output: compare state before commit

Before calling wlr_output_impl.{test,commit}, perform a cheap
comparison between the current and candidate state. Unset any
fields which didn't change.
This commit is contained in:
Simon Ser 2022-06-07 19:26:02 +02:00
parent 6688a3d9ea
commit 43a9b0fbb9

View file

@ -579,6 +579,63 @@ void output_pending_resolution(struct wlr_output *output,
}
}
/**
* Compare a struct wlr_output_state with the current state of a struct
* wlr_output.
*
* Returns a bitfield of the unchanged fields.
*
* Some fields are not checked: damage always changes in-between frames, the
* gamma LUT is too expensive to check, the contents of the buffer might have
* changed, etc.
*/
static uint32_t output_compare_state(struct wlr_output *output,
const struct wlr_output_state *state) {
uint32_t fields = 0;
if (state->committed & WLR_OUTPUT_STATE_MODE) {
bool unchanged = false;
switch (state->mode_type) {
case WLR_OUTPUT_STATE_MODE_FIXED:
unchanged = output->current_mode == state->mode;
break;
case WLR_OUTPUT_STATE_MODE_CUSTOM:
unchanged = output->width == state->custom_mode.width &&
output->height == state->custom_mode.height &&
output->refresh == state->custom_mode.refresh;
break;
}
if (unchanged) {
fields |= WLR_OUTPUT_STATE_MODE;
}
}
if ((state->committed & WLR_OUTPUT_STATE_ENABLED) && output->enabled == state->enabled) {
fields |= WLR_OUTPUT_STATE_ENABLED;
}
if ((state->committed & WLR_OUTPUT_STATE_SCALE) && output->scale == state->scale) {
fields |= WLR_OUTPUT_STATE_SCALE;
}
if ((state->committed & WLR_OUTPUT_STATE_TRANSFORM) &&
output->transform == state->transform) {
fields |= WLR_OUTPUT_STATE_TRANSFORM;
}
if (state->committed & WLR_OUTPUT_STATE_ADAPTIVE_SYNC_ENABLED) {
bool enabled =
output->adaptive_sync_status != WLR_OUTPUT_ADAPTIVE_SYNC_DISABLED;
if (enabled == state->adaptive_sync_enabled) {
fields |= WLR_OUTPUT_STATE_ADAPTIVE_SYNC_ENABLED;
}
}
if ((state->committed & WLR_OUTPUT_STATE_RENDER_FORMAT) &&
output->render_format == state->render_format) {
fields |= WLR_OUTPUT_STATE_RENDER_FORMAT;
}
if ((state->committed & WLR_OUTPUT_STATE_SUBPIXEL) &&
output->subpixel == state->subpixel) {
fields |= WLR_OUTPUT_STATE_SUBPIXEL;
}
return fields;
}
static bool output_basic_test(struct wlr_output *output,
const struct wlr_output_state *state) {
if (state->committed & WLR_OUTPUT_STATE_BUFFER) {
@ -680,7 +737,14 @@ static bool output_basic_test(struct wlr_output *output,
bool wlr_output_test_state(struct wlr_output *output,
const struct wlr_output_state *state) {
if (!output_basic_test(output, state)) {
uint32_t unchanged = output_compare_state(output, state);
// Create a shallow copy of the state with only the fields which have been
// changed and potentially a new buffer.
struct wlr_output_state copy = *state;
copy.committed &= ~unchanged;
if (!output_basic_test(output, &copy)) {
return false;
}
if (!output->impl->test) {
@ -688,13 +752,9 @@ bool wlr_output_test_state(struct wlr_output *output,
}
bool new_back_buffer = false;
if (!output_ensure_buffer(output, state, &new_back_buffer)) {
if (!output_ensure_buffer(output, &copy, &new_back_buffer)) {
return false;
}
// Create a shallow copy of the state with the new buffer
// potentially included to pass to the backend.
struct wlr_output_state copy = *state;
if (new_back_buffer) {
assert((copy.committed & WLR_OUTPUT_STATE_BUFFER) == 0);
copy.committed |= WLR_OUTPUT_STATE_BUFFER;
@ -714,21 +774,24 @@ bool wlr_output_test(struct wlr_output *output) {
bool wlr_output_commit_state(struct wlr_output *output,
const struct wlr_output_state *state) {
if (!output_basic_test(output, state)) {
uint32_t unchanged = output_compare_state(output, state);
// Create a shallow copy of the state with only the fields which have been
// changed and potentially a new buffer.
struct wlr_output_state pending = *state;
pending.committed &= ~unchanged;
if (!output_basic_test(output, &pending)) {
wlr_log(WLR_ERROR, "Basic output test failed for %s", output->name);
output_clear_back_buffer(output);
return false;
}
bool new_back_buffer = false;
if (!output_ensure_buffer(output, state, &new_back_buffer)) {
if (!output_ensure_buffer(output, &pending, &new_back_buffer)) {
output_clear_back_buffer(output);
return false;
}
// Create a shallow copy of the state with the new back buffer
// potentially included to pass to the backend.
struct wlr_output_state pending = *state;
if (new_back_buffer) {
assert((pending.committed & WLR_OUTPUT_STATE_BUFFER) == 0);
pending.committed |= WLR_OUTPUT_STATE_BUFFER;