allow user to start and escape experiments with keyboard and vr controllers

eegnb/experiments/Experiment.py

@@ -11,6 +11,7 @@
 from abc import abstractmethod
 from typing import Callable
 from psychopy import prefs
+from psychopy.visual.rift import Rift
 #change the pref libraty to PTB and set the latency mode to high precision
 prefs.hardware['audioLib'] = 'PTB'
 prefs.hardware['audioLatencyMode'] = 3
@@ -50,8 +51,11 @@ def __init__(self, exp_name, duration, eeg, save_fn, n_trials: int, iti: float,
         self.soa = soa
         self.jitter = jitter
         self.use_vr = use_vr
+        if use_vr:
+            # VR interface accessible by specific experiment classes for customizing and using controllers.
+            self.rift: Rift = visual.Rift(monoscopic=True, headLocked=True)
         self.use_fullscr = use_fullscr
-        self.window_size = [1600,800] 
+        self.window_size = [1600,800]
 
     @abstractmethod
     def load_stimulus(self):
@@ -86,7 +90,7 @@ def setup(self, instructions=True):
 
         # Setting up Graphics 
         self.window = (
-            visual.Rift(monoscopic=True, headLocked=True) if self.use_vr
+            self.rift if self.use_vr
             else visual.Window(self.window_size, monitor="testMonitor", units="deg", fullscr=self.use_fullscr))
 
         # Loading the stimulus from the specific experiment, throws an error if not overwritten in the specific experiment
@@ -123,15 +127,71 @@ def show_instructions(self):
         # Disabling the cursor during display of instructions
         self.window.mouseVisible = False
 
-        # Waiting for the user to press the spacebar to start the experiment
-        while len(event.getKeys(keyList="space")) == 0:
+        # clear/reset any old key/controller events
+        self.__clear_user_input()
+
+        # Waiting for the user to press the spacebar or controller button or trigger to start the experiment
+        while not self.__user_input('start'):
             # Displaying the instructions on the screen
             text = visual.TextStim(win=self.window, text=self.instruction_text, color=[-1, -1, -1])
             self.__draw(lambda: self.__draw_instructions(text))
 
             # Enabling the cursor again
             self.window.mouseVisible = True
 
+    def __user_input(self, input_type):
+        if input_type == 'start':
+            key_input = 'spacebar'
+            vr_inputs = [
+                ('RightTouch', 'A', True),
+                ('LeftTouch', 'X', True),
+                ('Xbox', 'A', None)
+            ]
+
+        elif input_type == 'cancel':
+            key_input = 'escape'
+            vr_inputs = [
+                ('RightTouch', 'B', False),
+                ('LeftTouch', 'Y', False),
+                ('Xbox', 'B', None)
+            ]
+
+        if len(event.getKeys(keyList=key_input)) > 0:
+            return True
+
+        if self.use_vr:
+            for controller, button, trigger in vr_inputs:
+                if self.get_vr_input(controller, button, trigger):
+                    return True
+
+        return False
+
+    def get_vr_input(self, vr_controller, button=None, trigger=False):
+        """
+        Method that returns True if the user presses the corresponding vr controller button or trigger
+        Args:
+            vr_controller: 'Xbox', 'LeftTouch' or 'RightTouch'
+            button: None, 'A', 'B', 'X' or 'Y'
+            trigger (bool): Set to True for trigger
+
+        Returns:
+
+        """
+        trigger_squeezed = False
+        if trigger:
+            for x in self.rift.getIndexTriggerValues(vr_controller):
+                if x > 0.0:
+                    trigger_squeezed = True
+
+        button_pressed = False
+        if button is not None:
+            button_pressed, tsec = self.rift.getButtons([button], vr_controller, 'released')
+
+        if trigger_squeezed or button_pressed:
+            return True
+
+        return False
+
     def __draw_instructions(self, text):
         text.draw()
         self.window.flip()
@@ -147,6 +207,17 @@ def __draw(self, present_stimulus: Callable):
             self.window.setDefaultView()
         present_stimulus()
 
+    def __clear_user_input(self):
+        event.getKeys()
+        self.clear_vr_input()
+
+    def clear_vr_input(self):
+        """
+        Clears/resets input events from vr controllers
+        """
+        if self.use_vr:
+            self.rift.updateInputState()
+
     def run(self, instructions=True):
         """ Do the present operation for a bunch of experiments """
 
@@ -171,7 +242,11 @@ def iti_with_jitter():
 
         # Current trial being rendered
         rendering_trial = -1
-        while len(event.getKeys()) == 0 and (time() - start) < self.record_duration:
+
+        # Clear/reset user input buffer
+        self.__clear_user_input()
+
+        while not self.__user_input('cancel') and (time() - start) < self.record_duration:
 
             current_experiment_seconds = time() - start
             # Do not present stimulus until current trial begins(Adhere to inter-trial interval).