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short Control(lpDevice, GETSETSCREENPARAMS, lpInData,
             lpOutData)
 
The GETSETSCREENPARAMS printer escape retrieves or sets the current screen
information for rendering halftones.
 
Parameter  Description
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lpInData   SCREENPARAMS FAR * Points to a SCREENPARAMS structure that
           contains the new screen information. For more information about
           this structure, see the following Comments section. This
           parameter may be NULL.
 
lpOutData  SCREENPARAMS FAR * Points to a SCREENPARAMS structure that
           retrieves the previous screen information. For more information
           about this structure, see the following Comments section. This
           parameter may be NULL.
 
Return Value
 
The return value specifies the outcome of the escape. This value is positive
if the escape is successful. Otherwise, it is negative.
 
Comments
 
This escape affects how device-independent bitmaps (DIBs) are rendered and
how color objects are filled.
 
The SCREENPARAMS structure has the following form:
 
typedef struct tagSCREENPARAMS {
  int   angle;
  int   frequency;
} SCREENPARAMS;
 
Following are the members of the SCREENPARAMS structure:
 
termdef
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angle      Specifies, in degrees, the angle of the halftone screen.
 
frequency  Specifies, in dots per inch, the screen frequency.
 
 
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