Renaming.

13 files changed, 395 insertions, 350 deletions

diff --git a/backend/CMakeLists.txt b/backend/CMakeLists.txt
index c962b8ed..2d6e734f 100644
--- a/backend/CMakeLists.txt
+++ b/backend/CMakeLists.txt
@@ -9,9 +9,9 @@ add_library(wlr-backend
     wayland/registry.c
     wayland/wl_seat.c
     wayland/wl_output.c
+    drm/backend.c
     drm/drm.c
     drm/event.c
-    drm/otd.c
     drm/session.c
     drm/udev.c
 )
diff --git a/backend/drm/backend.c b/backend/drm/backend.c
new file mode 100644
index 00000000..8c500190
--- /dev/null
+++ b/backend/drm/backend.c
@@ -0,0 +1,71 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "backend/drm/backend.h"
+#include "backend/drm/drm.h"
+#include "backend/drm/event.h"
+#include "backend/drm/session.h"
+#include "backend/drm/udev.h"
+
+struct wlr_drm_backend *wlr_drm_backend_init(void)
+{
+	struct wlr_drm_backend *backend = calloc(1, sizeof *backend);
+	if (!backend)
+		return NULL;
+
+	if (!wlr_session_start(&backend->session)) {
+		fprintf(stderr, "Could not create session\n");
+		goto error;
+	}
+
+	if (!wlr_udev_init(&backend->udev)) {
+		fprintf(stderr, "Could not start udev\n");
+		goto error_session;
+	}
+
+	backend->fd = wlr_udev_find_gpu(&backend->udev, &backend->session);
+	if (backend->fd == -1) {
+		fprintf(stderr, "Could not open GPU\n");
+		goto error_udev;
+	}
+
+	if (!wlr_drm_renderer_init(&backend->renderer, backend, backend->fd)) {
+		fprintf(stderr, "Could not initalise renderer\n");
+		goto error_fd;
+	}
+
+	wlr_drm_scan_connectors(backend);
+
+	return backend;
+
+error_fd:
+	wlr_session_release_device(&backend->session, backend->fd);
+error_udev:
+	wlr_udev_free(&backend->udev);
+error_session:
+	wlr_session_end(&backend->session);
+error:
+	free(backend);
+	return NULL;
+}
+
+void wlr_drm_backend_free(struct wlr_drm_backend *backend)
+{
+	if (!backend)
+		return;
+
+	for (size_t i = 0; i < backend->display_len; ++i) {
+		wlr_drm_display_free(&backend->displays[i]);
+	}
+
+	wlr_drm_renderer_free(&backend->renderer);
+	wlr_udev_free(&backend->udev);
+	wlr_session_release_device(&backend->session, backend->fd);
+	wlr_session_end(&backend->session);
+
+	free(backend->events);
+	free(backend->displays);
+	free(backend);
+}
+
diff --git a/backend/drm/drm.c b/backend/drm/drm.c
index 894d8513..c5b797c3 100644
--- a/backend/drm/drm.c
+++ b/backend/drm/drm.c
@@ -1,4 +1,4 @@
-#include "backend/drm/otd.h"
+#include "backend/drm/backend.h"
 #include "backend/drm/drm.h"
 #include "backend/drm/event.h"
 
@@ -51,7 +51,7 @@ static bool egl_exts()
 	return get_platform_display && create_platform_window_surface;
 }
 
-bool egl_get_config(EGLDisplay disp, EGLConfig *out)
+static bool egl_get_config(EGLDisplay disp, EGLConfig *out)
 {
 	EGLint count = 0, matched = 0, ret;
 
@@ -85,15 +85,16 @@ bool egl_get_config(EGLDisplay disp, EGLConfig *out)
 	return false;
 }
 
-bool init_renderer(struct otd *otd)
+bool wlr_drm_renderer_init(struct wlr_drm_renderer *renderer,
+		struct wlr_drm_backend *backend, int fd)
 {
 	if (!egl_exts()) {
 		fprintf(stderr, "Could not get EGL extensions\n");
 		return false;
 	}
 
-	otd->gbm = gbm_create_device(otd->fd);
-	if (!otd->gbm) {
+	renderer->gbm = gbm_create_device(fd);
+	if (!renderer->gbm) {
 		fprintf(stderr, "Could not create gbm device: %s\n", strerror(errno));
 		return false;
 	}
@@ -103,103 +104,109 @@ bool init_renderer(struct otd *otd)
 		goto error_gbm;
 	}
 
-	otd->egl.disp = get_platform_display(EGL_PLATFORM_GBM_MESA, otd->gbm, NULL);
-	if (otd->egl.disp == EGL_NO_DISPLAY) {
+	renderer->egl.disp = get_platform_display(EGL_PLATFORM_GBM_MESA, renderer->gbm, NULL);
+	if (renderer->egl.disp == EGL_NO_DISPLAY) {
 		fprintf(stderr, "Could not create EGL display\n");
 		goto error_gbm;
 	}
 
-	if (eglInitialize(otd->egl.disp, NULL, NULL) == EGL_FALSE) {
+	if (eglInitialize(renderer->egl.disp, NULL, NULL) == EGL_FALSE) {
 		fprintf(stderr, "Could not initalise EGL\n");
 		goto error_egl;
 	}
 
-	if (!egl_get_config(otd->egl.disp, &otd->egl.conf)) {
+	if (!egl_get_config(renderer->egl.disp, &renderer->egl.conf)) {
 		fprintf(stderr, "Could not get EGL config\n");
 		goto error_egl;
 	}
 
 	static const EGLint attribs[] = {EGL_CONTEXT_CLIENT_VERSION, 3, EGL_NONE};
-	otd->egl.context = eglCreateContext(otd->egl.disp, otd->egl.conf, EGL_NO_CONTEXT, attribs);
-	if (otd->egl.context == EGL_NO_CONTEXT) {
+
+	renderer->egl.context = eglCreateContext(renderer->egl.disp,
+			renderer->egl.conf, EGL_NO_CONTEXT, attribs);
+
+	if (renderer->egl.context == EGL_NO_CONTEXT) {
 		fprintf(stderr, "Could not create EGL context\n");
 		goto error_egl;
 	}
 
