GreNotifyTransformChange

GreNotifyTransformChange notifies the presentation driver of a change in the transform from world coordinates to device coordinates.

This function must be supported by the presentation driver.


 * Simulation support: None. This function is mandatory for all drivers.

Syntax
GreNotifyTransformChange(hdc, flFlags, pXformdata, pInstance, lFunction);

Parameters

 * hdc (HDC) - input
 * Device context handle.


 * flFlags (ULONG) - input
 * Flags.


 * A set of flags that pass information regarding the complexity of the 2x2 matrix of the M11, M12, M21, and M22 components (of the composite transform from world coordinates to device coordinates). These flags indicate if a translation is required. If the MATRIX_SIMPLE flag is not set, none of the other flags are valid.


 * MATRIX_SIMPLE
 * Two entries are 0.
 * MATRIX_UNITS
 * All entries are +1 or -1.
 * MATRIX_XY_EXCHANGE
 * Zeros are on the diagonal.
 * MATRIX_X_NEGATE
 * X is hit by negative (see Note).
 * MATRIX_Y_NEGATE
 * Y is hit by negative (see Note).
 * MATRIX_TRANSLATION
 * Non-zero translation.


 * Note:
 * MATRIX_X_NEGATE and MATRIX_Y_NEGATE are only meaningful when both MATRIX_SIMPLE and MATRIX_UNITS are set.


 * Examples:


 * Matrix = { 1.0, 0.0, 0.0, 1.0, 0, 0 } =>
 * Flags = MATRIX_SIMPLE | MATRIX_UNITS


 * Matrix = { 1.0, 0.0, 0.0, 1.0, 5, 10 } =>
 * Flags = MATRIX_SIMPLE | MATRIX_UNITS | MATRIX_TRANSLATION


 * Matrix = { 0.0, -1.0, 1.0, 0.0, 17, 5 } =>
 * Flags = MATRIX_SIMPLE | MATRIX_UNITS | MATRIX_XY_EXCHANGE |
 * MATRIX_Y_NEGATE | MATRIX_TRANSLATION


 * pXformdata (PNOTIFYTRANSFORMDATA) - input
 * Pointer to NOTIFYTRANSFORMDATA structure:
 * usType
 * Indicates fixed-point notation
 * xform
 * XFORM data structure contains fixed-point values
 * fxM11
 * Fixed-point matrix elements
 * fxM12
 * Fixed-point matrix elements
 * fxM21
 * Fixed-point matrix elements
 * fxM22
 * Fixed-point matrix elements
 * lM41
 * Long translations
 * lM42
 * Long translations


 * pInstance (PVOID) - input
 * Pointer to instance data.


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

Return Code

 * rc (BOOL) - returns : Return Code.


 * On completion, the handling routine must return a BOOLEAN value to indicate success or an error.


 * 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_BASE_ERROR
 * PMERR_COORDINATE_OVERFLOW
 * PMERR_DEV_FUNC_NOT_INSTALLED
 * PMERR_HDC_BUSY
 * PMERR_INV_COORD_SPACE
 * PMERR_INV_HDC
 * PMERR_INV_IN_AREA
 * PMERR_INV_IN_PATH
 * PMERR_INV_LENGTH_OR_COUNT
 * PMERR_INV_PATTERN_REF_PT_ATTR
 * PMERR_INV_PICK_APERTURE_POSN
 * PMERR_PATH_LIMIT_EXCEEDED


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

Remarks
This function is called by the graphics engine to provide sufficient information to allow the device to optimize its calling of the GreConvert function or, where possible, to make all point transformations itself. The minimum requirement is for the handling routine to update the current position and pattern origin, and then call back to the GreNotifyTransformChange routine in the graphics engine. Note that the handling routine must:


 * Check that the new current position is valid.
 * Check that the change will not cause an overflow of the 16-bit coordinates for the device space.
 * Fail safe. If an error is detected or the call back to the graphics engine fails, the routine must restore the initial values before returning FALSE.

Sample Code

 * 1) define INCL_GRE_DEVMISC2
 * 2) include 

HDC                    hdc;         /*  Device context handle. */ ULONG                  flFlags;     /*  Flags. */ PNOTIFYTRANSFORMDATA   pXformdata;  /*  Pointer to NOTIFYTRANSFORMDATA structure: */ PVOID                  pInstance;   /*  Pointer to instance data. */ ULONG                  lFunction;   /*  High-order WORD=flags; low-order WORD=NGreNotifyTransformChange. */ BOOL                   rc;          /*  Return Code. */

rc = GreNotifyTransformChange(hdc, flFlags,      pXformdata, pInstance, lFunction); 