clients/screenshot: Add support for weston output capture

libweston now provides a protocol which we can use for doing
screenshots, not needing to provide one ourselves. This imports
a simple client used in Weston but it has some changes to match
our current args.

Bug-AGL: SPEC-5095
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: I00c9e976975447c74668fbfe1045b9177c623064

3 files changed, 679 insertions, 627 deletions

diff --git a/clients/meson.build b/clients/meson.build
index 08b2c08..e636894 100644
--- a/clients/meson.build
+++ b/clients/meson.build
@@ -1,20 +1,19 @@
 dep_wayland_client = dependency('wayland-client', version: '>= 1.17.0')
+dep_pixman = dependency('pixman-1', version: '>= 0.25.2')
 
 clients = [
 {
 	'basename': 'agl-screenshooter',
 	'sources': [
-	  'screenshooter.c',
+	  'screenshot.c',
 	  '../shared/file-util.c',
 	  '../shared/os-compatibility.c',
 	  '../shared/xalloc.c',
-	  agl_screenshooter_client_protocol_h,
-	  agl_screenshooter_protocol_c,
-	  xdg_output_unstable_v1_client_protocol_h,
-	  xdg_output_unstable_v1_protocol_c,
+	  weston_output_capture_protocol_c,
+	  weston_output_capture_client_protocol_h,
 	],
-	'deps_objs' : [ dep_wayland_client ],
-	'deps': [ 'cairo' ],
+	'deps_objs' : [ dep_wayland_client, dep_pixman ],
+	'deps': [ 'cairo', ],
 },
 ]
 
diff --git a/clients/screenshooter.c b/clients/screenshooter.c
deleted file mode 100644
index 0066ed5..0000000
--- a/clients/screenshooter.c
+++ /dev/null
@@ -1,620 +0,0 @@
-/*
- * 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 <stdint.h>
-#include <errno.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <limits.h>
-#include <sys/param.h>
-#include <sys/mman.h>
-#include <getopt.h>
-#include <cairo.h>
-
-#include <wayland-client.h>
-#include "shared/helpers.h"
-#include "shared/xalloc.h"
-#include "shared/file-util.h"
-#include "shared/string-helpers.h"
-#include "shared/os-compatibility.h"
-#include "agl-screenshooter-client-protocol.h"
-#include "xdg-output-unstable-v1-client-protocol.h"
-
-struct screenshooter_data;
-
-struct screenshooter_output {
-	struct wl_output *output;
-	struct wl_buffer *buffer;
-
-	int width, height, offset_x, offset_y, scale;
-	void *data;
-	struct screenshooter_data *sh_data;
-
-	struct wl_list link;	/** screenshooter_data::output_list */
-};
-
-struct xdg_output_v1_info {
-	struct zxdg_output_v1 *xdg_output;
-	struct screenshooter_output *output;
-
-	char *name, *description;
-	struct wl_list link;	/** screenshooter_data::xdg_output_list */
-};
-
-
-struct buffer_size {
-	int width, height;
-
-	int min_x, min_y;
-	int max_x, max_y;
-};
-
-struct screenshooter_data {
-	struct wl_display *display;
-	struct wl_shm *shm;
-	struct wl_list output_list;	/** screenshooter_output::link */
-	struct wl_list xdg_output_list;	/** xdg_output_v1_info::link */
-
-	struct zxdg_output_manager_v1 *xdg_output_manager;
-	struct agl_screenshooter *screenshooter;
-	int buffer_copy_done;
-};
-
-static int opts = 0x0;
-
-#define OPT_SCREENSHOT_OUTPUT		1
-#define OPT_SHOW_ALL_OUTPUTS		2
-#define OPT_SCREENSHOT_ALL_OUTPUTS	3
-
-static void
-display_handle_geometry(void *data,
-			struct wl_output *wl_output,
-			int x,
-			int y,
-			int physical_width,
-			int physical_height,
-			int subpixel,
-			const char *make,
-			const char *model,
-			int transform)
-{
-	struct screenshooter_output *output;
-
-	output = wl_output_get_user_data(wl_output);
-
-	if (wl_output == output->output) {
-		output->offset_x = x;
-		output->offset_y = y;
-	}
-}
-
-static void
-display_handle_mode(void *data,
-		    struct wl_output *wl_output,
-		    uint32_t flags,
-		    int width,
-		    int height,
-		    int refresh)
-{
-	struct screenshooter_output *output;
-
-	output = wl_output_get_user_data(wl_output);
-
-	if (wl_output == output->output && (flags & WL_OUTPUT_MODE_CURRENT)) {
-		output->width = width;
-		output->height = height;
-	}
-}
-
-static void
-display_handle_done(void *data, struct wl_output *wl_output)
-{
-
-}
-
-static void
-display_handle_scale(void *data, struct wl_output *wl_output,
-		int32_t scale)
-{
-	struct screenshooter_output *output = data;
-	output->scale = scale;
-}
-
-
-static const struct wl_output_listener output_listener = {
-	display_handle_geometry,
