Legacy
The legacy back-end is built on top of PyGame in non-OpenGL mode. The downside of this is that there is no hardware acceleration, and the timing properties are not as good as that of the psycho or xpyriment back-ends. The upside is that PyGame is very easy to use, very reliable, and well supported on a wide range of platforms.
Mouse-cursor visibility
On some systems, the mouse cursor is not visible when using the legacy back-end in fullscreen mode. You can work around this is the following ways:
- Open the legacy back-end settings and set “Double buffering” to “no”.
- Note: This may disable v-sync, which can be important for time critical experiments, as discussed here: /miscellaneous/timing/.
- Open the legacy back-end settings and set “Custom cursor” to “yes”.
- Switch to another back-end.
Using PyGame directly
PyGame is well documented and you can find everything you need to know about using PyGame on http://www.pygame.org/docs/. Specific to OpenSesame is the fact that the display surface is stored as self.experiment.window or simply win. So the following code snippet, which you could paste into an inline_script item, draws a red rectangle to the display:
import pygame # Import the PyGame module
pygame.draw.rect(self.experiment.window, pygame.Color("red"),
[20, 20, 100, 100]) # Draw a red rectangle. Not shown yet...
pygame.display.flip() # Update the display to show the red rectangle.
