wlroots-hyprland/backend/headless/output.c
Simon Ser 507d9bc19e Add wlr_output_impl.rollback
Most of the pending output state is not forwarded to the backend prior
to an output commit. For instance, wlr_output_set_mode just stashes the
mode without calling any wlr_output_impl function.
wlr_output_impl.commit is responsible for applying the pending mode.

However, there are exceptions to this rule. The first one is
wlr_output_attach_render. It won't go away before renderer v6 is
complete, because it needs to set the current EGL surface.

The second one is wlr_output_attach_buffer.
wlr_output_impl.attach_buffer is removed in [1].

When wlr_output_rollback is called, all pending state is supposed to be
cleared. This works for all the state except the two exceptions
mentionned above. To fix this, introduce wlr_output_impl.rollback.

Right now, the backend resets the current EGL surface. This prevents GL
commands from affecting the output after wlr_output_rollback.

This patch is required for FBO-based outputs to work properly. The
compositor might be using FBOs for its own purposes [2], having leftover
FBO state can have bad consequences.

[1]: https://github.com/swaywm/wlroots/pull/2097
[2]: https://github.com/swaywm/wlroots/pull/2063#issuecomment-597614312
2020-04-08 17:33:00 +02:00

194 lines
5.8 KiB
C

#include <assert.h>
#include <stdlib.h>
#include <wlr/interfaces/wlr_output.h>
#include <wlr/render/wlr_renderer.h>
#include <wlr/util/log.h>
#include "backend/headless.h"
#include "util/signal.h"
static struct wlr_headless_output *headless_output_from_output(
struct wlr_output *wlr_output) {
assert(wlr_output_is_headless(wlr_output));
return (struct wlr_headless_output *)wlr_output;
}
static EGLSurface egl_create_surface(struct wlr_egl *egl, unsigned int width,
unsigned int height) {
EGLint attribs[] = {EGL_WIDTH, width, EGL_HEIGHT, height, EGL_NONE};
EGLSurface surf = eglCreatePbufferSurface(egl->display, egl->config, attribs);
if (surf == EGL_NO_SURFACE) {
wlr_log(WLR_ERROR, "Failed to create EGL surface");
return EGL_NO_SURFACE;
}
return surf;
}
static bool output_set_custom_mode(struct wlr_output *wlr_output, int32_t width,
int32_t height, int32_t refresh) {
struct wlr_headless_output *output =
headless_output_from_output(wlr_output);
struct wlr_headless_backend *backend = output->backend;
if (refresh <= 0) {
refresh = HEADLESS_DEFAULT_REFRESH;
}
wlr_egl_destroy_surface(&backend->egl, output->egl_surface);
output->egl_surface = egl_create_surface(&backend->egl, width, height);
if (output->egl_surface == EGL_NO_SURFACE) {
wlr_log(WLR_ERROR, "Failed to recreate EGL surface");
wlr_output_destroy(wlr_output);
return false;
}
output->frame_delay = 1000000 / refresh;
wlr_output_update_custom_mode(&output->wlr_output, width, height, refresh);
return true;
}
static bool output_attach_render(struct wlr_output *wlr_output,
int *buffer_age) {
struct wlr_headless_output *output =
headless_output_from_output(wlr_output);
return wlr_egl_make_current(&output->backend->egl, output->egl_surface,
buffer_age);
}
static bool output_test(struct wlr_output *wlr_output) {
if (wlr_output->pending.committed & WLR_OUTPUT_STATE_ENABLED) {
wlr_log(WLR_DEBUG, "Cannot disable a headless output");
return false;
}
if (wlr_output->pending.committed & WLR_OUTPUT_STATE_MODE) {
assert(wlr_output->pending.mode_type == WLR_OUTPUT_STATE_MODE_CUSTOM);
}
return true;
}
static bool output_commit(struct wlr_output *wlr_output) {
struct wlr_headless_output *output =