+	renderer->fd = fd;
+	renderer->backend = backend;
+
 	return true;
 
 error_egl:
-	eglTerminate(otd->egl.disp);
+	eglTerminate(renderer->egl.disp);
 	eglReleaseThread();
 	eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
 
 error_gbm:
-	gbm_device_destroy(otd->gbm);
+	gbm_device_destroy(renderer->gbm);
 
 	return false;
 }
 
-void destroy_renderer(struct otd *otd)
+void wlr_drm_renderer_free(struct wlr_drm_renderer *renderer)
 {
-	if (!otd)
+	if (!renderer)
 		return;
 
-	eglDestroyContext(otd->egl.disp, otd->egl.context);
-	eglTerminate(otd->egl.disp);
+	eglDestroyContext(renderer->egl.disp, renderer->egl.context);
+	eglTerminate(renderer->egl.disp);
 	eglReleaseThread();
 	eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
 
-	gbm_device_destroy(otd->gbm);
+	gbm_device_destroy(renderer->gbm);
 }
 
-void scan_connectors(struct otd *otd)
+void wlr_drm_scan_connectors(struct wlr_drm_backend *backend)
 {
-	drmModeRes *res = drmModeGetResources(otd->fd);
+	drmModeRes *res = drmModeGetResources(backend->fd);
 	if (!res)
 		return;
 
 	// I don't know if this needs to be allocated with realloc like this,
 	// as it may not even be possible for the number of connectors to change.
 	// I'll just have to see how DisplayPort MST works with DRM.
-	if ((size_t)res->count_connectors > otd->display_len) {
-		struct otd_display *new = realloc(otd->displays, sizeof *new * res->count_connectors);
+	if ((size_t)res->count_connectors > backend->display_len) {
+		struct wlr_drm_display *new = realloc(backend->displays, sizeof *new * res->count_connectors);
 		if (!new)
 			goto error;
 
-		for (int i = otd->display_len; i < res->count_connectors; ++i) {
-			new[i] = (struct otd_display) {
-				.state = OTD_DISP_INVALID,
-				.otd = otd,
+		for (int i = backend->display_len; i < res->count_connectors; ++i) {
+			new[i] = (struct wlr_drm_display) {
+				.state = DRM_DISP_INVALID,
+				.renderer = &backend->renderer,
 			};
 		}
 
-		otd->display_len = res->count_connectors;
-		otd->displays = new;
+		backend->display_len = res->count_connectors;
+		backend->displays = new;
 	}
 
 	for (int i = 0; i < res->count_connectors; ++i) {
-		struct otd_display *disp = &otd->displays[i];
-		drmModeConnector *conn = drmModeGetConnector(otd->fd, res->connectors[i]);
+		struct wlr_drm_display *disp = &backend->displays[i];
+		drmModeConnector *conn = drmModeGetConnector(backend->fd, res->connectors[i]);
 		if (!conn)
 			continue;
 
-		if (otd->displays[i].state == OTD_DISP_INVALID) {
-			disp->state = OTD_DISP_DISCONNECTED;
+		if (backend->displays[i].state == DRM_DISP_INVALID) {
+			disp->state = DRM_DISP_DISCONNECTED;
 			disp->connector = res->connectors[i];
 			snprintf(disp->name, sizeof disp->name, "%s-%"PRIu32,
 				 conn_name[conn->connector_type],
 				 conn->connector_type_id);
 		}
 
-		if (disp->state == OTD_DISP_DISCONNECTED &&
+		if (disp->state == DRM_DISP_DISCONNECTED &&
 		    conn->connection == DRM_MODE_CONNECTED) {
-			disp->state = OTD_DISP_NEEDS_MODESET;
-			event_add(otd, disp, OTD_EV_DISPLAY_ADD);
+			disp->state = DRM_DISP_NEEDS_MODESET;
+			wlr_drm_add_event(backend, disp, DRM_EV_DISPLAY_ADD);
 
-		} else if (disp->state == OTD_DISP_CONNECTED &&
+		} else if (disp->state == DRM_DISP_CONNECTED &&
 		    conn->connection != DRM_MODE_CONNECTED) {
-			disp->state = OTD_DISP_DISCONNECTED;
-			event_add(otd, disp, OTD_EV_DISPLAY_REM);
+			disp->state = DRM_DISP_DISCONNECTED;
+			wlr_drm_add_event(backend, disp, DRM_EV_DISPLAY_REM);
 		}
 
 		drmModeFreeConnector(conn);
@@ -238,44 +245,49 @@ static uint32_t get_fb_for_bo(int fd, struct gbm_bo *bo)
 	return *id;
 }
 
-static void init_display_renderer(struct otd *otd, struct otd_display *disp)
+static bool display_init_renderer(struct wlr_drm_renderer *renderer,
+		struct wlr_drm_display *disp)
 {
-	disp->gbm = gbm_surface_create(otd->gbm,
+	disp->renderer = renderer;
+
+	disp->gbm = gbm_surface_create(renderer->gbm,
 				       disp->width, disp->height,
 				       GBM_FORMAT_XRGB8888,
 				       GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING);
 	if (!disp->gbm)
-		return;
+		return false;
 
-	disp->egl = create_platform_window_surface(otd->egl.disp, otd->egl.conf,
+	disp->egl = create_platform_window_surface(renderer->egl.disp, renderer->egl.conf,
 						   disp->gbm, NULL);
 	if (disp->egl == EGL_NO_SURFACE)
-		return;
+		return false;
 
 	// Render black frame
 
-	eglMakeCurrent(otd->egl.disp, disp->egl, disp->egl, otd->egl.context);
+	eglMakeCurrent(renderer->egl.disp, disp->egl, disp->egl, renderer->egl.context);
 
 	glViewport(0, 0, disp->width, disp->height);
 	glClearColor(0.0, 0.0, 0.0, 1.0);
 	glClear(GL_COLOR_BUFFER_BIT);
 
-	eglSwapBuffers(otd->egl.disp, disp->egl);
+	eglSwapBuffers(renderer->egl.disp, disp->egl);
 
 	struct gbm_bo *bo = gbm_surface_lock_front_buffer(disp->gbm);
-	uint32_t fb_id = get_fb_for_bo(otd->fd, bo);
+	uint32_t fb_id = get_fb_for_bo(renderer->fd, bo);
 