-	display_handle_mode,
-	display_handle_done,
-	display_handle_scale,
-	NULL,
-	NULL
-};
-
-static void
-handle_xdg_output_v1_logical_position(void *data, struct zxdg_output_v1 *output,
-                                      int32_t x, int32_t y)
-{
-}
-
-static void
-handle_xdg_output_v1_logical_size(void *data, struct zxdg_output_v1 *output,
-                                      int32_t width, int32_t height)
-{
-}
-
-static void
-handle_xdg_output_v1_done(void *data, struct zxdg_output_v1 *output)
-{
-	/* Don't bother waiting for this; there's no good reason a
-	 * compositor will wait more than one roundtrip before sending
-	 * these initial events. */
-}
-
-static void
-handle_xdg_output_v1_name(void *data, struct zxdg_output_v1 *output,
-                          const char *name)
-{
-	struct xdg_output_v1_info *xdg_output = data;
-	xdg_output->name = strdup(name);
-}
-
-static void
-handle_xdg_output_v1_description(void *data, struct zxdg_output_v1 *output,
-                          const char *description)
-{
-	struct xdg_output_v1_info *xdg_output = data;
-	xdg_output->description = strdup(description);
-}
-
-static const struct zxdg_output_v1_listener xdg_output_v1_listener = {
-	.logical_position = handle_xdg_output_v1_logical_position,
-	.logical_size = handle_xdg_output_v1_logical_size,
-	.done = handle_xdg_output_v1_done,
-	.name = handle_xdg_output_v1_name,
-	.description = handle_xdg_output_v1_description,
-};
-
-static void
-add_xdg_output_v1_info(struct screenshooter_data *shooter_data,
-                       struct screenshooter_output *output)
-{
-	struct xdg_output_v1_info *xdg_output = zalloc(sizeof(*xdg_output));
-	if (!xdg_output)
-		return;
-
-	wl_list_insert(&shooter_data->xdg_output_list, &xdg_output->link);
-
-	xdg_output->xdg_output =
-		zxdg_output_manager_v1_get_xdg_output(shooter_data->xdg_output_manager,
-						      output->output);
-
-	zxdg_output_v1_add_listener(xdg_output->xdg_output,
-				    &xdg_output_v1_listener, xdg_output);
-	xdg_output->output = output;
-}
-
-static void
-screenshot_done(void *data, struct agl_screenshooter *screenshooter, uint32_t status)
-{
-	struct screenshooter_data *sh_data = data;
-	sh_data->buffer_copy_done = 1;
-}
-
-static const struct agl_screenshooter_listener screenshooter_listener = {
-	screenshot_done
-};
-
-static void
-handle_global(void *data, struct wl_registry *registry,
-	      uint32_t name, const char *interface, uint32_t version)
-{
-	struct screenshooter_output *output;
-	struct screenshooter_data *sh_data = data;
-
-	if (strcmp(interface, "wl_output") == 0) {
-		output = zalloc(sizeof(*output));
-		if (!output)
-			return;
-
-		output->output = wl_registry_bind(registry, name,
-						  &wl_output_interface, 1);
-		output->sh_data = sh_data;
-		wl_list_insert(&sh_data->output_list, &output->link);
-		wl_output_add_listener(output->output, &output_listener, output);
-	} else if (strcmp(interface, "wl_shm") == 0) {
-		sh_data->shm = wl_registry_bind(registry, name, &wl_shm_interface, 1);
-	} else if (strcmp(interface, "agl_screenshooter") == 0) {
-		sh_data->screenshooter = wl_registry_bind(registry, name,
-							  &agl_screenshooter_interface, 1);
-
-		agl_screenshooter_add_listener(sh_data->screenshooter,
-					       &screenshooter_listener, sh_data);
-	} else if (strcmp(interface, "zxdg_output_manager_v1") == 0) {
-		sh_data->xdg_output_manager = wl_registry_bind(registry, name,
-					&zxdg_output_manager_v1_interface, version);
-	}
-}
-
-static void
-handle_global_remove(void *data, struct wl_registry *registry, uint32_t name)
-{
-	/* XXX: unimplemented */
-}
-
-static const struct wl_registry_listener registry_listener = {
-	handle_global,
-	handle_global_remove
-};
-
-static struct wl_buffer *
-screenshot_create_shm_buffer(int width, int height, void **data_out,
-			     struct wl_shm *shm)
-{
-	struct wl_shm_pool *pool;
-	struct wl_buffer *buffer;
-	int fd, size, stride;
-	void *data;
-
-	stride = width * 4;
-	size = stride * height;
-
-	fd = os_create_anonymous_file(size);
-	if (fd < 0) {
-		fprintf(stderr, "creating a buffer file for %d B failed: %s\n",
-			size, strerror(errno));
-		return NULL;
-	}
-
-	data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-	if (data == MAP_FAILED) {
