C++ library for drawing graphics [closed]

Question

Someone can suggest me a good, free, easy to use library for c++ that allow to draw a mathematical function in a window for microsoft windows? (e.g. the parabola x^2+5x+3=0)

Answer 1

Since you need a ready-made plotting widget, use Qwt.

It uses Qt.

You could use Qt directly as in contero's answer, without Qwt, as the task is simple enough. However, Qwt has lots of graph features built in, and the usage is straightforward.

Answer 2

Another option is wxMathPlot which is wxWidgets based.
From it's website:
wxMathPlot main features:

• Completely mouse-driven view control: pan, zoom, scroll, box positioning.
• Printing class.
• Screenshot saving of plot window (BMP, PNG and JPEG formats).
• Overlay movable boxes with legend or mouse coordinate display.
• Can set margins to avoid plots to cover axis labels.
• Flexible axis positioning
• A series of useful layer to directly plot data from STL vector, movable objects, covariance ellipse, bitmaps, etc.
• Multi-platform: runs everywhere wxWidgets does.

Answer 3

You mention your language (C++) and platform (Windows), but there are frameworks available for writing a Windows C++ application: Qt, MFC, C++Builder... Additionally, C and C++ can interface with just about anything. So your decision for which plotting library to use will depend on what framework you're using for your UI and on what kind of external interfaces or dependencies you're willing to introduce:

• If you're using Qt, you should use Qwt, as Stefan Monov said.
• If you're using C++Builder, you should try TeeChart or TMS Advanced Charts.
• For wxWidgets, try wxMathPlot or wxArt2D, recommended by Eugen Constantin Dinca's answer and Parsa Jamshidi's answer.
• If you don't mind calling an external program to do your plotting, then Gnuplot is a popular and powerful solution. C and C++ libraries exist to simplify calling Gnuplot.
• If you're willing to embed Python, then Matplotlib is very popular, and Python could simplify the development of some of your charts.
• For an atypical solution, you could have your C++ library generate a jqPlot web page then point an embedded web browser at it.
• For a framework-independent C or C++ library with no external dependencies, the most promising solution I've found is PLplot, although I haven't yet had a chance to use it.

Answer 4

Definitely gnuplot, and the library gnuplot++

Answer 5

I wrote a program similar to this using Qt. Qt is wonderful once you get it set up, but it may take a bit of effort if you've never used it (as will OpenGL, DirectX, etc..).

You can create a QImage and set it to whatever background color you want, then run your program through the width of the image pixel by pixel calling your function to get the y value. Roughly:

for (int i = 0; i < imageWidth; i++) {
   image->setPixel(i, yourFunction(i), lineColor);
}

Once you've created your QImage, you can attach it to a QLabel using setPixmap(). Once you've attached it you can then display the image in a layout.

Answer 6

You can use GDI/+, OpenGL, Direct3D, Direct2D as well if you're using Vista/7. There's plenty out there.