-	drmModeSetCrtc(otd->fd, disp->crtc, fb_id, 0, 0,
+	drmModeSetCrtc(renderer->fd, disp->crtc, fb_id, 0, 0,
 		       &disp->connector, 1, disp->active_mode);
-	drmModePageFlip(otd->fd, disp->crtc, fb_id, DRM_MODE_PAGE_FLIP_EVENT, disp);
+	drmModePageFlip(renderer->fd, disp->crtc, fb_id, DRM_MODE_PAGE_FLIP_EVENT, disp);
 
 	gbm_surface_release_buffer(disp->gbm, bo);
+
+	return true;
 }
 
 static drmModeModeInfo *select_mode(size_t num_modes,
-				    drmModeModeInfo modes[static num_modes],
-				    drmModeCrtc *old_crtc,
-				    const char *str)
+		drmModeModeInfo modes[static num_modes],
+		drmModeCrtc *old_crtc,
+		const char *str)
 {
 	if (strcmp(str, "preferred") == 0)
 		return &modes[0];
@@ -315,9 +327,10 @@ static drmModeModeInfo *select_mode(size_t num_modes,
 	return NULL;
 }
 
-bool modeset_str(struct otd *otd, struct otd_display *disp, const char *str)
+bool wlr_drm_display_modeset(struct wlr_drm_backend *backend,
+		struct wlr_drm_display *disp, const char *str)
 {
-	drmModeConnector *conn = drmModeGetConnector(otd->fd, disp->connector);
+	drmModeConnector *conn = drmModeGetConnector(backend->fd, disp->connector);
 	if (!conn || conn->connection != DRM_MODE_CONNECTED || conn->count_modes == 0)
 		goto error;
 
@@ -327,9 +340,9 @@ bool modeset_str(struct otd *otd, struct otd_display *disp, const char *str)
 		goto error;
 	memcpy(disp->modes, conn->modes, sizeof *disp->modes * disp->num_modes);
 
-	drmModeEncoder *curr_enc = drmModeGetEncoder(otd->fd, conn->encoder_id);
+	drmModeEncoder *curr_enc = drmModeGetEncoder(backend->fd, conn->encoder_id);
 	if (curr_enc) {
-		disp->old_crtc = drmModeGetCrtc(otd->fd, curr_enc->crtc_id);
+		disp->old_crtc = drmModeGetCrtc(backend->fd, curr_enc->crtc_id);
 		free(curr_enc);
 	}
 
@@ -343,13 +356,13 @@ bool modeset_str(struct otd *otd, struct otd_display *disp, const char *str)
 		disp->name, disp->active_mode->hdisplay, disp->active_mode->vdisplay,
 		disp->active_mode->vrefresh);
 
-	drmModeRes *res = drmModeGetResources(otd->fd);
+	drmModeRes *res = drmModeGetResources(backend->fd);
 	if (!res)
 		goto error;
 
 	bool success = false;
 	for (int i = 0; !success && i < conn->count_encoders; ++i) {
-		drmModeEncoder *enc = drmModeGetEncoder(otd->fd, conn->encoders[i]);
+		drmModeEncoder *enc = drmModeGetEncoder(backend->fd, conn->encoders[i]);
 		if (!enc)
 			continue;
 
@@ -357,8 +370,8 @@ bool modeset_str(struct otd *otd, struct otd_display *disp, const char *str)
 			if ((enc->possible_crtcs & (1 << j)) == 0)
 				continue;
 
-			if ((otd->taken_crtcs & (1 << j)) == 0) {
-				otd->taken_crtcs |= 1 << j;
+			if ((backend->taken_crtcs & (1 << j)) == 0) {
+				backend->taken_crtcs |= 1 << j;
 				disp->crtc = res->crtcs[j];
 
 				success = true;
@@ -374,45 +387,48 @@ bool modeset_str(struct otd *otd, struct otd_display *disp, const char *str)
 	if (!success)
 		goto error;
 
-	disp->state = OTD_DISP_CONNECTED;
+	disp->state = DRM_DISP_CONNECTED;
 	drmModeFreeConnector(conn);
 
 	disp->width = disp->active_mode->hdisplay;
 	disp->height = disp->active_mode->vdisplay;
 
-	init_display_renderer(otd, disp);
+	display_init_renderer(&backend->renderer, disp);
 
 	return true;
 error:
-	disp->state = OTD_DISP_DISCONNECTED;
+	disp->state = DRM_DISP_DISCONNECTED;
 	drmModeFreeConnector(conn);
 
-	event_add(otd, disp, OTD_EV_DISPLAY_REM);
+	wlr_drm_add_event(backend, disp, DRM_EV_DISPLAY_REM);
 
 	return false;
 }
 
-
-void page_flip_handler(int fd,
-		       unsigned seq,
-		       unsigned tv_sec,
-		       unsigned tv_usec,
-		       void *user)
+static void page_flip_handler(int fd,
+		unsigned seq,
+		unsigned tv_sec,
+		unsigned tv_usec,
+		void *user)
 {
-	struct otd_display *disp = user;
+	struct wlr_drm_display *disp = user;
 
 	disp->pageflip_pending = true;
 	if (!disp->cleanup)
-		event_add(disp->otd, disp, OTD_EV_RENDER);
+		wlr_drm_add_event(disp->renderer->backend, disp, DRM_EV_RENDER);
 }
 
-void destroy_display_renderer(struct otd *otd, struct otd_display *disp)
+void wlr_drm_display_free(struct wlr_drm_display *disp)
 {
-	if (!otd || !disp || disp->state != OTD_DISP_CONNECTED)
+	if (!disp || disp->state != DRM_DISP_CONNECTED)
 		return;
 
+	struct wlr_drm_renderer *renderer = disp->renderer;
+
 	drmModeCrtc *crtc = disp->old_crtc;
 	if (crtc) {
+		// Wait for exising page flips to finish
+
 		drmEventContext event = {
 			.version = DRM_EVENT_CONTEXT_VERSION,
 			.page_flip_handler = page_flip_handler,
@@ -420,45 +436,45 @@ void destroy_display_renderer(struct otd *otd, struct otd_display *disp)
 
 		disp->cleanup = true;
 		while (disp->pageflip_pending)
-			drmHandleEvent(otd->fd, &event);
+			drmHandleEvent(renderer->fd, &event);
 
