Add a shm buffer sharing mechanism

compositor/shm.c

@@ -0,0 +1,156 @@
+/*
+ * Copyright © 2010 Kristian Høgsberg
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "compositor.h"
+
+
+static void
+destroy_buffer(struct wl_resource *resource, struct wl_client *client)
+{
+	struct wlsc_shm_buffer *buffer =
+		container_of(resource, struct wlsc_shm_buffer, base.base);
+
+	munmap(buffer->data, buffer->stride * buffer->base.height);
+	free(buffer);
+}
+
+static void
+buffer_destroy(struct wl_client *client, struct wl_buffer *buffer)
+{
+	// wl_resource_destroy(&buffer->base, client);
+}
+
+const static struct wl_buffer_interface buffer_interface = {
+	buffer_destroy
+};
+
+static void
+shm_buffer_attach(struct wl_buffer *buffer_base, struct wl_surface *surface)
+{
+	struct wlsc_surface *es = (struct wlsc_surface *) surface;
+	struct wlsc_shm_buffer *buffer =
+		(struct wlsc_shm_buffer *) buffer_base;
+
+	glBindTexture(GL_TEXTURE_2D, es->texture);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB,
+		     buffer->base.width, buffer->base.height, 0,
+		     GL_RGBA, GL_UNSIGNED_BYTE, buffer->data);
+	es->visual = buffer->base.visual;
+}
+
+static void
+shm_buffer_damage(struct wl_buffer *buffer_base,
+		  struct wl_surface *surface,
+		  int32_t x, int32_t y, int32_t width, int32_t height)
+{
+	struct wlsc_surface *es = (struct wlsc_surface *) surface;
+	struct wlsc_shm_buffer *buffer =
+		(struct wlsc_shm_buffer *) buffer_base;
+
+	glBindTexture(GL_TEXTURE_2D, es->texture);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB,
+		     buffer->base.width, buffer->base.height, 0,
+		     GL_RGBA, GL_UNSIGNED_BYTE, buffer->data);
+
+	/* Hmm, should use glTexSubImage2D() here but GLES2 doesn't
+	 * support any unpack attributes except GL_UNPACK_ALIGNMENT. */
+}
+
+static void
+shm_create_buffer(struct wl_client *client, struct wl_shm *shm,
+		  uint32_t id, int fd, int32_t width, int32_t height,
+		  uint32_t stride, struct wl_visual *visual)
+{
+	struct wlsc_compositor *compositor =
+		container_of((struct wlsc_shm *) shm,
+			     struct wlsc_compositor, shm);
+	struct wlsc_shm_buffer *buffer;
+
+	if (visual != &compositor->argb_visual &&
+	    visual != &compositor->premultiplied_argb_visual &&
+	    visual != &compositor->rgb_visual) {
+		/* FIXME: Define a real exception event instead of
+		 * abusing this one */
+		wl_client_post_event(client,
+				     (struct wl_object *) compositor->wl_display,
+				     WL_DISPLAY_INVALID_OBJECT, 0);
+		fprintf(stderr, "invalid visual in create_buffer\n");
+		close(fd);
+		return;
+	}
+
+	buffer = malloc(sizeof *buffer);
+	if (buffer == NULL) {
+		close(fd);
+		wl_client_post_no_memory(client);
+		return;
+	}
+
+	buffer->base.compositor = (struct wl_compositor *) compositor;
+	buffer->base.width = width;
+	buffer->base.height = height;
+	buffer->base.visual = visual;
+	buffer->base.attach = shm_buffer_attach;
+	buffer->base.damage = shm_buffer_damage;
+	buffer->stride = stride;
+	buffer->data =
+		mmap(NULL, stride * height, PROT_READ, MAP_SHARED, fd, 0);
+	close(fd);
+	if (buffer->data == MAP_FAILED) {
+		/* FIXME: Define a real exception event instead of
+		 * abusing this one */
+		free(buffer);
+		wl_client_post_event(client,
+				     (struct wl_object *) compositor->wl_display,
+				     WL_DISPLAY_INVALID_OBJECT, 0);
+		fprintf(stderr, "failed to create image for fd %d\n", fd);
+		return;
+	}
+
+	buffer->base.base.base.id = id;
+	buffer->base.base.base.interface = &wl_buffer_interface;
+	buffer->base.base.base.implementation = (void (**)(void))
+		&buffer_interface;
+
+	buffer->base.base.destroy = destroy_buffer;
+
+	wl_client_add_resource(client, &buffer->base.base);
+}
+
+const static struct wl_shm_interface shm_interface = {
+	shm_create_buffer
+};
+
+int
+wlsc_shm_init(struct wlsc_compositor *ec)
+{
+	struct wlsc_shm *shm = &ec->shm;
+
+	shm->base.interface = &wl_shm_interface;
+	shm->base.implementation = (void (**)(void)) &shm_interface;
+	wl_display_add_object(ec->wl_display, &shm->base);
+	wl_display_add_global(ec->wl_display, &shm->base, NULL);
+
+	return 0;
+}