-		fprintf(stderr, "mmap failed: %s\n", strerror(errno));
-		close(fd);
-		return NULL;
-	}
-
-	pool = wl_shm_create_pool(shm, fd, size);
-	close(fd);
-	buffer = wl_shm_pool_create_buffer(pool, 0, width, height, stride,
-					   WL_SHM_FORMAT_XRGB8888);
-	wl_shm_pool_destroy(pool);
-
-	*data_out = data;
-
-	return buffer;
-}
-
-static void
-screenshot_write_png_per_output(const struct buffer_size *buff_size,
-				struct screenshooter_output *sh_output,
-				const char *fn)
-{
-	int output_stride, buffer_stride, i;
-	cairo_surface_t *surface;
-	void *data, *d, *s;
-	FILE *fp;
-	char filepath[PATH_MAX];
-	char *filename_to_write;
-
-	buffer_stride = buff_size->width * 4;
-	data = xmalloc(buffer_stride * buff_size->height);
-	if (!data)
-		return;
-
-	output_stride = sh_output->width * 4;
-	s = sh_output->data;
-	d = data + (sh_output->offset_y - buff_size->min_y) * buffer_stride +
-		   (sh_output->offset_x - buff_size->min_x) * 4;
-
-	for (i = 0; i < sh_output->height; i++) {
-		memcpy(d, s, output_stride);
-		d += buffer_stride;
-		s += output_stride;
-	}
-
-	surface = cairo_image_surface_create_for_data(data,
-						      CAIRO_FORMAT_ARGB32,
-						      buff_size->width,
-						      buff_size->height,
-						      buffer_stride);
-
-	if (fn)
-		str_printf(&filename_to_write, "agl-screenshot-%s-", fn);
-	else
-		str_printf(&filename_to_write, "agl-screenshot-");
-
-	fp = file_create_dated(getenv("XDG_PICTURES_DIR"), filename_to_write,
-			       ".png", filepath, sizeof(filepath));
-	if (fp) {
-		fclose(fp);
-		cairo_surface_write_to_png(surface, filepath);
-	}
-
-	cairo_surface_destroy(surface);
-	free(filename_to_write);
-	free(data);
-}
-
-static void
-screenshot_set_buffer_size_per_output(struct buffer_size *buff_size,
-				      struct screenshooter_output *output)
-{
-	buff_size->min_x = MIN(buff_size->min_x, output->offset_x);
-	buff_size->min_y = MIN(buff_size->min_y, output->offset_y);
-	buff_size->max_x = MAX(buff_size->max_x, output->offset_x + output->width);
-	buff_size->max_y = MAX(buff_size->max_y, output->offset_y + output->height);
-
-	buff_size->width = buff_size->max_x - buff_size->min_x;
-	buff_size->height = buff_size->max_y - buff_size->min_y;
-}
-
-static void
-screenshot_compute_output_offset(int *pos, struct screenshooter_output *sh_output)
-{
-	sh_output->offset_x = *pos;
-	*pos += sh_output->width;
-}
-
-static struct screenshooter_output *
-agl_shooter_search_for_output(const char *output_name,
-			      struct screenshooter_data *sh_data)
-{
-	struct screenshooter_output *found_output = NULL;
-	struct xdg_output_v1_info *output;
-
-	if (!output_name)
-		return found_output;
-
-	wl_list_for_each(output, &sh_data->xdg_output_list, link) {
-		if (output->name && strcmp(output->name, output_name) == 0) {
-			found_output = output->output;
-			break;
-		}
-	}
-
-	return found_output;
-}
-
-static char *
-agl_shooter_search_get_output_name(struct screenshooter_output *sh_output)
-{
-	struct xdg_output_v1_info *output;
-	struct screenshooter_data *sh_data;
-
-	if (!sh_output)
-		return NULL;
-
-	sh_data = sh_output->sh_data;
-
-	wl_list_for_each(output, &sh_data->xdg_output_list, link) {
-		if (output->output == sh_output) {
-			return output->name;
-		}
-	}
-
-	return NULL;
-}
-
-static void
-agl_shooter_display_all_outputs(struct screenshooter_data *sh_data)
-{
-	struct xdg_output_v1_info *xdg_output;
-	wl_list_for_each(xdg_output, &sh_data->xdg_output_list, link) {
-		fprintf(stdout, "Output '%s', desc: '%s'\n", xdg_output->name,
-				xdg_output->description);
-	}
-}
-
-
-static void
-agl_shooter_screenshot_all_outputs(struct screenshooter_data *sh_data)
-{
-	struct xdg_output_v1_info *xdg_output;
-
-	wl_list_for_each(xdg_output, &sh_data->xdg_output_list, link) {
-		struct buffer_size buff_size = {};
-		int pos = 0;
-		struct screenshooter_output *output = xdg_output->output;
-
-		screenshot_compute_output_offset(&pos, output);
-		screenshot_set_buffer_size_per_output(&buff_size, output);
-
-		output->buffer =
-			screenshot_create_shm_buffer(output->width,
-						     output->height,
-						     &output->data,
-						     sh_data->shm);
-
-		agl_screenshooter_take_shot(sh_data->screenshooter,
-					    output->output,
