[client] spice: added new input:autoCapture mode

This new mode if enabled (disabled by default) will cause the client to
attempt to hold onto the mouse when a title/game has it captured in the
guest. This is best effort and is not a replacement for full capture
mode.

client/src/config.c

@@ -296,6 +296,13 @@ static struct Option options[] =
     .type           = OPTION_TYPE_BOOL,
     .value.x_bool   = true,
   },
+  {
+    .module         = "input",
+    .name           = "autoCapture",
+    .description    = "Try to keep the mouse captured when needed",
+    .type           = OPTION_TYPE_BOOL,
+    .value.x_bool   = false
+  },
 
   // spice options
   {
@@ -462,6 +469,7 @@ bool config_load(int argc, char * argv[])
   params.mouseSens           = option_get_int ("input", "mouseSens"          );
   params.rawMouse            = option_get_bool("input", "rawMouse"           );
   params.mouseRedraw         = option_get_bool("input", "mouseRedraw"        );
+  params.autoCapture         = option_get_bool("input", "autoCapture"        );
 
   params.minimizeOnFocusLoss = option_get_bool("win", "minimizeOnFocusLoss");
 

client/src/main.c

@@ -979,11 +979,29 @@ static void handleMouseNormal(double ex, double ey)
   if (x == 0 && y == 0)
     return;
 
+  if (params.autoCapture)
+  {
+    g_cursor.delta.x += x;
+    g_cursor.delta.y += y;
+
+    if (abs(g_cursor.delta.x) > 50 || abs(g_cursor.delta.y) > 50)
+    {
+      g_cursor.delta.x = 0;
+      g_cursor.delta.y = 0;
+      warpMouse(g_state.windowCX, g_state.windowCY, false);
+    }
+
+    g_cursor.guest.x = g_state.srcSize.x / 2;
+    g_cursor.guest.y = g_state.srcSize.y / 2;
+  }
+  else
+  {
     /* assume the mouse will move to the location we attempt to move it to so we
      * avoid warp out of window issues. The cursorThread will correct this if
      * wrong after the movement has ocurred on the guest */
     g_cursor.guest.x += x;
     g_cursor.guest.y += y;
+  }
 
   if (!spice_mouse_motion(x, y))
     DEBUG_ERROR("failed to send mouse motion message");

client/src/main.h

@@ -138,6 +138,7 @@ struct AppParams
   bool         mouseRedraw;
   int          mouseSens;
   bool         rawMouse;
+  bool         autoCapture;
 };
 
 struct CBRequest
@@ -215,6 +216,9 @@ struct CursorState
   /* the local X & Y position */
   struct DoublePoint pos;
 
+  /* the delta since last warp when in auto capture mode */
+  struct DoublePoint delta;
+
   /* the scale factor for the mouse sensitiviy */
   int sens;