[PATCH v6 0/1] MR4809: Draft: wip! winewayland.drv: Try to support smooth scroll events
Wayland has 3 types of scrolling events: - axis. Used for e.g., touchpad 2 finger smooth scrolling - axis_discrete. Used for mouse scroll wheels (i.e., notches) - axis_value120. Used for high resolution input devices Wine currently only supports axis_discrete, meaning that 2 finger scroll events get ignored. This commit tries to add basic support for axis scrolling events, by translating the smooth motion in scroll increments using some primitive assumptions about line height and number of lines to scroll. -- v6: wip! winewayland.drv: Try to support smooth scroll events https://gitlab.winehq.org/wine/wine/-/merge_requests/4809
From: Ray Strode <rstrode(a)redhat.com> Wayland has 3 types of scrolling events: - axis. Used for e.g., touchpad 2 finger smooth scrolling - axis_discrete. Used for mouse scroll wheels (i.e., notches) - axis_value120. Used for high resolution input devices Wine currently only supports axis_discrete, meaning that 2 finger scroll events get ignored. This commit tries to add basic support for axis scrolling events, by translating the smooth motion in scroll increments using some primitive assumptions about line height and number of lines to scroll. --- dlls/winewayland.drv/wayland_pointer.c | 85 ++++++++++++++++++++++++++ dlls/winewayland.drv/waylanddrv.h | 2 + 2 files changed, 87 insertions(+) diff --git a/dlls/winewayland.drv/wayland_pointer.c b/dlls/winewayland.drv/wayland_pointer.c index fad75c8506c..4386481f401 100644 --- a/dlls/winewayland.drv/wayland_pointer.c +++ b/dlls/winewayland.drv/wayland_pointer.c @@ -191,10 +191,91 @@ static void pointer_handle_button(void *data, struct wl_pointer *wl_pointer, static void pointer_handle_axis(void *data, struct wl_pointer *wl_pointer, uint32_t time, uint32_t axis, wl_fixed_t value) { + struct wayland_pointer *pointer = &process_wayland.pointer; + INPUT input = {0}; + HWND hwnd; + /* wheel events aren't in pixel units but a fractional unit proportional + * to the number of lines to scroll. By default a value of WHEEL_DELTA means + * scroll the application content by 3 lines. + * + * When smooth scrolling with two fingers on a touchpad instead of with a + * wheel, we don't want to scroll by 3 lines, since that makes it hard to + * scroll to a precise line, and any lost speed can be made up for by doing + * a bigger swipe anyway. It's better to scroll a line at a time for small + * swipes. + * + * We also don't know exactly how big a "line" is in pixel units, which is + * what gets reported to this event handler. We can approximate it by + * saying a line is 18 pixels, and we're probably in the right ballpark + * most of the time. + * + * We also don't want to scroll the full swipe value in one go, because if + * it's a big swipe, it's likely to be several lines which can look + * discontinuous and jarring. For it to scroll relatively smoothly, we + * should report intermediate events every half line or so. + */ + const double pixels_per_line = 18.0; + const double lines_per_wheel_spin = 3.0; + const double wheel_delta_per_line = (WHEEL_DELTA / lines_per_wheel_spin); + const int32_t events_per_line = 2; + bool invert = false; + double lines_to_scroll; + double wheel_delta_for_value; + int32_t wheel_delta_per_event; + + double pixels_scrolled; + + if (!(hwnd = wayland_pointer_get_focused_hwnd())) return; + + if (pointer->scroll_frame_number == pointer->next_frame_number) return; + + input.type = INPUT_MOUSE; + + pixels_scrolled = wl_fixed_to_double(value); + + lines_to_scroll = pixels_scrolled / pixels_per_line; + wheel_delta_for_value = lines_to_scroll * wheel_delta_per_line; + + switch (axis) + { + case WL_POINTER_AXIS_VERTICAL_SCROLL: + input.mi.dwFlags = MOUSEEVENTF_WHEEL; + invert = true; + break; + case WL_POINTER_AXIS_HORIZONTAL_SCROLL: + input.mi.dwFlags = MOUSEEVENTF_HWHEEL; + break; + default: break; + } + + TRACE("hwnd=%p axis=%u value=%lf\n", hwnd, axis, pixels_scrolled); + + wheel_delta_per_event = (int32_t) round(wheel_delta_per_line / events_per_line); + for (int32_t i = 0; i < ((int) lines_to_scroll) * events_per_line; i++) + { + if (wheel_delta_for_value < wheel_delta_per_event) break; + + wheel_delta_for_value -= wheel_delta_per_event; + + if (wheel_delta_for_value < wheel_delta_per_event) + { + wheel_delta_per_event += (int32_t) round(wheel_delta_for_value); + wheel_delta_for_value = 0.0; + } + input.mi.mouseData = wheel_delta_per_event; + + if (invert) + input.mi.mouseData *= -1; + + __wine_send_input(hwnd, &input, NULL); + } } static void pointer_handle_frame(void *data, struct wl_pointer *wl_pointer) { + struct wayland_pointer *pointer = &process_wayland.pointer; + + pointer->next_frame_number++; } static void pointer_handle_axis_source(void *data, struct wl_pointer *wl_pointer, @@ -210,6 +291,7 @@ static void pointer_handle_axis_stop(void *data, struct wl_pointer *wl_pointer, static void pointer_handle_axis_discrete(void *data, struct wl_pointer *wl_pointer, uint32_t axis, int32_t discrete) { + struct wayland_pointer *pointer = &process_wayland.pointer; INPUT input = {0}; HWND hwnd; @@ -233,6 +315,7 @@ static void pointer_handle_axis_discrete(void *data, struct wl_pointer *wl_point TRACE("hwnd=%p axis=%u discrete=%d\n", hwnd, axis, discrete); __wine_send_input(hwnd, &input, NULL); + pointer->scroll_frame_number = pointer->next_frame_number; } static const struct wl_pointer_listener pointer_listener = @@ -333,6 +416,7 @@ void wayland_pointer_init(struct wl_pointer *wl_pointer) pointer->wl_pointer = wl_pointer; pointer->focused_hwnd = NULL; pointer->enter_serial = 0; + pointer->next_frame_number = 0; pthread_mutex_unlock(&pointer->mutex); wl_pointer_add_listener(pointer->wl_pointer, &pointer_listener, NULL); } @@ -361,6 +445,7 @@ void wayland_pointer_deinit(void) pointer->wl_pointer = NULL; pointer->focused_hwnd = NULL; pointer->enter_serial = 0; + pointer->next_frame_number = 0; pthread_mutex_unlock(&pointer->mutex); } diff --git a/dlls/winewayland.drv/waylanddrv.h b/dlls/winewayland.drv/waylanddrv.h index 0883c43f1ff..fc7fd6ee3fc 100644 --- a/dlls/winewayland.drv/waylanddrv.h +++ b/dlls/winewayland.drv/waylanddrv.h @@ -99,6 +99,8 @@ struct wayland_pointer HWND constraint_hwnd; uint32_t enter_serial; uint32_t button_serial; + uint32_t scroll_frame_number; + uint32_t next_frame_number; struct wayland_cursor cursor; pthread_mutex_t mutex; }; -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/4809
How does XWayland decide in this regard? -- https://gitlab.winehq.org/wine/wine/-/merge_requests/4809#note_56975
On Tue Jan 9 07:56:10 2024 +0000, Ray Strode wrote:
thanks for testing, i just pushed a new (untested) algorithm but given what you're saying I think it will probably be worse. I guess we probably need increase the lines scrolled per swipe in a non-linear way If you have an Apple device with macOS, I encourage you to try it. They do non-linearly and in my opinion is fantastic.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/4809#note_56982
On Tue Jan 9 13:15:02 2024 +0000, Warren Togami wrote:
How does XWayland decide in this regard? good question! Taking a peek at the wine and xwayland source code, I think what's happening is X11 wine is relying on the legacy feature where e.g., mouse button 4 is scroll up, mouse button 5 is scroll down, mouse button 6 is scroll left, mouse button 7 is scroll right. Xwayland looks at the smooth motion, and emulates those compat mouse button presses by taking the motion in pixel space and dividing by 10. It considers this to be normalized such that 1.0 is one scroll increment (emulated button press). So if the user two finger swipes the equivalent of 37 pixels, it considers that a scroll of 3.7, which is 3 button presses, and 0.7 stashed away in an accumulator to be added to the next swipe. In other words, it's pretending like there's an invisible scroll wheel without detents in the touchpad, and every time the scroll moves enough, it generates a click, and if it doesn't generate enough, the invisible wheel stays where the finger last put it.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/4809#note_56995
participants (4)
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Ray Strode -
Ray Strode (＠halfline)
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Warren Togami (＠wtogami)
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Ícar N. S.