-		drmModeSetCrtc(otd->fd, crtc->crtc_id, crtc->buffer_id,
+		drmModeSetCrtc(renderer->fd, crtc->crtc_id, crtc->buffer_id,
 			       crtc->x, crtc->y, &disp->connector,
 			       1, &crtc->mode);
 		drmModeFreeCrtc(crtc);
 	}
 
-	eglDestroySurface(otd->egl.disp, disp->egl);
+	eglDestroySurface(renderer->egl.disp, disp->egl);
 	gbm_surface_destroy(disp->gbm);
 
 	free(disp->modes);
 }
 
-void get_drm_event(struct otd *otd)
+void wlr_drm_event(int fd)
 {
 	drmEventContext event = {
 		.version = DRM_EVENT_CONTEXT_VERSION,
 		.page_flip_handler = page_flip_handler,
 	};
 
-	drmHandleEvent(otd->fd, &event);
+	drmHandleEvent(fd, &event);
 }
 
-void rendering_begin(struct otd_display *disp)
+void wlr_drm_display_begin(struct wlr_drm_display *disp)
 {
-	struct otd *otd = disp->otd;
-	eglMakeCurrent(otd->egl.disp, disp->egl, disp->egl, otd->egl.context);
+	struct wlr_drm_renderer *renderer = disp->renderer;
+	eglMakeCurrent(renderer->egl.disp, disp->egl, disp->egl, renderer->egl.context);
 }
 
-void rendering_end(struct otd_display *disp)
+void wlr_drm_display_end(struct wlr_drm_display *disp)
 {
-	struct otd *otd = disp->otd;
-	eglSwapBuffers(otd->egl.disp, disp->egl);
+	struct wlr_drm_renderer *renderer = disp->renderer;
+	eglSwapBuffers(renderer->egl.disp, disp->egl);
 
 	struct gbm_bo *bo = gbm_surface_lock_front_buffer(disp->gbm);
-	uint32_t fb_id = get_fb_for_bo(otd->fd, bo);
+	uint32_t fb_id = get_fb_for_bo(renderer->fd, bo);
 
-	drmModePageFlip(otd->fd, disp->crtc, fb_id, DRM_MODE_PAGE_FLIP_EVENT, disp);
+	drmModePageFlip(renderer->fd, disp->crtc, fb_id, DRM_MODE_PAGE_FLIP_EVENT, disp);
 
 	gbm_surface_release_buffer(disp->gbm, bo);
 
diff --git a/backend/drm/event.c b/backend/drm/event.c
index 34679514..db17b5b7 100644
--- a/backend/drm/event.c
+++ b/backend/drm/event.c
@@ -1,47 +1,48 @@
-#include "backend/drm/otd.h"
-#include "backend/drm/event.h"
-#include "backend/drm/drm.h"
-#include "backend/drm/udev.h"
-
 #include <stdbool.h>
 #include <stdlib.h>
 #include <poll.h>
 
-static inline void event_swap(struct otd_event *a, struct otd_event *b)
+#include "backend/drm/backend.h"
+#include "backend/drm/event.h"
+#include "backend/drm/drm.h"
+#include "backend/drm/udev.h"
+
+static inline void event_swap(struct wlr_drm_event *a, struct wlr_drm_event *b)
 {
-	struct otd_event tmp = *a;
+	struct wlr_drm_event tmp = *a;
 	*a = *b;
 	*b = tmp;
 }
 
-bool otd_get_event(struct otd *otd, struct otd_event *restrict ret)
+bool wlr_drm_get_event(struct wlr_drm_backend *backend,
+		struct wlr_drm_event *restrict ret)
 {
 	struct pollfd fds[] = {
-		{ .fd = otd->fd, .events = POLLIN },
-		{ .fd = otd->udev_fd, .events = POLLIN },
+		{ .fd = backend->fd, .events = POLLIN },
+		{ .fd = backend->udev.mon_fd, .events = POLLIN },
 	};
 
 	while (poll(fds, 2, 0) > 0) {
 		if (fds[0].revents)
-			get_drm_event(otd);
+			wlr_drm_event(backend->fd);
 		if (fds[1].revents)
-			otd_udev_event(otd);
+			wlr_udev_event(backend);
 	}
 
-	if (otd->event_len == 0) {
-		ret->type = OTD_EV_NONE;
+	if (backend->event_len == 0) {
+		ret->type = DRM_EV_NONE;
 		ret->display = NULL;
 		return false;
 	}
 
-	struct otd_event *ev = otd->events;
+	struct wlr_drm_event *ev = backend->events;
 
 	// Downheap
 	*ret = ev[0];
-	ev[0] = ev[--otd->event_len];
+	ev[0] = ev[--backend->event_len];
 
 	size_t i = 0;
-	while (i < otd->event_len / 2) {
+	while (i < backend->event_len / 2) {
 		size_t left = i * 2 + 1;
 		size_t right = i * 2 + 2;
 		size_t max = (ev[left].type > ev[right].type) ? left : right;
@@ -57,27 +58,28 @@ bool otd_get_event(struct otd *otd, struct otd_event *restrict ret)
 	return true;
 }
 
-bool event_add(struct otd *otd, struct otd_display *disp, enum otd_event_type type)
+bool wlr_drm_add_event(struct wlr_drm_backend *backend,
+		struct wlr_drm_display *disp, enum wlr_drm_event_type type)
 {
-	if (type == OTD_EV_NONE)
+	if (type == DRM_EV_NONE)
 		return true;
 
-	if (otd->event_len == otd->event_cap) {
-		size_t new_size = (otd->event_cap == 0) ? 8 : otd->event_cap * 2;
+	if (backend->event_len == backend->event_cap) {
+		size_t new_size = (backend->event_cap == 0) ? 8 : backend->event_cap * 2;
 
-		struct otd_event *new = realloc(otd->events, sizeof *new * new_size);
+		struct wlr_drm_event *new = realloc(backend->events, sizeof *new * new_size);
 		if (!new) {
 			return false;
 		}
 
