BUG: Arc Drawn Incorrectly When Bounding Rectangle Large

MS-DOS                      | WINDOWS

The information in this article applies to:

• The C Run-time (CRT), included with:

      - Microsoft C for MS-DOS, versions 5.1, 6.0, 6.0a, and 6.0ax
      - Microsoft C/C++ for MS-DOS, version 7.0
      - Microsoft Visual C++ for Windows, versions 1.0, 1.5, and 1.51
  

SYMPTOMS

The first four parameters of the _arc() and _arc_w() functions specify the x and y coordinates of the bounding rectangle for the arc. If an application specifies large values for these x and y coordinates, the arc may incorrectly draw to the edge of the viewport.

RESOLUTION

Avoid x values for the bounding rectangle that are more than 24 times larger than the viewport or window coordinates x dimension and y values for the bounding rectangle that are more than 45 times larger than the viewport or window coordinates y dimension.

STATUS

Microsoft has confirmed this to be a problem in the products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following program draws 2 very different arcs. It should draw two similar arcs, one above the other.

Sample Code

#include <conio.h>
#include <graph.h>

void main()

  _setvideomode(_ERESCOLOR);

  _arc(-7720, 15441, 7720, 0, 10, 0, -10, 0);
  _arc(-7721, 15441, 7721, 5, 10, 0, -10, 0);

  getch();
  _setvideomode(_DEFAULTMODE);