Fix up wayland client implementation

Now it receives frame callbacks and renders properly, and is double
buffered and such.

include/client/buffer.h

@@ -0,0 +1,8 @@
+#ifndef _BUFFER_H
+#define _BUFFER_H
+
+#include "client/client.h"
+
+struct buffer *get_next_buffer(struct client_state *state);
+
+#endif

include/client/client.h

@@ -10,13 +10,16 @@
 struct output_state {
     struct wl_output *output;
     uint32_t flags;
-    int width, height;
+    uint32_t width, height;
 };
 
 struct buffer {
     struct wl_buffer *buffer;
-    struct wl_shm_pool *pool;
+    cairo_surface_t *surface;
+    cairo_t *cairo;
+    PangoContext *pango;
     uint32_t width, height;
+    bool busy;
 };
 
 struct client_state {
@@ -26,20 +29,18 @@ struct client_state {
     struct wl_seat *seat;
     struct wl_shell *shell;
     struct wl_shm *shm;
+    struct buffer buffers[2];
     struct buffer *buffer;
     struct wl_surface *surface;
     struct wl_shell_surface *shell_surface;
     struct wl_callback *frame_cb;
-    bool busy;
+    uint32_t width, height;
     cairo_t *cairo;
-    cairo_surface_t *cairo_surface;
-    PangoContext *pango;
     list_t *outputs;
 };
 
-struct client_state *client_setup(void);
+struct client_state *client_setup(uint32_t width, uint32_t height);
 void client_teardown(struct client_state *state);
-struct buffer *create_memory_pool(struct client_state *state, int32_t width, int32_t height, uint32_t format);
 int client_prerender(struct client_state *state);
 int client_render(struct client_state *state);
 

swaybg/main.c

@@ -2,7 +2,7 @@
 #include <stdlib.h>
 #include <wayland-client.h>
 #include <time.h>
-#include "client.h"
+#include "client/client.h"
 #include "log.h"
 
 struct client_state *state;
@@ -14,36 +14,23 @@ void sway_terminate(void) {
 
 int main(int argc, char **argv) {
 	init_log(L_INFO);
-	if (!(state = client_setup())) {
+	if (!(state = client_setup(100, 100))) {
 		return -1;
 	}
 
-	uint8_t r = 0, g = 0, b = 0;
+	uint8_t r = 100, g = 100, b = 100;
 
-	long last_ms = 0;
-	int rs;
 	do {
-		struct timespec spec;
-		clock_gettime(CLOCK_MONOTONIC, &spec);
-		long ms = round(spec.tv_nsec / 1.0e6);
+		if (client_prerender(state)) {
+			cairo_set_source_rgb(state->cairo, r / 256.0, g / 256.0, b / 256.0);
+			cairo_rectangle(state->cairo, 0, 0, state->width, state->height);
+			cairo_fill(state->cairo);
 
-		cairo_set_source_rgb(state->cairo, r, g, b);
-		cairo_rectangle(state->cairo, 0, 0, 100, 100);
-		cairo_fill(state->cairo);
+			client_render(state);
 
-		rs = client_render(state);
-
-		if (ms - last_ms > 100) {
-			r++;
-			if (r == 0) {
-				g++;
-				if (g == 0) {
-					b++;
-				}
-			}
-			ms = last_ms;
+			r++; if (r == 0) { g++; if (g == 0) { b++; } }
 		}
-	} while (rs);
+	} while (wl_display_dispatch(state->display) != -1);
 
 	client_teardown(state);
 	return 0;

