Cannot scroll on a touchpad with -M option

[stormseal]

Environment

• OS: Fedora 42
• Scrcpy version: 3.3
• Installation method: copr
• Device model: Samsung
• Android version: 15

Describe the bug

scrcpy --no-video --no-audio --keyboard=uhid --mouse=uhid --gamepad=uhid

Using these options, nothing happens when trying to scroll with 2 fingers.

Sometimes the page will go back to the top instantly, but that's as much as it will happen.

--Vverbose output when that happens (scrolling results in all 00 00 00 00)

VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 

[rom1v]

Weird, on my laptop it works (01 when I scroll up, FF when I scroll down):

VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 

Can you check the values here, please (add some logs if you're comfortable with adding code):

scrcpy/app/src/input_manager.c

Lines 899 to 905 in 696402c

	#if SDL_VERSION_ATLEAST(2, 0, 18)
	.hscroll = CLAMP(event->preciseX, -1.0f, 1.0f),
	.vscroll = CLAMP(event->preciseY, -1.0f, 1.0f),
	#else
	.hscroll = CLAMP(event->x, -1, 1),
	.vscroll = CLAMP(event->y, -1, 1),
	#endif

What's your SDL version? (run scrcpy --version)

[stormseal]

scrcpy 3.3 <https://github.com/Genymobile/scrcpy>

Dependencies (compiled / linked):
 - SDL: 2.32.56 / 2.32.56
 - libavcodec: 61.19.101 / 61.19.101
 - libavformat: 61.7.100 / 61.7.100
 - libavutil: 59.39.100 / 59.39.100
 - libavdevice: 61.3.100 / 61.3.100
 - libusb: - / 1.0.28

[rom1v]

Please add these logs:

diff --git app/src/input_manager.c app/src/input_manager.c
index 635825c9f..5ddf30989 100644
--- app/src/input_manager.c
+++ app/src/input_manager.c
@@ -906,6 +906,10 @@ sc_input_manager_process_mouse_wheel(struct sc_input_manager *im,
         .buttons_state = im->mouse_buttons_state,
     };
 
+    LOGI("%f, %f (%f, %f)",
+         event->preciseX, event->preciseY,
+         evt.hscroll, evt.vscroll);
+
     im->mp->ops->process_mouse_scroll(im->mp, &evt);
 }
 

[stormseal]

normal scrolling

INFO: 0.000000, -0.011328 (0.000000, -0.011328)
INFO: 0.000000, -0.017188 (0.000000, -0.017188)
INFO: 0.000000, -0.034766 (0.000000, -0.034766)
INFO: 0.000000, -0.028906 (0.000000, -0.028906)
INFO: 0.000000, -0.017188 (0.000000, -0.017188)
INFO: 0.000000, -0.028906 (0.000000, -0.028906)
INFO: 0.000000, -0.017188 (0.000000, -0.017188)
INFO: 0.000000, -0.023047 (0.000000, -0.023047)
INFO: 0.000000, -0.017188 (0.000000, -0.017188)
INFO: 0.000000, -0.023047 (0.000000, -0.023047)
INFO: 0.000000, -0.034766 (0.000000, -0.034766)
INFO: 0.000000, -0.034766 (0.000000, -0.034766)
INFO: 0.000000, -0.017188 (0.000000, -0.017188)
INFO: 0.000000, -0.034766 (0.000000, -0.034766)
INFO: 0.000000, -0.011328 (0.000000, -0.011328)

with -Vverobse

INFO: 0.000000, -0.011328 (0.000000, -0.011328)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.028906 (0.000000, -0.028906)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.011328 (0.000000, -0.011328)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.005469 (0.000000, -0.005469)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.023047 (0.000000, -0.023047)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.023047 (0.000000, -0.023047)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.005469 (0.000000, -0.005469)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.005469 (0.000000, -0.005469)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.017188 (0.000000, -0.017188)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, -0.005469 (0.000000, -0.005469)
VERBOSE: input: UHID input [2] 00 00 00 00 

