how to draw a dynamic curve

jhwurmbach

What is your problem? In OnDraw(), you draw the curve (MoveTo(), LineTo()) into the client rect. Whenever you get new data and fell the need to redraw, you Invalidate().

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chandu004

have you googled to for "Active X Control to draw a curve" there are somany articles and active X controls related to that topic. or if you want to develop one active X control, then i can guide you.

nibabug

hello thanks for your answer my problem is, how to make the curve move smoothly? it move from right to left with time going

wuhuaiji

Hamid Taebi

See An MFC Curve Control[^] and GDI+ Line/Curve Drawing and Hit Test[^].

jhwurmbach

Do you want algorithms to interpolate and smooth the curve-data? Or do you want to reduce flicker on the screen? Either case, there are articles here on codeproject and on the net. E.G. here[^].

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Hamid Taebi

But why he must uses of Activexs control?

nibabug

thanks i have googled, and now i know how to draw a static curve but i want to draw a dynamic curve, which can move smoothly with time going

wuhuaiji

chandu004

good question, but as he said, he want to draw it on a picture. so i thought, he would have to develop an AX to fulfil his task. iam not sure, weather any existing control, has a mixture of both image and a graph on it.

chandu004

what is the difference you are referring to as static and dynamic curves. you mean, you want to see the curve increasing from time to time, at run time? if it is so, put your plotting code in a thread. but i can suggest ful fledgedly, only, if u can provide a sample of code here, how you made it static. gud luck.

Cedric Moonen

Why are you so obsessed with ActiveX controls :omg:. Why not simply use a custom control ? Do you know why ActiveX are used ? Do you know that the purpose of ActiveX is to have a control that can be used in different languages. If you just developping a C++ app, why bothering with an ActiveX when you can simply use a custom control.

Cédric Moonen Software developer
Charting control [v1.2]

Nishad S

Why you cant draw a curve with existing APIs? What kind of data and curve are you intended to use?

- NS -

Cedric Moonen

You have two options: 1) Use an existing control, there are plenty existing on this website. I also developped one control that can do that (see the link in my sig). I think it is the easiest solution and the one that will save you a lot of troubles. 2) Create your own control. You seem to have some problems with the fact that the line should move. Well, there is no miracle: if you want to do such a thing, you have to make it move yourself (redraw the line completely). I warn you that this is far from being the easiest solution. If you are completely new to this, I suggest you take the first option. But if you have some time and want to learn how it works, then it can be interesting to take that path. But then, start by reading some tutorials about how to create custom controls before starting to create your own.

Cédric Moonen Software developer
Charting control [v1.2]

chandu004

yes you are right. But i feel comfortable with AX because most of the times I use it in other languages also. Thats why i'm used to that. Thank You.

Cedric Moonen

Well, but for somebody that only wants to use a control in its C++ application, this is a bad advice to tell him to develop its own ActiveX control. Why do you want to make things even more complex to him ? Developping an ActiveX control is more complicated than developping a simple custom control.

Cédric Moonen Software developer
Charting control [v1.2]

nibabug

thanks a lot first, i am a newbie, ;P then, i just want draw a curve, which can move now i have got many friends' help, thanks for all of your answer and i think maybe i have found the solution indeed, the question is a little problem, the big problem is that i am fresh in VC

wuhuaiji

chandu004

yes and thanks, i agree to your point.