tests: Add agl-client-shell test

[src/agl-compositor.git] / tests / weston-test-client-helper.c

/*
 * Copyright © 2012 Intel Corporation
 * Copyright © 2015 Samsung Electronics Co., Ltd
 * Copyright 2016, 2017 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 <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/mman.h>
#include <cairo.h>

#include "test-config.h"
#include "shared/os-compatibility.h"
#include "shared/xalloc.h"
#include <libweston/zalloc.h>
#include "weston-test-client-helper.h"

#define max(a, b) (((a) > (b)) ? (a) : (b))
#define min(a, b) (((a) > (b)) ? (b) : (a))
#define clip(x, a, b)  min(max(x, a), b)

int
surface_contains(struct surface *surface, int x, int y)
{
        /* test whether a global x,y point is contained in the surface */
        int sx = surface->x;
        int sy = surface->y;
        int sw = surface->width;
        int sh = surface->height;
        return x >= sx && y >= sy && x < sx + sw && y < sy + sh;
}

static void
frame_callback_handler(void *data, struct wl_callback *callback, uint32_t time)
{
        int *done = data;

        *done = 1;

        wl_callback_destroy(callback);
}

static const struct wl_callback_listener frame_listener = {
        frame_callback_handler
};

struct wl_callback *
frame_callback_set(struct wl_surface *surface, int *done)
{
        struct wl_callback *callback;

        *done = 0;
        callback = wl_surface_frame(surface);
        wl_callback_add_listener(callback, &frame_listener, done);

        return callback;
}

int
frame_callback_wait_nofail(struct client *client, int *done)
{
        while (!*done) {
                if (wl_display_dispatch(client->wl_display) < 0)
                        return 0;
        }

        return 1;
}

void
move_client(struct client *client, int x, int y)
{
        struct surface *surface = client->surface;
        int done;

        client->surface->x = x;
        client->surface->y = y;
        weston_test_move_surface(client->test->weston_test, surface->wl_surface,
                             surface->x, surface->y);
        /* The attach here is necessary because commit() will call configure
         * only on surfaces newly attached, and the one that sets the surface
         * position is the configure. */
        wl_surface_attach(surface->wl_surface, surface->buffer->proxy, 0, 0);
        wl_surface_damage(surface->wl_surface, 0, 0, surface->width,
                          surface->height);

        frame_callback_set(surface->wl_surface, &done);

        wl_surface_commit(surface->wl_surface);

        frame_callback_wait(client, &done);
}

static void
pointer_handle_enter(void *data, struct wl_pointer *wl_pointer,
                     uint32_t serial, struct wl_surface *wl_surface,
                     wl_fixed_t x, wl_fixed_t y)
{
        struct pointer *pointer = data;

        if (wl_surface)
                pointer->focus = wl_surface_get_user_data(wl_surface);
        else
                pointer->focus = NULL;

        pointer->x = wl_fixed_to_int(x);
        pointer->y = wl_fixed_to_int(y);

        testlog("test-client: got pointer enter %d %d, surface %p\n",
                pointer->x, pointer->y, pointer->focus);
}

static void
pointer_handle_leave(void *data, struct wl_pointer *wl_pointer,
                     uint32_t serial, struct wl_surface *wl_surface)
{
        struct pointer *pointer = data;

        pointer->focus = NULL;

        testlog("test-client: got pointer leave, surface %p\n",
                wl_surface ? wl_surface_get_user_data(wl_surface) : NULL);
}

static void
pointer_handle_motion(void *data, struct wl_pointer *wl_pointer,
                      uint32_t time_msec, wl_fixed_t x, wl_fixed_t y)
{
        struct pointer *pointer = data;

        pointer->x = wl_fixed_to_int(x);
        pointer->y = wl_fixed_to_int(y);
        pointer->motion_time_msec = time_msec;
        pointer->motion_time_timespec = pointer->input_timestamp;
        pointer->input_timestamp = (struct timespec) { 0 };

        testlog("test-client: got pointer motion %d %d\n",
                pointer->x, pointer->y);
}

static void
pointer_handle_button(void *data, struct wl_pointer *wl_pointer,
                      uint32_t serial, uint32_t time_msec, uint32_t button,
                      uint32_t state)
{
        struct pointer *pointer = data;

        pointer->button = button;
        pointer->state = state;
        pointer->button_time_msec = time_msec;
        pointer->button_time_timespec = pointer->input_timestamp;
        pointer->input_timestamp = (struct timespec) { 0 };

        testlog("test-client: got pointer button %u %u\n", button, state);
}

static void
pointer_handle_axis(void *data, struct wl_pointer *wl_pointer,
                    uint32_t time_msec, uint32_t axis, wl_fixed_t value)
{
        struct pointer *pointer = data;

        pointer->axis = axis;
        pointer->axis_value = wl_fixed_to_double(value);
        pointer->axis_time_msec = time_msec;
        pointer->axis_time_timespec = pointer->input_timestamp;
        pointer->input_timestamp = (struct timespec) { 0 };

        testlog("test-client: got pointer axis %u %f\n",
                axis, wl_fixed_to_double(value));
}

static void
pointer_handle_frame(void *data, struct wl_pointer *wl_pointer)
{
        testlog("test-client: got pointer frame\n");
}

static void
pointer_handle_axis_source(void *data, struct wl_pointer *wl_pointer,
                             uint32_t source)
{
        testlog("test-client: got pointer axis source %u\n", source);
}

static void
pointer_handle_axis_stop(void *data, struct wl_pointer *wl_pointer,
                         uint32_t time_msec, uint32_t axis)
{
        struct pointer *pointer = data;

        pointer->axis = axis;
        pointer->axis_stop_time_msec = time_msec;
        pointer->axis_stop_time_timespec = pointer->input_timestamp;
        pointer->input_timestamp = (struct timespec) { 0 };

        testlog("test-client: got pointer axis stop %u\n", axis);
}

static void
pointer_handle_axis_discrete(void *data, struct wl_pointer *wl_pointer,
                             uint32_t axis, int32_t value)
{
        testlog("test-client: got pointer axis discrete %u %d\n", axis, value);
}

static const struct wl_pointer_listener pointer_listener = {
        pointer_handle_enter,
        pointer_handle_leave,
        pointer_handle_motion,
        pointer_handle_button,
        pointer_handle_axis,
        pointer_handle_frame,
        pointer_handle_axis_source,
        pointer_handle_axis_stop,
        pointer_handle_axis_discrete,
};

static void
keyboard_handle_keymap(void *data, struct wl_keyboard *wl_keyboard,
                       uint32_t format, int fd, uint32_t size)
{
        close(fd);

