short Escape(hDC, GETSETSCREENPARAMS, sizeof(SCREENPARAMS),lpInData,lpOutData)
This escape retrieves or sets the current screen information for rendering halftones.
| Parameter | Type/Description |
| hDC | HDC Identifies the device context. | |
| lpInData | SCREENPARAMS FAR * Points to a SCREENPARAMS data structure that contains the new screen information. This parameter may be NULL. | |
| lpOutData | SCREENPARAMS FAR * Points to a SCREENPARAMS data structure that retrieves the previous screen information. This parameter may be NULL. |
The return value specifies the outcome of the escape. It is positive if the escape is successful. Otherwise, it is negative.
This escape affects how device-independent bitmaps (DIBs) are rendered and how color objects are filled.
The SCREENPARAMS data structure has the following format:
typedef struct {
int angle;
int frequency;
DWORD types;
} SCREENPARAMS;
The SCREENPARAMS structure has the following fields:
| Field | Description |
| angle | Specifies in degrees the angle of the halftone screen. |
| frequency | Specifies in dots per inch of the screen frequency. |
| types | Is a mask containing bits which indicate the type of screen cell. If a pointer to this structure is passed as the lpInData parameter, only one bit may be set. If the lpOutData parameter contains a pointer to this structure, when the escape returns, the types field will have a bit set for each type supported by the printer driver. Acceptable bit values are: |
| DIAMOND | |
| DOT | |
| ELLIPSE | |
| LINE |