Animals such as gliding frogs, squirrels and snakes have rather poor gliding angles, having not developed proper wings. As in aircraft spars or box-sections, the other function of the veins in the wings of an is to stiffen the cantilever that each wing actually is. The stiffening is greater near the front, so that even a crude up and down flapping will tend to produce lift and forward motion, as the angle of incidence changes during each flapping cycle. In fact the motion of the wings is very complex, and the attachment to the thorax, and the musculature and structure of the thorax, all contribute to the ability to fly. Some damsels can fly towards a spider's web, collect the spiders' prey, and fly backwards with the booty.
Most dragonflies can catch prey on the wing.
They are superb fliers. Some can fly from dawn to dusk, catching all the food they need, and looking for a mate as well. Others only perch, and dart out when prey is seen. With up to 20000 ommatidia, or individual sensing tubes, in each eye, the dragonfly can sense quite slow movements and small objects. Making reasonable assumptions, it is not difficult to calculate the smallest size and speed of what a dragonfly can see.