From 7a35b1e67c7eb0bf37ae2f464a6ec541a02cd608 Mon Sep 17 00:00:00 2001
From: Consolatis <35009135+Consolatis@users.noreply.github.com>
Date: Mon, 15 Jul 2024 04:30:05 +0200
Subject: [PATCH] src/output-state.c: add a FPS debug option

Logs the FPS per output every $timeout ms via wlr_log() if enabled.

By default this patch does nothing unless the FPS_TIMEOUT define has
been set, for example via `meson configure build -DFPS_TIMEOUT=5000`.
---
 include/labwc.h    |  2 ++
 src/output-state.c | 26 ++++++++++++++++++++++++++
 src/output.c       |  5 +++++
 3 files changed, 33 insertions(+)

diff --git a/include/labwc.h b/include/labwc.h
index 21cab83b..0a4c9793 100644
--- a/include/labwc.h
+++ b/include/labwc.h
@@ -371,6 +371,7 @@ struct output {
 	struct server *server;
 	struct wlr_output *wlr_output;
 	struct wlr_output_state pending;
+	struct wl_event_source *fps_timer;
 	struct wlr_scene_output *scene_output;
 	struct wlr_scene_tree *layer_tree[LAB_NR_LAYERS];
 	struct wlr_scene_tree *layer_popup_tree;
@@ -389,6 +390,7 @@ struct output {
 
 	bool leased;
 	bool gamma_lut_changed;
+	uint32_t frames;
 };
 
 #undef LAB_NR_LAYERS
diff --git a/src/output-state.c b/src/output-state.c
index 602149a2..24fe02cc 100644
--- a/src/output-state.c
+++ b/src/output-state.c
@@ -2,9 +2,25 @@
 
 #include <wlr/types/wlr_output.h>
 #include <wlr/types/wlr_output_management_v1.h>
+#include <wlr/util/log.h>
 #include "labwc.h"
 #include "output-state.h"
 
+//#define FPS_TIMEOUT (2 * 1000)
+
+#ifdef FPS_TIMEOUT
+static int
+handle_fps_timer(void *data)
+{
+	struct output *output = data;
+	wlr_log(WLR_DEBUG, "%s commit: avg %.2f fps",
+		output->wlr_output->name, (double)output->frames / (FPS_TIMEOUT / 1000));
+	wl_event_source_timer_update(output->fps_timer, FPS_TIMEOUT);
+	output->frames = 0;
+	return 0;
+}
+#endif
+
 void
 output_state_init(struct output *output)
 {
@@ -37,8 +53,18 @@ bool
 wlr_output_commit(struct wlr_output *wlr_output)
 {
 	struct output *output = wlr_output->data;
+#ifdef FPS_TIMEOUT
+	if (!output->fps_timer) {
+		output->fps_timer = wl_event_loop_add_timer(
+			output->server->wl_event_loop, handle_fps_timer, output);
+		wl_event_source_timer_update(output->fps_timer, FPS_TIMEOUT);
+	}
+#endif
 	bool committed = wlr_output_commit_state(wlr_output, &output->pending);
 	if (committed) {
+#ifdef FPS_TIMEOUT
+		output->frames++;
+#endif
 		wlr_output_state_finish(&output->pending);
 		wlr_output_state_init(&output->pending);
 	} else {
diff --git a/src/output.c b/src/output.c
index 8ca93c47..4ae7a41f 100644
--- a/src/output.c
+++ b/src/output.c
@@ -168,6 +168,11 @@ output_destroy_notify(struct wl_listener *listener, void *data)
 	 */
 	output->wlr_output->data = NULL;
 
+	if (output->fps_timer) {
+		wl_event_source_remove(output->fps_timer);
+		output->fps_timer = NULL;
+	}
+
 	/*
 	 * output->scene_output (if still around at this point) is
 	 * destroyed automatically when the wlr_output is destroyed