        testlog("test-client: got keyboard keymap\n");
}

static void
keyboard_handle_enter(void *data, struct wl_keyboard *wl_keyboard,
                      uint32_t serial, struct wl_surface *wl_surface,
                      struct wl_array *keys)
{
        struct keyboard *keyboard = data;

        if (wl_surface)
                keyboard->focus = wl_surface_get_user_data(wl_surface);
        else
                keyboard->focus = NULL;

        testlog("test-client: got keyboard enter, surface %p\n",
                keyboard->focus);
}

static void
keyboard_handle_leave(void *data, struct wl_keyboard *wl_keyboard,
                      uint32_t serial, struct wl_surface *wl_surface)
{
        struct keyboard *keyboard = data;

        keyboard->focus = NULL;

        testlog("test-client: got keyboard leave, surface %p\n",
                wl_surface ? wl_surface_get_user_data(wl_surface) : NULL);
}

static void
keyboard_handle_key(void *data, struct wl_keyboard *wl_keyboard,
                    uint32_t serial, uint32_t time_msec, uint32_t key,
                    uint32_t state)
{
        struct keyboard *keyboard = data;

        keyboard->key = key;
        keyboard->state = state;
        keyboard->key_time_msec = time_msec;
        keyboard->key_time_timespec = keyboard->input_timestamp;
        keyboard->input_timestamp = (struct timespec) { 0 };

        testlog("test-client: got keyboard key %u %u\n", key, state);
}

static void
keyboard_handle_modifiers(void *data, struct wl_keyboard *wl_keyboard,
                          uint32_t serial, uint32_t mods_depressed,
                          uint32_t mods_latched, uint32_t mods_locked,
                          uint32_t group)
{
        struct keyboard *keyboard = data;

        keyboard->mods_depressed = mods_depressed;
        keyboard->mods_latched = mods_latched;
        keyboard->mods_locked = mods_locked;
        keyboard->group = group;

        testlog("test-client: got keyboard modifiers %u %u %u %u\n",
                mods_depressed, mods_latched, mods_locked, group);
}

static void
keyboard_handle_repeat_info(void *data, struct wl_keyboard *wl_keyboard,
                            int32_t rate, int32_t delay)
{
        struct keyboard *keyboard = data;

        keyboard->repeat_info.rate = rate;
        keyboard->repeat_info.delay = delay;

        testlog("test-client: got keyboard repeat_info %d %d\n", rate, delay);
}

static const struct wl_keyboard_listener keyboard_listener = {
        keyboard_handle_keymap,
        keyboard_handle_enter,
        keyboard_handle_leave,
        keyboard_handle_key,
        keyboard_handle_modifiers,
        keyboard_handle_repeat_info,
};

static void
touch_handle_down(void *data, struct wl_touch *wl_touch,
                  uint32_t serial, uint32_t time_msec,
                  struct wl_surface *surface, int32_t id,
                  wl_fixed_t x_w, wl_fixed_t y_w)
{
        struct touch *touch = data;

        touch->down_x = wl_fixed_to_int(x_w);
        touch->down_y = wl_fixed_to_int(y_w);
        touch->id = id;
        touch->down_time_msec = time_msec;
        touch->down_time_timespec = touch->input_timestamp;
        touch->input_timestamp = (struct timespec) { 0 };

        testlog("test-client: got touch down %d %d, surf: %p, id: %d\n",
                touch->down_x, touch->down_y, surface, id);
}

static void
touch_handle_up(void *data, struct wl_touch *wl_touch,
                uint32_t serial, uint32_t time_msec, int32_t id)
{
        struct touch *touch = data;
        touch->up_id = id;
        touch->up_time_msec = time_msec;
        touch->up_time_timespec = touch->input_timestamp;
        touch->input_timestamp = (struct timespec) { 0 };

        testlog("test-client: got touch up, id: %d\n", id);
}

static void
touch_handle_motion(void *data, struct wl_touch *wl_touch,
                    uint32_t time_msec, int32_t id,
                    wl_fixed_t x_w, wl_fixed_t y_w)
{
        struct touch *touch = data;
        touch->x = wl_fixed_to_int(x_w);
        touch->y = wl_fixed_to_int(y_w);
        touch->motion_time_msec = time_msec;
        touch->motion_time_timespec = touch->input_timestamp;
        touch->input_timestamp = (struct timespec) { 0 };

        testlog("test-client: got touch motion, %d %d, id: %d\n",
                touch->x, touch->y, id);
}

static void
touch_handle_frame(void *data, struct wl_touch *wl_touch)
{
        struct touch *touch = data;

        ++touch->frame_no;

        testlog("test-client: got touch frame (%d)\n", touch->frame_no);
}

static void
touch_handle_cancel(void *data, struct wl_touch *wl_touch)
{
        struct touch *touch = data;

        ++touch->cancel_no;

        testlog("test-client: got touch cancel (%d)\n", touch->cancel_no);
}

static const struct wl_touch_listener touch_listener = {
        touch_handle_down,
        touch_handle_up,
        touch_handle_motion,
        touch_handle_frame,
        touch_handle_cancel,
};

static void
surface_enter(void *data,
              struct wl_surface *wl_surface, struct wl_output *output)
{
        struct surface *surface = data;

        surface->output = wl_output_get_user_data(output);

        testlog("test-client: got surface enter output %p\n", surface->output);
}

static void
surface_leave(void *data,
              struct wl_surface *wl_surface, struct wl_output *output)
{
        struct surface *surface = data;

        surface->output = NULL;

        testlog("test-client: got surface leave output %p\n",
                wl_output_get_user_data(output));
}

static const struct wl_surface_listener surface_listener = {
        surface_enter,
        surface_leave
};

static struct buffer *
create_shm_buffer(struct client *client, int width, int height,
                  pixman_format_code_t format, uint32_t wlfmt)
{
        struct wl_shm *shm = client->wl_shm;
        struct buffer *buf;
        size_t stride_bytes;
        struct wl_shm_pool *pool;
        int fd;
        void *data;
        size_t bytes_pp;

        assert(width > 0);
        assert(height > 0);

        buf = xzalloc(sizeof *buf);

        bytes_pp = PIXMAN_FORMAT_BPP(format) / 8;
        stride_bytes = width * bytes_pp;
        /* round up to multiple of 4 bytes for Pixman */
        stride_bytes = (stride_bytes + 3) & ~3u;
        assert(stride_bytes / bytes_pp >= (unsigned)width);

        buf->len = stride_bytes * height;
        assert(buf->len / stride_bytes == (unsigned)height);

        fd = os_create_anonymous_file(buf->len);
        assert(fd >= 0);

        data = mmap(NULL, buf->len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
        if (data == MAP_FAILED) {
                close(fd);
                assert(data != MAP_FAILED);
        }

