acc_scroll

app/src/control_msg.c

@@ -127,14 +127,10 @@ sc_control_msg_serialize(const struct sc_control_msg *msg, uint8_t *buf) {
             return 32;
         case SC_CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT:
             write_position(&buf[1], &msg->inject_scroll_event.position);
-            // Accept values in the range [-16, 16].
-            // Normalize to [-1, 1] in order to use sc_float_to_i16fp().
-            float hscroll_norm = msg->inject_scroll_event.hscroll / 16;
-            hscroll_norm = CLAMP(hscroll_norm, -1, 1);
-            float vscroll_norm = msg->inject_scroll_event.vscroll / 16;
-            vscroll_norm = CLAMP(vscroll_norm, -1, 1);
-            int16_t hscroll = sc_float_to_i16fp(hscroll_norm);
-            int16_t vscroll = sc_float_to_i16fp(vscroll_norm);
+            int16_t hscroll =
+                sc_float_to_i16fp(msg->inject_scroll_event.hscroll);
+            int16_t vscroll =
+                sc_float_to_i16fp(msg->inject_scroll_event.vscroll);
             sc_write16be(&buf[13], (uint16_t) hscroll);
             sc_write16be(&buf[15], (uint16_t) vscroll);
             sc_write32be(&buf[17], msg->inject_scroll_event.buttons);

app/src/hid/hid_mouse.c

@@ -3,8 +3,8 @@
 #include <stdint.h>
 
 // 1 byte for buttons + padding, 1 byte for X position, 1 byte for Y position,
-// 1 byte for wheel motion, 1 byte for hozizontal scrolling
-#define SC_HID_MOUSE_INPUT_SIZE 5
+// 1 byte for wheel motion
+#define SC_HID_MOUSE_INPUT_SIZE 4
 
 /**
  * Mouse descriptor from the specification:
@@ -75,21 +75,6 @@ static const uint8_t SC_HID_MOUSE_REPORT_DESC[] = {
     // Input (Data, Variable, Relative): 3 position bytes (X, Y, Wheel)
     0x81, 0x06,
 
-    // Usage Page (Consumer Page)
-    0x05, 0x0C,
-    // Usage(AC Pan)
-    0x0A, 0x38, 0x02,
-    // Logical Minimum (-127)
-    0x15, 0x81,
-    // Logical Maximum (127)
-    0x25, 0x7F,
-    // Report Size (8)
-    0x75, 0x08,
-    // Report Count (1)
-    0x95, 0x01,
-    // Input (Data, Variable, Relative): 1 byte (AC Pan)
-    0x81, 0x06,
-
     // End Collection
     0xC0,
 
@@ -166,6 +151,11 @@ sc_hid_buttons_from_buttons_state(uint8_t buttons_state) {
     return c;
 }
 
+void
+sc_hid_mouse_init(struct sc_hid_mouse *hid) {
+    hid->acc_vscroll = 0;
+}
+
 void
 sc_hid_mouse_generate_input_from_motion(struct sc_hid_input *hid_input,
                                     const struct sc_mouse_motion_event *event) {
@@ -175,8 +165,7 @@ sc_hid_mouse_generate_input_from_motion(struct sc_hid_input *hid_input,
     data[0] = sc_hid_buttons_from_buttons_state(event->buttons_state);
     data[1] = CLAMP(event->xrel, -127, 127);
     data[2] = CLAMP(event->yrel, -127, 127);
-    data[3] = 0; // no vertical scrolling
-    data[4] = 0; // no horizontal scrolling
+    data[3] = 0; // wheel coordinates only used for scrolling
 }
 
 void
@@ -188,27 +177,33 @@ sc_hid_mouse_generate_input_from_click(struct sc_hid_input *hid_input,
     data[0] = sc_hid_buttons_from_buttons_state(event->buttons_state);
     data[1] = 0; // no x motion
     data[2] = 0; // no y motion
-    data[3] = 0; // no vertical scrolling
-    data[4] = 0; // no horizontal scrolling
+    data[3] = 0; // wheel coordinates only used for scrolling
 }
 
