circle method, forming arcs, small problem

[wengang]

This is modified from an example I found in one of my books:

For t = 1 To 10
arc1 = arc2
arc2 = arc1 + (2 * 3.14159) * (0.1)
tColor = 20 * t
Picture1.FillColor = RGB(Int(tColor) / 2, tColor, 255 - tColor)
Picture1.Circle (Picture1.ScaleWidth / 2, Picture1.ScaleHeight / 2), (Picture1.ScaleHeight / 2.1), , -arc1, -arc2
Next t

If you follow that, it makes 10 arcs,each one 1/10 of a full circle
and each one starting where the last one stopped.
(Don't worry about the color, just for a clear picture of what's happening)

I used this to make a pie chart where 10 is the number of groups form my database. Then 0.1 is actually the ratio of group value to total value. (not relevant to the problem)

The problem, which is really just an annoyance, is that the first arc, beginning at zero, is not closed, and therefore does not hold color. It will remain the color of the background (picture or the form where it is drawn). I've tried to overlap it, but vb won't allow continuing past 2pi, I've tried putting a new arc of the same value at positions 0 and value 1 * 2pi (basically drawing the arc again on top of itself), but the arc that begins at zero has no line connecting it back to the center of the circle.

I know I could do a line command to make a radius out to the circle, then use floodfill to color in the area, but that is risky as the values change, and also I believe there should be a mathematical (geometric) solution that I've overlooked. Anybody?

PS, please don't suggest MS Chart control.
I'm really trying to make add-on object-free apps.

Thanks all.

Wengang

[wengang]

This is a temporary workaround that works pretty well,



arc1 = 0
arc2 = 0.001 '1/600 of circle
Picture1.Circle (Picture1.ScaleWidth / 2, Picture1.ScaleHeight / 2), (Picture1.ScaleHeight / 2.1), , -arc1, -arc2


For t = 1 To 10
arc1 = arc2
arc2 = arc1 + (2 * 3.14159) * (0.1)
'/////////add this line
If i = 1 Then arc2 = arc2 - 0.001
'////////
tColor = 20 * t
Picture1.FillColor = RGB(Int(tColor) / 2, tColor, 255 - tColor)
Picture1.Circle (Picture1.ScaleWidth / 2, Picture1.ScaleHeight / 2), (Picture1.ScaleHeight / 2.1), , -arc1, -arc2
Next t


adding the small slice has no visible impact on the pie, and it is compensated for in the largest slice of pie ( a piece of code I didn't include puts the groups in order largest to smallest, so that the 0.001 is taken from the largest piece)

I may leave it at that