-		otd->event_cap = new_size;
-		otd->events = new;
+		backend->event_cap = new_size;
+		backend->events = new;
 	}
 
-	struct otd_event *ev = otd->events;
+	struct wlr_drm_event *ev = backend->events;
 
 	// Upheap
-	size_t i = otd->event_len++;
+	size_t i = backend->event_len++;
 	ev[i].type = type;
 	ev[i].display = disp;
 
diff --git a/backend/drm/otd.c b/backend/drm/otd.c
deleted file mode 100644
index f5960793..00000000
--- a/backend/drm/otd.c
+++ /dev/null
@@ -1,71 +0,0 @@
-#include <unistd.h>
-#include <stdlib.h>
-#include <stdio.h>
-
-#include "backend/drm/otd.h"
-#include "backend/drm/drm.h"
-#include "backend/drm/event.h"
-#include "backend/drm/session.h"
-#include "backend/drm/udev.h"
-
-struct otd *otd_start(void)
-{
-	struct otd *otd = calloc(1, sizeof *otd);
-	if (!otd)
-		return NULL;
-
-	if (!otd_new_session(otd)) {
-		fprintf(stderr, "Could not create session\n");
-		goto error;
-	}
-
-	if (!otd_udev_start(otd)) {
-		fprintf(stderr, "Could not start udev\n");
-		goto error_session;
-	}
-
-	otd_udev_find_gpu(otd);
-	if (otd->fd == -1) {
-		fprintf(stderr, "Could not open GPU\n");
-		goto error_udev;
-	}
-
-	if (!init_renderer(otd)) {
-		fprintf(stderr, "Could not initalise renderer\n");
-		goto error_fd;
-	}
-
-	scan_connectors(otd);
-
-	return otd;
-
-error_fd:
-	release_device(otd, otd->fd);
-error_udev:
-	otd_udev_finish(otd);
-error_session:
-	otd_close_session(otd);
-error:
-	free(otd);
-	return NULL;
-}
-
-void otd_finish(struct otd *otd)
-{
-	if (!otd)
-		return;
-
-	for (size_t i = 0; i < otd->display_len; ++i) {
-		destroy_display_renderer(otd, &otd->displays[i]);
-	}
-
-	destroy_renderer(otd);
-	otd_close_session(otd);
-	otd_udev_finish(otd);
-
-	close(otd->fd);
-	free(otd->events);
-	free(otd->displays);
-	free(otd);
-}
-
diff --git a/backend/drm/session.c b/backend/drm/session.c
index 261c5ac6..285f31b9 100644
--- a/backend/drm/session.c
+++ b/backend/drm/session.c
@@ -11,18 +11,17 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include "backend/drm/backend.h"
 #include "backend/drm/session.h"
-#include "backend/drm/otd.h"
 
-int take_device(struct otd *restrict otd,
-		       const char *restrict path,
-		       bool *restrict paused_out)
+int wlr_session_take_device(struct wlr_session *restrict session,
+		const char *restrict path,
+		bool *restrict paused_out)
 {
 	int ret;
 	int fd = -1;
 	sd_bus_message *msg = NULL;
 	sd_bus_error error = SD_BUS_ERROR_NULL;
-	struct otd_session *s = &otd->session;
 
 	struct stat st;
 	if (stat(path, &st) < 0) {
@@ -30,9 +29,9 @@ int take_device(struct otd *restrict otd,
 		return -1;
 	}
 
-	ret = sd_bus_call_method(s->bus,
+	ret = sd_bus_call_method(session->bus,
 				 "org.freedesktop.login1",
-				 s->path,
+				 session->path,
 				 "org.freedesktop.login1.Session",
 				 "TakeDevice",
 				 &error, &msg,
@@ -62,12 +61,11 @@ error:
 	return fd;
 }
 
-void release_device(struct otd *otd, int fd)
+void wlr_session_release_device(struct wlr_session *session, int fd)
 {
 	int ret;
 	sd_bus_message *msg = NULL;
 	sd_bus_error error = SD_BUS_ERROR_NULL;
-	struct otd_session *s = &otd->session;
 
 	struct stat st;
 	if (fstat(fd, &st) < 0) {
@@ -75,9 +73,9 @@ void release_device(struct otd *otd, int fd)
 		return;
 	}
 
-	ret = sd_bus_call_method(s->bus,
+	ret = sd_bus_call_method(session->bus,
 				 "org.freedesktop.login1",
-				 s->path,
+				 session->path,
 				 "org.freedesktop.login1.Session",
 				 "ReleaseDevice",
 				 &error, &msg,
@@ -90,16 +88,15 @@ void release_device(struct otd *otd, int fd)
 	sd_bus_message_unref(msg);
 }
 
-static bool session_activate(struct otd *otd)
+static bool session_activate(struct wlr_session *session)
 {
 	int ret;
 	sd_bus_message *msg = NULL;
 	sd_bus_error error = SD_BUS_ERROR_NULL;
-	struct otd_session *s = &otd->session;
 
-	ret = sd_bus_call_method(s->bus,
+	ret = sd_bus_call_method(session->bus,
 				 "org.freedesktop.login1",
-				 s->path,
+				 session->path,
 				 "org.freedesktop.login1.Session",
 				 "Activate",
 				 &error, &msg,
@@ -113,16 +110,15 @@ static bool session_activate(struct otd *otd)
 	return ret >= 0;
 }
 
-static bool take_control(struct otd *otd)
+static bool take_control(struct wlr_session *session)
 {
 	int ret;
 	sd_bus_message *msg = NULL;
 	sd_bus_error error = SD_BUS_ERROR_NULL;
-	struct otd_session *s = &otd->session;
 
-	ret = sd_bus_call_method(s->bus,
+	ret = sd_bus_call_method(session->bus,
 				 "org.freedesktop.login1",
-				 s->path,
+				 session->path,
 				 "org.freedesktop.login1.Session",
 				 "TakeControl",
 				 &error, &msg,
@@ -136,16 +132,15 @@ static bool take_control(struct otd *otd)
 	return ret >= 0;
 }
 
-static void release_control(struct otd *otd)
+static void release_control(struct wlr_session *session)
 {
 	int ret;
 	sd_bus_message *msg = NULL;
 	sd_bus_error error = SD_BUS_ERROR_NULL;
-	struct otd_session *s = &otd->session;
 
