pdata->brwin.rrect, &xrect);
+					inserts += rmdRectInsert(&pdata->rect_root, &xrect);
+				}
 			}
 		}
 	}