Extract conversion from u16 fixed-point to float

PR #3369 <#3369>

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

@@ -12,4 +12,16 @@ public static int toUnsigned(short value) {
     public static int toUnsigned(byte value) {
         return value & 0xff;
     }
+
+    /**
+     * Convert unsigned 16-bit fixed-point to a float between 0 and 1
+     *
+     * @param value encoded value
+     * @return Float value between 0 and 1
+     */
+    public static float u16FixedPointToFloat(short value) {
+        int unsignedShort = Binary.toUnsigned(value);
+        // 0x1p16f is 2^16 as float
+        return unsignedShort == 0xffff ? 1f : (unsignedShort / 0x1p16f);
+    }
 }

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

@@ -139,10 +139,7 @@ private ControlMessage parseInjectTouchEvent() {
         int action = Binary.toUnsigned(buffer.get());
         long pointerId = buffer.getLong();
         Position position = readPosition(buffer);
-        // 16 bits fixed-point
-        int pressureInt = Binary.toUnsigned(buffer.getShort());
-        // convert it to a float between 0 and 1 (0x1p16f is 2^16 as float)
-        float pressure = pressureInt == 0xffff ? 1f : (pressureInt / 0x1p16f);
+        float pressure = Binary.u16FixedPointToFloat(buffer.getShort());
         int buttons = buffer.getInt();
         return ControlMessage.createInjectTouchEvent(action, pointerId, position, pressure, buttons);
     }