Legacy Document

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

Layout Shape Omit Byte Masks and Shifts

The gxOmitLayoutMask1 enumeration defines which bits in an omit byte correspond to the data compression opcode for parameters for the GXNewLayout function. The sequence of data is also defined. The omit byte and its related data sequence is given in the section "Layout Shape Data" beginning on page 7-33.

enum gxOmitLayoutMask1 {
   gxOmitLayoutLengthMask     = 0xC0,
   gxOmitLayoutPositionXMask  = 0x30,
   gxOmitLayoutPositionYMask  = 0x0C,
   gxOmitLayoutDataMask       = 0x02
};

Constant descriptions

gxOmitLayoutLengthMask

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

gxOmitLayoutPositionXMask

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

gxOmitLayoutPositionYMask

The mask used to select the data compression bits for the position.Y parameters.

gxOmitLayoutDataMask

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

Once one of the gxOmitLayoutMask1 enumeration masks has been used to select a data compression opcode for the parameters for the GXNewLayout function, the corresponding bit shift from the gxOmitLayoutShift1 enumeration can be applied to the selected bits. The selected bits must be moved to the right by the indicated number of bits to isolate the data compression opcode so that it can be compared to other values.

enum gxOmitLayoutShift1 {
   gxOmitLayoutLengthShift    = 6,
   gxOmitLayoutPositionXShift = 4,
   gxOmitLayoutPositionYShift = 2,
   gxOmitLayoutDataShift      = 1
};

Constant descriptions

gxOmitLayoutLengthShift

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

gxOmitLayoutPositionXShift

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

gxOmitLayoutPositionYShift

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

gxOmitLayoutDataShift

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

The gxOmitLayoutMask2 enumeration defines which bits in a second omit byte correspond to the data compression opcode for additional parameters for the GXNewLayout function. The sequence of data is also defined. The omit byte and its related data sequence is given in the section "Layout Shape Data" beginning on page 7-33.

enum gxOmitLayoutMask2 {
   gxOmitLayoutWidthMask   = 0xC0,
   gxOmitLayoutFlushMask   = 0x30,
   gxOmitLayoutJustMask    = 0x0C,
   gxOmitLayoutOptionsMask = 0x03
};

Constant descriptions

gxOmitLayoutWidthMask

The mask used to select the data compression bits for the width field descriptor.

gxOmitLayoutFlushMask

The mask used to select the data compression bits for the flush field descriptor.

gxOmitLayoutJustMask

The mask used to select the data compression bits for the just field descriptor.

gxOmitLayoutOptionsMask

The mask used to select the data compression bits for the flags field descriptor.

Once one of the gxOmitLayoutMask2 enumeration masks has been used to select a data compression opcode for the parameters for the GXNewLayout function, the corresponding bit shift from the gxOmitLayoutShift2 enumeration can be applied to the selected bits. The selected bits must be moved to the right by the indicated number of bits to isolate the data compression opcode so that it can be compared to other values.

enum gxOmitLayoutShift2 {
   gxOmitLayoutWidthShift     = 6,
   gxOmitLayoutFlushShift     = 4,
   gxOmitLayoutJustShift      = 2,
   gxOmitLayoutOptionsShift   = 0
};

Constant descriptions

gxOmitLayoutWidthShift

The bit shift required to isolate the compression bits for the width field descriptor.

gxOmitLayoutFlushShift

The bit shift required to isolate the compression bits for the flush field descriptor.

gxOmitLayoutJustShift

The bit shift required to isolate the compression bits for the just field descriptor.

gxOmitLayoutOptionsShift

The bit shift required to isolate the compression bits for the flags field descriptor.

The gxOmitLayoutMask3 enumeration defines which bits in a third omit byte correspond to the data compression opcode for additional parameters for the GXNewLayout function. The sequence of data is also defined. The omit byte and its related data sequence is given in the section "Layout Shape Data" beginning on page 7-33.

enum gxOmitLayoutMask3 {
   gxOmitLayoutStyleRunNumberMask= 0xC0,
   gxOmitLayoutLevelRunNumberMask= 0x30,
   gxOmitLayoutHasBaselineMask   = 0x08,
   gxOmitLayoutStyleRunsMask     = 0x04,
   gxOmitLayoutStylesMask        = 0x03
};

Constant descriptions

gxOmitLayoutStyleRunNumberMask

The mask used to select the data compression bits for the styleRunCount field descriptor.

gxOmitLayoutLevelRunNumberMask

The mask used to select the data compression bits for the levelRunCount field descriptor.

gxOmitLayoutHasBaselineMask

The mask used to select the data compression bits for the hasBaseline field descriptor.

gxOmitLayoutStyleRunsMask

The mask used to select the data compression bits for the styleRunLengths field descriptor.

gxOmitLayoutStylesMask

The mask used to select the data compression bits for the ??? field descriptor.

Once one of the gxOmitLayoutMask3 enumeration masks has been used to select a data compression opcode for the parameters for the GXNewLayout function, the corresponding bit shift from the gxOmitLayoutShift3 enumeration can be applied to the selected bits. The selected bits must be moved to the right by the indicated number of bits to isolate the data compression opcode so that it can be compared to other values.

enum gxOmitLayoutShift3 {
   gxOmitLayoutStyleRunNumberShift  = 6,
   gxOmitLayoutLevelRunNumberShift  = 4,
   gxOmitLayoutHasBaselineShift     = 3,
   gxOmitLayoutStyleRunsShift       = 2,
   gxOmitLayoutStylesShift          = 0
};

Constant descriptions

gxOmitLayoutStyleRunNumberShift

The bit shift required to isolate the compression bits for the styleRunCount field descriptor.

gxOmitLayoutLevelRunNumberShift

The bit shift required to isolate the compression bits for the levelRunCount field descriptor.

gxOmitLayoutHasBaselineShift

The bit shift required to isolate the compression bits for the hasBaseline field descriptor.

gxOmitLayoutStyleRunsShift

The bit shift required to isolate the compression bits for the styleRunLengths field descriptor.

gxOmitLayoutStylesShift

The bit shift required to isolate the compression bits for the ??? field descriptor.

The gxOmitLayoutMask4 enumeration defines which bits in a fourth omit byte correspond to the data compression opcode for additional parameters for the GXNewLayout function. The sequence of data is also defined. The omit byte and its related data sequence is given in the section "Layout Shape Data" beginning on page 7-33.

enum gxOmitLayoutMask4 {
   gxOmitLayoutLevelRunsMask     = 0x80,
   gxOmitLayoutLevelsMask        = 0x40
};

Constant descriptions

gxOmitLayoutLevelRunsMask

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

gxOmitLayoutLevelsMask

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

Once one of the gxOmitLayoutMask4 enumeration masks has been used to a select data compression opcode for the parameters for the GXNewLayout function, the corresponding bit shift from the gxOmitLayoutShift4 enumeration can be applied to the selected bits. The selected bits must be moved to the right by the indicated number of bits to isolate the data compression opcode so that it can be compared to other values.

enum gxOmitLayoutShift4 {
   gxOmitLayoutLevelRunsShift = 7,
   gxOmitLayoutLevelsShift    = 6
};

Constant descriptions

gxOmitLayoutLevelRunsShift

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

gxOmitLayoutLevelsShift

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