 bool
-sc_hid_mouse_generate_input_from_scroll(struct sc_hid_input *hid_input,
+sc_hid_mouse_generate_input_from_scroll(struct sc_hid_mouse *hid,
+                                        struct sc_hid_input *hid_input,
                                     const struct sc_mouse_scroll_event *event) {
-    if (!event->vscroll_int && !event->hscroll_int) {
-        // Need a full integral value for HID
-        return false;
-    }
-
     sc_hid_mouse_input_init(hid_input);
 
     uint8_t *data = hid_input->data;
     data[0] = 0; // buttons state irrelevant (and unknown)
     data[1] = 0; // no x motion
     data[2] = 0; // no y motion
-    data[3] = CLAMP(event->vscroll_int, -127, 127);
-    data[4] = CLAMP(event->hscroll_int, -127, 127);
+
+    hid->acc_vscroll += event->vscroll;
+    if (hid->acc_vscroll > -1 && hid->acc_vscroll < 1) {
+        // Not enough scrolling to inject a scroll tick
+        return false;
+    }
+
+    hid->acc_vscroll = CLAMP(hid->acc_vscroll, -127, 127);
+    int8_t consume = hid->acc_vscroll; // truncate towards 0
+    assert(consume);
+    hid->acc_vscroll -= consume;
+    data[3] = consume;
     return true;
+    // Horizontal scrolling ignored
 }
 
 void sc_hid_mouse_generate_open(struct sc_hid_open *hid_open) {

app/src/hid/hid_mouse.h

@@ -8,6 +8,13 @@
 
 #define SC_HID_ID_MOUSE 2
 
+struct sc_hid_mouse {
+    float acc_vscroll;
+};
+
+void
+sc_hid_mouse_init(struct sc_hid_mouse *hid);
+
 void
 sc_hid_mouse_generate_open(struct sc_hid_open *hid_open);
 
@@ -23,7 +30,8 @@ sc_hid_mouse_generate_input_from_click(struct sc_hid_input *hid_input,
                                     const struct sc_mouse_click_event *event);
 
 bool
-sc_hid_mouse_generate_input_from_scroll(struct sc_hid_input *hid_input,
+sc_hid_mouse_generate_input_from_scroll(struct sc_hid_mouse *hid,
+                                        struct sc_hid_input *hid_input,
                                     const struct sc_mouse_scroll_event *event);
 
 #endif

app/src/input_events.h

@@ -393,8 +393,6 @@ struct sc_mouse_scroll_event {
     struct sc_position position;
     float hscroll;
     float vscroll;
-    int32_t hscroll_int;
-    int32_t vscroll_int;
     uint8_t buttons_state; // bitwise-OR of sc_mouse_button values
 };
 

app/src/input_manager.c

@@ -897,14 +897,12 @@ 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)
-        .hscroll = event->preciseX,
-        .vscroll = event->preciseY,
+        .hscroll = CLAMP(event->preciseX, -1.0f, 1.0f),
+        .vscroll = CLAMP(event->preciseY, -1.0f, 1.0f),
 #else
-        .hscroll = event->x,
-        .vscroll = event->y,
+        .hscroll = CLAMP(event->x, -1, 1),
+        .vscroll = CLAMP(event->y, -1, 1),
 #endif
-        .hscroll_int = event->x,
-        .vscroll_int = event->y,
         .buttons_state = im->mouse_buttons_state,
     };
 

app/src/uhid/mouse_uhid.c

@@ -55,7 +55,8 @@ sc_mouse_processor_process_mouse_scroll(struct sc_mouse_processor *mp,
     struct sc_mouse_uhid *mouse = DOWNCAST(mp);
 
     struct sc_hid_input hid_input;
-    if (!sc_hid_mouse_generate_input_from_scroll(&hid_input, event)) {
+    if (!sc_hid_mouse_generate_input_from_scroll(&mouse->hid, &hid_input,
+                                                 event)) {
         return;
     }
 