-					    output->buffer);
-
-		sh_data->buffer_copy_done = 0;
-		while (!sh_data->buffer_copy_done)
-			wl_display_roundtrip(sh_data->display);
-
-		screenshot_write_png_per_output(&buff_size, output, xdg_output->name);
-	}
-}
-
-static void
-agl_shooter_screenshot_output(struct screenshooter_output *sh_output)
-{
-	int pos = 0;
-	struct buffer_size buff_size = {};
-	struct screenshooter_data *sh_data = sh_output->sh_data;
-	char *output_name;
-
-	screenshot_compute_output_offset(&pos, sh_output);
-	screenshot_set_buffer_size_per_output(&buff_size, sh_output);
-
-	sh_output->buffer =
-		screenshot_create_shm_buffer(sh_output->width,
-					     sh_output->height,
-					     &sh_output->data, sh_data->shm);
-
-	agl_screenshooter_take_shot(sh_data->screenshooter,
-				    sh_output->output,
-				    sh_output->buffer);
-
-	sh_data->buffer_copy_done = 0;
-	while (!sh_data->buffer_copy_done)
-		wl_display_roundtrip(sh_data->display);
-
-	output_name = agl_shooter_search_get_output_name(sh_output);
-	assert(output_name);
-	screenshot_write_png_per_output(&buff_size, sh_output, output_name);
-}
-
-static void
-agl_shooter_destroy_xdg_output_manager(struct screenshooter_data *sh_data)
-{
-	struct xdg_output_v1_info *xdg_output;
-
-	wl_list_for_each(xdg_output, &sh_data->xdg_output_list, link) {
-		free(xdg_output->name);
-		free(xdg_output->description);
-		zxdg_output_v1_destroy(xdg_output->xdg_output);
-	}
-
-	zxdg_output_manager_v1_destroy(sh_data->xdg_output_manager);
-}
-
-static void
-print_usage_and_exit(void)
-{
-	fprintf(stderr, "./agl-screenshooter [-o OUTPUT_NAME] [-l] [-a]\n");
-
-	fprintf(stderr, "\t-o OUTPUT_NAME -- take a screenshot of the output "
-				"specified by OUTPUT_NAME\n");
-	fprintf(stderr, "\t-a  -- take a screenshot of all the outputs found\n");
-	fprintf(stderr, "\t-l  -- list all the outputs found\n");
-	exit(EXIT_FAILURE);
-}
-
-int main(int argc, char *argv[])
-{
-	struct wl_display *display;
-	struct wl_registry *registry;
-
-	struct screenshooter_data sh_data = {};
-	struct screenshooter_output *sh_output = NULL;
-	int c, option_index;
-
-	char *output_name = NULL;
-
-	static struct option long_options[] = {
-		{"output", 	required_argument, 0,  'o' },
-		{"list", 	required_argument, 0,  'l' },
-		{"all", 	required_argument, 0,  'a' },
-		{"help",	no_argument      , 0,  'h' },
-		{0, 0, 0, 0}
-	};
-
-	while ((c = getopt_long(argc, argv, "o:lah",
-				long_options, &option_index)) != -1) {
-		switch (c) {
-		case 'o':
-			output_name = optarg;
-			opts |= (1 << OPT_SCREENSHOT_OUTPUT);
-			break;
-		case 'l':
-			opts |= (1 << OPT_SHOW_ALL_OUTPUTS);
-			break;
-		case 'a':
-			opts |= (1 << OPT_SCREENSHOT_ALL_OUTPUTS);
-			break;
-		default:
-			print_usage_and_exit();
-		}
-	}
-
-	display = wl_display_connect(NULL);
-	if (display == NULL) {
-		fprintf(stderr, "failed to create display: %s\n",
-			strerror(errno));
-		return EXIT_FAILURE;
-	}
-
-	wl_list_init(&sh_data.output_list);
-	wl_list_init(&sh_data.xdg_output_list);
-	sh_data.display = display;
-
-	registry = wl_display_get_registry(display);
-	wl_registry_add_listener(registry, &registry_listener, &sh_data);
-
-	wl_display_dispatch(display);
-	wl_display_roundtrip(display);
-
-
-	if (sh_data.screenshooter == NULL) {
-		fprintf(stderr, "Compositor doesn't support screenshooter\n");
-		return EXIT_FAILURE;
-	}
-
-	wl_list_for_each(sh_output, &sh_data.output_list, link)
-		add_xdg_output_v1_info(&sh_data, sh_output);
-
-	/* do another round-trip for xdg_output */
-	wl_display_roundtrip(sh_data.display);
-
-	if (opts & (1 << OPT_SHOW_ALL_OUTPUTS)) {
-		agl_shooter_display_all_outputs(&sh_data);
-		agl_shooter_destroy_xdg_output_manager(&sh_data);
-		return EXIT_SUCCESS;
-	}
-
-	if (opts & (1 << OPT_SCREENSHOT_ALL_OUTPUTS)) {
-		agl_shooter_screenshot_all_outputs(&sh_data);
-		agl_shooter_destroy_xdg_output_manager(&sh_data);
-		return EXIT_SUCCESS;
-	}
-
-	sh_output = NULL;
-	if (output_name)
-		sh_output = agl_shooter_search_for_output(output_name, &sh_data);
-
-	if (!sh_output && (opts & (1 << OPT_SCREENSHOT_OUTPUT))) {
-		fprintf(stderr, "Could not find an output matching '%s'\n",
-				output_name);
-		agl_shooter_destroy_xdg_output_manager(&sh_data);
-		return EXIT_FAILURE;
-	}
-
