Implement wp_single_pixel_buffer_v1 protocol

This protocol allows clients to create single-pixel RGBA buffers. Now
that we have proper support for these buffers internally within Weston,
we can expose them to clients.

This bumps the build container version, as we now depend on
wayland-protocols v1.26.

Signed-off-by: Daniel Stone <daniels@collabora.com>

.gitlab-ci.yml

@@ -43,7 +43,7 @@
 variables:
   FDO_UPSTREAM_REPO: wayland/weston
   FDO_REPO_SUFFIX: "$BUILD_OS/$BUILD_ARCH"
-  FDO_DISTRIBUTION_TAG: '2022-06-28.00-graphviz'
+  FDO_DISTRIBUTION_TAG: '2022-07-13.00-wayland-protocols-1.26'
 
 
 include:

.gitlab-ci/build-deps.sh

@@ -107,7 +107,7 @@ rm -rf wayland
 # Keep this version in sync with our dependency in meson.build. If you wish to
 # raise a MR against custom protocol, please change this reference to clone
 # your relevant tree, and make sure you bump $FDO_DISTRIBUTION_TAG.
-git clone --branch 1.24 --depth=1 https://gitlab.freedesktop.org/wayland/wayland-protocols
+git clone --branch 1.26 --depth=1 https://gitlab.freedesktop.org/wayland/wayland-protocols
 cd wayland-protocols
 git show -s HEAD
 meson build

include/libweston/libweston.h

@@ -1318,6 +1318,10 @@ struct weston_compositor {
 	bool warned_about_unmapped_surface_or_view;
 };
 
+struct solid_buffer_values {
+	float r, g, b, a;
+};
+
 struct weston_buffer {
 	struct wl_resource *resource;
 	struct wl_signal destroy_signal;
@@ -1334,9 +1338,7 @@ struct weston_buffer {
 		struct wl_shm_buffer *shm_buffer;
 		void *dmabuf;
 		void *legacy_buffer;
-		struct {
+		struct solid_buffer_values solid;
-			float r, g, b, a;
-		} solid;
 	};
 
 	int32_t width, height;

libweston/compositor.c

@@ -65,6 +65,7 @@
 #include "xdg-output-unstable-v1-server-protocol.h"
 #include "linux-explicit-synchronization-unstable-v1-server-protocol.h"
 #include "linux-explicit-synchronization.h"
+#include "single-pixel-buffer-v1-server-protocol.h"
 #include "shared/fd-util.h"
 #include "shared/helpers.h"
 #include "shared/os-compatibility.h"
@@ -2414,6 +2415,9 @@ destroy_surface(struct wl_resource *resource)
 	weston_surface_unref(surface);
 }
 
+static struct solid_buffer_values *
+single_pixel_buffer_get(struct wl_resource *resource);
+
 static void
 weston_buffer_destroy_handler(struct wl_listener *listener, void *data)
 {
@@ -2438,6 +2442,7 @@ weston_buffer_from_resource(struct weston_compositor *ec,
 	struct wl_shm_buffer *shm;
 	struct linux_dmabuf_buffer *dmabuf;
 	struct wl_listener *listener;
+	struct solid_buffer_values *solid;
 
 	listener = wl_resource_get_destroy_listener(resource,
 						    weston_buffer_destroy_handler);
@@ -2485,6 +2490,19 @@ weston_buffer_from_resource(struct weston_compositor *ec,
 			buffer->buffer_origin = ORIGIN_BOTTOM_LEFT;
 		else
 			buffer->buffer_origin = ORIGIN_TOP_LEFT;
+	} else if ((solid = single_pixel_buffer_get(buffer->resource))) {
+		buffer->type = WESTON_BUFFER_SOLID;
+		buffer->solid = *solid;
+		buffer->width = 1;
+		buffer->height = 1;
+		if (buffer->solid.a == 1.0) {
+			buffer->pixel_format =
+				pixel_format_get_info(DRM_FORMAT_XRGB8888);
+		} else {
+			buffer->pixel_format =
+				pixel_format_get_info(DRM_FORMAT_ARGB8888);
+		}
+		buffer->format_modifier = DRM_FORMAT_MOD_LINEAR;
 	} else {
 		/* Only taken for legacy EGL buffers */
 		if (!ec->renderer->fill_buffer_info ||
@@ -2701,6 +2719,97 @@ weston_buffer_destroy_solid(struct weston_buffer_reference *buffer_ref)
 	free(buffer_ref);
 }
 
