Help with circles

Is there a way to make a graphic go in a circle in a loop? I want to make several green circles go around a charcter for a cure spell in an RPG, and wasn't sure if a circle equation was easy to do, if you can help, many thanks to you...

This example demonstrates a neet circle effect using the Circle() Function. There is also a circle method for some of the objects. If you are using a picturebox this should not be that hard.

Put a timer and a picturebox on the form and paste this code. Also put a small graphic in the picbox so you can see the circles flashing around it.

<pre><font color=blue>Option Explicit</font color=blue>

<font color=blue>Private Sub</font color=blue> Form_Load()

<font color=blue>With</font color=blue> Timer1
.Interval = 100
.Enabled = <font color=blue>True</font color=blue>
<font color=blue>End With</font color=blue>

Picture1.Move 50, 50, 400, 400

<font color=blue>With</font color=blue> Me
.Height = 5000
.Width = 5000
.Left = (Screen.Width / 2) - (Me.Width / 2)
.Top = (Screen.Height / 2) - (Me.Height / 2)
<font color=blue>End With</font color=blue>

<font color=blue>End Sub</font color=blue>

<font color=blue>Private Sub</font color=blue> Timer1_Timer()

<font color=blue>Dim</font color=blue> sngX <font color=blue>As Single</font color=blue>
<font color=blue>Dim</font color=blue> sngY <font color=blue>As Single</font color=blue>
<font color=blue>Dim</font color=blue> sngRadius <font color=blue>As Single</font color=blue>
<font color=blue>Dim</font color=blue> sngLimit <font color=blue>As Single</font color=blue>

ScaleMode = 3 <font color=green>'<---------------------------Set scale to pixels.</font color=green>
sngX = ScaleWidth / 2 <font color=green>'<-------------------Set X position.</font color=green>
sngY = ScaleHeight / 2 <font color=green>'<------------------Set Y position.</font color=green>

<font color=blue>If</font color=blue> sngX > sngY <font color=blue>Then</font color=blue>
sngLimit = sngY
<font color=blue>Else</font color=blue>
sngLimit = sngX
<font color=blue>End If</font color=blue>

<font color=blue>For</font color=blue> sngRadius = 100 <font color=blue>To</font color=blue> sngLimit <font color=blue>Step</font color=blue> 1 <font color=green>'<----Set radius.</font color=green>
Picture1.<font color=blue>Circle</font color=blue> (sngX, sngY), sngRadius, RGB(Rnd * 255, Rnd * 255, Rnd * 255)
<font color=blue>Circle</font color=blue> (sngX, sngY), sngRadius, RGB(Rnd * 255, Rnd * 255, Rnd * 255)
<font color=blue>Next</font color=blue> sngRadius

<font color=blue>End Sub</font color=blue></pre>


Good Luck

JDT

Oh ya, play around with the Step in the For Loop to see some differences, like Step 5. And you can also change the starting value in the For Loop to a higher number for less circles and a lower number for more.

JDT

....or did you mean you want an image of a circle to move in a circular orbit around the character?

"I have a plan so cunning you could put a tail on it and call it a weasel!" - Edmund Blackadder

im gonna use it for a sorta cheaper :) way of making splashes of water in my game, but I was wondering
if you could make it like light blue on the inner circles than the circles get larger and become darker..?

i am making a sorta of rpg
more of a boat game where you shoot other boats and its for the water effects of cannon balls hitting water

~

BillSoo,

I don't know if he meant that or not, but could you share that with us. It could be pretty cool for getting attention on a form.

Don

Time is the best teacher; unfortunately it kills all its students.

Well....it's a bit complicated because it depends somewhat on how you were drawing the circles in the first place...let's suppose the circle is a SHAPE control in the form of a circle. In other words, it's an object which we'll call shp. Let's also suppose, you want it to orbit a point designated by X, Y at a radius of R. These variables could change (ie. if the RPG character is walking or something). You could do something like:

<pre><font color=blue>Option Explicit</font color=blue>

<font color=blue>Const</font color=blue> PI = 3.14159265358979
<font color=blue>Dim</font color=blue> X#, Y#, R#

<font color=blue>Sub</font color=blue> Timer1_Timer()
<font color=green>'x,y and r are set outside this function somewhere...</font color=green>
<font color=blue>Static</font color=blue> theta# <font color=green>'angle in radians</font color=green>
<font color=blue>Dim</font color=blue> sx#, sy#

sx = Cos(theta) * R + X
sy = Sin(theta) * R + Y
shp.Move sx, sy
theta = theta + 5 * PI / 180 <font color=green>'increment by 5 degrees</font color=green>
<font color=blue>End Sub</font color=blue>

</pre>




"I have a plan so cunning you could put a tail on it and call it a weasel!" - Edmund Blackadder

Hey BillSoo, yeah, I wanted the cureballs to orbit the character, I didn't think I made it that clear at first, anyway, just to clarify

You said...

Const PI = 3.14 (jadda-jadda-jadda)

Does the computer have a thing where you could just say PI, or do you have to dimension it?

I've been declaring my own PI constants (and TWOPI and HALFPI) since VB3. I don't know if they've since added it to the language, but I doubt it....



"I have a plan so cunning you could put a tail on it and call it a weasel!" - Edmund Blackadder