I tried rotating a ship to build a list of rotated images, but the
rotated versions are often larger than the original, making it hard to
figure out where to place them. How can that problem be addressed?
You shouldn't build a list of images unless absolutely necessary. It will hurt your performance because of memory issues...
To figure out where to place the ships is easy.
The bliting coordinates specify the position of the top left corner of the image. You want to specify the location of the center. The center of an image is defined as the point directly between each pair of two sides. Half of the distance across and half of the distance down is the center, so:
surface = pygame.transform.rotate(image,80)
size = surface.get_size()
BlitPosition = #Where you want the image to be: e.g. (1,4)
BlitPosition[0] -= size[0]/2.0 #These are negative because the surface must be moved away from the center.
BlitPosition[1] -= size[1]/2.0 #These are negative because the surface must be moved away from the center.
HTH,
Ian