        pool = wl_shm_create_pool(shm, fd, buf->len);
        buf->proxy = wl_shm_pool_create_buffer(pool, 0, width, height,
                                               stride_bytes, wlfmt);
        wl_shm_pool_destroy(pool);
        close(fd);

        buf->image = pixman_image_create_bits(format, width, height,
                                              data, stride_bytes);

        assert(buf->proxy);
        assert(buf->image);

        return buf;
}

struct buffer *
create_shm_buffer_a8r8g8b8(struct client *client, int width, int height)
{
        assert(client->has_argb);

        return create_shm_buffer(client, width, height,
                                 PIXMAN_a8r8g8b8, WL_SHM_FORMAT_ARGB8888);
}

void
buffer_destroy(struct buffer *buf)
{
        void *pixels;

        pixels = pixman_image_get_data(buf->image);

        if (buf->proxy) {
                wl_buffer_destroy(buf->proxy);
                assert(munmap(pixels, buf->len) == 0);
        }

        assert(pixman_image_unref(buf->image));

        free(buf);
}

static void
shm_format(void *data, struct wl_shm *wl_shm, uint32_t format)
{
        struct client *client = data;

        if (format == WL_SHM_FORMAT_ARGB8888)
                client->has_argb = 1;
}

struct wl_shm_listener shm_listener = {
        shm_format
};

static void
test_handle_pointer_position(void *data, struct weston_test *weston_test,
                             wl_fixed_t x, wl_fixed_t y)
{
        struct test *test = data;
        test->pointer_x = wl_fixed_to_int(x);
        test->pointer_y = wl_fixed_to_int(y);

        testlog("test-client: got global pointer %d %d\n",
                test->pointer_x, test->pointer_y);
}

static void
test_handle_capture_screenshot_done(void *data, struct weston_test *weston_test)
{
        struct test *test = data;

        testlog("Screenshot has been captured\n");
        test->buffer_copy_done = 1;
}

static const struct weston_test_listener test_listener = {
        test_handle_pointer_position,
        test_handle_capture_screenshot_done,
};

static void
input_destroy(struct input *inp)
{
        if (inp->pointer) {
                wl_pointer_release(inp->pointer->wl_pointer);
                free(inp->pointer);
        }
        if (inp->keyboard) {
                wl_keyboard_release(inp->keyboard->wl_keyboard);
                free(inp->keyboard);
        }
        if (inp->touch) {
                wl_touch_release(inp->touch->wl_touch);
                free(inp->touch);
        }
        wl_list_remove(&inp->link);
        wl_seat_release(inp->wl_seat);
        free(inp->seat_name);
        free(inp);
}

static void
input_update_devices(struct input *input)
{
        struct pointer *pointer;
        struct keyboard *keyboard;
        struct touch *touch;

        struct wl_seat *seat = input->wl_seat;
        enum wl_seat_capability caps = input->caps;

        if ((caps & WL_SEAT_CAPABILITY_POINTER) && !input->pointer) {
                pointer = xzalloc(sizeof *pointer);
                pointer->wl_pointer = wl_seat_get_pointer(seat);
                wl_pointer_set_user_data(pointer->wl_pointer, pointer);
                wl_pointer_add_listener(pointer->wl_pointer, &pointer_listener,
                                        pointer);
                input->pointer = pointer;
        } else if (!(caps & WL_SEAT_CAPABILITY_POINTER) && input->pointer) {
                wl_pointer_destroy(input->pointer->wl_pointer);
                free(input->pointer);
                input->pointer = NULL;
        }

        if ((caps & WL_SEAT_CAPABILITY_KEYBOARD) && !input->keyboard) {
                keyboard = xzalloc(sizeof *keyboard);
                keyboard->wl_keyboard = wl_seat_get_keyboard(seat);
                wl_keyboard_set_user_data(keyboard->wl_keyboard, keyboard);
                wl_keyboard_add_listener(keyboard->wl_keyboard, &keyboard_listener,
                                         keyboard);
                input->keyboard = keyboard;
        } else if (!(caps & WL_SEAT_CAPABILITY_KEYBOARD) && input->keyboard) {
                wl_keyboard_destroy(input->keyboard->wl_keyboard);
                free(input->keyboard);
                input->keyboard = NULL;
        }

        if ((caps & WL_SEAT_CAPABILITY_TOUCH) && !input->touch) {
                touch = xzalloc(sizeof *touch);
                touch->wl_touch = wl_seat_get_touch(seat);
                wl_touch_set_user_data(touch->wl_touch, touch);
                wl_touch_add_listener(touch->wl_touch, &touch_listener,
                                         touch);
                input->touch = touch;
        } else if (!(caps & WL_SEAT_CAPABILITY_TOUCH) && input->touch) {
                wl_touch_destroy(input->touch->wl_touch);
                free(input->touch);
                input->touch = NULL;
        }
}

static void
seat_handle_capabilities(void *data, struct wl_seat *seat,
                         enum wl_seat_capability caps)
{
        struct input *input = data;

        input->caps = caps;

        /* we will create/update the devices only with the right (test) seat.
         * If we haven't discovered which seat is the test seat, just
         * store capabilities and bail out */
        if (input->seat_name && strcmp(input->seat_name, "test-seat") == 0)
                input_update_devices(input);

        testlog("test-client: got seat %p capabilities: %x\n", input, caps);
}

static void
seat_handle_name(void *data, struct wl_seat *seat, const char *name)
{
        struct input *input = data;

        input->seat_name = strdup(name);
        assert(input->seat_name && "No memory");

        /* We only update the devices and set client input for the test seat */
        if (strcmp(name, "test-seat") == 0) {
                assert(!input->client->input &&
                       "Multiple test seats detected!");

                input_update_devices(input);
                input->client->input = input;
        }

        testlog("test-client: got seat %p name: \'%s\'\n", input, name);
}

static const struct wl_seat_listener seat_listener = {
        seat_handle_capabilities,
        seat_handle_name,
};

static void
output_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)
{
        struct output *output = data;

        output->x = x;
        output->y = y;
}

static void
output_handle_mode(void *data,
                   struct wl_output *wl_output,
                   uint32_t flags,
                   int width,
                   int height,
                   int refresh)
{
        struct output *output = data;

        if (flags & WL_OUTPUT_MODE_CURRENT) {
                output->width = width;
                output->height = height;
        }
}

static void
output_handle_scale(void *data,
                    struct wl_output *wl_output,
                    int scale)
{
        struct output *output = data;

        output->scale = scale;
}

static void
output_handle_done(void *data,
                   struct wl_output *wl_output)
{
        struct output *output = data;

        output->initialized = 1;
}

static const struct wl_output_listener output_listener = {
        output_handle_geometry,
        output_handle_mode,
        output_handle_done,
        output_handle_scale,
};

static void
output_destroy(struct output *output)
{
        assert(wl_proxy_get_version((struct wl_proxy *)output->wl_output) >= 3);
        wl_output_release(output->wl_output);
        wl_list_remove(&output->link);
        free(output);
}

static void
handle_global(void *data, struct wl_registry *registry,
              uint32_t id, const char *interface, uint32_t version)
{
        struct client *client = data;
        struct output *output;
        struct test *test;
        struct global *global;
        struct input *input;

        global = xzalloc(sizeof *global);
        global->name = id;
        global->interface = strdup(interface);
        assert(interface);
        global->version = version;
        wl_list_insert(client->global_list.prev, &global->link);

