Inside Macintosh: QuickDraw GX Environment and Utilities /

Chapter 7 - QuickDraw GX Stream Format / QuickDraw GX Stream Format Reference

Shape Object Omit Byte Constants and Data Types

Picture Shape Omit Byte Masks and Shifts

The gxOmitPictureParametersMask enumeration defines which bits in an omit byte correspond to the data compression opcode for parameters of the GXDrawPicture function. The sequence of data is also defined. The omit byte and its related data sequence is given in the section "Picture Shape Data" beginning on page 7-34.

enum gxOmitPictureParametersMask {
   gxOmitPictureShapeMask        = 0xC0,
   gxOmitOverrideStyleMask       = 0x30,
   gxOmitOverrideInkMask         = 0x0C,
   gxOmitOverrideTransformMask   = 0x03
};

Constant descriptions

gxOmitPictureShapeMask

The mask used to select the data compression bits for the shapes parameter.

gxOmitOverrideStyleMask

The mask used to select the data compression bits for the styles parameter.

gxOmitOverrideInkMask

The mask used to select the data compression bits for the inks parameter.

gxOmitOverrideTransformMask

The mask used to select the data compression bits for the transforms parameter.

enum gxOmitPictureParametersShift {
   gxOmitPictureShapeShift       = 0x6,
   gxOmitOverrideStyleShift      = 0x4,
   gxOmitOverrideInkShift        = 0x2,
   gxOmitOverrideTransformShift  = 0x0
};

Constant descriptions

gxOmitPictureShapeShift

The bit shift required to isolate the compression bits for the shapes parameter.

gxOmitOverrideStyleShift

The bit shift required to isolate the compression bits for the styles parameter.

gxOmitOverrideInkShift

The bit shift required to isolate the compression bits for the inks parameter.

gxOmitOverrideTransformShift

The bit shift required to isolate the compression bits for the transforms parameter.