GpiQueryArcParams
This function returns the current arc parameters used to draw full, partial, and 3-point arcs.
Syntax
GpiQueryArcParams(hps, parcpArcParams)
Parameters
- hps (HPS) - input
- Presentation-space handle.
- parcpArcParams (PARCPARAMS) - output
- Arc parameters.
Return Value
- rc (BOOL) - returns
- Success indicator.
- TRUE - Successful completion
- FALSE - Error occurred.
Remarks
Arc parameters are set by GpiSetArcParams. This function is invalid when the drawing mode (see GpiSetDrawingMode) is set to retain.
Errors
Possible returns from WinGetLastError:
- PMERR_INV_HPS (0x207F)
- An invalid presentation-space handle was specified.
- PMERR_PS_BUSY (0x20F4)
- An attempt was made to access the presentation space from more than one thread simultaneously.
- PMERR_INV_IN_RETAIN_MODE (0x208C)
- An attempt was made to issue a function (for example, query) that is invalid when the actual drawing mode is not draw or draw-and-retain.
- PMERR_INV_DC_TYPE (0x2060)
- An invalid type parameter was specified with DevOpenDC, or a function was issued that is invalid for a OD_METAFILE_NOQUERY device context.
Example Code
This example uses GpiQueryArcParams to return the current arc parameters used to draw full, partial, and 3-point arcs. The example queries the arc parameters and assigns a variable to the P coefficient if the query succeeds.
#define INCL_GPIPRIMITIVES /* Primitive functions */ #include <os2.h> BOOL fSuccess; /* success indicator */ HPS hps; /* Presentation-space handle */ ARCPARAMS parcpArcParams; /* Arc parameters */ LONG lPcoefficient; /* p coefficient of arc definition */ fSuccess = GpiQueryArcParams(hps, &parcpArcParams); /* if successful, assign value of P coefficient */ if (fSuccess == TRUE) lPcoefficient = parcpArcParams.lP;