wayland/buffers.c

@@ -0,0 +1,116 @@
+#include <wayland-client.h>
+#include <cairo/cairo.h>
+#include <pango/pangocairo.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include "client/buffer.h"
+#include "list.h"
+#include "log.h"
+
+static int create_pool_file(size_t size) {
+    static const char template[] = "/sway-client-XXXXXX";
+    const char *path = getenv("XDG_RUNTIME_DIR");
+	if (!path) {
+        return -1;
+    }
+
+    int ts = (path[strlen(path) - 1] == '/');
+
+    char *name = malloc(
+		strlen(template) +
+		strlen(path) +
+		(ts ? 1 : 0) + 1);
+	sprintf(name, "%s%s%s", path, ts ? "" : "/", template);
+
+    int fd = mkstemp(name);
+    free(name);
+
+    if (fd < 0) {
+        return -1;
+    }
+
+    if (ftruncate(fd, size) < 0) {
+        close(fd);
+        return -1;
+    }
+
+    return fd;
+}
+
+static void buffer_release(void *data, struct wl_buffer *wl_buffer) {
+	struct buffer *buffer = data;
+	buffer->busy = false;
+}
+
+static const struct wl_buffer_listener buffer_listener = {
+	.release = buffer_release
+};
+
+static struct buffer *create_buffer(struct client_state *state, struct buffer *buf,
+		int32_t width, int32_t height, uint32_t format) {
+
+	uint32_t stride = width * 4;
+	uint32_t size = stride * height;
+
+	int fd = create_pool_file(size);
+	void *data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	struct wl_shm_pool *pool = wl_shm_create_pool(state->shm, fd, size);
+	buf->buffer = wl_shm_pool_create_buffer(pool, 0, width, height, stride, format);
+	wl_shm_pool_destroy(pool);
+	close(fd);
+	fd = -1;
+
+	buf->surface = cairo_image_surface_create_for_data(data, CAIRO_FORMAT_ARGB32, width, height, stride);
+	buf->cairo = cairo_create(buf->surface);
+	buf->pango = pango_cairo_create_context(buf->cairo);
+
+	wl_buffer_add_listener(buf->buffer, &buffer_listener, state);
+	return buf;
+}
+
+static void destroy_buffer(struct buffer *buffer) {
+    if (buffer->buffer) {
+	wl_buffer_destroy(buffer->buffer);
+    }
+    if (buffer->cairo) {
+	cairo_destroy(buffer->cairo);
+    }
+    if (buffer->surface) {
+	cairo_surface_destroy(buffer->surface);
+    }
+    memset(buffer, 0, sizeof(struct buffer));
+}
+
+struct buffer *get_next_buffer(struct client_state *state) {
+    struct buffer *buffer = NULL;
+
+    int i;
+    for (i = 0; i < 2; ++i) {
+	if (state->buffers[i].busy) {
+	    continue;
+	}
+	buffer = &state->buffers[i];
+    }
+
+    if (!buffer) {
+	return NULL;
+    }
+
+    if (buffer->width != state->width || buffer->height != state->height) {
+	destroy_buffer(buffer);
+    }
+
+    if (!buffer->buffer) {
+	if (!create_buffer(state, buffer, state->width, state->height, WL_SHM_FORMAT_ARGB8888)) {
+	    return NULL;
+	}
+    }
+    
+    state->cairo = buffer->cairo;
+    state->buffer = buffer;
+    return buffer;
+}

wayland/client.c

@@ -7,7 +7,8 @@
 #include <unistd.h>
 #include <errno.h>
 #include <sys/mman.h>
-#include "client.h"
+#include "client/client.h"
+#include "client/buffer.h"
 #include "list.h"
 #include "log.h"
 
@@ -73,87 +74,12 @@ static const struct wl_registry_listener registry_listener = {
 	.global_remove = registry_global_remove
 };
 
