From dd9c61e5f6807dd2ba039cc3bff41e0d229f63fa Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 9 Jan 2026 14:44:40 +0530
Subject: [PATCH] ...

---
 glfw/momentum-scroll.c | 10 +++++-----
 kitty/glfw.c           |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/glfw/momentum-scroll.c b/glfw/momentum-scroll.c
index b3a4a800a..3556f62e6 100644
--- a/glfw/momentum-scroll.c
+++ b/glfw/momentum-scroll.c
@@ -20,7 +20,7 @@ typedef struct ScrollSample {
 typedef enum ScrollerState { NONE, PHYSICAL_EVENT_IN_PROGRESS, MOMENTUM_IN_PROGRESS } ScrollerState;
 
 typedef struct MomentumScroller {
-    double friction,  // Deceleration factor (0-1, lower = longer coast)
+    double friction,  // Deceleration inverse factor (0-1, higher = longer coast)
            min_velocity, // Minimum velocity before stopping
            max_velocity, // Maximum velocity to prevent runaway scrolling
            velocity_scale; // Scale factor for initial velocity
@@ -39,7 +39,7 @@ typedef struct MomentumScroller {
 } MomentumScroller;
 
 static const MomentumScroller defaults = {
-    .friction = 0.04,
+    .friction = 0.96,
     .min_velocity = 0.5,
     .max_velocity = 100,
     .timer_interval = 10,
@@ -49,8 +49,9 @@ static MomentumScroller s = defaults;
 GLFWAPI void
 glfwConfigureMomentumScroller(double friction, double min_velocity, double max_velocity, unsigned timer_interval_ms) {
     s.timer_interval = timer_interval_ms ? ms_to_monotonic_t(timer_interval_ms) : defaults.timer_interval;
+    s.friction = friction < 0 ? defaults.friction : MAX(0, MIN(friction, 1));
 #define S(w) s.w = w >= 0 ? w : defaults.w
-    S(friction); S(min_velocity); S(max_velocity);
+    S(min_velocity); S(max_velocity);
 #undef S
 }
 
@@ -140,8 +141,7 @@ send_momentum_event(bool is_start) {
         cancel_existing_scroll(true);
         return;
     }
-    double friction = 1.0 - MAX(0, MIN(s.friction, 1.));
-    s.velocity.x *= friction; s.velocity.y *= friction;
+    s.velocity.x *= s.friction; s.velocity.y *= s.friction;
     if (fabs(s.velocity.x) < s.min_velocity) s.velocity.x = 0;
     if (fabs(s.velocity.y) < s.min_velocity) s.velocity.y = 0;
 
diff --git a/kitty/glfw.c b/kitty/glfw.c
index 62a365b3e..ea197e051 100644
--- a/kitty/glfw.c
+++ b/kitty/glfw.c
@@ -1354,7 +1354,7 @@ create_os_window(PyObject UNUSED *self, PyObject *args, PyObject *kw) {
 
     static bool is_first_window = true;
     if (is_first_window) {
-        if (global_state.is_wayland) glfwConfigureMomentumScroller(1. - OPT(momentum_scroll), -1, -1, 0);
+        if (global_state.is_wayland) glfwConfigureMomentumScroller(OPT(momentum_scroll), -1, -1, 0);
         glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, OPENGL_REQUIRED_VERSION_MAJOR);
         glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, OPENGL_REQUIRED_VERSION_MINOR);
         glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, true);