-	/* if we're still here just pick the first one available
-	 * and use that. Still useful in case we are run without
-	 * any args whatsoever */
-	if (!sh_output)
-		sh_output = container_of(sh_data.output_list.next,
-					 struct screenshooter_output, link);
-
-	/* take a screenshot only of that specific output */
-	agl_shooter_screenshot_output(sh_output);
-	agl_shooter_destroy_xdg_output_manager(&sh_data);
-
-	return 0;
-}
diff --git a/clients/screenshot.c b/clients/screenshot.c
new file mode 100644
index 0000000..214d065
--- /dev/null
+++ b/clients/screenshot.c
@@ -0,0 +1,673 @@
+/*
+ * Copyright 2024 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 <stdint.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+#include <sys/param.h>
+#include <sys/mman.h>
+#include <pixman.h>
+#include <cairo.h>
+#include <getopt.h>
+#include <assert.h>
+
+#include <wayland-client.h>
+#include "weston-output-capture-client-protocol.h"
+#include "shared/os-compatibility.h"
+#include "shared/xalloc.h"
+#include "shared/file-util.h"
+#include "shared/pixel-formats.h"
+#include "shared/helpers.h"
+#include "shared/string-helpers.h"
+
+static int opts = 0x0;
+
+#define OPT_SCREENSHOT_OUTPUT		1
+#define OPT_SHOW_ALL_OUTPUTS		2
+#define OPT_SCREENSHOT_ALL_OUTPUTS	3
+
+struct screenshooter_app {
+	struct wl_display *display;
+	struct wl_registry *registry;
+	struct wl_shm *shm;
+	struct weston_capture_v1 *capture_factory;
+
+	struct wl_list output_list; /* struct screenshooter_output::link */
+
+	bool retry;
+	bool failed;
+	int waitcount;
+};
+
+struct screenshooter_buffer {
+	size_t len;
+	void *data;
+	struct wl_buffer *wl_buffer;
+	pixman_image_t *image;
+};
+
+struct screenshooter_output {
+	struct screenshooter_app *app;
+	struct wl_list link; /* struct screenshooter_app::output_list */
+
+	struct wl_output *wl_output;
+	int offset_x, offset_y;
+	char *name;
+
+	struct weston_capture_source_v1 *source;
+
+	int buffer_width;
+	int buffer_height;
+	const struct pixel_format_info *fmt;
+	struct screenshooter_buffer *buffer;
+};
+
+struct buffer_size {
+	int width, height;
+
+	int min_x, min_y;
+	int max_x, max_y;
+};
+
+static struct screenshooter_buffer *
+screenshot_create_shm_buffer(struct screenshooter_app *app,
+			     size_t width, size_t height,
+			     const struct pixel_format_info *fmt)
+{
+	struct screenshooter_buffer *buffer;
+	struct wl_shm_pool *pool;
+	int fd;
+	size_t bytes_pp;
+	size_t stride;
+
+	assert(width > 0);
+	assert(height > 0);
+	assert(fmt && fmt->bpp > 0);
+	assert(fmt->pixman_format);
+
+	buffer = xzalloc(sizeof *buffer);
+
+	bytes_pp = fmt->bpp / 8;
+	stride = width * bytes_pp;
+	buffer->len = stride * height;
+
+	assert(width == stride / bytes_pp);
+	assert(height == buffer->len / stride);
+
+	fd = os_create_anonymous_file(buffer->len);
+	if (fd < 0) {
+		fprintf(stderr, "creating a buffer file for %zd B failed: %s\n",
+			buffer->len, strerror(errno));
+		free(buffer);
+		return NULL;
+	}
+
+	buffer->data = mmap(NULL, buffer->len, PROT_READ | PROT_WRITE,
+			    MAP_SHARED, fd, 0);
+	if (buffer->data == MAP_FAILED) {
+		fprintf(stderr, "mmap failed: %s\n", strerror(errno));
+		close(fd);
+		free(buffer);
+		return NULL;
+	}
+
+	pool = wl_shm_create_pool(app->shm, fd, buffer->len);
+	close(fd);
+	buffer->wl_buffer =
+		wl_shm_pool_create_buffer(pool, 0, width, height, stride,
+					  pixel_format_get_shm_format(fmt));
+	wl_shm_pool_destroy(pool);
+
+	buffer->image = pixman_image_create_bits(fmt->pixman_format,
+						 width, height,
+						 buffer->data, stride);
+	if (!buffer->image) {
+		fprintf(stderr, "Failed to create buffer image!\n");
+		close(fd);
+		free(buffer);
+		return NULL;
+	}
+
+	return buffer;
+}
+
+static void
+screenshooter_buffer_destroy(struct screenshooter_buffer *buffer)
+{
+	if (!buffer)
+		return;
+
+	pixman_image_unref(buffer->image);
+	munmap(buffer->data, buffer->len);
+	wl_buffer_destroy(buffer->wl_buffer);
+	free(buffer);
+}
+
+static void
+capture_source_handle_format(void *data,
+			     struct weston_capture_source_v1 *proxy,
+			     uint32_t drm_format)
+{
+	struct screenshooter_output *output = data;
+
+	assert(output->source == proxy);
+
+	output->fmt = pixel_format_get_info(drm_format);
+}
+
+static void
