DLI Implementation and Reference Guide - Datalogics

12.2 DLI Implementation and Reference Guide
Library Color Descriptions
Concepts and Facilities: Guide to the DL Pager Composition System
Color can be added to pages produced via DLI only with the color fields of the
PDEGraphicState. There are two fields which establish color:
• strokeColorSpec
• fillColorSpec
strokeColorSpec defines the color that applied to lines which are stroked and
fillColorSpec defines the color applied to areas which are filled.
NOTE: Type is generally filled rather than stroked.
Color Description Components
The color description consists of two components:
• The first is a pointer to a PDEColorSpace structure, which describes a color
space. This identifies the type of color: Black and White, RGB, CMYK, etc.
• The second component is an array of from one to seven ASFixed values, which
describe the amount of color in each of the components of the given color model.
These components are frequently called color channels. For example, the color
Black can be described variously as (RGB, 0.0, 0.0, 0.0), (grayScale,
0.0) or (CMYK 0.0, 0.0, 0.0, 1.0); all are different ways of saying
“Black.”
Patterned Colors
Patterned colors, which may be used in addition to (or instead of) a solid color, are
carried in a separate field within the DLPDFCONTENT structure, and are set with a
specific set of calls to DLPDFCONTENT.