> I need to be able to display different colored shapes on my picture
> control:rectangles, arrows, trapezoids now I know I can draw them
> using bitmaps but the hard part is that depending on other info I'll
> have to display them at different coordinates and more importantly
> facing all kinds of different ways, so how should I do this? I need to
> say have an arrow that will be facing a circle that I have drawn on my
> picture control, but it can me facing it from 360 different degrees
> and I'm sincerely hoping there is a way to do this without making 360
> bitmaps, please help!
If I were doing this, I wouldn't use bitmaps at all. The picture
control is quite good at drawing vector graphics such as lines,
rectangles and polygons. Rotating the points of
these shapes just
involves some simple trig and basic math.
I don't have enough details of what you are trying to draw, but if the
arrows are simply three lines, you can compute the primary point
tangential to the circle and compute three other points, one at the same
angle but with a longer radius and two at plus and minus 15 degree
angles. If you want to change color or other line attributes that
shouldn't be a problem either.
If you want the triangles filled, compute the same four points and
append them to make an array of points to send to the polygon VI.
It is true that there are higher performance graphics techniques, but
you can get quite a bit done with the picture control in a very short
amount of time. For examples that do similar things, you can look at
the robot arm example.
Greg McKaskle