+capture_source_handle_size(void *data,
+			   struct weston_capture_source_v1 *proxy,
+			   int32_t width, int32_t height)
+{
+	struct screenshooter_output *output = data;
+
+	assert(width > 0);
+	assert(height > 0);
+
+	output->buffer_width = width;
+	output->buffer_height = height;
+}
+
+static void
+capture_source_handle_complete(void *data,
+			       struct weston_capture_source_v1 *proxy)
+{
+	struct screenshooter_output *output = data;
+
+	output->app->waitcount--;
+}
+
+static void
+capture_source_handle_retry(void *data,
+			    struct weston_capture_source_v1 *proxy)
+{
+	struct screenshooter_output *output = data;
+
+	output->app->waitcount--;
+	output->app->retry = true;
+}
+
+static void
+capture_source_handle_failed(void *data,
+			     struct weston_capture_source_v1 *proxy,
+			     const char *msg)
+{
+	struct screenshooter_output *output = data;
+
+	output->app->waitcount--;
+	output->app->failed = true;
+
+	if (msg)
+		fprintf(stderr, "Output capture error: %s\n", msg);
+}
+
+static const struct weston_capture_source_v1_listener capture_source_handlers = {
+	.format = capture_source_handle_format,
+	.size = capture_source_handle_size,
+	.complete = capture_source_handle_complete,
+	.retry = capture_source_handle_retry,
+	.failed = capture_source_handle_failed,
+};
+
+static void
+display_handle_geometry(void *data,
+		struct wl_output *wl_output,
+		int x, int y,
+		int physical_width,
+		int physical_height,
+		int subpixel,
+		const char *make,
+		const char *model,
+		int32_t transform)
+{
+}
+
+static void
+display_handle_mode(void *data,
+		struct wl_output *wl_output,
+		uint32_t flags,
+		int width,
+		int height,
+		int refresh)
+{
+}
+
+static void
+display_handle_scale(void *data,
+		struct wl_output *wl_output,
+		int scale)
+{
+}
+
+static void
+display_handle_name(void *data, struct wl_output *wl_output, const char *name)
+{
+	struct screenshooter_output *output = data;
+	output->name = strdup(name);
+}
+
+static void
+display_handle_description(void *data, struct wl_output *wl_output, const char *desc)
+{
+}
+
+static void
+display_handle_done(void *data,
+		struct wl_output *wl_output)
+{
+}
+
+
+static const struct wl_output_listener output_listener = {
+	display_handle_geometry,
+	display_handle_mode,
+	display_handle_done,
+	display_handle_scale,
+	display_handle_name,
+	display_handle_description,
+};
+
+static void
+create_output(struct screenshooter_app *app, uint32_t output_name, uint32_t version)
+{
+	struct screenshooter_output *output;
+
+	version = MIN(version, 4);
+	output = xzalloc(sizeof *output);
+	output->app = app;
+	output->wl_output = wl_registry_bind(app->registry, output_name,
+					     &wl_output_interface, version);
+	if (!output->wl_output) {
+		fprintf(stderr, "Failed to get bind output!\n");
+		exit(EXIT_FAILURE);
+	}
+
+	wl_output_add_listener(output->wl_output, &output_listener, output);
+
+	output->source = weston_capture_v1_create(app->capture_factory,
+						  output->wl_output,
+						  WESTON_CAPTURE_V1_SOURCE_FRAMEBUFFER);
+	if (!output->source) {
+		fprintf(stderr, "Failed to get a capture source!\n");
+		exit(EXIT_FAILURE);
+	}
+	weston_capture_source_v1_add_listener(output->source,
+					      &capture_source_handlers, output);
+
+	wl_list_insert(&app->output_list, &output->link);
+}
+
+static void
+destroy_output(struct screenshooter_output *output)
+{
+	weston_capture_source_v1_destroy(output->source);
+
+	if (wl_output_get_version(output->wl_output) >= WL_OUTPUT_RELEASE_SINCE_VERSION)
+		wl_output_release(output->wl_output);
+	else
+		wl_output_destroy(output->wl_output);
+
+	screenshooter_buffer_destroy(output->buffer);
+	wl_list_remove(&output->link);
+	free(output->name);
+	free(output);
+}
+
+static void
+handle_global(void *data, struct wl_registry *registry,
+	      uint32_t name, const char *interface, uint32_t version)
+{
+	struct screenshooter_app *app = data;
+
+	if (strcmp(interface, wl_output_interface.name) == 0) {
+		create_output(app, name, version);
+	} else if (strcmp(interface, wl_shm_interface.name) == 0) {
+		app->shm = wl_registry_bind(registry, name, &wl_shm_interface, 1);
+		/*
+		 * Not listening for format advertisements,
+		 * weston_capture_source_v1.format event tells us what to use.
