Thread: Drawing polygons?

How do I draw polygons, like a triangle in dos? Can anyone help?

Are you using a library or your own homemade code?

a libary I think, I'm trying to do it in turbo C++ using graphics.h but I cant get it right

Yeah, you're using the BGI graphics library (most likely).

Code:

#include <graphics.h>
#include <conio.h>

int main()
{
   int gdriver = DETECT, gmode;
   int triangle[8];

   // Let's define a triangle with vertices at A(1, 1), B(30, 100), and C(100, 150).
   triangle[0] = 1; // x of vertex A.
   triangle[1] = 1; // y of vertex A.
   triangle[2] = 30; // x of vertex B.
   triangle[3] = 100; // y of vertex B.
   triangle[4] = 100; // x of vertex C.
   triangle[5] = 150; // y of vertex C.
   triangle[6] = triangle[0]; // Close triangle.
   triangle[7] = triangle[1];

   initgraph(&gdriver, &gmode, ""); // Init the graphics mode.
   setcolor(15); // Set color to white.
   drawpoly(4, triangle);  // Draw the three sided figure!

   getch();
   closegraph(); // Exit graphics mode.
   return 0;
}

Cool Thanks!

Hmmm. when i compiled that with Borland 3.1 C++ it compiled and linked with out a problem but when i executed it, it said this in the DOS shell "BGI Error: Graphics not initialized (use 'initgraph')", Does anyone have any suggestions why i received that error even thought it linked fine?

U have to use a dos based compiler like Turbo C++ that uses graphics.h which is meant for BGI graphics

>Hmmm. when i compiled that with Borland 3.1 C++ it compiled and linked with out a problem but when i executed it, it said this in the DOS shell "BGI Error: Graphics not initialized (use 'initgraph')", Does anyone have any suggestions why i received that error even thought it linked fine?<

Go to your Borland C++ directory. Look for a subdirectory called BGI. In there, should be a file called egavga.bgi. Copy it to the location of the program. Now try running it.


>U have to use a dos based compiler like Turbo C++ that uses graphics.h which is meant for BGI graphics<

If I'm not mistaken, Borland C++ 3.1 is for DOS.

Hmm.... Actually i do not have that file, could somebody please e-mail that file to [email protected]

Your wish is my command

I don't have graphics.h...
can someone please paste the source of it here?