-	ret = sd_bus_call_method(s->bus,
+	ret = sd_bus_call_method(session->bus,
 				 "org.freedesktop.login1",
-				 s->path,
+				 session->path,
 				 "org.freedesktop.login1.Session",
 				 "ReleaseControl",
 				 &error, &msg,
@@ -158,29 +153,27 @@ static void release_control(struct otd *otd)
 	sd_bus_message_unref(msg);
 }
 
-void otd_close_session(struct otd *otd)
+void wlr_session_end(struct wlr_session *session)
 {
-	release_device(otd, otd->fd);
-	release_control(otd);
+	release_control(session);
 
-	sd_bus_unref(otd->session.bus);
-	free(otd->session.id);
-	free(otd->session.path);
-	free(otd->session.seat);
+	sd_bus_unref(session->bus);
+	free(session->id);
+	free(session->path);
+	free(session->seat);
 }
 
-bool otd_new_session(struct otd *otd)
+bool wlr_session_start(struct wlr_session *session)
 {
 	int ret;
-	struct otd_session *s = &otd->session;
 
-	ret = sd_pid_get_session(getpid(), &s->id);
+	ret = sd_pid_get_session(getpid(), &session->id);
 	if (ret < 0) {
 		fprintf(stderr, "Could not get session\n");
 		goto error;
 	}
 
-	ret = sd_session_get_seat(s->id, &s->seat);
+	ret = sd_session_get_seat(session->id, &session->seat);
 	if (ret < 0) {
 		fprintf(stderr, "Could not get seat\n");
 		goto error;
@@ -189,26 +182,26 @@ bool otd_new_session(struct otd *otd)
 	// This could be done using asprintf, but I don't want to define _GNU_SOURCE
 
 	const char *fmt = "/org/freedesktop/login1/session/%s";
-	int len = snprintf(NULL, 0, fmt, s->id);
+	int len = snprintf(NULL, 0, fmt, session->id);
 
-	s->path = malloc(len + 1);
-	if (!s->path)
+	session->path = malloc(len + 1);
+	if (!session->path)
 		goto error;
 
-	sprintf(s->path, fmt, s->id);
+	sprintf(session->path, fmt, session->id);
 
-	ret = sd_bus_open_system(&s->bus);
+	ret = sd_bus_open_system(&session->bus);
 	if (ret < 0) {
 		fprintf(stderr, "Could not open bus\n");
 		goto error;
 	}
 
-	if (!session_activate(otd)) {
+	if (!session_activate(session)) {
 		fprintf(stderr, "Could not activate session\n");
 		goto error_bus;
 	}
 
-	if (!take_control(otd)) {
+	if (!take_control(session)) {
 		fprintf(stderr, "Could not take control of session\n");
 		goto error_bus;
 	}
@@ -216,11 +209,11 @@ bool otd_new_session(struct otd *otd)
 	return true;
 
 error_bus:
-	sd_bus_unref(s->bus);
+	sd_bus_unref(session->bus);
 
 error:
-	free(s->path);
-	free(s->id);
-	free(s->seat);
+	free(session->path);
+	free(session->id);
+	free(session->seat);
 	return false;
 }
diff --git a/backend/drm/udev.c b/backend/drm/udev.c
index 5f20a1be..c5440303 100644
--- a/backend/drm/udev.c
+++ b/backend/drm/udev.c
@@ -8,12 +8,15 @@
 #include <xf86drm.h>
 #include <xf86drmMode.h>
 
-#include "backend/drm/otd.h"
+#include "backend/drm/backend.h"
 #include "backend/drm/udev.h"
 #include "backend/drm/session.h"
 #include "backend/drm/drm.h"
 
-static bool device_is_kms(struct otd *otd, struct udev_device *dev)
+static bool device_is_kms(struct wlr_udev *udev,
+		struct wlr_session *session,
+		struct udev_device *dev,
+		int *fd_out)
 {
 	const char *path = udev_device_get_devnode(dev);
 	int fd;
@@ -21,7 +24,7 @@ static bool device_is_kms(struct otd *otd, struct udev_device *dev)
 	if (!path)
 		return false;
 
-	fd = take_device(otd, path, &otd->paused);
+	fd = wlr_session_take_device(session, path, NULL);
 	if (fd < 0)
 		return false;
 
@@ -33,13 +36,13 @@ static bool device_is_kms(struct otd *otd, struct udev_device *dev)
 	    res->count_encoders <= 0)
 		goto out_res;
 
-	if (otd->fd >= 0) {
-		release_device(otd, otd->fd);
-		free(otd->drm_path);
+	if (*fd_out >= 0) {
+		wlr_session_release_device(session, *fd_out);
+		free(udev->drm_path);
 	}
 
-	otd->fd = fd;
-	otd->drm_path = strdup(path);
+	*fd_out = fd;
+	udev->drm_path = strdup(path);
 
 	drmModeFreeResources(res);
 	return true;
@@ -47,18 +50,17 @@ static bool device_is_kms(struct otd *otd, struct udev_device *dev)
 out_res:
 	drmModeFreeResources(res);
 out_fd:
-	release_device(otd, fd);
+	wlr_session_release_device(session, fd);
 	return false;
 }
 
-void otd_udev_find_gpu(struct otd *otd)
+int wlr_udev_find_gpu(struct wlr_udev *udev, struct wlr_session *session)
 {
-	struct udev *udev = otd->udev;
-	otd->fd = -1;
+	int fd = -1;
 
-	struct udev_enumerate *en = udev_enumerate_new(udev);
+	struct udev_enumerate *en = udev_enumerate_new(udev->udev);
 	if (!en)
-		return;
+		return -1;
 
 	udev_enumerate_add_match_subsystem(en, "drm");
 	udev_enumerate_add_match_sysname(en, "card[0-9]*");
@@ -69,14 +71,14 @@ void otd_udev_find_gpu(struct otd *otd)
 		bool is_boot_vga = false;
 
 		const char *path = udev_list_entry_get_name(entry);
-		struct udev_device *dev = udev_device_new_from_syspath(udev, path);
+		struct udev_device *dev = udev_device_new_from_syspath(udev->udev, path);
 		if (!dev)
 			continue;
 
 		const char *seat = udev_device_get_property_value(dev, "ID_SEAT");
 		if (!seat)
 			seat = "seat0";
-		if (strcmp(otd->session.seat, seat) != 0) {
+		if (strcmp(session->seat, seat) != 0) {
 			udev_device_unref(dev);
 			continue;
 		}
@@ -92,12 +94,12 @@ void otd_udev_find_gpu(struct otd *otd)
 			udev_device_unref(pci);
 		}
 
