Xref:	news2.mv.net comp.os.msdos.djgpp:2025
From:	nicolas AT dsys DOT ceng DOT cea DOT fr (Eric NICOLAS)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Problems with GRX 1.03 and 20 !!
Date:	21 Mar 1996 10:36:10 GMT
Organization:	Commissariat a l'energie atomique
Lines:	148
Message-ID:	<4irbeq$a3c@news.cea.fr>
Reply-To:	nicolas AT dsys DOT ceng DOT cea DOT fr
NNTP-Posting-Host:	hudson.ceng.cea.fr
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

I posted this message a few weeks ago directly to csaba, but
didn't have any answer. Perhaps someone else could have
answers. Thanks !

----

I have some questions about strange behaviour of your libgrx
library.

At the end of this message you will find a sample program that
will show you those problems. Try it. Compile with commands :
        GNU 1 & GRX 1 : gcc graph.cc -lgrx -o graph
        GNU 2 & GRX20 : gcc graph.cc -D_V2_ -lgrx20 -o graph

Problem in both Grx1 and Grx20 versions : As you can see in the middle
    of the code, I tried to hide the mouse cursor and to wait for any
    user action (in fact the goal of that is to build a screen saver in
    my GUI). So I called GrMouseEraseCursor to hide the cursor. Indeed
    it deseapear from the screen, but each time I ask libgrx for an
    user action (GrMouseGetEvent), the cursor come back to the screen and
    then go away again. The result is that the cursor is 'flashing' during
    the waiting loop... Are there other ways to hide the cursor ? Am I
    doing something wrong ?

Problem in Grx20 only : As you can see at the end of the code, I want to
    show some message when my application come back in text mode. With
    LibGrx1, no problem, but with grx20, the application terminate
    without troubles, but there is nothing on the text screen ! Do you
    have a hint for this ?

Problem in Grx20 only (possibly corrected in more recent versions)
    (not in the sample program) : When I try to draw XORed lines on the
    screen, simply adding the constant Gr_XOR to the color, everything
    works fine with grx1, but with grx20 nothing appears on the screen.
    Is there another way to draw XORed lines with grx20 ? Or is this
    feature still not implemented ?


I have been using libgrx for so much time that I thought I never could
find a bug ! well, finally I did :-)

Thanks a lot for your (coming...) answers.


----- Sample program "graph.cc" begin here -----------------------------------

#include <conio.h>
#include <stdio.h>

#ifdef _V2_
  #include <grx20.h>
  typedef long color;
#else
  #include <grx.h>
  #include <mousex.h>
  #define GrMouseEvent         MouseEvent
  #define GrMouseGetEvent      MouseGetEvent
  #define GrMouseSetCursor     MouseSetCursor
  #define GrMouseEraseCursor   MouseEraseCursor
  #define GrMouseDisplayCursor MouseDisplayCursor
  #define GrMouseDetect        MouseDetect
  #define GrMouseEventMode     MouseEventMode
  #define GrMouseEventEnable   MouseEventEnable
  #define GrMouseInit          MouseInit
  #define GrMouseUnInit        MouseUnInit
  #define GR_M_KEYPRESS        M_KEYPRESS
  #define GR_M_POLL            M_POLL
  #define GR_M_EVENT           M_EVENT
  typedef int color;
#endif

char MouseArrow[16*12] =
  {    1, 1, 1,00,00,00,00,00,00,00,00,00  ,
       1, 4, 1, 1,00,00,00,00,00,00,00,00  ,
       1, 4, 5, 1, 1,00,00,00,00,00,00,00  ,
       1, 4, 5, 5, 1, 1,00,00,00,00,00,00  ,
       1, 4, 4, 5, 5, 1, 1,00,00,00,00,00  ,
       1, 4, 4, 5, 5, 5, 1, 1,00,00,00,00  ,
       1, 4, 4, 4, 5, 5, 5, 1, 1,00,00,00  ,
       1, 4, 4, 4, 5, 5, 5, 5, 1, 1,00,00  ,
       1, 4, 4, 4, 5, 5, 5, 5, 5, 1, 1,00  ,
       1, 4, 4, 4, 4, 5, 5, 5, 5, 5, 1, 1  ,
       1, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 1  ,
       1, 4, 4, 4, 4, 1, 1, 1, 1, 1, 1, 1  ,
       1, 4, 4, 4, 1, 1,00,00,00,00,00,00  ,
       1, 4, 4, 1, 1,00,00,00,00,00,00,00  ,
       1, 4, 1, 1,00,00,00,00,00,00,00,00  ,
       1, 1, 1,00,00,00,00,00,00,00,00,00   };

int main()
{ GrCursor    *CurMouse;
  GrMouseEvent evt;
  int          i;
  // Init Graphic mode
  GrSetMode(GR_width_height_color_graphics,640,480,16);
  // Init Colors
  color ColorTable[6];
  color NoSysColor[5];
  ColorTable[0]=5;
  for(i=0;i<5;i++)
  { NoSysColor[i]  =GrAllocColor(i*255/4,i*255/4,i*255/4);
    ColorTable[i+1]=NoSysColor[i];
  }
  // Init Mouse
  #ifdef _V2_
    CurMouse=GrBuildCursor(MouseArrow,12,12,16, 1, 1,ColorTable);
  #else
    CurMouse=GrBuildCursor(MouseArrow,12,16, 1, 1,ColorTable);
  #endif
  if (!GrMouseDetect())
  { GrSetMode(GR_80_25_text);
    return 1;
  }
  GrMouseEventMode(1);
  GrMouseEventEnable(1,1);
  GrMouseInit();
  GrMouseSetCursor(CurMouse);
  GrMouseDisplayCursor();
  // Message loop : Wait for a key hit
  do
  { GrMouseGetEvent(GR_M_EVENT | GR_M_POLL,&evt);
  } while (!(evt.flags & GR_M_KEYPRESS));
  // Hide cursor test
  // :: 1 Hide cursor
  GrMouseEraseCursor();
  // :: 2 Wait for an action
  do
  { GrMouseGetEvent(GR_M_EVENT | GR_M_POLL,&evt);
  } while (!(evt.flags & GR_M_EVENT));
  // :: 3 Show cursor
  GrMouseDisplayCursor();
  // Destroy mouse cursor
  GrMouseUnInit();
  GrDestroyCursor(CurMouse);
  // Close Graphic mode
  GrSetMode(GR_80_25_text);
  printf("Back to text mode !\n");
  return 0;
}




-- 
Eric Nicolas <nicolas AT dsys DOT ceng DOT cea DOT fr>

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