@@ -65,6 +66,8 @@ sc_mouse_processor_process_mouse_scroll(struct sc_mouse_processor *mp,
 bool
 sc_mouse_uhid_init(struct sc_mouse_uhid *mouse,
                    struct sc_controller *controller) {
+    sc_hid_mouse_init(&mouse->hid);
+
     mouse->controller = controller;
 
     static const struct sc_mouse_processor_ops ops = {

app/src/uhid/mouse_uhid.h

@@ -4,11 +4,13 @@
 #include <stdbool.h>
 
 #include "controller.h"
+#include "hid/hid_mouse.h"
 #include "trait/mouse_processor.h"
 
 struct sc_mouse_uhid {
     struct sc_mouse_processor mouse_processor; // mouse processor trait
 
+    struct sc_hid_mouse hid;
     struct sc_controller *controller;
 };
 

app/src/usb/mouse_aoa.c

@@ -42,9 +42,7 @@ sc_mouse_processor_process_mouse_scroll(struct sc_mouse_processor *mp,
     struct sc_mouse_aoa *mouse = DOWNCAST(mp);
 
     struct sc_hid_input hid_input;
-    if (!sc_hid_mouse_generate_input_from_scroll(&hid_input, event)) {
-        return;
-    }
+    sc_hid_mouse_generate_input_from_scroll(&mouse->hid, &hid_input, event);
 
     if (!sc_aoa_push_input(mouse->aoa, &hid_input)) {
         LOGW("Could not push AOA HID input (mouse scroll)");
@@ -64,6 +62,8 @@ sc_mouse_aoa_init(struct sc_mouse_aoa *mouse, struct sc_aoa *aoa) {
         return false;
     }
 
+    sc_hid_mouse_init(&mouse->hid);
+
     static const struct sc_mouse_processor_ops ops = {
         .process_mouse_motion = sc_mouse_processor_process_mouse_motion,
         .process_mouse_click = sc_mouse_processor_process_mouse_click,

app/src/usb/mouse_aoa.h

@@ -5,12 +5,14 @@
 
 #include <stdbool.h>
 
+#include "hid/hid_mouse.h"
 #include "usb/aoa_hid.h"
 #include "trait/mouse_processor.h"
 
 struct sc_mouse_aoa {
     struct sc_mouse_processor mouse_processor; // mouse processor trait
 
+    struct sc_hid_mouse hid;
     struct sc_aoa *aoa;
 };
 

app/src/usb/screen_otg.c

@@ -164,15 +164,8 @@ sc_screen_otg_process_mouse_wheel(struct sc_screen_otg *screen,
 
     struct sc_mouse_scroll_event evt = {
         // .position not used for HID events
-#if SDL_VERSION_ATLEAST(2, 0, 18)
-        .hscroll = event->preciseX,
-        .vscroll = event->preciseY,
-#else
         .hscroll = event->x,
         .vscroll = event->y,
-#endif
-        .hscroll_int = event->x,
-        .vscroll_int = event->y,
         .buttons_state = sc_mouse_buttons_state_from_sdl(sdl_buttons_state),
     };
 

server/src/main/java/com/genymobile/scrcpy/Server.java

@@ -97,6 +97,7 @@ public final class Server {
         boolean audio = options.getAudio();
         boolean sendDummyByte = options.getSendDummyByte();
 
+        prepareMainLooper();
         Workarounds.apply();
 
         List<AsyncProcessor> asyncProcessors = new ArrayList<>();
@@ -229,8 +230,6 @@ public final class Server {
             Ln.e("Exception on thread " + t, e);
         });
 
-        prepareMainLooper();
-
         Options options = Options.parse(args);
 
         Ln.disableSystemStreams();

server/src/main/java/com/genymobile/scrcpy/control/ControlMessageReader.java

@@ -112,9 +112,8 @@ public class ControlMessageReader {
 
     private ControlMessage parseInjectScrollEvent() throws IOException {
         Position position = parsePosition();
-        // Binary.i16FixedPointToFloat() decodes values assuming the full range is [-1, 1], but the actual range is [-16, 16].
-        float hScroll = Binary.i16FixedPointToFloat(dis.readShort()) * 16;
-        float vScroll = Binary.i16FixedPointToFloat(dis.readShort()) * 16;
+        float hScroll = Binary.i16FixedPointToFloat(dis.readShort());
+        float vScroll = Binary.i16FixedPointToFloat(dis.readShort());
         int buttons = dis.readInt();
         return ControlMessage.createInjectScrollEvent(position, hScroll, vScroll, buttons);
     }