From fae4d6c935adf53c9786f0b1c55f42d7f977abd7 Mon Sep 17 00:00:00 2001
From: yuiiio <atbjyk@protonmail.com>
Date: Mon, 17 Nov 2025 21:56:24 +0900
Subject: [PATCH] Ensure the maximum cursor latency(10Hz)

---
 include/wlr/types/wlr_output.h |  3 ++-
 types/output/cursor.c          | 36 +++++++++++++++++++++++++++++-----
 types/scene/wlr_scene.c        |  5 ++++-
 3 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/include/wlr/types/wlr_output.h b/include/wlr/types/wlr_output.h
index 8ad741a3d..7c4029058 100644
--- a/include/wlr/types/wlr_output.h
+++ b/include/wlr/types/wlr_output.h
@@ -51,6 +51,7 @@ struct wlr_output_cursor {
 	uint64_t wait_point;
 	struct wl_list link;
 
+	struct timespec last_presentation;
 	bool deferred;
 	double deferred_x, deferred_y;
 
@@ -462,7 +463,7 @@ bool wlr_output_cursor_set_buffer(struct wlr_output_cursor *cursor,
 	struct wlr_buffer *buffer, int32_t hotspot_x, int32_t hotspot_y);
 bool wlr_output_cursor_move(struct wlr_output_cursor *cursor,
 	double x, double y);
-void wlr_output_cursor_move_all_deferred(struct wlr_output *output);
+void wlr_output_cursor_move_all_deferred(struct wlr_output *output, struct timespec *now);
 void wlr_output_cursor_destroy(struct wlr_output_cursor *cursor);
 
 /**
diff --git a/types/output/cursor.c b/types/output/cursor.c
index 290168557..72b8ecb6b 100644
--- a/types/output/cursor.c
+++ b/types/output/cursor.c
@@ -13,6 +13,7 @@
 #include "render/color.h"
 #include "types/wlr_buffer.h"
 #include "types/wlr_output.h"
+#include <util/time.h>
 
 static bool output_set_hardware_cursor(struct wlr_output *output,
 		struct wlr_buffer *buffer, int hotspot_x, int hotspot_y) {
@@ -441,8 +442,9 @@ bool output_cursor_set_texture(struct wlr_output_cursor *cursor,
 }
 
 static bool output_cursor_move(struct wlr_output_cursor *cursor,
-		double x, double y) {
+		double x, double y, struct timespec *now) {
 	cursor->deferred = false;
+	cursor->last_presentation = *now;
 
 	// Scale coordinates for the output
 	x *= cursor->output->scale;
@@ -474,6 +476,22 @@ static bool output_cursor_move(struct wlr_output_cursor *cursor,
 	return output_move_hardware_cursor(cursor->output, (int)x, (int)y);
 }
 
+
+static bool output_cursor_move_should_defer(struct wlr_output_cursor *cursor,
+		struct timespec *now) {
+	if (cursor->output->adaptive_sync_status != WLR_OUTPUT_ADAPTIVE_SYNC_ENABLED)
+		return false;
+
+	struct timespec delta;
+	int32_t vrr_min = NSEC_PER_SEC / 10; // enforce 10fps minimum for now.
+	timespec_sub(&delta, now, &cursor->last_presentation);
+	if (delta.tv_sec || delta.tv_nsec >= vrr_min)
+		return false;
+
+	return true;
+}
+
+
 bool wlr_output_cursor_move(struct wlr_output_cursor *cursor,
 		double x, double y) {
 	// Scale coordinates for the output
@@ -484,21 +502,29 @@ bool wlr_output_cursor_move(struct wlr_output_cursor *cursor,
 		return true;
 	}
 
-	if (cursor->output->adaptive_sync_status == WLR_OUTPUT_ADAPTIVE_SYNC_ENABLED) {
+
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	if (output_cursor_move_should_defer(cursor, &now)) {
 		cursor->deferred_x = x;
 		cursor->deferred_y = y;
 		cursor->deferred = true;
 		return true;
 	}
 
-	return output_cursor_move(cursor, x, y);
+	return output_cursor_move(cursor, x, y, &now);
 }
 
-void wlr_output_cursor_move_all_deferred(struct wlr_output *output) {
+void wlr_output_cursor_move_all_deferred(struct wlr_output *output, struct timespec *now) {
 	struct wlr_output_cursor *cursor;
 	wl_list_for_each(cursor, &output->cursors, link) {
 		if (cursor->deferred)
-			output_cursor_move(cursor, cursor->deferred_x, cursor->deferred_y);
+			output_cursor_move(cursor, cursor->deferred_x, cursor->deferred_y, now);
+		else {
+			// Should be on wlr_output?
+			cursor->last_presentation = *now;
+		};
 	}
 }
 
diff --git a/types/scene/wlr_scene.c b/types/scene/wlr_scene.c
index 5e61d9de6..36e5d26ec 100644
--- a/types/scene/wlr_scene.c
+++ b/types/scene/wlr_scene.c
@@ -2321,7 +2321,10 @@ bool wlr_scene_output_build_state(struct wlr_scene_output *scene_output,
 
 	// before scanout early return,
 	// update cursor if deferred
-	wlr_output_cursor_move_all_deferred(output);
+
+	struct timespec cursor_now;
+	clock_gettime(CLOCK_MONOTONIC, &cursor_now);
+	wlr_output_cursor_move_all_deferred(output, &cursor_now);
 
 	// We only want to try direct scanout if:
 	// - There is only one entry in the render list