when it jumps to the top

VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.578125 (0.000000, 0.578125)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.718359 (0.000000, 0.718359)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.952344 (0.000000, 0.952344)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 1.255859 (0.000000, 1.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 1.437109 (0.000000, 1.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.981250 (0.000000, 0.981250)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 1.367188 (0.000000, 1.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 1.098438 (0.000000, 1.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 1.063281 (0.000000, 1.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 1.203516 (0.000000, 1.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 1.110156 (0.000000, 1.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 1.004688 (0.000000, 1.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.695312 (0.000000, 0.695312)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.583984 (0.000000, 0.583984)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.636719 (0.000000, 0.636719)
VERBOSE: input: UHID input [2] 00 00 00 00 

[rom1v]

diff --git app/src/hid/hid_mouse.c app/src/hid/hid_mouse.c
index 29cfc5942..9e53bc05b 100644
--- app/src/hid/hid_mouse.c
+++ app/src/hid/hid_mouse.c
@@ -186,7 +186,7 @@ sc_hid_mouse_generate_input_from_scroll(struct sc_hid_input *hid_input,
     data[2] = 0; // no y motion
     // In practice, vscroll is always -1, 0 or 1, but in theory other values
     // are possible
-    data[3] = CLAMP(event->vscroll, -127, 127);
+    data[3] = event->vscroll < 0 ? -1 : 1;
     // Horizontal scrolling ignored
 }
 

Is it better with this?

[rom1v]

Also please test the following diff (remove all your previous changes):

diff --git app/src/input_manager.c app/src/input_manager.c
index 635825c9f..1e2d40582 100644
--- app/src/input_manager.c
+++ app/src/input_manager.c
@@ -896,7 +896,7 @@ sc_input_manager_process_mouse_wheel(struct sc_input_manager *im,
 
     struct sc_mouse_scroll_event evt = {
         .position = sc_input_manager_get_position(im, mouse_x, mouse_y),
-#if SDL_VERSION_ATLEAST(2, 0, 18)
+#if false && SDL_VERSION_ATLEAST(2, 0, 18)
         .hscroll = CLAMP(event->preciseX, -1.0f, 1.0f),
         .vscroll = CLAMP(event->preciseY, -1.0f, 1.0f),
 #else
@@ -906,6 +906,10 @@ sc_input_manager_process_mouse_wheel(struct sc_input_manager *im,
         .buttons_state = im->mouse_buttons_state,
     };
 
+    LOGI("%f, %f | %d %d (%f, %f)",
+         event->preciseX, event->preciseY, (int) event->x, (int) event->y,
+         evt.hscroll, evt.vscroll);
+
     im->mp->ops->process_mouse_scroll(im->mp, &evt);
 }
 

(and post the output)

[stormseal]

when modifying only hid_mouse.c, scrolling works, but is very fast; if the content isn't long enough it feels like it jumps to the top or the bottom

VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 

---

modifying only input_manager.c; it works only when scrolling up, depending on the application it works worse or better. The scrolling is stuttering and not smooth.

INFO: 0.000000, 0.034766 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.046484 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.028906 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.028906 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.028906 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.023047 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.028906 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.023047 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.017188 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.040625 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.017188 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 00 

---

modifying both, the scrolling is smoother, but it only works when scrolling to the top.

INFO: 0.000000, 0.011328 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.023047 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.011328 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.017188 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.034766 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.017188 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 
INFO: 0.000000, 0.005469 | 0 0 (0.000000, 0.000000)
VERBOSE: input: UHID input [2] 00 00 00 01 

[rom1v]

Apparently, we can only inject integral values over HID (not fractional values). Even if the range is [-127, 127], 1 increment always means a full "scroll tick" (not 1/127 of a scroll tick). I'm not sure it is possible to change the report descriptor to allow this.

If we can't, then I think we should accumulate float values internally and only inject an event by packets of "integer values" (when the absolute value of the accumulation is >= 1).

