add trackball-use-alt-keys

panda/src/tform/config_tform.cxx

@@ -54,6 +54,13 @@ ConfigVariableDouble drive_horizontal_ramp_down_time
 ConfigVariableDouble inactivity_timeout
 ("inactivity-timeout", 0.0);
 
+ConfigVariableBool trackball_use_alt_keys
+("trackball-use-alt-keys", true,
+ PRC_DESC("Set this true to use the command and option/control keys in "
+	  "conjunction with the first mouse button to simulate the behavior of "
+	  "the second and third mouse buttons in trackball mode.  Particularly "
+	  "useful for Macs, or laptops with limited mouse buttons."));
+
 ConfigureFn(config_tform) {
   DriveInterface::init_type();
   ButtonThrower::init_type();

panda/src/tform/config_tform.h

@@ -18,6 +18,7 @@
 #include "pandabase.h"
 #include "notifyCategoryProxy.h"
 #include "configVariableDouble.h"
+#include "configVariableBool.h"
 
 NotifyCategoryDecl(tform, EXPCL_PANDA_TFORM, EXPTP_PANDA_TFORM);
 
@@ -36,4 +37,6 @@ extern EXPCL_PANDA_TFORM ConfigVariableDouble drive_horizontal_ramp_down_time;
 
 extern EXPCL_PANDA_TFORM ConfigVariableDouble inactivity_timeout;
 
+extern EXPCL_PANDA_TFORM ConfigVariableBool trackball_use_alt_keys;
+
 #endif

panda/src/tform/trackball.cxx

@@ -63,12 +63,13 @@ Trackball(const string &name) :
   watch_button(MouseButton::two());
   watch_button(MouseButton::three());
 
-#ifdef IS_OSX
-  // In OSX mode, we need to use the command and option key in
-  // conjunction with the (one) mouse button.
-  watch_button(KeyboardButton::meta());
-  watch_button(KeyboardButton::alt());
-#endif
+  if (trackball_use_alt_keys) {
+    // In OSX mode, we need to use the command and option key in
+    // conjunction with the (one) mouse button.
+    watch_button(KeyboardButton::control());
+    watch_button(KeyboardButton::meta());
+    watch_button(KeyboardButton::alt());
+  }
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -554,15 +555,14 @@ do_transmit_data(DataGraphTraverser *, const DataNodeTransmit &input,
     int this_button = 0;
     
     if (is_down(MouseButton::one())) {
-#ifdef IS_OSX
       if (is_down(KeyboardButton::alt())) {
         // B1 + alt (option) = B2.
         this_button |= B2_MASK;
-        if (is_down(KeyboardButton::meta())) {
+        if (is_down(KeyboardButton::meta()) || is_down(KeyboardButton::control())) {
           this_button |= B3_MASK;
         }
 
-      } else if (is_down(KeyboardButton::meta())) {
+      } else if (is_down(KeyboardButton::meta()) || is_down(KeyboardButton::control())) {
         // B1 + meta (command) = B3.
         this_button |= B3_MASK;
 
@@ -570,9 +570,6 @@ do_transmit_data(DataGraphTraverser *, const DataNodeTransmit &input,
         // Without a special key, B1 is B1.
         this_button |= B1_MASK;
       }
-#else   // IS_OSX
-      this_button |= B1_MASK;
-#endif  // IS_OSX
     }
     if (is_down(MouseButton::two())) {
       this_button |= B2_MASK;