GreDisjointLines

GreDisjointLines draws a sequence of disjoint straight lines using the end-point pairs specified. If COM_TRANSFORM is not set, the pairs are expected in screen coordinates.

This function is supported by the graphics engine and can be hooked by the presentation driver.

Simulation support

None. This function is mandatory for all drivers.

Syntax

GreDisjointLines(hdc, paptlPoint, cPoints, pInstance, lFunction, rc)

Parameters

hdc (HDC) - input

Device context handle.

paptlPoint (PPOINTL) - input

Pointer to an array of cPoints (X,Y) pairs.

Pointer to an array of cPoints (X,Y) pairs containing the end-points for the lines.

cPoints (LONG) - input

Number of (X,Y) pairs in the points array.

When this is passed as 0, the handling routine takes no action except to return Success.

pInstance (PVOID) - input

Pointer to instance data.

lFunction (ULONG) - input

High-order WORD=flags; low-order WORD=NGreDisjointLines.

Returns

rc (LONG)

Return Codes.

On completion, the handling routine must return an integer (cHits) indicating, where appropriate, whether correlation hits were detected:

• GPI_OK Successful
• GPI_HITS Successful with correlation hit (returned by display drivers when the correlation flag is ON, and a hit is detected)
• GPI_ERROR 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_BASE_ERROR
• PMERR_BITMAP_NOT_SELECTED
• PMERR_COORDINATE_OVERFLOW
• PMERR_DEV_FUNC_NOT_INSTALLED
• PMERR_HDC_BUSY
• PMERR_INV_COLOR_DATA
• PMERR_INV_COLOR_INDEX
• PMERR_INV_COORD_SPACE
• PMERR_INV_HDC
• PMERR_INV_IN_AREA
• PMERR_INV_IN_PATH
• PMERR_INV_LENGTH_OR_COUNT
• PMERR_INV_PICK_APERTURE_POSN
• PMERR_INV_RECT
• PMERR_PATH_LIMIT_EXCEEDED
• PMERR_PATH_UNKNOWN

Refer to the "Error Explanations" section in the Presentation Manager Programming Reference for further explanation.

Sample

#define INCL_GRE_LINES
#include <os2.h>

HDC        hdc;         /*  Device context handle. */
PPOINTL    paptlPoint;  /*  Pointer to an array of cPoints (X,Y) pairs. */
LONG       cPoints;     /*  Number of (X,Y) pairs in the points array. */
PVOID      pInstance;   /*  Pointer to instance data. */
ULONG      lFunction;
LONG       rc;          /*  Return Codes. */

GreDisjointLines(hdc, paptlPoint, cPoints, pInstance, lFunction, rc);