Newby drawing question

[gregston]

Hi
I'm trying to do some drawing in my plugin window using the gui, and I was hoping to use GetLoc to give me my current pen position, but in the example 'where' is always 0,0.

CDrawContext *DC,
CPoint where;

DC->moveTo(20, 20); // works
DC->getLoc (where); // always 0,0

So what would actually move the pen? I was even hoping that DC->drawString () would move the pen so I can find out where the string has ended. Any ideas?
As usual any help appreciated.

Greg Chapman

[aciddose]

you should probably check the documentation for gdi if you're using vstgui in windows. i think those functions are just wrappers directly to the functions for gdi/quartz.

http://msdn.microsoft.com/library/defau ... t_9ezp.asp

ok, they're actually not. read vstgui.cpp from line 542 to see which functions modify ("CPoint penLoc")

for example

Code: Select all

  920 void CDrawContext::moveTo (const CPoint &_point)
  921 {
  922 	CPoint point (_point);
  923 	point.offset (offset.h, offset.v);
  924 
  925 #if WINDOWS
  926 	#if GDIPLUS
  927 	penLoc = point;
  928 	#else
  929 	MoveToEx ((HDC)pSystemContext, point.h, point.v, NULL);
  930 	#endif
  931 
  932 #elif MAC
  933   	penLoc = point;
  934 
  935 #endif
  936 }

notice the very important #if GDIPLUS
obviously you must define GDIPLUS if you want getLoc() to work.

http://msdn.microsoft.com/library/defau ... v_4660.asp

here you can see, the implementation in vstgui is bugged and should be, in the getLoc() function:

Code: Select all

#ifdef WINDOWS
#ifdef GDIPLUS
return penLoc;
#else
::POINT p;
MoveToEx(hDC, 0, 0, &p);
MoveToEx(hDC, p.x, p.y, 0);
return CPoint(p.x, p.y);
#endif
#endif
 ... etc

you can do this modification yourself if you like, of course.

[gregston]

Thanks for your reply. I was a bit in the dark because I didn't have the gui source but now I've got the latest version.
Greg