GreSetStyleRatio

GreSetStyleRatio sets the style ratio used by the presentation driver's line-drawing algorithm to determine which pels are turned ON to draw a sloping line.


 * Simulation support: This function is mandatory for display drivers. For other drivers, it is simulated by a handling routine in the graphics engine.

Syntax
GreSetStyleRatio(hdc, pRatio, pInstance, lFunction);

Parameters

 * hdc (HDC) - input
 * The device context handle.


 * pRatio (PBYTE) - input
 * Pointer to two unsigned bytes corresponding to the aspect of the pels on which a line is drawn. The style ratio is defined as a two-byte value. The low-order byte indicates a step in the X-direction, and the high-order byte a step in the Y-direction. Typical values for style ratios are:


 * For EGA devices, X-direction equals 64 and Y-direction equals 85.
 * For one-to-one devices, X-direction equals 64 and Y-direction equals 64. In this case, the style ratio steps are set to 64:64 rather than 1:1 to ensure that a single dot in a line-style pattern is a sensible length. The length of a single dot in the pattern is (256/step_value) pels.


 * pInstance (PVOID) - input
 * A pointer to instance data.


 * lFunction (ULONG) - input
 * High-order WORD=flags; low-order WORD=NGreSetStyleRatio.

Return Code

 * fSuccess (BOOL) - returns
 * Return codes.


 * On completion, the handling routine must return BOOLEAN (fSuccess).


 * TRUE Successful
 * FALSE Error


 * Possible Errors Detected: When an error is detected, the handling routine must call WinSetErrorInfo to post the condition. Error codes for conditions that the handling routine is expected to check include:
 * PMERR_DEV_FUNC_NOT_INSTALLED
 * PMERR_INV_HDC

Remarks
Display drivers must support this function so that a hardcopy driver (whose device can have a different style ratio) can use the display driver to draw into a bit map that the hardcopy driver can use.

Declaration

 * 1) define INCL_GRE_DEVMISC2
 * 2) include 

HDC     hdc;        /*  The device context handle. */ PBYTE   pRatio; PVOID   pInstance;  /*  A pointer to instance data. */ ULONG   lFunction;  /*  High-order WORD=flags; low-order WORD=NGreSetStyleRatio. */ BOOL    fSuccess;   /*  Return codes. */

fSuccess = GreSetStyleRatio(hdc, pRatio, pInstance,            lFunction);