-		if (!is_boot_vga && otd->fd >= 0) {
+		if (!is_boot_vga && fd >= 0) {
 			udev_device_unref(dev);
 			continue;
 		}
 
-		if (!device_is_kms(otd, dev)) {
+		if (!device_is_kms(udev, session, dev, &fd)) {
 			udev_device_unref(dev);
 			continue;
 		}
@@ -108,52 +110,59 @@ void otd_udev_find_gpu(struct otd *otd)
 	}
 
 	udev_enumerate_unref(en);
+
+	return fd;
 }
 
-bool otd_udev_start(struct otd *otd)
+bool wlr_udev_init(struct wlr_udev *udev)
 {
-	otd->udev = udev_new();
-	if (!otd->udev)
+	udev->udev = udev_new();
+	if (!udev->udev)
 		return false;
 
-	otd->mon = udev_monitor_new_from_netlink(otd->udev, "udev");
-	if (!otd->mon) {
-		udev_unref(otd->udev);
+	udev->mon = udev_monitor_new_from_netlink(udev->udev, "udev");
+	if (!udev->mon) {
+		udev_unref(udev->udev);
 		return false;
 	}
 
-	udev_monitor_filter_add_match_subsystem_devtype(otd->mon, "drm", NULL);
-	udev_monitor_enable_receiving(otd->mon);
+	udev_monitor_filter_add_match_subsystem_devtype(udev->mon, "drm", NULL);
+	udev_monitor_enable_receiving(udev->mon);
 
-	otd->udev_fd = udev_monitor_get_fd(otd->mon);
+	udev->mon_fd = udev_monitor_get_fd(udev->mon);
+	udev->drm_path = NULL;
 
 	return true;
 }
 
-void otd_udev_finish(struct otd *otd)
+void wlr_udev_free(struct wlr_udev *udev)
+
 {
-	if (!otd)
+	if (!udev)
 		return;
 
-	udev_monitor_unref(otd->mon);
-	udev_unref(otd->udev);
+	udev_monitor_unref(udev->mon);
+	udev_unref(udev->udev);
+	free(udev->drm_path);
 }
 
-void otd_udev_event(struct otd *otd)
+void wlr_udev_event(struct wlr_drm_backend *backend)
 {
-	struct udev_device *dev = udev_monitor_receive_device(otd->mon);
+	struct wlr_udev *udev = &backend->udev;
+
+	struct udev_device *dev = udev_monitor_receive_device(udev->mon);
 	if (!dev)
 		return;
 
 	const char *path = udev_device_get_devnode(dev);
-	if (!path || strcmp(path, otd->drm_path) != 0)
+	if (!path || strcmp(path, udev->drm_path) != 0)
 		goto out;
 
 	const char *action = udev_device_get_action(dev);
 	if (!action || strcmp(action, "change") != 0)
 		goto out;
 
-	scan_connectors(otd);
+	wlr_drm_scan_connectors(backend);
 
 out:
 	udev_device_unref(dev);
diff --git a/include/backend/drm/backend.h b/include/backend/drm/backend.h
new file mode 100644
index 00000000..caa18bcc
--- /dev/null
+++ b/include/backend/drm/backend.h
@@ -0,0 +1,37 @@
+#ifndef DRM_BACKEND_H
+#define DRM_BACKEND_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <EGL/egl.h>
+#include <gbm.h>
+#include <libudev.h>
+
+#include "session.h"
+#include "udev.h"
+#include "event.h"
+#include "drm.h"
+
+struct wlr_drm_backend {
+	int fd;
+	bool paused;
+
+	// Priority Queue (Max-heap)
+	size_t event_cap;
+	size_t event_len;
+	struct wlr_drm_event *events;
+
+	size_t display_len;
+	struct wlr_drm_display *displays;
+
+	uint32_t taken_crtcs;
+
+	struct wlr_drm_renderer renderer;
+	struct wlr_session session;
+	struct wlr_udev udev;
+};
+
+struct wlr_drm_backend *wlr_drm_backend_init(void);
+void wlr_drm_backend_free(struct wlr_drm_backend *backend);
+
+#endif
diff --git a/include/backend/drm/drm.h b/include/backend/drm/drm.h
index 8744b440..bd3d4105 100644
--- a/include/backend/drm/drm.h
+++ b/include/backend/drm/drm.h
@@ -7,17 +7,35 @@
 #include <EGL/egl.h>
 #include <gbm.h>
 
-enum otd_display_state {
-	OTD_DISP_INVALID,
-	OTD_DISP_DISCONNECTED,
-	OTD_DISP_NEEDS_MODESET,
-	OTD_DISP_CONNECTED,
+struct wlr_drm_renderer {
+	int fd;
+
+	// Currently here so that rendering has access to the event queue.
+	// Ideally this is will be removed later once the way events are
+	// handled is changed.
+	struct wlr_drm_backend *backend;
+
+	struct gbm_device *gbm;
+	struct {
+		EGLDisplay disp;
+		EGLConfig conf;
+		EGLContext context;
+	} egl;
 };
 
-struct otd_display {
-	struct otd *otd;
+bool wlr_drm_renderer_init(struct wlr_drm_renderer *renderer,
+		struct wlr_drm_backend *backend, int fd);
+void wlr_drm_renderer_free(struct wlr_drm_renderer *renderer);
 
-	enum otd_display_state state;
+enum wlr_drm_display_state {
+	DRM_DISP_INVALID,
+	DRM_DISP_DISCONNECTED,
+	DRM_DISP_NEEDS_MODESET,
+	DRM_DISP_CONNECTED,
+};
+
+struct wlr_drm_display {
+	enum wlr_drm_display_state state;
 	uint32_t connector;
 	char name[16];
 
