[PATCH weston v10 01/61] Clip co-ordinates in surface->buffer translation

[Daniel Stone]

Since performing the surface -> buffer translation may introduce
rounding error taking our desired co-ordinates out of bounds, introduce
a hard clip to the bounds specified by the client's viewport.

Signed-off-by: Daniel Stone <daniels at collabora.com>
---
 libweston/compositor.c | 9 +++++++++
 1 file changed, 9 insertions(+)

v10: New.

diff --git a/libweston/compositor.c b/libweston/compositor.c
index e8dd151d..b2f4c610 100644
--- a/libweston/compositor.c
+++ b/libweston/compositor.c
@@ -777,7 +777,16 @@ viewport_surface_to_buffer(struct weston_surface *surface,
 	}
 
 	*bx = sx * src_width / surface->width + src_x;
+	if (*bx < src_x)
+		*bx = src_x;
+	if (*bx > src_x + src_width)
+		*bx = src_x + src_width;
+
 	*by = sy * src_height / surface->height + src_y;
+	if (*by < src_y)
+		*by = src_y;
+	if (*by > src_y + src_height)
+		*by = src_y + src_height;
 }
 
 WL_EXPORT void
-- 
2.12.2