Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

◄Function Group►  ◄Overview►                          ◄Up► ◄Next► ◄Previous►
────────────────────────────────────────────────────────────────────────────
 
#define INCL_GPIPRIMITIVES
 
LONG GpiFullArc(hps, flFlags, fxMultiplier)
HPS hps;               /* presentation-space handle  */
LONG flFlags;          /* fill and outline indicator */
FIXED fxMultiplier;    /* arc-size multiplier        */
 
The GpiFullArc function creates a full arc. A full arc is a complete circle
or ellipse, drawn by using the current arc parameters. The function first
scales the width and height of the arc by using the multipier specified by
the fxMultiplier parameter, then draws either the outline of the arc, the
interior of the arc, or both, depending on the flags specified by the
flFlags parameter.
 
The function uses the current position as the center of the arc but does not
change the current position. The function uses the arc parameters to
determine whether to draw the full arc clockwise or counterclockwise. When
an arc is used as part of an area or path, the direction in which the arc is
drawn can affect how it is filled.
 
Parameter     Description
────────────────────────────────────────────────────────────────────────────
 
hps           Identifies the presentation space.
 
flFlags       Specifies whether to fill and/or outline the arc. It can be
              one of the following values:
 
              Value            Meaning
              ──────────────────────────────────────────────────────────────
              DRO_FILL         Fills the interior of the arc with the
                               current fill pattern.
 
              DRO_OUTLINE      Draws the outline of the arc by using the
                               current line style and color.
 
              DRO_OUTLINEFILL  Draws the outline and fills the arc
                               interior.
 
              Do not use DRO_FILL or DRO_OUTLINEFILL when using GpiFullArc
              in an area bracket.
 
fxMultiplier  Specifies how much to scale the width and height of the arc.
              It must be a fixed-point value in the range 1 through 255 (or
              in the range 0x10000 through 0xFF0000 if expressed as 32-bit
              values). This means the function can scale the arc from 1 to
              255 times the current arc-parameter dimensions.
 
Return Value
 
The return value is GPI_OK or GPI_HITS if the function is successful (it is
GPI_HITS if the detectable attribute is set for the presentation space and a
correlation hit occurs). The return value is GPI_ERROR if an error occurs.
 
Errors
 
Use the WinGetLastError function to retrieve the error value, which may be
one of the following:
 
     PMERR_INV_ARC_CONTROL
     PMERR_INV_HPS
     PMERR_INV_MULTIPLIER
     PMERR_PS_BUSY
 
Comments
 
When correlating an arc, the system generates a hit if the arc boundary
intersects the pick aperture. If the pick aperture is inside the arc, the
system generates a hit only if the interior of the arc has been filled.
 
Example
 
This example uses GpiFullArc to draw five concentric circles. The arc
parameters are set before drawing the arc. Only the outline is drawn for the
arc.
 
SHORT i;
ARCPARAMS arcp = { 1, 1, 0, 0 };
 
GpiSetArcParams(hps, &arcp);
 
for (i = 5; i > 0; i --)
    GpiFullArc(hps,             /* presentation-space handle       */
        DRO_OUTLINE,            /* outline                         */
        MAKEFIXED(i, 0));       /* converts integer to fixed point */
 
See Also
 
GpiMove, GpiPointArc, GpiQueryArcParams, GpiSetArcParams, GpiSetAttrs,
GpiSetColor, GpiSetCurrentPosition, GpiSetLineType, WinGetLastError
 
                                      ♦