        /* We deliberately bind all globals with the maximum (advertised)
         * version, because this test suite must be kept up-to-date with
         * Weston. We must always implement at least the version advertised
         * by Weston. This is not ok for normal clients, but it is ok in
         * this test suite.
         */

        if (strcmp(interface, "wl_compositor") == 0) {
                client->wl_compositor =
                        wl_registry_bind(registry, id,
                                         &wl_compositor_interface, version);
        } else if (strcmp(interface, "wl_seat") == 0) {
                input = xzalloc(sizeof *input);
                input->client = client;
                input->global_name = global->name;
                input->wl_seat =
                        wl_registry_bind(registry, id,
                                         &wl_seat_interface, version);
                wl_seat_add_listener(input->wl_seat, &seat_listener, input);
                wl_list_insert(&client->inputs, &input->link);
        } else if (strcmp(interface, "wl_shm") == 0) {
                client->wl_shm =
                        wl_registry_bind(registry, id,
                                         &wl_shm_interface, version);
                wl_shm_add_listener(client->wl_shm, &shm_listener, client);
        } else if (strcmp(interface, "wl_output") == 0) {
                output = xzalloc(sizeof *output);
                output->wl_output =
                        wl_registry_bind(registry, id,
                                         &wl_output_interface, version);
                wl_output_add_listener(output->wl_output,
                                       &output_listener, output);
                wl_list_insert(&client->output_list, &output->link);
                client->output = output;
        } else if (strcmp(interface, "weston_test") == 0) {
                test = xzalloc(sizeof *test);
                test->weston_test =
                        wl_registry_bind(registry, id,
                                         &weston_test_interface, version);
                weston_test_add_listener(test->weston_test, &test_listener, test);
                client->test = test;
        } else if (strcmp(interface, "wl_drm") == 0) {
                client->has_wl_drm = true;
        }
}

static struct global *
client_find_global_with_name(struct client *client, uint32_t name)
{
        struct global *global;

        wl_list_for_each(global, &client->global_list, link) {
                if (global->name == name)
                        return global;
        }

        return NULL;
}

static struct input *
client_find_input_with_name(struct client *client, uint32_t name)
{
        struct input *input;

        wl_list_for_each(input, &client->inputs, link) {
                if (input->global_name == name)
                        return input;
        }

        return NULL;
}

static void
global_destroy(struct global *global)
{
        wl_list_remove(&global->link);
        free(global->interface);
        free(global);
}

static void
handle_global_remove(void *data, struct wl_registry *registry, uint32_t name)
{
        struct client *client = data;
        struct global *global;
        struct input *input;

        global = client_find_global_with_name(client, name);
        assert(global && "Request to remove unknown global");

        if (strcmp(global->interface, "wl_seat") == 0) {
                input = client_find_input_with_name(client, name);
                if (input) {
                        if (client->input == input)
                                client->input = NULL;
                        input_destroy(input);
                }
        }

        /* XXX: handle wl_output */

        global_destroy(global);
}

static const struct wl_registry_listener registry_listener = {
        handle_global,
        handle_global_remove,
};

void
skip(const char *fmt, ...)
{
        va_list argp;

        va_start(argp, fmt);
        vfprintf(stderr, fmt, argp);
        va_end(argp);

        /* automake tests uses exit code 77. weston-test-runner will see
         * this and use it, and then weston-test's sigchld handler (in the
         * weston process) will use that as an exit status, which is what
         * ninja will see in the end. */
        exit(77);
}

void
expect_protocol_error(struct client *client,
                      const struct wl_interface *intf,
                      uint32_t code)
{
        int err;
        uint32_t errcode, failed = 0;
        const struct wl_interface *interface;
        unsigned int id;

        /* if the error has not come yet, make it happen */
        wl_display_roundtrip(client->wl_display);

        err = wl_display_get_error(client->wl_display);

        assert(err && "Expected protocol error but nothing came");
        assert(err == EPROTO && "Expected protocol error but got local error");

        errcode = wl_display_get_protocol_error(client->wl_display,
                                                &interface, &id);

        /* check error */
        if (errcode != code) {
                testlog("Should get error code %d but got %d\n", code, errcode);
                failed = 1;
        }

        /* this should be definitely set */
        assert(interface);

        if (strcmp(intf->name, interface->name) != 0) {
                testlog("Should get interface '%s' but got '%s'\n",
                        intf->name, interface->name);
                failed = 1;
        }

        if (failed) {
                testlog("Expected other protocol error\n");
                abort();
        }

        /* all OK */
        testlog("Got expected protocol error on '%s' (object id: %d) "
                "with code %d\n", interface->name, id, errcode);
}

static void
log_handler(const char *fmt, va_list args)
{
        fprintf(stderr, "libwayland: ");
        vfprintf(stderr, fmt, args);
}

struct client *
create_client(void)
{
        struct client *client;

        wl_log_set_handler_client(log_handler);

        /* connect to display */
        client = xzalloc(sizeof *client);
        client->wl_display = wl_display_connect(NULL);
        assert(client->wl_display);
        wl_list_init(&client->global_list);
        wl_list_init(&client->inputs);
        wl_list_init(&client->output_list);

        /* setup registry so we can bind to interfaces */
        client->wl_registry = wl_display_get_registry(client->wl_display);
        wl_registry_add_listener(client->wl_registry, &registry_listener,
                                 client);

        /* this roundtrip makes sure we have all globals and we bound to them */
        client_roundtrip(client);
        /* this roundtrip makes sure we got all wl_shm.format and wl_seat.*
         * events */
        client_roundtrip(client);

        /* must have WL_SHM_FORMAT_ARGB32 */
        assert(client->has_argb);

        /* must have weston_test interface */
        assert(client->test);

        /* must have an output */
        assert(client->output);

        /* the output must be initialized */
        assert(client->output->initialized == 1);