[rom1v]

I think we should accumulate float values internally and only inject an event by packets of "integer values" (when the absolute value of the accumulation is >= 1).

I implemented a prototype for that.

Could you please test: f9b3f97 (branch issue6156.1)?

(I cannot test, I currently have no system where SDL sends intermediate fractional scroll values.)

[stormseal]

The issue still persists; the amount scrolled is still too big, however the sensibility is reduced so it's better and more precise.

I recorded some videos to illustrate what I mean.

long_text_firefox.mp4

VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 ED 00 00 
VERBOSE: input: UHID input [2] 00 F9 00 00 

notes.mp4

VERBOSE: input: UHID input [2] 00 F1 F5 00 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 FB FC 00 
VERBOSE: input: UHID input [2] 00 FA FB 00 
VERBOSE: input: UHID input [2] 00 F8 FB 00 
VERBOSE: input: UHID input [2] 00 F9 FB 00 
VERBOSE: input: UHID input [2] 00 F8 FA 00 
VERBOSE: input: UHID input [2] 00 F8 FB 00 
VERBOSE: input: UHID input [2] 00 F3 F6 00 
VERBOSE: input: UHID input [2] 00 F2 F8 00 
VERBOSE: input: UHID input [2] 00 E6 F6 00 
VERBOSE: input: UHID input [2] 00 DF F9 00 
VERBOSE: input: UHID input [2] 00 D4 FC 00 
VERBOSE: input: UHID input [2] 00 CA FF 00 
VERBOSE: input: UHID input [2] 00 AD 02 00 
VERBOSE: input: UHID input [2] 00 AF 04 00 
VERBOSE: input: UHID input [2] 00 A7 06 00 
VERBOSE: input: UHID input [2] 00 A3 06 00 
VERBOSE: input: UHID input [2] 00 A0 07 00 
VERBOSE: input: UHID input [2] 00 9D 06 00 
VERBOSE: input: UHID input [2] 00 9D 06 00 
VERBOSE: input: UHID input [2] 00 C0 02 00 
VERBOSE: input: UHID input [2] 00 81 03 00 
VERBOSE: input: UHID input [2] 00 A1 00 00 
VERBOSE: input: UHID input [2] 00 9E FD 00 
VERBOSE: input: UHID input [2] 00 9D F6 00 
VERBOSE: input: UHID input [2] 00 BF F6 00 
VERBOSE: input: UHID input [2] 00 A3 F2 00 
VERBOSE: input: UHID input [2] 00 A7 F1 00 
VERBOSE: input: UHID input [2] 00 A8 F3 00 
VERBOSE: input: UHID input [2] 00 AD F3 00 
VERBOSE: input: UHID input [2] 00 AF F6 00 
VERBOSE: input: UHID input [2] 00 B0 F8 00 
VERBOSE: input: UHID input [2] 00 B2 F9 00 
VERBOSE: input: UHID input [2] 00 B1 FC 00 
VERBOSE: input: UHID input [2] 00 94 FC 00 
VERBOSE: input: UHID input [2] 00 AB FA 00 
VERBOSE: input: UHID input [2] 00 C7 FC 00 
VERBOSE: input: UHID input [2] 00 B1 FA 00 
VERBOSE: input: UHID input [2] 00 B7 F6 00 
VERBOSE: input: UHID input [2] 00 DA FA 00 
VERBOSE: input: UHID input [2] 00 C8 F7 00 
VERBOSE: input: UHID input [2] 00 D2 F7 00 
VERBOSE: input: UHID input [2] 00 DC F7 00 
VERBOSE: input: UHID input [2] 00 E5 F9 00 
VERBOSE: input: UHID input [2] 00 ED FA 00 
VERBOSE: input: UHID input [2] 00 F4 FB 00 
VERBOSE: input: UHID input [2] 00 FA FC 00 
VERBOSE: input: UHID input [2] 00 FC FD 00 
VERBOSE: input: UHID input [2] 00 FE FC 00 
VERBOSE: input: UHID input [2] 00 FF FC 00 
VERBOSE: input: UHID input [2] 00 01 F8 00 
VERBOSE: input: UHID input [2] 00 04 F7 00 
VERBOSE: input: UHID input [2] 00 06 F6 00 
VERBOSE: input: UHID input [2] 00 08 F7 00 
VERBOSE: input: UHID input [2] 00 0A F8 00 
VERBOSE: input: UHID input [2] 00 0D F9 00 
VERBOSE: input: UHID input [2] 00 1A F4 00 
VERBOSE: input: UHID input [2] 00 1E F5 00 
VERBOSE: input: UHID input [2] 00 2A F1 00 
