QuickTime 4 Reference

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. For information about transfer modes, see "Transfer Modes" .

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;

};

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" .
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" .
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" , and "Source Color Limits" .
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" , and "Source Color Limits" .
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" , and "Destination Color Limits" .
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" , and "Destination Color Limits" .
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" , and "Result Color Limits" .
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" , and "Result Color Limits" .
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" , and "Highlight Transfer Mode" .