        /* must have seat set */
        assert(client->input);

        return client;
}

struct surface *
create_test_surface(struct client *client)
{
        struct surface *surface;

        surface = xzalloc(sizeof *surface);

        surface->wl_surface =
                wl_compositor_create_surface(client->wl_compositor);
        assert(surface->wl_surface);

        wl_surface_add_listener(surface->wl_surface, &surface_listener,
                                surface);

        wl_surface_set_user_data(surface->wl_surface, surface);

        return surface;
}

void
surface_destroy(struct surface *surface)
{
        if (surface->wl_surface)
                wl_surface_destroy(surface->wl_surface);
        if (surface->buffer)
                buffer_destroy(surface->buffer);
        free(surface);
}

struct client *
create_client_and_test_surface(int x, int y, int width, int height)
{
        struct client *client;
        struct surface *surface;
        pixman_color_t color = { 16384, 16384, 16384, 16384 }; /* uint16_t */
        pixman_image_t *solid;

        client = create_client();

        /* initialize the client surface */
        surface = create_test_surface(client);
        client->surface = surface;

        surface->width = width;
        surface->height = height;
        surface->buffer = create_shm_buffer_a8r8g8b8(client, width, height);

        solid = pixman_image_create_solid_fill(&color);
        pixman_image_composite32(PIXMAN_OP_SRC,
                                 solid, /* src */
                                 NULL, /* mask */
                                 surface->buffer->image, /* dst */
                                 0, 0, /* src x,y */
                                 0, 0, /* mask x,y */
                                 0, 0, /* dst x,y */
                                 width, height);
        pixman_image_unref(solid);

        move_client(client, x, y);

        return client;
}

void
client_destroy(struct client *client)
{
        if (client->surface)
                surface_destroy(client->surface);

        while (!wl_list_empty(&client->inputs)) {
                input_destroy(container_of(client->inputs.next,
                                           struct input, link));
        }

        while (!wl_list_empty(&client->output_list)) {
                output_destroy(container_of(client->output_list.next,
                                            struct output, link));
        }

        while (!wl_list_empty(&client->global_list)) {
                global_destroy(container_of(client->global_list.next,
                                            struct global, link));
        }

        if (client->test) {
                weston_test_destroy(client->test->weston_test);
                free(client->test);
        }

        if (client->wl_shm)
                wl_shm_destroy(client->wl_shm);
        if (client->wl_compositor)
                wl_compositor_destroy(client->wl_compositor);
        if (client->wl_registry)
                wl_registry_destroy(client->wl_registry);

        client_roundtrip(client);

        if (client->wl_display)
                wl_display_disconnect(client->wl_display);
        free(client);
}

static const char*
output_path(void)
{
        char *path = getenv("WESTON_TEST_OUTPUT_PATH");

        if (!path)
                return ".";

        return path;
}

char*
screenshot_output_filename(const char *basename, uint32_t seq)
{
        char *filename;

        if (asprintf(&filename, "%s/%s-%02d.png",
                                 output_path(), basename, seq) < 0)
                return NULL;
        return filename;
}

static const char*
reference_path(void)
{
        char *path = getenv("WESTON_TEST_REFERENCE_PATH");

        if (!path)
                return WESTON_TEST_REFERENCE_PATH;
        return path;
}

char*
screenshot_reference_filename(const char *basename, uint32_t seq)
{
        char *filename;

        if (asprintf(&filename, "%s/%s-%02d.png",
                                 reference_path(), basename, seq) < 0)
                return NULL;
        return filename;
}

char *
image_filename(const char *basename)
{
        char *filename;

        if (asprintf(&filename, "%s/%s.png", reference_path(), basename) < 0)
                assert(0);
        return filename;
}

struct format_map_entry {
        cairo_format_t cairo;
        pixman_format_code_t pixman;
};

static const struct format_map_entry format_map[] = {
        { CAIRO_FORMAT_ARGB32,    PIXMAN_a8r8g8b8 },
        { CAIRO_FORMAT_RGB24,     PIXMAN_x8r8g8b8 },
        { CAIRO_FORMAT_A8,        PIXMAN_a8 },
        { CAIRO_FORMAT_RGB16_565, PIXMAN_r5g6b5 },
};

static pixman_format_code_t
format_cairo2pixman(cairo_format_t fmt)
{
        unsigned i;

        for (i = 0; i < ARRAY_LENGTH(format_map); i++)
                if (format_map[i].cairo == fmt)
                        return format_map[i].pixman;

        assert(0 && "unknown Cairo pixel format");
}

static cairo_format_t
format_pixman2cairo(pixman_format_code_t fmt)
{
        unsigned i;

        for (i = 0; i < ARRAY_LENGTH(format_map); i++)
                if (format_map[i].pixman == fmt)
                        return format_map[i].cairo;

        assert(0 && "unknown Pixman pixel format");
}

/**
 * Validate range
 *
 * \param r Range to validate or NULL.
 * \return The given range, or {0, 0} for NULL.
 *
 * Will abort if range is invalid, that is a > b.
 */
static struct range
range_get(const struct range *r)
{
        if (!r)
                return (struct range){ 0, 0 };

        assert(r->a <= r->b);
        return *r;
}

/**
 * Compute the ROI for image comparisons
 *
 * \param img_a An image.
 * \param img_b Another image.
 * \param clip_rect Explicit ROI, or NULL for using the whole
 * image area.
 *
 * \return The region of interest (ROI) that is guaranteed to be inside both
 * images.
 *
 * If clip_rect is given, it must fall inside of both images.
 * If clip_rect is NULL, the images must be of the same size.
 * If any precondition is violated, this function aborts with an error.
 *
 * The ROI is given as pixman_box32_t, where x2,y2 are non-inclusive.
 */
static pixman_box32_t
image_check_get_roi(pixman_image_t *img_a, pixman_image_t *img_b,
                   const struct rectangle *clip_rect)
{
        int width_a;
        int width_b;
        int height_a;
        int height_b;
        pixman_box32_t box;

        width_a = pixman_image_get_width(img_a);
        height_a = pixman_image_get_height(img_a);

        width_b = pixman_image_get_width(img_b);
        height_b = pixman_image_get_height(img_b);

        if (clip_rect) {
                box.x1 = clip_rect->x;
                box.y1 = clip_rect->y;
                box.x2 = clip_rect->x + clip_rect->width;
                box.y2 = clip_rect->y + clip_rect->height;
        } else {
                box.x1 = 0;
                box.y1 = 0;
                box.x2 = max(width_a, width_b);
                box.y2 = max(height_a, height_b);
        }

        assert(box.x1 >= 0);
        assert(box.y1 >= 0);
        assert(box.x2 > box.x1);
        assert(box.y2 > box.y1);
        assert(box.x2 <= width_a);
        assert(box.x2 <= width_b);
        assert(box.y2 <= height_a);
        assert(box.y2 <= height_b);

        return box;
}

struct image_iterator {
        char *data;
        int stride; /* bytes */
};