+static void
+single_pixel_buffer_destroy(struct wl_resource *resource)
+{
+	struct solid_buffer_values *solid =
+		wl_resource_get_user_data(resource);
+	free(solid);
+}
+
+static void
+single_pixel_buffer_handle_buffer_destroy(struct wl_client *client,
+					  struct wl_resource *resource)
+{
+	wl_resource_destroy(resource);
+}
+
+static const struct wl_buffer_interface single_pixel_buffer_implementation = {
+	single_pixel_buffer_handle_buffer_destroy,
+};
+
+static struct solid_buffer_values *
+single_pixel_buffer_get(struct wl_resource *resource)
+{
+	if (!resource)
+		return NULL;
+
+	if (!wl_resource_instance_of(resource, &wl_buffer_interface,
+				     &single_pixel_buffer_implementation))
+		return NULL;
+
+	return wl_resource_get_user_data(resource);
+}
+
+static void
+single_pixel_buffer_manager_destroy(struct wl_client *client,
+				    struct wl_resource *resource)
+{
+	wl_resource_destroy(resource);
+}
+
+static void
+single_pixel_buffer_create(struct wl_client *client, struct wl_resource *resource,
+			   uint32_t id, uint32_t r, uint32_t g, uint32_t b, uint32_t a)
+{
+	struct solid_buffer_values *solid = zalloc(sizeof(*solid));
+	struct wl_resource *buffer;
+
+	if (!solid) {
+		wl_client_post_no_memory(client);
+		return;
+	}
+
+	solid->r = r / (double) 0xffffffff;
+	solid->g = g / (double) 0xffffffff;
+	solid->b = b / (double) 0xffffffff;
+	solid->a = a / (double) 0xffffffff;
+
+	buffer = wl_resource_create(client, &wl_buffer_interface, 1, id);
+	if (!buffer) {
+		wl_client_post_no_memory(client);
+		free(solid);
+		return;
+	}
+	wl_resource_set_implementation(buffer,
+				       &single_pixel_buffer_implementation,
+				       solid, single_pixel_buffer_destroy);
+}
+
+static const struct wp_single_pixel_buffer_manager_v1_interface
+single_pixel_buffer_manager_implementation = {
+	single_pixel_buffer_manager_destroy,
+	single_pixel_buffer_create,
+};
+
+static void
+bind_single_pixel_buffer(struct wl_client *client, void *data, uint32_t version,
+			 uint32_t id)
+{
+	struct wl_resource *resource;
+
+	resource = wl_resource_create(client,
+				      &wp_single_pixel_buffer_manager_v1_interface, 1,
+				      id);
+	if (!resource) {
+		wl_client_post_no_memory(client);
+		return;
+	}
+	wl_resource_set_implementation(resource,
+				       &single_pixel_buffer_manager_implementation,
+				       NULL, NULL);
+}
+
 static void
 weston_surface_attach(struct weston_surface *surface,
 		      struct weston_buffer *buffer)
@@ -8232,6 +8341,11 @@ weston_compositor_create(struct wl_display *display,
 			      ec, bind_presentation))
 		goto fail;
 
+	if (!wl_global_create(ec->wl_display,
+			      &wp_single_pixel_buffer_manager_v1_interface, 1,
+			      NULL, bind_single_pixel_buffer))
+		goto fail;
+
 	if (weston_input_init(ec) != 0)
 		goto fail;
 

libweston/meson.build

@@ -51,6 +51,8 @@ srcs_libweston = [
 	relative_pointer_unstable_v1_server_protocol_h,
 	weston_screenshooter_protocol_c,
 	weston_screenshooter_server_protocol_h,
+	single_pixel_buffer_v1_protocol_c,
+	single_pixel_buffer_v1_server_protocol_h,
 	text_cursor_position_protocol_c,
 	text_cursor_position_server_protocol_h,
 	text_input_unstable_v1_protocol_c,

protocol/meson.build

@@ -1,7 +1,7 @@
 dep_scanner = dependency('wayland-scanner', native: true)
 prog_scanner = find_program(dep_scanner.get_pkgconfig_variable('wayland_scanner'))
 
-dep_wp = dependency('wayland-protocols', version: '>= 1.24',
+dep_wp = dependency('wayland-protocols', version: '>= 1.26',
 	fallback: ['wayland-protocols', 'wayland_protocols'])
 dir_wp_base = dep_wp.get_variable(pkgconfig: 'pkgdatadir', internal: 'pkgdatadir')
 