-static int create_pool_file(size_t size) {
-    static const char template[] = "/swaybg-XXXXXX";
-    const char *path = getenv("XDG_RUNTIME_DIR");
-	if (!path) {
-        return -1;
-    }
-
-    int ts = (path[strlen(path) - 1] == '/');
-
-    char *name = malloc(
-		strlen(template) +
-		strlen(path) +
-		(ts ? 1 : 0) + 1);
-	sprintf(name, "%s%s%s", path, ts ? "" : "/", template);
-
-    int fd = mkstemp(name);
-    free(name);
-
-    if (fd < 0) {
-        return -1;
-    }
-
-    if (ftruncate(fd, size) < 0) {
-        close(fd);
-        return -1;
-    }
-
-    return fd;
-}
-
-static void buffer_release(void *data, struct wl_buffer *buffer) {
-	struct client_state *state = data;
-	state->busy = false;
-	sway_log(L_INFO, "buffer release");
-}
-
-static const struct wl_buffer_listener buffer_listener = {
-	.release = buffer_release
-};
-
-struct buffer *create_buffer(struct client_state *state,
-		int32_t width, int32_t height, uint32_t format) {
-
-	struct buffer *buf = malloc(sizeof(struct buffer));
-	memset(buf, 0, sizeof(struct buffer));
-	uint32_t stride = width * 4;
-	uint32_t size = stride * height;
-
-	int fd = create_pool_file(size);
-	void *data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-	buf->pool = wl_shm_create_pool(state->shm, fd, size);
-	buf->buffer = wl_shm_pool_create_buffer(buf->pool, 0, width, height, stride, format);
-	wl_shm_pool_destroy(buf->pool);
-	close(fd);
-	fd = -1;
-
-	state->cairo_surface = cairo_image_surface_create_for_data(data, CAIRO_FORMAT_ARGB32, width, height, stride);
-	state->cairo = cairo_create(state->cairo_surface);
-	state->pango = pango_cairo_create_context(state->cairo);
-
-	wl_buffer_add_listener(buf->buffer, &buffer_listener, state);
-
-	sway_log(L_INFO, "%p %p", buf->pool, buf->buffer);
-	return buf;
-}
-
-static void frame_callback(void *data, struct wl_callback *callback, uint32_t time) {
-	sway_log(L_INFO, "frame callback");
-	struct client_state *state = data;
-	wl_callback_destroy(callback);
-	state->frame_cb = NULL;
-}
-
-static const struct wl_callback_listener listener = {
-	frame_callback
-};
-
-struct client_state *client_setup(void) {
+struct client_state *client_setup(uint32_t width, uint32_t height) {
 	struct client_state *state = malloc(sizeof(struct client_state));
 	memset(state, 0, sizeof(struct client_state));
 	state->outputs = create_list();
+	state->width = width;
+	state->height = height;
 
 	state->display = wl_display_connect(NULL);
 	if (!state->display) {
@@ -168,22 +94,33 @@ struct client_state *client_setup(void) {
 	wl_display_roundtrip(state->display);
 	wl_registry_destroy(registry);
 
-	state->buffer = create_buffer(state, 100, 100, WL_SHM_FORMAT_ARGB8888);
 	state->surface = wl_compositor_create_surface(state->compositor);
 	state->shell_surface = wl_shell_get_shell_surface(state->shell, state->surface);
 	wl_shell_surface_set_toplevel(state->shell_surface);
 
-	wl_surface_damage(state->surface, 0, 0, 100, 100);
-
 	return state;
 }
 
-int client_render(struct client_state *state) {
-	if (state->frame_cb || state->busy) {
-		return 2;
-	}
-	sway_log(L_INFO, "Rendering");
+static void frame_callback(void *data, struct wl_callback *callback, uint32_t time) {
+	struct client_state *state = data;
+	wl_callback_destroy(callback);
+	state->frame_cb = NULL;
+}
 
+static const struct wl_callback_listener listener = {
+	frame_callback
+};
+
+int client_prerender(struct client_state *state) {
+	if (state->frame_cb) {
+		return 0;
+	}
+
+	get_next_buffer(state);
+	return 1;
+}
+
+int client_render(struct client_state *state) {
 	state->frame_cb = wl_surface_frame(state->surface);
 	wl_callback_add_listener(state->frame_cb, &listener, state);
 
@@ -191,9 +128,7 @@ int client_render(struct client_state *state) {
 	wl_surface_attach(state->surface, state->buffer->buffer, 0, 0);
 	wl_surface_commit(state->surface);
 
-	state->busy = true;
-
-	return wl_display_dispatch(state->display) != -1;
+	return 1;
 }
 
 void client_teardown(struct client_state *state) {