backend/x11: re-send last buffer on expose event

Instead of requesting a new frame from the compositor when we
receive an expose event, re-submit the last frame. This makes the
X11 backend behave like the other backends and removes the last
wlr_output_update_needs_frame() call in backends, at the cost of
keeping the current buffer locked for potentially a longer time.
This commit is contained in:
Simon Ser 2023-08-16 10:42:56 +02:00
parent 664ec59095
commit 5da9ad3e34
3 changed files with 81 additions and 27 deletions

View file

@ -92,6 +92,7 @@ static void output_destroy(struct wlr_output *wlr_output) {
wlr_pointer_finish(&output->pointer);
wlr_touch_finish(&output->touch);
wlr_buffer_unlock(output->current_buffer);
struct wlr_x11_buffer *buffer, *buffer_tmp;
wl_list_for_each_safe(buffer, buffer_tmp, &output->buffers, link) {
@ -286,6 +287,34 @@ static struct wlr_x11_buffer *get_or_create_x11_buffer(
return create_x11_buffer(output, wlr_buffer);
}
static xcb_xfixes_region_t create_region(struct wlr_x11_backend *x11,
const pixman_region32_t *region) {
int rects_len = 0;
const pixman_box32_t *rects = pixman_region32_rectangles(region, &rects_len);
xcb_rectangle_t *xcb_rects = calloc(rects_len, sizeof(xcb_rectangle_t));
if (!xcb_rects) {
return XCB_NONE;
}
for (int i = 0; i < rects_len; i++) {
const pixman_box32_t *box = &rects[i];
xcb_rects[i] = (struct xcb_rectangle_t){
.x = box->x1,
.y = box->y1,
.width = box->x2 - box->x1,
.height = box->y2 - box->y1,
};
}
xcb_xfixes_region_t x11_region = xcb_generate_id(x11->xcb);
xcb_xfixes_create_region(x11->xcb, x11_region, rects_len, xcb_rects);
free(xcb_rects);
return x11_region;
}
static bool output_commit_buffer(struct wlr_x11_output *output,
const struct wlr_output_state *state) {
struct wlr_x11_backend *x11 = output->x11;
@ -300,29 +329,7 @@ static bool output_commit_buffer(struct wlr_x11_output *output,
xcb_xfixes_region_t region = XCB_NONE;
if (state->committed & WLR_OUTPUT_STATE_DAMAGE) {
pixman_region32_union(&output->exposed, &output->exposed, &state->damage);
int rects_len = 0;
const pixman_box32_t *rects = pixman_region32_rectangles(&output->exposed, &rects_len);
xcb_rectangle_t *xcb_rects = calloc(rects_len, sizeof(xcb_rectangle_t));
if (!xcb_rects) {
goto error;
}
for (int i = 0; i < rects_len; i++) {
const pixman_box32_t *box = &rects[i];
xcb_rects[i] = (struct xcb_rectangle_t){
.x = box->x1,
.y = box->y1,
.width = box->x2 - box->x1,
.height = box->y2 - box->y1,
};
}
region = xcb_generate_id(x11->xcb);
xcb_xfixes_create_region(x11->xcb, region, rects_len, xcb_rects);
free(xcb_rects);
region = create_region(x11, &output->exposed);
}
pixman_region32_clear(&output->exposed);
@ -338,6 +345,9 @@ static bool output_commit_buffer(struct wlr_x11_output *output,
xcb_xfixes_destroy_region(x11->xcb, region);
}
wlr_buffer_unlock(output->current_buffer);
output->current_buffer = wlr_buffer_lock(buffer);
return true;
error:
@ -705,6 +715,12 @@ void handle_x11_present_event(struct wlr_x11_backend *x11,
return;
}
if (output->last_msc == complete_notify->msc && complete_notify->serial == 0) {
// This is a present complete event triggered by a synthetic
// present request sent from handle_x11_expose_event()
return;
}
output->last_msc = complete_notify->msc;
struct timespec t;
@ -732,3 +748,39 @@ void handle_x11_present_event(struct wlr_x11_backend *x11,
wlr_log(WLR_DEBUG, "Unhandled Present event %"PRIu16, event->event_type);
}
}
void handle_x11_expose_event(struct wlr_x11_output *output,
xcb_expose_event_t *ev) {
struct wlr_x11_backend *x11 = output->x11;
pixman_region32_union_rect(&output->exposed, &output->exposed,
ev->x, ev->y, ev->width, ev->height);
if (output->current_buffer == NULL) {
return;
}
// If we have access to the last submitted buffer, re-send the previous
// present request
struct wlr_x11_buffer *x11_buffer =
get_or_create_x11_buffer(output, output->current_buffer);
if (!x11_buffer) {
return;
}
xcb_xfixes_region_t region = create_region(x11, &output->exposed);
pixman_region32_clear(&output->exposed);
uint32_t serial = 0;
uint32_t options = 0;
uint64_t target_msc = output->last_msc;
xcb_present_pixmap(x11->xcb, output->win, x11_buffer->pixmap, serial,
0, region, 0, 0, XCB_NONE, XCB_NONE, XCB_NONE, options, target_msc,
0, 0, 0, NULL);
if (region != XCB_NONE) {
xcb_xfixes_destroy_region(x11->xcb, region);
}
}