Inside Macintosh: QuickDraw GX Objects /

Chapter 5 - Ink Objects / Ink Objects Reference

Constants and Data Types

Transfer Component Structure

There are up to four transfer component structures in a transfer mode structure. Each transfer component structure describes how the transfer mode operation is to be applied to a given component in the transfer mode's color space. The transfer component structure is of data type gxTransferComponent:

struct gxTransferComponent{
      gxComponentMode   mode;
      gxComponentFlag   flags;
      gxColorValue      sourceMinimum;
      gxColorValue      sourceMaximum;
      gxColorValue      deviceMinimum;
      gxColorValue      deviceMaximum;
      gxColorValue      clampMinimum;
      gxColorValue      clampMaximum;
      gxColorValue      operand;
};

Field Description

mode

The component mode (type of transfer mode, such as gxCopyMode or gxBlendMode) to apply to this color component. Component modes are described in the section "Transfer Mode Types" beginning on page 5-11.

flags

The component flags, which control clamping behavior and whether source and destination are to be reversed for this component. The component flags are described in the section "Transfer Component Flags" on page 5-35.

sourceMinimum

The minimum acceptable value for source color in this color component. No drawing occurs if the source component value is below sourceMinimum. For more information, see "Color Limits" beginning on page 5-27, and "Source Color Limits" on page 5-31.

sourceMaximum

The maximum acceptable value for source color in this color component. No drawing occurs if the source component value is greater than sourceMaximum. For more information, see "Color Limits" beginning on page 5-27, and "Source Color Limits" on page 5-31.

deviceMinimum

The minimum acceptable value for destination color in this color component. No drawing occurs if the destination component value is below deviceMinimum. For more information, see "Color Limits" beginning on page 5-27, and "Destination Color Limits" on page 5-32.

deviceMaximum

The maximum acceptable value for destination color in this color component. No drawing occurs if the destination component value is greater than deviceMaximum. For more information, see "Color Limits" beginning on page 5-27, and "Destination Color Limits" on page 5-32.

clampMinimum

The minimum acceptable value for result color in this
color component. If the result component value is below deviceMinimum, it is pinned, or clamped, to the value
of deviceMinimum. For more information, see "Color Limits" beginning on page 5-27, and "Result Color Limits" on page 5-32.

clampMaximum

The maximum acceptable value for result color in this
color component. If the result component value is greater
than deviceMaximum, it is pinned, or clamped, to the value of deviceMaximum. For more information, see "Color Limits" beginning on page 5-27, and "Result Color Limits" on page 5-32.

operand

A value used as an input to the gxBlendMode, gxMigrateMode, and gxHighlightMode component modes. If you are using these modes, you must supply a proper value for operand. For more information, see "Arithmetic Transfer Modes" beginning on page 5-12, and "Highlight Transfer Mode" on page 5-15.