static void
image_iter_init(struct image_iterator *it, pixman_image_t *image)
{
        pixman_format_code_t fmt;

        it->stride = pixman_image_get_stride(image);
        it->data = (void *)pixman_image_get_data(image);

        fmt = pixman_image_get_format(image);
        assert(PIXMAN_FORMAT_BPP(fmt) == 32);
}

static uint32_t *
image_iter_get_row(struct image_iterator *it, int y)
{
        return (uint32_t *)(it->data + y * it->stride);
}

struct pixel_diff_stat {
        struct pixel_diff_stat_channel {
                int min_diff;
                int max_diff;
        } ch[4];
};

static void
testlog_pixel_diff_stat(const struct pixel_diff_stat *stat)
{
        int i;

        testlog("Image difference statistics:\n");
        for (i = 0; i < 4; i++) {
                testlog("\tch %d: [%d, %d]\n",
                        i, stat->ch[i].min_diff, stat->ch[i].max_diff);
        }
}

static bool
fuzzy_match_pixels(uint32_t pix_a, uint32_t pix_b,
                   const struct range *fuzz,
                   struct pixel_diff_stat *stat)
{
        bool ret = true;
        int shift;
        int i;

        for (shift = 0, i = 0; i < 4; shift += 8, i++) {
                int val_a = (pix_a >> shift) & 0xffu;
                int val_b = (pix_b >> shift) & 0xffu;
                int d = val_b - val_a;

                stat->ch[i].min_diff = min(stat->ch[i].min_diff, d);
                stat->ch[i].max_diff = max(stat->ch[i].max_diff, d);

                if (d < fuzz->a || d > fuzz->b)
                        ret = false;
        }

        return ret;
}

/**
 * Test if a given region within two images are pixel-identical
 *
 * Returns true if the two images pixel-wise identical, and false otherwise.
 *
 * \param img_a First image.
 * \param img_b Second image.
 * \param clip_rect The region of interest, or NULL for comparing the whole
 * images.
 * \param prec Per-channel allowed difference, or NULL for identical match
 * required.
 *
 * This function hard-fails if clip_rect is not inside both images. If clip_rect
 * is given, the images do not have to match in size, otherwise size mismatch
 * will be a hard failure.
 *
 * The per-pixel, per-channel difference is computed as img_b - img_a which is
 * required to be in the range [prec->a, prec->b] inclusive. The difference is
 * signed. All four channels are compared the same way, without any special
 * meaning on alpha channel.
 */
bool
check_images_match(pixman_image_t *img_a, pixman_image_t *img_b,
                   const struct rectangle *clip_rect, const struct range *prec)
{
        struct range fuzz = range_get(prec);
        struct pixel_diff_stat diffstat = {};
        struct image_iterator it_a;
        struct image_iterator it_b;
        pixman_box32_t box;
        int x, y;
        uint32_t *pix_a;
        uint32_t *pix_b;

        box = image_check_get_roi(img_a, img_b, clip_rect);

        image_iter_init(&it_a, img_a);
        image_iter_init(&it_b, img_b);

        for (y = box.y1; y < box.y2; y++) {
                pix_a = image_iter_get_row(&it_a, y) + box.x1;
                pix_b = image_iter_get_row(&it_b, y) + box.x1;

                for (x = box.x1; x < box.x2; x++) {
                        if (!fuzzy_match_pixels(*pix_a, *pix_b,
                                                &fuzz, &diffstat))
                                return false;

                        pix_a++;
                        pix_b++;
                }
        }

        return true;
}

/**
 * Tint a color
 *
 * \param src Source pixel as x8r8g8b8.
 * \param add The tint as x8r8g8b8, x8 must be zero; r8, g8 and b8 must be
 * no greater than 0xc0 to avoid overflow to another channel.
 * \return The tinted pixel color as x8r8g8b8, x8 guaranteed to be 0xff.
 *
 * The source pixel RGB values are divided by 4, and then the tint is added.
 * To achieve colors outside of the range of src, a tint color channel must be
 * at least 0x40. (0xff / 4 = 0x3f, 0xff - 0x3f = 0xc0)
 */
static uint32_t
tint(uint32_t src, uint32_t add)
{
        uint32_t v;

        v = ((src & 0xfcfcfcfc) >> 2) | 0xff000000;

        return v + add;
}

/**
 * Create a visualization of image differences.
 *
 * \param img_a First image, which is used as the basis for the output.
 * \param img_b Second image.
 * \param clip_rect The region of interest, or NULL for comparing the whole
 * images.
 * \param prec Per-channel allowed difference, or NULL for identical match
 * required.
 * \return A new image with the differences highlighted.
 *
 * Regions outside of the region of interest are shaded with black, matching
 * pixels are shaded with green, and differing pixels are shaded with
 * bright red.
 *
 * This function hard-fails if clip_rect is not inside both images. If clip_rect
 * is given, the images do not have to match in size, otherwise size mismatch
 * will be a hard failure.
 *
 * The per-pixel, per-channel difference is computed as img_b - img_a which is
 * required to be in the range [prec->a, prec->b] inclusive. The difference is
 * signed. All four channels are compared the same way, without any special
 * meaning on alpha channel.
 */
pixman_image_t *
visualize_image_difference(pixman_image_t *img_a, pixman_image_t *img_b,
                           const struct rectangle *clip_rect,
                           const struct range *prec)
{
        struct range fuzz = range_get(prec);
        struct pixel_diff_stat diffstat = {};
        pixman_image_t *diffimg;
        pixman_image_t *shade;
        struct image_iterator it_a;
        struct image_iterator it_b;
        struct image_iterator it_d;
        int width;
        int height;
        pixman_box32_t box;
        int x, y;
        uint32_t *pix_a;
        uint32_t *pix_b;
        uint32_t *pix_d;
        pixman_color_t shade_color = { 0, 0, 0, 32768 };

        width = pixman_image_get_width(img_a);
        height = pixman_image_get_height(img_a);
        box = image_check_get_roi(img_a, img_b, clip_rect);

        diffimg = pixman_image_create_bits_no_clear(PIXMAN_x8r8g8b8,
                                                    width, height, NULL, 0);