+		 */
+	} else if (strcmp(interface, weston_capture_v1_interface.name) == 0) {
+		app->capture_factory = wl_registry_bind(registry, name,
+							&weston_capture_v1_interface,
+							1);
+	}
+}
+
+static void
+handle_global_remove(void *data, struct wl_registry *registry, uint32_t name)
+{
+	/* Dynamic output removals will just fail the respective shot. */
+}
+
+static const struct wl_registry_listener registry_listener = {
+	handle_global,
+	handle_global_remove
+};
+
+static void
+screenshooter_output_capture(struct screenshooter_output *output)
+{
+	screenshooter_buffer_destroy(output->buffer);
+	output->buffer = screenshot_create_shm_buffer(output->app,
+						      output->buffer_width,
+						      output->buffer_height,
+						      output->fmt);
+	if (!output->buffer) {
+		fprintf(stderr, "Failed to create output buffer\n");
+		exit(EXIT_FAILURE);
+	}
+
+	weston_capture_source_v1_capture(output->source,
+					 output->buffer->wl_buffer);
+	output->app->waitcount++;
+}
+
+static void
+screenshot_write_png_per_output(const struct buffer_size *buff_size,
+				struct screenshooter_output *output,
+				const char *fn)
+{
+	pixman_image_t *shot;
+	cairo_surface_t *surface;
+	FILE *fp;
+	char filepath[PATH_MAX];
+	char *filename_to_write;
+
+	shot = pixman_image_create_bits(PIXMAN_a8r8g8b8,
+					buff_size->width, buff_size->height,
+					NULL, 0);
+	if (!shot) {
+		fprintf(stderr, "Failed to create shot\n");
+		exit(EXIT_FAILURE);
+	}
+
+
+	pixman_image_composite32(PIXMAN_OP_SRC,
+				 output->buffer->image, /* src */
+				 NULL, /* mask */
+				 shot, /* dest */
+				 0, 0, /* src x,y */
+				 0, 0, /* mask x,y */
+				 output->offset_x, output->offset_y, /* dst x,y */
+				 output->buffer_width, output->buffer_height);
+
+	surface = cairo_image_surface_create_for_data((void *)pixman_image_get_data(shot),
+						      CAIRO_FORMAT_ARGB32,
+						      pixman_image_get_width(shot),
+						      pixman_image_get_height(shot),
+						      pixman_image_get_stride(shot));
+	if (fn)
+		str_printf(&filename_to_write, "agl-screenshot-%s-", fn);
+	else
+		str_printf(&filename_to_write, "agl-screenshot-");
+
+	fp = file_create_dated(getenv("XDG_PICTURES_DIR"), filename_to_write,
+			       ".png", filepath, sizeof(filepath));
+	if (fp) {
+		fclose(fp);
+		cairo_surface_write_to_png(surface, filepath);
+	}
+	cairo_surface_destroy(surface);
+	pixman_image_unref(shot);
+}
+
+static void
+screenshot_set_buffer_size_per_output(struct buffer_size *buff_size,
+				      struct screenshooter_output *output)
+{
+	buff_size->min_x = MIN(buff_size->min_x, output->offset_x);
+	buff_size->min_y = MIN(buff_size->min_y, output->offset_y);
+	buff_size->max_x = MAX(buff_size->max_x, output->offset_x + output->buffer_width);
+	buff_size->max_y = MAX(buff_size->max_y, output->offset_y + output->buffer_height);
+
+	buff_size->width = buff_size->max_x - buff_size->min_x;
+	buff_size->height = buff_size->max_y - buff_size->min_y;
+}
+
+static void
+screenshot_compute_output_offset(int *pos, struct screenshooter_output *sh_output)
+{
+	sh_output->offset_x = *pos;
+	*pos += sh_output->buffer_width;
+}
+
+static struct screenshooter_output *
+agl_shooter_search_for_output(const char *output_name,
+			      struct screenshooter_app *app)
+{
+	struct screenshooter_output *found_output = NULL;
+	struct screenshooter_output *output;
+
+	if (!output_name)
+		return found_output;
+
+	wl_list_for_each(output, &app->output_list, link) {
+		if (output->name && strcmp(output->name, output_name) == 0) {
+			found_output = output;
+			break;
+		}
+	}
+
+	return found_output;
+}
+
+static char *
+agl_shooter_search_get_output_name(struct screenshooter_output *sh_output)
+{
+	struct screenshooter_app *app;
+	struct screenshooter_output *output;
+
+	if (!sh_output)
+		return NULL;
+
+	app = sh_output->app;
+
+	wl_list_for_each(output, &app->output_list, link) {
+		if (output == sh_output) {
+			return output->name;
+		}
+	}
+
+	return NULL;
+}
+
+static void
+agl_shooter_display_all_outputs(struct screenshooter_app *app)
+{
+	struct screenshooter_output *output;
+
+	wl_list_for_each(output, &app->output_list, link) {
+		fprintf(stdout, "Output '%s'\n", output->name);
+	}
+}
+
+static void
