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                          Using Marker Primitives
 
You can use marker functions to perform the following tasks:
 
♦  Draw a single marker or a series of markers.
 
♦  Determine the local identifier (lcid) for the current marker set.
 
♦  Select a character set as the new marker set.
 
♦  Determine the value that identifies the current marker.
 
♦  Select a character as the new marker.
 
♦  Set or change the size of the marker box.
 
♦  Set or change the color of a marker.
 
Drawing a Series of Markers
 
The following code fragment shows how to draw a graph by calling the
GpiPolyLine and GpiPolyMarker functions:
 
HPS hps;         /* presentation-space handle */
POINTL aptl[6];  /* array of points           */
    .
    .
    .
aptl[0].x = 10; aptl[0].y = 15;         /* assigns points       */
aptl[1].x = 150; aptl[1].y = 30;
aptl[2].x = 200; aptl[2].y = 32;
aptl[3].x = 250; aptl[3].y = 70;
aptl[4].x = 360; aptl[4].y = 120;
aptl[5].x = 380; aptl[5].y = 98;
GpiMove(hps, aptl);                    /* sets current position */
GpiPolyMarker(hps, 6L, aptl);          /* plots points          */
GpiPolyLine(hps, 6L, aptl);            /* draws lines           */
 
Selecting a New Marker
 
The following code fragment shows how to check whether the default marker
set and marker are currently being used. If they are, it replaces the
default marker with a six-pointed star:
 
if ((GpiQueryMarker(hps) == MARKSYM_DEFAULT) &&
        (GpiQueryMarkerSet(hps) == LCID_DEFAULT))
   GpiSetMarker(hps, MARKSYM_SIXPOINTSTAR);
 
Selecting a New Marker Set
 
The following code fragment shows how to load a Helvetica vector font, use
it as the new marker set, and select the smile-face character as the new
marker primitive:
 
GpiLoadFonts(hps, "helv");                   /* loads helv.dll     */
lFontCount = GpiQueryFonts(hps,              /* loads array of fm  */
   0x00000002, "Helvetica", &lCount,
   (LONG) (sizeof(fm)), (PFONTMETRICS) afm);
fat.usRecordLength = sizeof(fat);            /* sets record length */
fat.usCodePage = 850;                        /* sets code page     */
fat.lMatch = afm[0].lMatch;                  /* uses first metrics */
fat.fsFontUse = FATTR_FONTUSE_TRANSFORMABLE; /* uses vector font   */
GpiCreateLogFont(hps, (PSTR8) buffer, ++lcid,
   (PFATTRS) &fat);
mbnd.usSet = lcid;                      /* uses font as marker set */
mbnd.usSymbol = 2;                      /* uses smile character    */
GpiSetAttrs(hps, PRIM_MARKER,
   MBB_SYMBOL | MBB_SET,
   0L, &mbnd);
 
Changing the Marker Color
 
The following code fragment shows how to set the marker foreground color to
green:
 
mbnd.lColor = CLR_GREEN;
GpiSetAttrs(hps, PRIM_MARKER, MBB_COLOR, 0L, &mbnd);
 
 
                                      ♦