@@ -31,24 +49,22 @@ struct otd_display {
 	uint32_t crtc;
 	drmModeCrtc *old_crtc;
 
+	struct wlr_drm_renderer *renderer;
 	struct gbm_surface *gbm;
 	EGLSurface *egl;
-	uint32_t fb_id;
 
 	bool pageflip_pending;
 	bool cleanup;
 };
 
-bool init_renderer(struct otd *otd);
-void destroy_renderer(struct otd *otd);
-
-void scan_connectors(struct otd *otd);
-bool modeset_str(struct otd *otd, struct otd_display *disp, const char *str);
-void destroy_display_renderer(struct otd *otd, struct otd_display *disp);
+bool wlr_drm_display_modeset(struct wlr_drm_backend *backend,
+		struct wlr_drm_display *disp, const char *str);
+void wlr_drm_display_free(struct wlr_drm_display *disp);
 
-void get_drm_event(struct otd *otd);
+void wlr_drm_display_begin(struct wlr_drm_display *disp);
+void wlr_drm_display_end(struct wlr_drm_display *disp);
 
-void rendering_begin(struct otd_display *disp);
-void rendering_end(struct otd_display *disp);
+void wlr_drm_scan_connectors(struct wlr_drm_backend *backend);
+void wlr_drm_event(int fd);
 
 #endif
diff --git a/include/backend/drm/event.h b/include/backend/drm/event.h
index fc4f6f9a..2155bd32 100644
--- a/include/backend/drm/event.h
+++ b/include/backend/drm/event.h
@@ -2,20 +2,24 @@
 #define EVENT_H
 
 #include <stdbool.h>
+#include "drm.h"
 
-enum otd_event_type {
-	OTD_EV_NONE,
-	OTD_EV_RENDER,
-	OTD_EV_DISPLAY_REM,
-	OTD_EV_DISPLAY_ADD,
+enum wlr_drm_event_type {
+	DRM_EV_NONE,
+	DRM_EV_RENDER,
+	DRM_EV_DISPLAY_REM,
+	DRM_EV_DISPLAY_ADD,
 };
 
-struct otd_event {
-	enum otd_event_type type;
-	struct otd_display *display;
+struct wlr_drm_event {
+	enum wlr_drm_event_type type;
+	struct wlr_drm_display *display;
 };
 
-bool otd_get_event(struct otd *otd, struct otd_event *restrict ret);
-bool event_add(struct otd *otd, struct otd_display *disp, enum otd_event_type type);
+struct wlr_drm_backend;
+bool wlr_drm_get_event(struct wlr_drm_backend *backend,
+		struct wlr_drm_event *restrict ret);
+bool wlr_drm_add_event(struct wlr_drm_backend *backend,
+		struct wlr_drm_display *disp, enum wlr_drm_event_type type);
 
 #endif
diff --git a/include/backend/drm/otd.h b/include/backend/drm/otd.h
deleted file mode 100644
index eef0e991..00000000
--- a/include/backend/drm/otd.h
+++ /dev/null
@@ -1,44 +0,0 @@
-#ifndef LIBOTD_H
-#define LIBOTD_H
-
-#include <stdbool.h>
-#include <stddef.h>
-#include <EGL/egl.h>
-#include <gbm.h>
-#include <libudev.h>
-
-#include "session.h"
-
-struct otd {
-	int fd;
-	bool paused;
-
-	// Priority Queue (Max-heap)
-	size_t event_cap;
-	size_t event_len;
-	struct otd_event *events;
-
-	size_t display_len;
-	struct otd_display *displays;
-
-	uint32_t taken_crtcs;
-
-	struct gbm_device *gbm;
-	struct {
-		EGLDisplay disp;
-		EGLConfig conf;
-		EGLContext context;
-	} egl;
-
-	struct otd_session session;
-
-	struct udev *udev;
-	struct udev_monitor *mon;
-	int udev_fd;
-	char *drm_path;
-};
-
-struct otd *otd_start(void);
-void otd_finish(struct otd *otd);
-
-#endif
diff --git a/include/backend/drm/session.h b/include/backend/drm/session.h
index c21900e9..6936b19a 100644
--- a/include/backend/drm/session.h
+++ b/include/backend/drm/session.h
@@ -4,22 +4,21 @@
 #include <systemd/sd-bus.h>
 #include <stdbool.h>
 
-struct otd_session {
+struct wlr_session {
+	sd_bus *bus;
+
 	char *id;
 	char *path;
 	char *seat;
-
-	sd_bus *bus;
 };
 
-struct otd;
-bool otd_new_session(struct otd *otd);
-void otd_close_session(struct otd *otd);
+bool wlr_session_start(struct wlr_session *session);
+void wlr_session_end(struct wlr_session *session);
 
-int take_device(struct otd *restrict otd,
-		       const char *restrict path,
-		       bool *restrict paused_out);
+int wlr_session_take_device(struct wlr_session *restrict session,
+		const char *restrict path,
+		bool *restrict paused_out);
 
-void release_device(struct otd *otd, int fd);
+void wlr_session_release_device(struct wlr_session *session, int fd);
 
 #endif
diff --git a/include/backend/drm/udev.h b/include/backend/drm/udev.h
index 9bd4c0d0..6b10c9ec 100644
--- a/include/backend/drm/udev.h
+++ b/include/backend/drm/udev.h
@@ -1,9 +1,22 @@
 #ifndef UDEV_H
 #define UDEV_H
 
-bool otd_udev_start(struct otd *otd);
-void otd_udev_finish(struct otd *otd);
-void otd_udev_find_gpu(struct otd *otd);
-void otd_udev_event(struct otd *otd);
+#include <libudev.h>
+
+#include "backend/drm/session.h"
+
+struct wlr_udev {
+	struct udev *udev;
+	struct udev_monitor *mon;
+	int mon_fd;
+	char *drm_path;
+};
+
+bool wlr_udev_init(struct wlr_udev *udev);
+void wlr_udev_free(struct wlr_udev *udev);
+int wlr_udev_find_gpu(struct wlr_udev *udev, struct wlr_session *session);
+
+struct wlr_drm_backend;
+void wlr_udev_event(struct wlr_drm_backend *backend);
 
 #endif