VERBOSE: input: UHID input [2] 00 2F EF 00 
VERBOSE: input: UHID input [2] 00 30 EC 00 
VERBOSE: input: UHID input [2] 00 20 F0 00 
VERBOSE: input: UHID input [2] 00 2A E9 00 
VERBOSE: input: UHID input [2] 00 27 E7 00 
VERBOSE: input: UHID input [2] 00 23 E7 00 
VERBOSE: input: UHID input [2] 00 1F EB 00 
VERBOSE: input: UHID input [2] 00 1B EC 00 
VERBOSE: input: UHID input [2] 00 18 F0 00 
VERBOSE: input: UHID input [2] 00 14 F2 00 
VERBOSE: input: UHID input [2] 00 0F F7 00 
VERBOSE: input: UHID input [2] 00 0F F8 00 
VERBOSE: input: UHID input [2] 00 0F F8 00 
VERBOSE: input: UHID input [2] 00 12 F8 00 
VERBOSE: input: UHID input [2] 00 14 F7 00 
VERBOSE: input: UHID input [2] 00 14 F6 00 
VERBOSE: input: UHID input [2] 00 14 F5 00 
VERBOSE: input: UHID input [2] 00 13 F4 00 
VERBOSE: input: UHID input [2] 00 12 F2 00 
VERBOSE: input: UHID input [2] 00 0E F4 00 
VERBOSE: input: UHID input [2] 00 0D F3 00 
VERBOSE: input: UHID input [2] 00 09 F7 00 
VERBOSE: input: UHID input [2] 00 07 F8 00 
VERBOSE: input: UHID input [2] 00 06 F9 00 
VERBOSE: input: UHID input [2] 00 03 FD 00 
VERBOSE: input: UHID input [2] 00 02 FD 00 
VERBOSE: input: UHID input [2] 00 01 00 00 
VERBOSE: input: UHID input [2] 00 01 FF 00 
VERBOSE: input: UHID input [2] 00 00 FF 00 
VERBOSE: input: UHID input [2] 00 00 FE 00 
VERBOSE: input: UHID input [2] 00 00 FF 00 
VERBOSE: input: UHID input [2] 00 00 FF 00 
VERBOSE: input: UHID input [2] 00 00 FF 00 
VERBOSE: input: UHID input [2] 00 00 FF 00 
VERBOSE: input: UHID input [2] 01 00 00 00 
VERBOSE: input: UHID input [2] 00 00 00 00 
VERBOSE: input: UHID input [2] 00 0E FD 00 
VERBOSE: input: UHID input [2] 00 1A 00 00 
VERBOSE: input: UHID input [2] 00 27 07 00 
VERBOSE: input: UHID input [2] 00 2B 0B 00 
VERBOSE: input: UHID input [2] 00 2D 0A 00 
VERBOSE: input: UHID input [2] 00 1D 07 00 
VERBOSE: input: UHID input [2] 00 27 0A 00 
VERBOSE: input: UHID input [2] 00 22 08 00 
VERBOSE: input: UHID input [2] 00 1D 06 00 
VERBOSE: input: UHID input [2] 00 19 05 00 
VERBOSE: input: UHID input [2] 00 15 03 00 
VERBOSE: input: UHID input [2] 00 13 03 00 
VERBOSE: input: UHID input [2] 00 13 02 00 
VERBOSE: input: UHID input [2] 00 1B 03 00 
VERBOSE: input: UHID input [2] 00 1C 04 00 
VERBOSE: input: UHID input [2] 00 24 05 00 
VERBOSE: input: UHID input [2] 00 29 09 00 
VERBOSE: input: UHID input [2] 00 1F 07 00 
VERBOSE: input: UHID input [2] 00 26 0B 00 
VERBOSE: input: UHID input [2] 00 23 0A 00 
VERBOSE: input: UHID input [2] 00 20 09 00 
VERBOSE: input: UHID input [2] 00 1A 09 00 
VERBOSE: input: UHID input [2] 00 15 06 00 
VERBOSE: input: UHID input [2] 00 10 05 00 
VERBOSE: input: UHID input [2] 00 0B 03 00 
VERBOSE: input: UHID input [2] 00 07 02 00 
VERBOSE: input: UHID input [2] 00 05 02 00 
VERBOSE: input: UHID input [2] 00 04 01 00 
VERBOSE: input: UHID input [2] 00 01 00 00 
VERBOSE: input: UHID input [2] 00 04 02 00 
VERBOSE: input: UHID input [2] 00 02 01 00 
VERBOSE: input: UHID input [2] 00 02 01 00 
VERBOSE: input: UHID input [2] 00 02 01 00 
VERBOSE: input: UHID input [2] 00 01 01 00 
VERBOSE: input: UHID input [2] 00 03 01 00 
VERBOSE: input: UHID input [2] 00 02 01 00 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 FF 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01

