protocol: unify wl_viewport src and dst size rules
Let's make the source and destination size rules consistent: neither can
have zero, {-1, -1} disables it, and other negatives are not allowed.
The sanity of allowing zero sized source rectangle as debatable. Now the
minimum becomes 1/256x1/256, and with output_scale the actual samples
may be even smaller. That should be enough.
On not allowed values, raise a protocol error. This should help catch
bugs in clients that accidentally send garbage values.
The old wl_viewport.set request remains the same, and can still produce
zero sized source rectangle.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/protocol/scaler.xml b/protocol/scaler.xml
index 5094616..e21ae5b 100644
--- a/protocol/scaler.xml
+++ b/protocol/scaler.xml
@@ -86,7 +86,8 @@
dst_width, dst_height. The source (rectangle) is scaled to exactly
this size. This overrides whatever the attached wl_buffer size is,
unless the wl_buffer is NULL. If the wl_buffer is NULL, the surface
- has no content and therefore no size.
+ has no content and therefore no size. Otherwise, the size is always
+ at least 1x1 in surface coordinates.
If the source rectangle is set, it defines what area of the
wl_buffer is taken as the source. If the source rectangle is set and
@@ -131,7 +132,7 @@
<enum name="error">
<entry name="bad_value" value="0"
- summary="negative values in width or height"/>
+ summary="negative or zero values in width or height"/>
</enum>
<request name="set">
@@ -167,8 +168,10 @@
wl_viewport for the description, and relation to the wl_buffer
size.
- If width and/or height are negative, the source rectangle is unset
- instead.
+ If width is -1.0 and height is -1.0, the destination size is unset
+ instead. Any other pair of values for width and height that
+ contains zero or negative values raises the bad_value protocol
+ error.
The crop and scale state is double-buffered state, and will be
applied on the next wl_surface.commit.
@@ -186,8 +189,10 @@
wl_viewport for the description, and relation to the wl_buffer
size.
- If width and/or height are negative or zero, the destination size
- is unset instead.
+ If width is -1 and height is -1, the destination size is unset
+ instead. Any other pair of values for width and height that
+ contains zero or negative values raises the bad_value protocol
+ error.
The crop and scale state is double-buffered state, and will be
applied on the next wl_surface.commit.
diff --git a/src/compositor.c b/src/compositor.c
index ea27be4..a076291 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -3452,16 +3452,27 @@
assert(surface->viewport_resource != NULL);
- if (wl_fixed_to_double(src_width) < 0 ||
- wl_fixed_to_double(src_height) < 0) {
+ if (src_width == wl_fixed_from_int(-1) &&
+ src_height == wl_fixed_from_int(-1)) {
+ /* unset source size */
surface->pending.buffer_viewport.buffer.src_width =
wl_fixed_from_int(-1);
- } else {
- surface->pending.buffer_viewport.buffer.src_x = src_x;
- surface->pending.buffer_viewport.buffer.src_y = src_y;
- surface->pending.buffer_viewport.buffer.src_width = src_width;
- surface->pending.buffer_viewport.buffer.src_height = src_height;
+ return;
}
+
+ if (src_width <= 0 || src_height <= 0) {
+ wl_resource_post_error(resource,
+ WL_VIEWPORT_ERROR_BAD_VALUE,
+ "source size must be positive (%fx%f)",
+ wl_fixed_to_double(src_width),
+ wl_fixed_to_double(src_height));
+ return;
+ }
+
+ surface->pending.buffer_viewport.buffer.src_x = src_x;
+ surface->pending.buffer_viewport.buffer.src_y = src_y;
+ surface->pending.buffer_viewport.buffer.src_width = src_width;
+ surface->pending.buffer_viewport.buffer.src_height = src_height;
}
static void
@@ -3475,12 +3486,22 @@
assert(surface->viewport_resource != NULL);
- if (dst_width <= 0 || dst_height <= 0) {
+ if (dst_width == -1 && dst_height == -1) {
+ /* unset destination size */
surface->pending.buffer_viewport.surface.width = -1;
- } else {
- surface->pending.buffer_viewport.surface.width = dst_width;
- surface->pending.buffer_viewport.surface.height = dst_height;
+ return;
}
+
+ if (dst_width <= 0 || dst_height <= 0) {
+ wl_resource_post_error(resource,
+ WL_VIEWPORT_ERROR_BAD_VALUE,
+ "destination size must be positive (%dx%d)",
+ dst_width, dst_height);
+ return;
+ }
+
+ surface->pending.buffer_viewport.surface.width = dst_width;
+ surface->pending.buffer_viewport.surface.height = dst_height;
}
static const struct wl_viewport_interface viewport_interface = {