wayland-client/compositor.c

#include "common/shm.h"
#include "protocols/xdg-shell-client-protocol.h"

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <wayland/wayland-client.h>

struct client_state
{
    /* Globals */
    struct wl_display *wl_display;
    struct wl_registry *wl_registry;
    struct wl_shm *wl_shm;
    struct wl_compositor *wl_compositor;
    struct xdg_wm_base *xdg_wm_base;

    /* Objects */
    struct wl_surface *wl_surface;
    struct xdg_surface *xdg_surface;
    struct xdg_toplevel *xdg_toplevel;
};

static struct wl_buffer *draw_frame(struct client_state *state);

static void registry_handle_global(void *data, struct wl_registry *registry, uint32_t name, const char *interface,
                                   uint32_t version)
{
    struct client_state *state = data;

    if (strcmp(interface, wl_compositor_interface.name) == 0) {
        state->wl_compositor = wl_registry_bind(registry, name, &wl_compositor_interface, 5);
    } else if (strcmp(interface, wl_shm_interface.name) == 0) {
        state->wl_shm = wl_registry_bind(registry, name, &wl_shm_interface, 1);
    } else if (strcmp(interface, xdg_wm_base_interface.name) == 0) {
        state->xdg_wm_base = wl_registry_bind(registry, name, &xdg_wm_base_interface, 4);
    }
}

static void registry_handle_global_remove(void *data, struct wl_registry *registry, uint32_t name)
{
    // This space deliberately left blank
}

static void shm_handle_format(void *data, struct wl_shm *wl_shm, uint32_t format)
{
    struct client_state *state = data;
}

static void wm_base_handle_ping(void *data, struct xdg_wm_base *xdg_wm_base, uint32_t serial)
{
    struct client_state *state = data;

    // TODO !
}

static void surface_handle_configure(void *data, struct xdg_surface *xdg_surface, uint32_t serial)
{
    struct client_state *state = data;

    xdg_surface_ack_configure(xdg_surface, serial);

    struct wl_buffer *buffer = draw_frame(state);
    wl_surface_attach(state->wl_surface, buffer, 0, 0);
    wl_surface_commit(state->wl_surface);
}

static const struct wl_registry_listener wl_registry_listener = {
    .global = registry_handle_global,
    .global_remove = registry_handle_global_remove,
};

static const struct wl_shm_listener wl_shm_listener = {
    .format = shm_handle_format,
};

static const struct xdg_wm_base_listener xdg_wm_base_listener = {
    .ping = wm_base_handle_ping,
};

static const struct xdg_surface_listener xdg_surface_listener = {
    .configure = surface_handle_configure,
};

static void wl_buffer_release(void *data, struct wl_buffer *wl_buffer)
{
    /* Sent by the compositor when it's no longer using this buffer */
    wl_buffer_destroy(wl_buffer);
}

static const struct wl_buffer_listener wl_buffer_listener = {
    .release = wl_buffer_release,
};

static struct wl_buffer *draw_frame(struct client_state *state)
{
    const int width = 640, height = 480;
    int stride = width * 4;
    int size = stride * height;
    int offset = 0;

    int fd = allocate_shm_file(size);
    if (fd == -1) {
        return NULL;
    }

    uint32_t *data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (data == MAP_FAILED) {
        close(fd);
        return NULL;
    }

    struct wl_shm_pool *pool = wl_shm_create_pool(state->wl_shm, fd, size);
    struct wl_buffer *buffer = wl_shm_pool_create_buffer(pool, 0, width, height, stride, WL_SHM_FORMAT_XRGB8888);
    wl_shm_pool_destroy(pool);
    close(fd);

    // Solid white
    // uint32_t *pixels = (uint32_t *)&data[offset];
    // memset(pixels, 255, width * height * 4);

    // Checkerboard pattern
    uint32_t *pixels = (uint32_t *)&data[offset];
    for (int y = 0; y < height; ++y) {
        for (int x = 0; x < width; ++x) {
            if ((x + y / 8 * 8) % 16 < 8) {
                pixels[y * width + x] = 0xFF666666;
            } else {
                pixels[y * width + x] = 0xFFEEEEEE;
            }
        }
    }

    munmap(data, size);
    wl_buffer_add_listener(buffer, &wl_buffer_listener, NULL);
    return buffer;
}

int main(int argc, char *argv[])
{
    struct client_state state = {0};

    state.wl_display = wl_display_connect(NULL);

    state.wl_registry = wl_display_get_registry(state.wl_display);

    wl_registry_add_listener(state.wl_registry, &wl_registry_listener, &state);

    wl_display_roundtrip(state.wl_display);

    state.wl_surface = wl_compositor_create_surface(state.wl_compositor);

    wl_shm_add_listener(state.wl_shm, &wl_shm_listener, &state);

    state.xdg_surface = xdg_wm_base_get_xdg_surface(state.xdg_wm_base, state.wl_surface);
    xdg_surface_add_listener(state.xdg_surface, &xdg_surface_listener, &state);

    state.xdg_toplevel = xdg_surface_get_toplevel(state.xdg_surface);

    xdg_toplevel_set_title(state.xdg_toplevel, "Example client");
    wl_surface_commit(state.wl_surface);

    while (wl_display_dispatch(state.wl_display)) {
        /* This space deliberately left blank */
    }

    return 0;
}