        /* Fill diffimg with a black-shaded copy of img_a, and then fill
         * the clip_rect area with original img_a.
         */
        shade = pixman_image_create_solid_fill(&shade_color);
        pixman_image_composite32(PIXMAN_OP_SRC, img_a, shade, diffimg,
                                 0, 0, 0, 0, 0, 0, width, height);
        pixman_image_unref(shade);
        pixman_image_composite32(PIXMAN_OP_SRC, img_a, NULL, diffimg,
                                 box.x1, box.y1, 0, 0, box.x1, box.y1,
                                 box.x2 - box.x1, box.y2 - box.y1);

        image_iter_init(&it_a, img_a);
        image_iter_init(&it_b, img_b);
        image_iter_init(&it_d, diffimg);

        for (y = box.y1; y < box.y2; y++) {
                pix_a = image_iter_get_row(&it_a, y) + box.x1;
                pix_b = image_iter_get_row(&it_b, y) + box.x1;
                pix_d = image_iter_get_row(&it_d, y) + box.x1;

                for (x = box.x1; x < box.x2; x++) {
                        if (fuzzy_match_pixels(*pix_a, *pix_b,
                                               &fuzz, &diffstat))
                                *pix_d = tint(*pix_d, 0x00008000); /* green */
                        else
                                *pix_d = tint(*pix_d, 0x00c00000); /* red */

                        pix_a++;
                        pix_b++;
                        pix_d++;
                }
        }

        testlog_pixel_diff_stat(&diffstat);

        return diffimg;
}

/**
 * Write an image into a PNG file.
 *
 * \param image The image.
 * \param fname The name and path for the file.
 *
 * \returns true if successfully saved file; false otherwise.
 *
 * \note Only image formats directly supported by Cairo are accepted, not all
 * Pixman formats.
 */
bool
write_image_as_png(pixman_image_t *image, const char *fname)
{
        cairo_surface_t *cairo_surface;
        cairo_status_t status;
        cairo_format_t fmt;

        fmt = format_pixman2cairo(pixman_image_get_format(image));

        cairo_surface = cairo_image_surface_create_for_data(
                        (void *)pixman_image_get_data(image),
                        fmt,
                        pixman_image_get_width(image),
                        pixman_image_get_height(image),
                        pixman_image_get_stride(image));

        status = cairo_surface_write_to_png(cairo_surface, fname);
        if (status != CAIRO_STATUS_SUCCESS) {
                testlog("Failed to save image '%s': %s\n", fname,
                        cairo_status_to_string(status));

                return false;
        }

        cairo_surface_destroy(cairo_surface);

        return true;
}

static pixman_image_t *
image_convert_to_a8r8g8b8(pixman_image_t *image)
{
        pixman_image_t *ret;
        int width;
        int height;

        if (pixman_image_get_format(image) == PIXMAN_a8r8g8b8)
                return pixman_image_ref(image);

        width = pixman_image_get_width(image);
        height = pixman_image_get_height(image);

        ret = pixman_image_create_bits_no_clear(PIXMAN_a8r8g8b8, width, height,
                                                NULL, 0);
        assert(ret);

        pixman_image_composite32(PIXMAN_OP_SRC, image, NULL, ret,
                                 0, 0, 0, 0, 0, 0, width, height);

        return ret;
}

static void
destroy_cairo_surface(pixman_image_t *image, void *data)
{
        cairo_surface_t *surface = data;

        cairo_surface_destroy(surface);
}

/**
 * Load an image from a PNG file
 *
 * Reads a PNG image from disk using the given filename (and path)
 * and returns as a Pixman image. Use pixman_image_unref() to free it.
 *
 * The returned image is always in PIXMAN_a8r8g8b8 format.
 *
 * @returns Pixman image, or NULL in case of error.
 */
pixman_image_t *
load_image_from_png(const char *fname)
{
        pixman_image_t *image;
        pixman_image_t *converted;
        cairo_format_t cairo_fmt;
        pixman_format_code_t pixman_fmt;
        cairo_surface_t *reference_cairo_surface;
        cairo_status_t status;
        int width;
        int height;
        int stride;
        void *data;

        reference_cairo_surface = cairo_image_surface_create_from_png(fname);
        cairo_surface_flush(reference_cairo_surface);
        status = cairo_surface_status(reference_cairo_surface);
        if (status != CAIRO_STATUS_SUCCESS) {
                testlog("Could not open %s: %s\n", fname,
                        cairo_status_to_string(status));
                cairo_surface_destroy(reference_cairo_surface);
                return NULL;
        }

        cairo_fmt = cairo_image_surface_get_format(reference_cairo_surface);
        pixman_fmt = format_cairo2pixman(cairo_fmt);

        width = cairo_image_surface_get_width(reference_cairo_surface);
        height = cairo_image_surface_get_height(reference_cairo_surface);
        stride = cairo_image_surface_get_stride(reference_cairo_surface);
        data = cairo_image_surface_get_data(reference_cairo_surface);

        /* The Cairo surface will own the data, so we keep it around. */
        image = pixman_image_create_bits_no_clear(pixman_fmt,
                                                  width, height, data, stride);
        assert(image);

        pixman_image_set_destroy_function(image, destroy_cairo_surface,
                                          reference_cairo_surface);

        converted = image_convert_to_a8r8g8b8(image);
        pixman_image_unref(image);

        return converted;
}

/**
 * Take screenshot of a single output
 *
 * Requests a screenshot from the server of the output that the
 * client appears on. This implies that the compositor goes through an output
 * repaint to provide the screenshot before this function returns. This
 * function is therefore both a server roundtrip and a wait for a repaint.
 *
 * @returns A new buffer object, that should be freed with buffer_destroy().
 */
struct buffer *
capture_screenshot_of_output(struct client *client)
{
        struct buffer *buffer;

        buffer = create_shm_buffer_a8r8g8b8(client,
                                            client->output->width,
                                            client->output->height);

        client->test->buffer_copy_done = 0;
        weston_test_capture_screenshot(client->test->weston_test,
                                       client->output->wl_output,
                                       buffer->proxy);
        while (client->test->buffer_copy_done == 0)
                if (wl_display_dispatch(client->wl_display) < 0)
                        break;

        /* FIXME: Document somewhere the orientation the screenshot is taken
         * and how the clip coords are interpreted, in case of scaling/transform.
         * If we're using read_pixels() just make sure it is documented somewhere.
         * Protocol docs in the XML, comparison function docs in Doxygen style.
         */

        return buffer;
}

static void
write_visual_diff(pixman_image_t *ref_image,
                  struct buffer *shot,
                  const struct rectangle *clip,
                  const char *test_name,
                  int seq_no,
                  const struct range *fuzz)
{
        char *fname;
        char *ext_test_name;
        pixman_image_t *diff;
        int ret;

        ret = asprintf(&ext_test_name, "%s-diff", test_name);
        assert(ret >= 0);

        fname = screenshot_output_filename(ext_test_name, seq_no);
        diff = visualize_image_difference(ref_image, shot->image, clip, fuzz);
        write_image_as_png(diff, fname);