i tested on a 12 page note and I only used 3 "scrolls" to go from bottom to top

VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 01 

[rom1v]

1 and -1 (FF) is the minimum amount of scroll that can be sent in one event (in fact, this is almost always what is sent in practice):

VERBOSE: input: UHID input [2] 00 00 00 01 
VERBOSE: input: UHID input [2] 00 00 00 FF

If a single event scrolls too much on your device, I guess that's a device configuration issue.

Or is it because too much events are sent? Can you try to scroll so that only 1 event is sent?

Can you reproduce with another device?
Can you reproduce with --mouse=aoa?
Can you reproduce when scrolling with a mouse instead of the touchpad?
Can you reproduce with a physical mouse (connected by bluetooth directly to the device)?

[stormseal]

I forgot I put the sensibility to the maximum while i was testing stuff :(
Putting it to the minimum works fine

I retested with only this modification and it works fine... sorry for the extra work

diff --git app/src/hid/hid_mouse.c app/src/hid/hid_mouse.c
index 29cfc5942..9e53bc05b 100644
--- app/src/hid/hid_mouse.c
+++ app/src/hid/hid_mouse.c
@@ -186,7 +186,7 @@ sc_hid_mouse_generate_input_from_scroll(struct sc_hid_input *hid_input,
     data[2] = 0; // no y motion
     // In practice, vscroll is always -1, 0 or 1, but in theory other values
     // are possible
-    data[3] = CLAMP(event->vscroll, -127, 127);
+    data[3] = event->vscroll < 0 ? -1 : 1;
     // Horizontal scrolling ignored
 }

I will test it some more later and see If everything works good.

Thanks

[rom1v]

I forgot I put the sensibility to the maximum while i was testing stuff :(
Putting it to the minimum works fine

👍

In theory, I think #6156 (comment) would be better.
In practice, is it smoother?

[stormseal]

In practice #6156 (comment) the scrolling speed is better, more manageable (scrolling speed is still set to the minimum though).

One thing I noticed is that the scrolling is more or less smooth depending on the application, for example in Firefox it is quite smooth, but in Samsung Notes and YouTube is "stuttery", not smooth.

Also, tried using aoa, the results are the same. Scrolling doesn't work without the modifications, but works the same after the patch.

[rom1v]

OK, thank you for your tests 👍

I'll finalize the prototype from #6156 (comment) and merge it.