headless_output_from_output(wlr_output);
if (!output_test(wlr_output)) {
return false;
}
if (wlr_output->pending.committed & WLR_OUTPUT_STATE_MODE) {
if (!output_set_custom_mode(wlr_output,
wlr_output->pending.custom_mode.width,
wlr_output->pending.custom_mode.height,
wlr_output->pending.custom_mode.refresh)) {
return false;
}
}
if (wlr_output->pending.committed & WLR_OUTPUT_STATE_BUFFER) {
// Nothing needs to be done for pbuffers
wlr_output_send_present(wlr_output, NULL);
}
wlr_egl_make_current(&output->backend->egl, EGL_NO_SURFACE, NULL);
return true;
}
static void output_rollback(struct wlr_output *wlr_output) {
struct wlr_headless_output *output =
headless_output_from_output(wlr_output);
wlr_egl_make_current(&output->backend->egl, EGL_NO_SURFACE, NULL);
}
static void output_destroy(struct wlr_output *wlr_output) {
struct wlr_headless_output *output =
headless_output_from_output(wlr_output);
wl_list_remove(&output->link);
wl_event_source_remove(output->frame_timer);
wlr_egl_destroy_surface(&output->backend->egl, output->egl_surface);
free(output);
}
static const struct wlr_output_impl output_impl = {
.destroy = output_destroy,
.attach_render = output_attach_render,
.commit = output_commit,
.rollback = output_rollback,
};
bool wlr_output_is_headless(struct wlr_output *wlr_output) {
return wlr_output->impl == &output_impl;
}
static int signal_frame(void *data) {
struct wlr_headless_output *output = data;
wlr_output_send_frame(&output->wlr_output);
wl_event_source_timer_update(output->frame_timer, output->frame_delay);
return 0;
}
struct wlr_output *wlr_headless_add_output(struct wlr_backend *wlr_backend,
unsigned int width, unsigned int height) {
struct wlr_headless_backend *backend =
headless_backend_from_backend(wlr_backend);
struct wlr_headless_output *output =
calloc(1, sizeof(struct wlr_headless_output));
if (output == NULL) {
wlr_log(WLR_ERROR, "Failed to allocate wlr_headless_output");
return NULL;
}
output->backend = backend;
wlr_output_init(&output->wlr_output, &backend->backend, &output_impl,
backend->display);
struct wlr_output *wlr_output = &output->wlr_output;
output->egl_surface = egl_create_surface(&backend->egl, width, height);
if (output->egl_surface == EGL_NO_SURFACE) {
wlr_log(WLR_ERROR, "Failed to create EGL surface");
goto error;
}
output_set_custom_mode(wlr_output, width, height, 0);
strncpy(wlr_output->make, "headless", sizeof(wlr_output->make));
strncpy(wlr_output->model, "headless", sizeof(wlr_output->model));
snprintf(wlr_output->name, sizeof(wlr_output->name), "HEADLESS-%zd",
++backend->last_output_num);
char description[128];
snprintf(description, sizeof(description),
"Headless output %zd", backend->last_output_num);
wlr_output_set_description(wlr_output, description);
if (!wlr_egl_make_current(&output->backend->egl, output->egl_surface,
NULL)) {
goto error;
}
wlr_renderer_begin(backend->renderer, wlr_output->width, wlr_output->height);
wlr_renderer_clear(backend->renderer, (float[]){ 1.0, 1.0, 1.0, 1.0 });
wlr_renderer_end(backend->renderer);
struct wl_event_loop *ev = wl_display_get_event_loop(backend->display);
output->frame_timer = wl_event_loop_add_timer(ev, signal_frame, output);
wl_list_insert(&backend->outputs, &output->link);
if (backend->started) {
wl_event_source_timer_update(output->frame_timer, output->frame_delay);
wlr_output_update_enabled(wlr_output, true);
wlr_signal_emit_safe(&backend->backend.events.new_output, wlr_output);
}
return wlr_output;
error:
wlr_output_destroy(&output->wlr_output);
return NULL;
}