        pixman_image_unref(diff);
        free(fname);
        free(ext_test_name);
}

/**
 * Take a screenshot and verify its contents
 *
 * Takes a screenshot and writes the image into a PNG file named with
 * get_test_name() and seq_no. Compares the contents to the given reference
 * image over the given clip rectangle, reports whether they match to the
 * test log, and if they do not match writes a visual diff into a PNG file.
 *
 * The compositor output size and the reference image size must both contain
 * the clip rectangle.
 *
 * This function uses the pixel value allowed fuzz approriate for GL-renderer
 * with 8 bits per channel data.
 *
 * \param client The client, for connecting to the compositor.
 * \param ref_image The reference image file basename, without sequence number
 * and .png suffix.
 * \param ref_seq_no The reference image sequence number.
 * \param clip The region of interest, or NULL for comparing the whole
 * images.
 * \param seq_no Test sequence number, for writing output files.
 * \return True if the screen contents matches the reference image,
 * false otherwise.
 *
 * For bootstrapping, ref_image can be NULL or the file can be missing.
 * In that case the screenshot file is written but no comparison is performed,
 * and false is returned.
 */
bool
verify_screen_content(struct client *client,
                      const char *ref_image,
                      int ref_seq_no,
                      const struct rectangle *clip,
                      int seq_no)
{
        const char *test_name = get_test_name();
        const struct range gl_fuzz = { -3, 4 };
        struct buffer *shot;
        pixman_image_t *ref = NULL;
        char *ref_fname = NULL;
        char *shot_fname;
        bool match;

        shot = capture_screenshot_of_output(client);
        assert(shot);
        shot_fname = screenshot_output_filename(test_name, seq_no);
        write_image_as_png(shot->image, shot_fname);

        if (ref_image) {
                ref_fname = screenshot_reference_filename(ref_image, ref_seq_no);
                ref = load_image_from_png(ref_fname);
        }

        if (ref) {
                match = check_images_match(ref, shot->image, clip, &gl_fuzz);
                testlog("Verify reference image %s vs. shot %s: %s\n",
                        ref_fname, shot_fname, match ? "PASS" : "FAIL");

                if (!match) {
                        write_visual_diff(ref, shot, clip,
                                          test_name, seq_no, &gl_fuzz);
                }

                pixman_image_unref(ref);
        } else {
                testlog("No reference image, shot %s: FAIL\n", shot_fname);
                match = false;
        }

        free(ref_fname);
        buffer_destroy(shot);
        free(shot_fname);

        return match;
}

/**
 * Create a wl_buffer from a PNG file
 *
 * Loads the named PNG file from the directory of reference images,
 * creates a wl_buffer with scale times the image dimensions in pixels,
 * and copies the image content into the buffer using nearest-neighbor filter.
 *
 * \param client The client, for the Wayland connection.
 * \param basename The PNG file name without .png suffix.
 * \param scale Upscaling factor >= 1.
 */
struct buffer *
client_buffer_from_image_file(struct client *client,
                              const char *basename,
                              int scale)
{
        struct buffer *buf;
        char *fname;
        pixman_image_t *img;
        int buf_w, buf_h;
        pixman_transform_t scaling;

        assert(scale >= 1);

        fname = image_filename(basename);
        img = load_image_from_png(fname);
        free(fname);
        assert(img);

        buf_w = scale * pixman_image_get_width(img);
        buf_h = scale * pixman_image_get_height(img);
        buf = create_shm_buffer_a8r8g8b8(client, buf_w, buf_h);

        pixman_transform_init_scale(&scaling,
                                    pixman_fixed_1 / scale,
                                    pixman_fixed_1 / scale);
        pixman_image_set_transform(img, &scaling);
        pixman_image_set_filter(img, PIXMAN_FILTER_NEAREST, NULL, 0);

        pixman_image_composite32(PIXMAN_OP_SRC,
                                 img, /* src */
                                 NULL, /* mask */
                                 buf->image, /* dst */
                                 0, 0, /* src x,y */
                                 0, 0, /* mask x,y */
                                 0, 0, /* dst x,y */
                                 buf_w, buf_h);
        pixman_image_unref(img);

        return buf;
}

/**
 * Bind to a singleton global in wl_registry
 *
 * \param client Client whose registry and globals to use.
 * \param iface The Wayland interface to look for.
 * \param version The version to bind the interface with.
 * \return A struct wl_proxy, which you need to cast to the proper type.
 *
 * Asserts that the global being searched for is a singleton and is found.
 *
 * Binds with the exact version given, does not take compositor interface
 * version into account.
 */
void *
bind_to_singleton_global(struct client *client,
                         const struct wl_interface *iface,
                         int version)
{
        struct global *tmp;
        struct global *g = NULL;
        struct wl_proxy *proxy;

        wl_list_for_each(tmp, &client->global_list, link) {
                if (strcmp(tmp->interface, iface->name))
                        continue;

                assert(!g && "multiple singleton objects");
                g = tmp;
        }

        assert(g && "singleton not found");

        proxy = wl_registry_bind(client->wl_registry, g->name, iface, version);
        assert(proxy);

        return proxy;
}

/**
 * Create a wp_viewport for the client surface
 *
 * \param client The client->surface to use.
 * \return A fresh viewport object.
 */
struct wp_viewport *
client_create_viewport(struct client *client)
{
        struct wp_viewporter *viewporter;
        struct wp_viewport *viewport;

        viewporter = bind_to_singleton_global(client,
                                              &wp_viewporter_interface, 1);
        viewport = wp_viewporter_get_viewport(viewporter,
                                              client->surface->wl_surface);
        assert(viewport);
        wp_viewporter_destroy(viewporter);

        return viewport;
}

/**
 * Fill the image with the given color
 *
 * \param image The image to write to.
 * \param color The color to use.
 */
void
fill_image_with_color(pixman_image_t *image, pixman_color_t *color)
{
        pixman_image_t *solid;
        int width;
        int height;

        width = pixman_image_get_width(image);
        height = pixman_image_get_height(image);

        solid = pixman_image_create_solid_fill(color);
        pixman_image_composite32(PIXMAN_OP_SRC,
                                 solid, /* src */
                                 NULL, /* mask */
                                 image, /* dst */
                                 0, 0, /* src x,y */
                                 0, 0, /* mask x,y */
                                 0, 0, /* dst x,y */
                                 width, height);
        pixman_image_unref(solid);
}

/**
 * Convert 8-bit RGB to opaque Pixman color
 *
 * \param tmp Pixman color struct to fill in.
 * \param r Red value, 0 - 255.
 * \param g Green value, 0 - 255.
 * \param b Blue value, 0 - 255.
 * \return tmp
 */
pixman_color_t *
color_rgb888(pixman_color_t *tmp, uint8_t r, uint8_t g, uint8_t b)
{
        tmp->alpha = 65535;
        tmp->red = (r << 8) + r;
        tmp->green = (g << 8) + g;
        tmp->blue = (b << 8) + b;

        return tmp;
}