Thread: How to make circle in C++?

Hello sir,
How to make circle in c++ i am using Dev C++

What exactly do you want to do ?

Create a class Circle that describes a circle

or

Draw some circles on the screen.

HI SIR,
how to make simple circle in c++ only

One option:

Code:

class Circle
{
  Circle(int x, int y, int radius): mCenterX(x), mCenterY(y), mRadius(radius)
  {}
  int GetCenterX() const {return mCenterX;}
  int GetCenterY() const { return mCenterY;}
  int GetRadius() const {return mRadius;}
private:
  int mCenterX, mCenterY, mRadius;
};

Originally Posted by GReaper

And if you wanted to draw the circle you could do something like this:

Code:

// It returns an array of vertices to be used with GL_LINE_STRIP or equivalent
const std::vector<glm::vec2> genMesh(int segments) {
    float step = 6.283185f/segments;
    float angle = 0.0f;
    std::vector<glm::vec2> vertices;

    vertices.reserve(segments + 1);
    for (int i = 0; i < segments; ++i, angle+=step) {
        float vertX = mCenterX + cosf(angle)*mRadius;
        float vertY = mCenterY + sinf(angle)*mRadius;
        vertices.push_back(glm::vec2(vertX, vertY));
    }
    vertices.push_back(glm::vec2(mCenterX+mRadius, mCenterY));

    return vertices;
}

Hello
How to make it
please tell full code

For windows users:

Code:

#include <Windows.h>
#include <iostream>

int LastWinError()
{
  DWORD err = ERROR_SUCCESS;

  err = GetLastError();
  std::cerr << "\aWindows error: " << err << "\n\n";
  return static_cast<int>(err);
}

int main()
{
  HWND hConsole = GetConsoleWindow();
  if (hConsole ==nullptr)
  {
    return LastWinError();
  }
  HDC hDC = GetDC(hConsole);
  if (hDC == nullptr)
  {
    return LastWinError();
  }
  Ellipse(hDC, 10, 10, 100, 100);
  Sleep(5000); // wait 5 seconds to admire the circle
  ReleaseDC(hConsole, hDC);
}

Normally you would create a full Windows application, but for simple demos the console is sufficient.

Originally Posted by OldGuy2

For windows users:

Code:

#include <Windows.h>
#include <iostream>

int LastWinError()
{
  DWORD err = ERROR_SUCCESS;

  err = GetLastError();
  std::cerr << "\aWindows error: " << err << "\n\n";
  return static_cast<int>(err);
}

int main()
{
  HWND hConsole = GetConsoleWindow();
  if (hConsole ==nullptr)
  {
    return LastWinError();
  }
  HDC hDC = GetDC(hConsole);
  if (hDC == nullptr)
  {
    return LastWinError();
  }
  Ellipse(hDC, 10, 10, 100, 100);
  Sleep(5000); // wait 5 seconds to admire the circle
  ReleaseDC(hConsole, hDC);
}

Normally you would create a full Windows application, but for simple demos the console is sufficient.

hello sir
it is showing error

You need to compile it with C++11 or replace nullptr with NULL or 0

hello sir,
now it showing error
how compile it with C++11

yes, now you have to make everything conform with that standard.
( I cannot make out whatever is in the photo)
essentially if you get an error, update that bit of code to conform to the c++11 standard, google is a good helper.
Just type in the error into the search, and refine it if needed to see if someone else had same problem.
So you can get the solution. or post everything in here and wait.

You need to include Gdi32.lib

Originally Posted by Rodaxoleaux

This guy has absolutely no idea what he's doing and hasn't explained why or shown anything that he's tried. I don't even think he knows what he's doing.

Well I guess that's the way nowadays with the internet. Instead of getting a book and learning people just ask questions on forums.