+agl_shooter_screenshot_output(struct screenshooter_output *output, int *pos)
+{
+	struct buffer_size buff_size = {};
+	struct screenshooter_app *app = output->app;
+	char *output_name;
+
+	do {
+		app->retry = false;
+		screenshooter_output_capture(output);
+
+		while (app->waitcount > 0 && !app->failed) {
+			if (wl_display_dispatch(app->display) < 0)
+				app->failed = true;
+			assert(app->waitcount >= 0);
+		}
+	} while (app->retry && !app->failed);
+
+	if (!app->failed) {
+		screenshot_compute_output_offset(pos, output);
+		screenshot_set_buffer_size_per_output(&buff_size, output);
+
+		output_name = agl_shooter_search_get_output_name(output);
+		assert(output_name);
+		screenshot_write_png_per_output(&buff_size, output, output_name);
+	} else {
+		fprintf(stderr, "Error: screenshot or protocol failure\n");
+	}
+}
+
+
+static void
+agl_shooter_screenshot_all_outputs(struct screenshooter_app *app)
+{
+	struct screenshooter_output *output;
+	int pos = 0;
+
+	wl_list_for_each(output, &app->output_list, link)
+		agl_shooter_screenshot_output(output, &pos);
+}
+
+static void
+print_usage_and_exit(void)
+{
+	fprintf(stderr, "./agl-screenshooter [-o OUTPUT_NAME] [-l] [-a]\n");
+
+	fprintf(stderr, "\t-o OUTPUT_NAME -- take a screenshot of the output "
+				"specified by OUTPUT_NAME\n");
+	fprintf(stderr, "\t-a  -- take a screenshot of all the outputs found\n");
+	fprintf(stderr, "\t-l  -- list all the outputs found\n");
+	exit(EXIT_FAILURE);
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct wl_display *display;
+	struct screenshooter_output *output;
+	struct screenshooter_output *sh_output = NULL;
+	struct screenshooter_output *tmp_output;
+	struct screenshooter_app app = {};
+
+	int c, option_index;
+	char *output_name = NULL;
+	int pos = 0;
+
+	wl_list_init(&app.output_list);
+
+	static struct option long_options[] = {
+		{"output", 	required_argument, 0,  'o' },
+		{"list", 	required_argument, 0,  'l' },
+		{"all", 	required_argument, 0,  'a' },
+		{"help",	no_argument      , 0,  'h' },
+		{0, 0, 0, 0}
+	};
+
+	while ((c = getopt_long(argc, argv, "o:lah",
+				long_options, &option_index)) != -1) {
+		switch (c) {
+		case 'o':
+			output_name = optarg;
+			opts |= (1 << OPT_SCREENSHOT_OUTPUT);
+			break;
+		case 'l':
+			opts |= (1 << OPT_SHOW_ALL_OUTPUTS);
+			break;
+		case 'a':
+			opts |= (1 << OPT_SCREENSHOT_ALL_OUTPUTS);
+			break;
+		default:
+			print_usage_and_exit();
+		}
+	}
+
+	display = wl_display_connect(NULL);
+	if (display == NULL) {
+		fprintf(stderr, "failed to create display: %s\n",
+			strerror(errno));
+		return -1;
+	}
+
+	app.display = display;
+	app.registry = wl_display_get_registry(display);
+	wl_registry_add_listener(app.registry, &registry_listener, &app);
+
+	/* Process wl_registry advertisements */
+	wl_display_roundtrip(display);
+
+	if (!app.shm) {
+		fprintf(stderr, "Error: display does not support wl_shm\n");
+		return -1;
+	}
+	if (!app.capture_factory) {
+		fprintf(stderr, "Error: display does not support weston_capture_v1\n");
+		return -1;
+	}
+
+	/* Process initial events for wl_output and weston_capture_source_v1 */
+	wl_display_roundtrip(display);
+
+	if (opts & (1 << OPT_SHOW_ALL_OUTPUTS)) {
+		agl_shooter_display_all_outputs(&app);
+		return EXIT_SUCCESS;
+	}
+
+	if (opts & (1 << OPT_SCREENSHOT_ALL_OUTPUTS)) {
+		agl_shooter_screenshot_all_outputs(&app);
+		return EXIT_SUCCESS;
+	}
+
+	sh_output = NULL;
+	if (output_name)
+		sh_output = agl_shooter_search_for_output(output_name, &app);
+
+	if (!sh_output && (opts & (1 << OPT_SCREENSHOT_OUTPUT))) {
+		fprintf(stderr, "Could not find an output matching '%s'\n",
+				output_name);
+		return EXIT_FAILURE;
+	}
+
+	/* if we're still here just pick the first one available
+	 * and use that. Still useful in case we are run without
+	 * any args whatsoever */
+	if (!sh_output)
+		sh_output = container_of(app.output_list.next,
+					 struct screenshooter_output, link);
+
+	/* take a screenshot only of that specific output */
+	agl_shooter_screenshot_output(sh_output, &pos);
+
+	wl_list_for_each_safe(output, tmp_output, &app.output_list, link)
+		destroy_output(output);
+
+	weston_capture_v1_destroy(app.capture_factory);
+	wl_shm_destroy(app.shm);
+	wl_registry_destroy(app.registry);
+	wl_display_disconnect(display);
+
+	return 0;
+}