Initialize headless backend

1 files changed, 156 insertions, 0 deletions

diff --git a/backend/headless/backend.c b/backend/headless/backend.c
new file mode 100644
index 00000000..c60eb7e5
--- /dev/null
+++ b/backend/headless/backend.c
@@ -0,0 +1,156 @@
+#include <stdlib.h>
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#include <wlr/util/log.h>
+#include "backend/headless.h"
+#include "glapi.h"
+
+static bool backend_start(struct wlr_backend *wlr_backend) {
+	struct wlr_headless_backend *backend =
+		(struct wlr_headless_backend *)wlr_backend;
+	wlr_log(L_INFO, "Initializating headless backend");
+
+	// TODO
+	for (size_t i = 0; i < 1; ++i) {
+		wlr_headless_add_output(&backend->backend, 1280, 720);
+	}
+
+	return true;
+}
+
+static void backend_destroy(struct wlr_backend *wlr_backend) {
+	struct wlr_headless_backend *backend =
+		(struct wlr_headless_backend *)wlr_backend;
+	if (!wlr_backend) {
+		return;
+	}
+
+	wl_list_remove(&backend->display_destroy.link);
+	wlr_egl_finish(&backend->egl);
+	free(backend);
+}
+
+static struct wlr_egl *backend_get_egl(struct wlr_backend *wlr_backend) {
+	struct wlr_headless_backend *backend =
+		(struct wlr_headless_backend *)wlr_backend;
+	return &backend->egl;
+}
+
+static const struct wlr_backend_impl backend_impl = {
+	.start = backend_start,
+	.destroy = backend_destroy,
+	.get_egl = backend_get_egl,
+};
+
+static void handle_display_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_headless_backend *backend =
+		wl_container_of(listener, backend, display_destroy);
+	backend_destroy(&backend->backend);
+}
+
+static bool egl_get_config(EGLDisplay disp, EGLConfig *out) {
+	EGLint count = 0, matched = 0, ret;
+
+	ret = eglGetConfigs(disp, NULL, 0, &count);
+	if (ret == EGL_FALSE || count == 0) {
+		wlr_log(L_ERROR, "eglGetConfigs returned no configs");
+		return false;
+	}
+
+	EGLConfig configs[count];
+
+	static const EGLint attribs[] = {
+		EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
+		EGL_NONE,
+	};
+
+	ret = eglChooseConfig(disp, attribs, configs, count, &matched);
+	if (ret == EGL_FALSE) {
+		wlr_log(L_ERROR, "eglChooseConfig failed");
+		return false;
+	}
+
+	// TODO
+	*out = configs[0];
+	return true;
+}
+
+static bool egl_init(struct wlr_egl *egl) {
+	if (!load_glapi()) {
+		return false;
+	}
+
+	if (eglBindAPI(EGL_OPENGL_ES_API) == EGL_FALSE) {
+		wlr_log(L_ERROR, "Failed to bind to the OpenGL ES API: %s", egl_error());
+		goto error;
+	}
+
+	egl->display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+	if (egl->display == EGL_NO_DISPLAY) {
+		wlr_log(L_ERROR, "Failed to create EGL display: %s", egl_error());
+		goto error;
+	}
+
+	EGLint major, minor;
+	if (eglInitialize(egl->display, &major, &minor) == EGL_FALSE) {
+		wlr_log(L_ERROR, "Failed to initialize EGL: %s", egl_error());
+		goto error;
+	}
+
+	if (!egl_get_config(egl->display, &egl->config)) {
+		wlr_log(L_ERROR, "Failed to get EGL config");
+		goto error;
+	}
+
+	static const EGLint attribs[] = {
+		EGL_CONTEXT_CLIENT_VERSION, 2,
+		EGL_NONE,
+	};
+
+	egl->context = eglCreateContext(egl->display, egl->config,
+		EGL_NO_CONTEXT, attribs);
+	if (egl->context == EGL_NO_CONTEXT) {
+		wlr_log(L_ERROR, "Failed to create EGL context: %s", egl_error());
+		goto error;
+	}
+
+	eglMakeCurrent(egl->display, EGL_NO_SURFACE, EGL_NO_SURFACE, egl->context);
+	egl->egl_exts = eglQueryString(egl->display, EGL_EXTENSIONS);
+	if (strstr(egl->egl_exts, "EGL_KHR_image_base") == NULL) {
+		wlr_log(L_ERROR, "Required egl extensions not supported");
+		goto error;
+	}
+
+	egl->gl_exts = (const char*) glGetString(GL_EXTENSIONS);
+	wlr_log(L_INFO, "Using EGL %d.%d", (int)major, (int)minor);
+	wlr_log(L_INFO, "Using %s", glGetString(GL_VERSION));
+	wlr_log(L_INFO, "Supported EGL extensions: %s", egl->egl_exts);
+	wlr_log(L_INFO, "Supported OpenGL ES extensions: %s", egl->gl_exts);
+	return true;
+
+error:
+	eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+	eglTerminate(egl->display);
+	eglReleaseThread();
+	return false;
+}
+
+struct wlr_backend *wlr_headless_backend_create(struct wl_display *display) {
+	wlr_log(L_INFO, "Creating headless backend");
+
+	struct wlr_headless_backend *backend =
+		calloc(1, sizeof(struct wlr_headless_backend));
+	if (!backend) {
+		wlr_log(L_ERROR, "Failed to allocate wlr_headless_backend");
+		return NULL;
+	}
+	wlr_backend_init(&backend->backend, &backend_impl);
+	backend->display = display;
+
+	egl_init(&backend->egl);
+
+	backend->display_destroy.notify = handle_display_destroy;
+	wl_display_add_destroy_listener(display, &backend->display_destroy);
+
+	return &backend->backend;
+}