how does a circuit maker works i.e how does it analyses the circuit given to it..

Are you talking about how a chip interprets the instructions given to it? If so that would be more on a site that talks about electromechanical engineering. Although a short version would be on the chip there are objects called logic gates, a current is passed through these gates and the gate has a chance to alter the current, the resulting current flow will be similar to a logical operator of and, or, nor, etc.

Even simpler version is the chip has millions of little on and off switches each interpreting a 0 or a 1.

Am I in the ballpark to what you are asking?

Ooops I just reread your post. I think i am way off lol.

Are you talking about the programs used in making circuits on the computer, and then testing it or simulating it?

It could potentially be done by hand. So the algorithms are programmed into the software, to be able to work with a circuit design.

actually i wanna create a small version of the circuitmaker in c++
can anybody give some idea on how to do so

Ignoring the modeling issues which are basically just a GUI to circuit definition, the simulation part is where the challenge is.

Each component of a circuit is essentially a function between a set of inputs and outputs. Connections between components have certain properties, such as current and resistance. These connections connect multiple components, which in turn alter the properties of the connections.

As an example - you have a wire going through a resistor. After applying some current to input of the resistor, the output will be altered.

Each circuit however has temporal properties - the response to input does not result in instance change in output. Depending on how accurate you want your simulation to be, these properties need to be taken into account.

The simulation the simply runs at some fixed time step, and at each step simulates the outputs of these individual components.

As a non-trivial example you can look at JK flip-flop(a simple 1 bit memory cell. The wikipedia page contains some approximations of how current changes. That's a somewhat abstracted view.

For accurate simulation of basic components you'll need to look into EE materials which describe the response functions of individual components. I don't have any practical advice with regard to that, logical gates is the lowest I've ever simulated.

BTW: this is considerably less trivial than it sounds if done accurately, approximations however may yield unexpected results, or be completely unable to simulate certain, even very basic circuits.

i wanna know:

suppose user clicks and gate button . then at first , i will draw a and gate on a corner on my opengl window. then user will try to move it to place it in its proper place......... how to make that movement possible

thanks

can someone provide me some help in making a circuit maker in c++
i.e how to represent and evaluate the circuit drawn by the user stc stc

someone please help

You need to ask a specific question. "I need help" is not a question.

We aren't going to tell you how to write your program. It's your program, hence *you* must figure it out. If you run into a roadblock, we can help you to get through something specific. If in general, you have no idea what you are doing, it's a clue that your expertise level is far too low.