WIP Add "inject touch" event

app/src/control_msg.c

@@ -1,6 +1,7 @@
 #include "control_msg.h"
 
 #include <string.h>
+#include <SDL2/SDL_assert.h>
 
 #include "config.h"
 #include "buffer_util.h"
@@ -24,6 +25,16 @@ write_string(const char *utf8, size_t max_len, unsigned char *buf) {
     return 2 + len;
 }
 
+static uint16_t
+to_fixed_point_16(float f) {
+    SDL_assert(f >= 0.0f && f <= 1.0f);
+    uint32_t u = f * 0x1p16f; // 2^16
+    if (u >= 0xffff) {
+        u = 0xffff;
+    }
+    return (uint16_t) u;
+}
+
 size_t
 control_msg_serialize(const struct control_msg *msg, unsigned char *buf) {
     buf[0] = msg->type;
@@ -43,6 +54,14 @@ control_msg_serialize(const struct control_msg *msg, unsigned char *buf) {
             buffer_write32be(&buf[2], msg->inject_mouse_event.buttons);
             write_position(&buf[6], &msg->inject_mouse_event.position);
             return 18;
+        case CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT:
+            buf[1] = msg->inject_touch_event.action;
+            buffer_write64be(&buf[2], msg->inject_touch_event.pointer_id);
+            write_position(&buf[10], &msg->inject_touch_event.position);
+            uint16_t pressure =
+                to_fixed_point_16(msg->inject_touch_event.pressure);
+            buffer_write16be(&buf[22], pressure);
+            return 24;
         case CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT:
             write_position(&buf[1], &msg->inject_scroll_event.position);
             buffer_write32be(&buf[13],

app/src/control_msg.h

@@ -19,6 +19,7 @@ enum control_msg_type {
     CONTROL_MSG_TYPE_INJECT_KEYCODE,
     CONTROL_MSG_TYPE_INJECT_TEXT,
     CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT,
+    CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT,
     CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT,
     CONTROL_MSG_TYPE_BACK_OR_SCREEN_ON,
     CONTROL_MSG_TYPE_EXPAND_NOTIFICATION_PANEL,
@@ -50,6 +51,12 @@ struct control_msg {
             enum android_motionevent_buttons buttons;
             struct position position;
         } inject_mouse_event;
+        struct {
+            enum android_motionevent_action action;
+            uint64_t pointer_id;
+            struct position position;
+            float pressure;
+        } inject_touch_event;
         struct {
             struct position position;
             int32_t hscroll;

app/tests/test_control_msg_serialize.c

@@ -99,6 +99,41 @@ static void test_serialize_inject_mouse_event(void) {
     };
     assert(!memcmp(buf, expected, sizeof(expected)));
 }
+#include <stdio.h>
+static void test_serialize_inject_touch_event(void) {
+    struct control_msg msg = {
+        .type = CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT,
+        .inject_touch_event = {
+            .action = AMOTION_EVENT_ACTION_DOWN,
+            .pointer_id = 0x1234567887654321L,
+            .position = {
+                .point = {
+                    .x = 100,
+                    .y = 200,
+                },
+                .screen_size = {
+                    .width = 1080,
+                    .height = 1920,
+                },
+            },
+            .pressure = 1.0f,
+        },
+    };
+
+    unsigned char buf[CONTROL_MSG_SERIALIZED_MAX_SIZE];
+    int size = control_msg_serialize(&msg, buf);
+    assert(size == 24);
+
+    const unsigned char expected[] = {
+        CONTROL_MSG_TYPE_INJECT_TOUCH_EVENT,
+        0x00, // AKEY_EVENT_ACTION_DOWN
+        0x12, 0x34, 0x56, 0x78, 0x87, 0x65, 0x43, 0x21, // pointer id
+        0x00, 0x00, 0x00, 0x64, 0x00, 0x00, 0x00, 0xc8, // 100 200
+        0x04, 0x38, 0x07, 0x80, // 1080 1920
+        0xff, 0xff, // pressure
+    };
+    assert(!memcmp(buf, expected, sizeof(expected)));
+}
 
 static void test_serialize_inject_scroll_event(void) {
     struct control_msg msg = {
@@ -237,6 +272,7 @@ int main(void) {
     test_serialize_inject_text();
     test_serialize_inject_text_long();
     test_serialize_inject_mouse_event();
+    test_serialize_inject_touch_event();
     test_serialize_inject_scroll_event();
     test_serialize_back_or_screen_on();
     test_serialize_expand_notification_panel();