@@ -25,6 +25,7 @@ generated_protocols = [
 	[ 'presentation-time', 'stable' ],
 	[ 'pointer-constraints', 'unstable', 'v1' ],
 	[ 'relative-pointer', 'unstable', 'v1' ],
+	[ 'single-pixel-buffer', 'staging', 'v1' ],
 	[ 'tablet', 'unstable', 'v2' ],
 	[ 'text-cursor-position', 'internal' ],
 	[ 'text-input', 'unstable', 'v1' ],
@@ -52,6 +53,9 @@ foreach proto: generated_protocols
 	elif proto[1] == 'unstable'
 		base_file = '@0@-unstable-@1@'.format(proto_name, proto[2])
 		xml_path = '@0@/unstable/@1@/@2@.xml'.format(dir_wp_base, proto_name, base_file)
+	elif proto[1] == 'staging'
+		base_file = '@0@-@1@'.format(proto_name, proto[2])
+		xml_path = '@0@/staging/@1@/@2@.xml'.format(dir_wp_base, proto_name, base_file)
 	endif
 
 	foreach output_type: [ 'client-header', 'server-header', 'private-code' ]

tests/meson.build

@@ -205,6 +205,14 @@ tests = [
 			xdg_shell_protocol_c,
 		],
 	},
+	{
+		'name': 'single-pixel-buffer',
+		'sources': [
+			'single-pixel-buffer-test.c',
+			single_pixel_buffer_v1_client_protocol_h,
+			single_pixel_buffer_v1_protocol_c,
+		]
+	},
 	{	'name': 'string', },
 	{	'name': 'subsurface', },
 	{	'name': 'subsurface-shot', },

tests/single-pixel-buffer-test.c

@@ -0,0 +1,111 @@
+/*
+ * Copyright © 2020 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <math.h>
+#include <unistd.h>
+
+#include "weston-test-client-helper.h"
+#include "weston-test-fixture-compositor.h"
+#include "single-pixel-buffer-v1-client-protocol.h"
+#include "shared/os-compatibility.h"
+#include "shared/xalloc.h"
+
+struct setup_args {
+	struct fixture_metadata meta;
+	enum renderer_type renderer;
+};
+
+static const struct setup_args my_setup_args[] = {
+	{
+		.renderer = RENDERER_PIXMAN,
+		.meta.name = "pixman"
+	},
+	{
+		.renderer = RENDERER_GL,
+		.meta.name = "GL"
+	},
+};
+
+static enum test_result_code
+fixture_setup(struct weston_test_harness *harness, const struct setup_args *arg)
+{
+	struct compositor_setup setup;
+
+	compositor_setup_defaults(&setup);
+	setup.renderer = arg->renderer;
+	setup.width = 320;
+	setup.height = 240;
+	setup.shell = SHELL_TEST_DESKTOP;
+	setup.logging_scopes = "log,test-harness-plugin";
+
+	return weston_test_harness_execute_as_client(harness, &setup);
+}
+DECLARE_FIXTURE_SETUP_WITH_ARG(fixture_setup, my_setup_args, meta);
+
+TEST(solid_buffer_argb_u32)
+{
+	struct client *client;
+	struct wp_single_pixel_buffer_manager_v1 *mgr;
+	struct wp_viewport *viewport;
+	struct wl_buffer *buffer;
+	int done;
+	bool match;
+
+	client = create_client();
+	client->surface = create_test_surface(client);
+	viewport = client_create_viewport(client);
+	wp_viewport_set_destination(viewport, 128, 128);
+
+	mgr = bind_to_singleton_global(client,
+				       &wp_single_pixel_buffer_manager_v1_interface,
+				       1);
+	buffer = wp_single_pixel_buffer_manager_v1_create_u32_rgba_buffer(mgr,
+									  0xcfffffff, /* r */
+									  0x8fffffff, /* g */
+									  0x4fffffff, /* b */
+									  0xffffffff /* a */);
+	assert(buffer);
+
+	weston_test_move_surface(client->test->weston_test,
+				 client->surface->wl_surface,
+				 64, 64);
+	wl_surface_attach(client->surface->wl_surface, buffer, 0, 0);
+	wl_surface_damage_buffer(client->surface->wl_surface, 0, 0, 1, 1);
+	frame_callback_set(client->surface->wl_surface, &done);
+	wl_surface_commit(client->surface->wl_surface);
+	frame_callback_wait(client, &done);
+
+	match = verify_screen_content(client, "single-pixel-buffer", 0, NULL, 0);
+	assert(match);
+
+	wl_buffer_destroy(buffer);
+	wp_viewport_destroy(viewport);
+	client_destroy(client);
+}